Refuse [::], 0.0.0.0, IPv6 multicast and documentation space (closes #341)

On Linux a connection to the unspecified address [::] or 0.0.0.0
reaches the host's own loopback, and the SSRF guard let [::] through.
Both unspecified addresses now sit in alwaysBlockedNetworks, so an
allowlist reaches loopback only through an entry that covers a
loopback address, never through one that covers only 0.0.0.0 or ::;
::/128 joins the default blocklist beside 0.0.0.0/8. IPv6 multicast
(ff00::/8) and documentation space (2001:db8::/32) are refused by
default. Every default blocklist entry gets a one-line comment, and the
README, the rules above each list, the two pinning tests and the
allowlist refusal test follow.

Model: opus-5-5

README.md

@@ -158,19 +158,20 @@ WireServer, which serves an Azure VM its credentials. Because it is a
 public address, listing it in `ALLOWED_EGRESS_CIDRS` reopens it.
 
 That is all the default blocklist covers: the IPv4 private and reserved
-ranges; of IPv6, only loopback (`::1`), unique local addresses
-(`fc00::/7`) and link-local addresses (`fe80::/10`); and certain public
-addresses. A public address belongs on the default blocklist only if it
-hands credentials, user data or bootstrap material to whatever can reach
-it, without the caller presenting anything. A provider's other public
-addresses are not refused. IBM Cloud, for example, serves its package
-mirrors, time servers and object storage on `161.26.0.0/16`, and the
-private endpoints of its own cloud services on `166.8.0.0/14`. Neither
-range hands out credentials that way: the token service among those
-endpoints issues a token only in exchange for something the caller
-presents, such as an API key. Reaching these services can be a
-legitimate delivery, and every cloud has some, so a partial list would
-promise coverage it does not give.
+ranges; of IPv6, only loopback (`::1`), the unspecified address (`::`),
+unique local addresses (`fc00::/7`), link-local addresses (`fe80::/10`),
+multicast (`ff00::/8`) and documentation space (`2001:db8::/32`); and
+certain public addresses. A public address belongs on the default
+blocklist only if it hands credentials, user data or bootstrap material
+to whatever can reach it, without the caller presenting anything. A
+provider's other public addresses are not refused. IBM Cloud, for
+example, serves its package mirrors, time servers and object storage on
+`161.26.0.0/16`, and the private endpoints of its own cloud services on
+`166.8.0.0/14`. Neither range hands out credentials that way: the token
+service among those endpoints issues a token only in exchange for
+something the caller presents, such as an API key. Reaching these
+services can be a legitimate delivery, and every cloud has some, so a
+partial list would promise coverage it does not give.
 
 That default is also inconvenient for the thing webhooker is mostly
 for: taking a public webhook and forwarding it to something on your own
@@ -210,16 +211,16 @@ Two things this setting cannot do:
   the list is always an allowlist; an empty list (the default) means
   every private and reserved range stays refused. Note that
   `0.0.0.0/0` gets you most of the way there anyway, per above.
-- **It cannot open link-local, or a cloud metadata endpoint at a
-  non-public address that discloses credentials or user data.** An
-  address is on the list below when it is not a public address and both
-  of these hold: the provider fixes it, so it cannot collide with
-  anything you run; and reaching it hands out credentials, user data or
-  bootstrap material. Those stay blocked no matter what you list,
-  including when you list them outright or list a supernet such as
-  `0.0.0.0/0`, `::/0`, `fd00::/8` or `100.64.0.0/10`. Treat this as best
-  effort rather than a guarantee — it is a hand-maintained list and the
-  caveat below the table applies:
+- **It cannot open link-local, the unspecified addresses, or a cloud
+  metadata endpoint at a non-public address that discloses credentials
+  or user data.** A metadata address is on the list below when it is not
+  a public address and both of these hold: the provider fixes it, so it
+  cannot collide with anything you run; and reaching it hands out
+  credentials, user data or bootstrap material. Those stay blocked no
+  matter what you list, including when you list them outright or list a
+  supernet such as `0.0.0.0/0`, `::/0`, `fd00::/8` or `100.64.0.0/10`.
+  Treat this as best effort rather than a guarantee — it is a
+  hand-maintained list and the caveat below the table applies:
 
   | Blocked unconditionally | What it is |
   | ----------------------- | ---------- |
@@ -233,14 +234,25 @@ Two things this setting cannot do:
   | `fd00:a9fe:a9fe::1/128` | Linode/Akamai metadata over IPv6 |
   | `100.100.100.200/32` | Alibaba Cloud metadata, inside CGNAT |
   | `192.0.0.192/32` | Oracle Cloud Classic metadata |
+  | `0.0.0.0/32` | IPv4 unspecified address, which reaches this host's loopback on Linux |
+  | `::/128` | IPv6 unspecified address, which reaches this host's loopback on Linux |
   | `::a9fe:a9fe/128` | `169.254.169.254` as an IPv4-compatible IPv6 address |
   | `64:ff9b::a9fe:a9fe/128` | `169.254.169.254` behind the NAT64 well-known prefix |
 
   The IPv4-mapped form `::ffff:169.254.169.254` is covered by the
-  `169.254.0.0/16` entry. Reaching any of these is credential or
-  user-data theft rather than delivery to an internal service. Every
-  entry outside the two link-local blocks is a single address, so
-  blocking it costs you nothing else on the network around it.
+  `169.254.0.0/16` entry. Reaching any of these but the two unspecified
+  addresses is credential or user-data theft rather than delivery to an
+  internal service. Every entry outside the two link-local blocks is a
+  single address, so blocking it costs you nothing else on the network
+  around it.
+
+  The unspecified addresses `0.0.0.0` and `::` hand out nothing
+  themselves, but no host can have either, and on Linux a connection to
+  one reaches this host's own loopback. They are listed so that an
+  allowlist reaches loopback only through an entry that covers a loopback
+  address, such as `127.0.0.0/8`, `::1` or `0.0.0.0/0`, never through one
+  that covers only `0.0.0.0` or `::`; `0.0.0.0/8`, for example, does not
+  open loopback.
 
   The six ULA entries, all inside `fd00::/8`, are why this matters in
   practice: `fd00::/8` is an ordinary block to allowlist for your own
@@ -3093,7 +3105,8 @@ check, see [The login endpoint](#the-login-endpoint).
   route through a single decision function, so they cannot disagree
   about a destination. An operator can permit specific blocks with
   [`ALLOWED_EGRESS_CIDRS`](#allowing-egress-to-your-own-network); the
-  guard cannot be switched off, and link-local plus a
+  guard cannot be switched off, and link-local, the unspecified
+  addresses `0.0.0.0` and `::`, and a
   [pinned set](#allowing-egress-to-your-own-network) of known cloud
   metadata endpoints — several of which are ULAs outside link-local —
   stay blocked whatever is listed, though listing `0.0.0.0/0` or

internal/config/config.go

@@ -196,12 +196,13 @@ type Config struct {
 	// otherwise refuse. The guard itself is always on: there is no
 	// setting that disables SSRF protection, and delivery's
 	// alwaysBlockedNetworks stays blocked no matter what is listed
-	// here. That set is link-local plus the cloud metadata
-	// endpoints outside it that disclose credentials or user data
-	// at a provider-fixed, non-public address; it is not
-	// exhaustive of every cloud's metadata address. See
-	// alwaysBlockedNetworks for the authoritative list and the
-	// criterion it is built from.
+	// here. That set is link-local, the unspecified addresses
+	// 0.0.0.0 and ::, and the cloud metadata endpoints outside
+	// link-local that disclose credentials or user data at a
+	// provider-fixed, non-public address; it is not exhaustive of
+	// every cloud's metadata address. See
+	// alwaysBlockedNetworks for the authoritative list and why
+	// each entry is on it.
 	AllowedEgressCIDRs []netip.Prefix
 
 	params *ConfigParams

internal/delivery/ssrf.go

@@ -37,8 +37,8 @@ var (
 		"blocked cloud metadata address",
 	)
 	errBlockedMetadata = errors.New(
-		"blocked link-local or cloud instance metadata " +
-			"address: ALLOWED_EGRESS_CIDRS cannot open it",
+		"blocked link-local, cloud instance metadata or " +
+			"unspecified address: ALLOWED_EGRESS_CIDRS cannot open it",
 	)
 	errInvalidScheme = errors.New(
 		"only http and https are allowed",
@@ -72,14 +72,17 @@ var blockedNetworks []*net.IPNet
 var blockedPublicNetworks []*net.IPNet
 
 // alwaysBlockedNetworks are the ranges no configuration can
-// open: the link-local blocks and the cloud instance metadata
-// endpoints that live outside them. Reaching one is credential
-// or user-data theft rather than delivery to an internal
-// service, so a supplied CIDR that covers such an address still
-// leaves it blocked.
+// open, so a supplied CIDR that covers one still leaves it
+// blocked. An entry is here for one of two reasons: it is a
+// metadata endpoint (the link-local blocks and the cloud
+// instance metadata endpoints that live outside them), or it is
+// an unspecified address. Reaching a metadata endpoint is
+// credential or user-data theft rather than delivery to an
+// internal service.
 //
-// Inclusion criterion — an address belongs here only if BOTH
-// hold, and every entry below satisfies both:
+// Inclusion criterion for metadata endpoints — one belongs here
+// only if BOTH hold, and every metadata entry below satisfies
+// both:
 //
 //  1. It is a fixed address assigned by the provider, or a
 //     range reserved by IANA — never one the operator chose.
@@ -90,8 +93,8 @@ var blockedPublicNetworks []*net.IPNet
 //     not cheaply rotated.
 //
 // Both halves are load-bearing, so use them to refuse a
-// candidate and say why. An endpoint disclosing only the
-// operator's own inventory (instance id, region, disks, NICs)
+// metadata candidate and say why. An endpoint disclosing only
+// the operator's own inventory (instance id, region, disks, NICs)
 // fails (2): letting a delivery target reach the operator's own
 // infrastructure is the feature ALLOWED_EGRESS_CIDRS exists to
 // provide. But (2) is not "IAM credentials only" either —
@@ -112,6 +115,15 @@ var blockedPublicNetworks []*net.IPNet
 // This is a criterion, not an enumeration of every metadata
 // address in existence.
 //
+// The unspecified addresses 0.0.0.0 and :: are here for a
+// separate reason: they disclose nothing, but no host can have
+// either, and on Linux a connection to one reaches this host's
+// own loopback. Listing them means an allowlist reaches loopback
+// only through an entry that covers a loopback address
+// (127.0.0.0/8, ::1/128, 0.0.0.0/0), never through one that
+// covers only 0.0.0.0 or :: (0.0.0.0/8, for example). Nothing
+// else lives at either address, so refusing them costs nothing.
+//
 // Every entry is either already in blockedNetworks — this list is
 // what makes it unconditional — or an alternate encoding of
 // 169.254.169.254 that Contains does not match against
@@ -131,23 +143,46 @@ var alwaysBlockedNetworks []*net.IPNet
 //nolint:gochecknoinits // init is the idiomatic way to parse CIDRs once at startup
 func init() {
 	blockedNetworks = mustParseCIDRs([]string{
+		// IPv4 loopback.
 		"127.0.0.0/8",
+		// RFC 1918 private network.
 		"10.0.0.0/8",
+		// RFC 1918 private network.
 		"172.16.0.0/12",
+		// RFC 1918 private network.
 		"192.168.0.0/16",
+		// IPv4 link-local.
 		"169.254.0.0/16",
+		// "This network", holding the IPv4 unspecified address 0.0.0.0.
 		"0.0.0.0/8",
+		// Carrier-grade NAT shared address space.
 		"100.64.0.0/10",
+		// IETF protocol assignments.
 		"192.0.0.0/24",
+		// IPv4 documentation (TEST-NET-1).
 		"192.0.2.0/24",
+		// Benchmarking.
 		"198.18.0.0/15",
+		// IPv4 documentation (TEST-NET-2).
 		"198.51.100.0/24",
+		// IPv4 documentation (TEST-NET-3).
 		"203.0.113.0/24",
+		// IPv4 multicast.
 		"224.0.0.0/4",
+		// Reserved, including the broadcast address.
 		"240.0.0.0/4",
+		// IPv6 loopback.
 		"::1/128",
+		// IPv6 unspecified address.
+		"::/128",
+		// IPv6 unique local addresses.
 		"fc00::/7",
+		// IPv6 link-local.
 		"fe80::/10",
+		// IPv6 multicast.
+		"ff00::/8",
+		// IPv6 documentation.
+		"2001:db8::/32",
 	})
 
 	blockedPublicNetworks = mustParseCIDRs([]string{
@@ -207,6 +242,14 @@ func init() {
 		// allowlist from opening it.
 		"192.0.0.192/32",
 
+		// The unspecified addresses, each of which reaches this
+		// host's loopback on Linux.
+		//
+		// IPv4 unspecified address, inside the blocked 0.0.0.0/8.
+		"0.0.0.0/32",
+		// IPv6 unspecified address.
+		"::/128",
+
 		// 169.254.169.254 as an IPv4-compatible IPv6 address.
 		"::a9fe:a9fe/128",
 		// 169.254.169.254 behind the NAT64 well-known prefix.
@@ -343,8 +386,9 @@ func (g *Guard) allows(ip net.IP) bool {
 // The order is the policy:
 //
 //  1. alwaysBlockedNetworks is refused before the allowlist is
-//     consulted, so no configured CIDR reaches link-local or a
-//     cloud metadata endpoint at a non-public address.
+//     consulted, so no configured CIDR reaches link-local, a
+//     cloud metadata endpoint at a non-public address, or an
+//     unspecified address.
 //  2. The allowlist is consulted next, so a listed private
 //     network, or a listed public address on the default
 //     blocklist, becomes reachable.

internal/delivery/ssrf_allowlist_test.go

@@ -168,12 +168,13 @@ func TestGuardAllowlist_UnlistedPrivateStillRefused(t *testing.T) {
 
 // TestGuardAllowlist_MetadataAlwaysRefused is the load-bearing
 // case: cloud instance metadata endpoints are credential theft
-// rather than delivery to an internal service, so no allowlist
-// reaches one. Every guard below names a CIDR that covers its
-// target — including 0.0.0.0/0, ::/0, and the ordinary ULA and
-// CGNAT blocks an operator would really list — and the address
-// must stay refused anyway, on both the validation and the
-// delivery path.
+// rather than delivery to an internal service, and the
+// unspecified addresses 0.0.0.0 and :: reach this host's loopback
+// on Linux, so no allowlist reaches any of them. Every guard
+// below names a CIDR that covers its target — including
+// 0.0.0.0/0, ::/0, and the ordinary ULA and CGNAT blocks an
+// operator would really list — and the address must stay
+// refused anyway, on both the validation and the delivery path.
 func TestGuardAllowlist_MetadataAlwaysRefused(t *testing.T) {
 	t.Parallel()
 
@@ -219,15 +220,17 @@ type metadataAlwaysRefusedCase struct {
 }
 
 // metadataAlwaysRefusedCases enumerates every unconditionally
-// blocked address together with an allowlist entry that would
-// otherwise reach it. Split by family of address only to stay
-// under the function-length limit.
+// blocked address (link-local, the cloud metadata endpoints and
+// the unspecified addresses) together with an allowlist entry
+// that would otherwise reach it. Split by family of address only
+// to stay under the function-length limit.
 func metadataAlwaysRefusedCases() []metadataAlwaysRefusedCase {
 	cases := linkLocalRefusedCases()
 	cases = append(cases, ulaMetadataRefusedCases()...)
 	cases = append(cases, ipv4MetadataRefusedCases()...)
+	cases = append(cases, encodedMetadataRefusedCases()...)
 
-	return append(cases, encodedMetadataRefusedCases()...)
+	return append(cases, unspecifiedRefusedCases()...)
 }
 
 // linkLocalRefusedCases covers the link-local blocks, including
@@ -367,6 +370,23 @@ func encodedMetadataRefusedCases() []metadataAlwaysRefusedCase {
 	}
 }
 
+// unspecifiedRefusedCases covers the unspecified addresses, each
+// of which reaches this host's loopback on Linux.
+func unspecifiedRefusedCases() []metadataAlwaysRefusedCase {
+	return []metadataAlwaysRefusedCase{
+		{
+			name:   "IPv4 unspecified address under 0.0.0.0/0",
+			allow:  allowAllIPv4,
+			target: "http://0.0.0.0:8080/hook",
+		},
+		{
+			name:   "IPv6 unspecified address under ::/0",
+			allow:  allowAllIPv6,
+			target: "http://[::]:8080/hook",
+		},
+	}
+}
+
 // TestGuardAllowlist_PublicUnaffected asserts the allowlist does
 // not narrow anything: public addresses were reachable before it
 // existed and stay reachable, whether or not a list is set.
@@ -524,6 +544,10 @@ func TestAlwaysBlockedNetworks_PinnedSet(t *testing.T) {
 		// Oracle Cloud Classic metadata, inside the blocked
 		// 192.0.0.0/24.
 		"192.0.0.192/32",
+		// The IPv4 and IPv6 unspecified addresses, each of
+		// which reaches this host's loopback on Linux.
+		"0.0.0.0/32",
+		"::/128",
 		// 169.254.169.254 as an IPv4-compatible IPv6 address.
 		"::a9fe:a9fe/128",
 		// 169.254.169.254 behind the NAT64 well-known prefix.
@@ -556,7 +580,8 @@ func TestDefaultBlocklist_PinnedSet(t *testing.T) {
 		{cidr: "172.16.0.0/12", reopenable: true},
 		{cidr: "192.168.0.0/16", reopenable: true},
 		{cidr: linkLocalIPv4, reopenable: false},
-		{cidr: "0.0.0.0/8", reopenable: true},
+		// Its first address, 0.0.0.0, is in the unconditional set.
+		{cidr: "0.0.0.0/8", reopenable: false},
 		{cidr: "100.64.0.0/10", reopenable: true},
 		{cidr: "192.0.0.0/24", reopenable: true},
 		{cidr: "192.0.2.0/24", reopenable: true},
@@ -566,8 +591,11 @@ func TestDefaultBlocklist_PinnedSet(t *testing.T) {
 		{cidr: "224.0.0.0/4", reopenable: true},
 		{cidr: "240.0.0.0/4", reopenable: true},
 		{cidr: "::1/128", reopenable: true},
+		{cidr: "::/128", reopenable: false},
 		{cidr: "fc00::/7", reopenable: true},
 		{cidr: "fe80::/10", reopenable: false},
+		{cidr: "ff00::/8", reopenable: true},
+		{cidr: "2001:db8::/32", reopenable: true},
 		{cidr: "168.63.129.16/32", public: true, reopenable: true},
 	}
 

internal/delivery/ssrf_test.go

@@ -101,6 +101,42 @@ func TestValidateTargetURL_Blocked(t *testing.T) {
 	}
 }
 
+// TestDefaultGuard_RefusesUnspecifiedMulticastAndDocumentation
+// covers the unspecified addresses and the IPv6 multicast and
+// documentation ranges: with no allowlist set, each is refused
+// both when a target is created and when a delivery dials it.
+func TestDefaultGuard_RefusesUnspecifiedMulticastAndDocumentation(
+	t *testing.T,
+) {
+	t.Parallel()
+
+	guard := delivery.NewTestGuard()
+
+	targets := []string{
+		// The unspecified addresses. On Linux a connection to
+		// either reaches this host's loopback.
+		"http://0.0.0.0:8080/hook",
+		"http://[::]:8080/hook",
+		// IPv6 multicast, all nodes.
+		"http://[ff02::1]/hook",
+		// IPv6 documentation.
+		"http://[2001:db8::1]/hook",
+	}
+
+	for _, target := range targets {
+		t.Run(target, func(t *testing.T) {
+			t.Parallel()
+
+			require.Error(t,
+				guard.ValidateTargetURL(context.Background(), target),
+				"%s must be refused at target creation", target,
+			)
+
+			assertDialRefused(t, guard, target)
+		})
+	}
+}
+
 func TestValidateTargetURL_Allowed(t *testing.T) {
 	t.Parallel()
 

internal/handlers/auth.go

@@ -333,7 +333,9 @@ func (h *Handlers) HandleLogout() http.HandlerFunc {
 			)
 		}
 
-		// Redirect to login page
-		http.Redirect(w, r, "/pages/login", http.StatusSeeOther)
+		http.Redirect(
+			w, r, withNotice("/pages/login", signedOut),
+			http.StatusSeeOther,
+		)
 	}
 }

internal/handlers/delivery_replay.go

@@ -11,72 +11,37 @@ import (
 	"sneak.berlin/go/webhooker/internal/delivery"
 )
 
-// replayOutcomeParam is the query parameter the replay POST redirects
-// with and the event log page reads its banner from.
-const replayOutcomeParam = "replay"
-
-// replayOutcomeCode is the outcome of a replay POST. The redirect
-// carries one of these fixed codes rather than a message, so nothing a
-// client submits can reach the rendered page through it.
-type replayOutcomeCode string
-
+// The outcomes of a replay POST, as the notice codes its redirect
+// carries. noticeFor holds the line each one shows.
 const (
 	// replayQueued reports that a new delivery was created and handed
 	// to the delivery engine.
-	replayQueued replayOutcomeCode = "queued"
+	replayQueued noticeCode = "replay-queued"
 
 	// replayTargetDeleted reports a target that once existed and has
 	// since been deleted. Deletes are soft and deliveries carry no
 	// foreign key to the target row, so the history survives its
 	// target and this is the ordinary case for an old event.
-	replayTargetDeleted replayOutcomeCode = "target-deleted"
+	replayTargetDeleted noticeCode = "replay-target-deleted"
 
 	// replayTargetMissing reports a target id that names no row at
 	// all, deleted or otherwise.
-	replayTargetMissing replayOutcomeCode = "target-missing"
+	replayTargetMissing noticeCode = "replay-target-missing"
 
 	// replayTargetInactive reports a target the operator has
 	// deactivated. A deactivated target receives no new deliveries, so
 	// a replay to it would be a delivery they switched off.
-	replayTargetInactive replayOutcomeCode = "target-inactive"
+	replayTargetInactive noticeCode = "replay-target-inactive"
 
 	// replayNotTerminal reports a delivery the engine has not finished
 	// with.
-	replayNotTerminal replayOutcomeCode = "not-terminal"
+	replayNotTerminal noticeCode = "replay-not-terminal"
 
 	// replayInFlight reports that an earlier replay of this event to
 	// this target is still running.
-	replayInFlight replayOutcomeCode = "in-flight"
+	replayInFlight noticeCode = "replay-in-flight"
 )
 
-// replayOutcome returns the banner the event log page shows for an
-// outcome code, and whether the replay was queued. An unrecognised
-// code yields no banner.
-func replayOutcome(code string) (string, bool) {
-	switch replayOutcomeCode(code) {
-	case replayQueued:
-		return "Replay queued: a new delivery was created against " +
-			"the target's current configuration.", true
-	case replayTargetDeleted:
-		return "Not replayed: the target this delivery was for has " +
-			"been deleted. Recreate the target, then replay.", false
-	case replayTargetMissing:
-		return "Not replayed: the target this delivery was for no " +
-			"longer exists.", false
-	case replayTargetInactive:
-		return "Not replayed: the target this delivery was for is " +
-			"deactivated. Activate it, then replay.", false
-	case replayNotTerminal:
-		return "Not replayed: this delivery has not finished yet.",
-			false
-	case replayInFlight:
-		return "Not replayed: a delivery of this event to this " +
-			"target is already in flight.", false
-	default:
-		return "", false
-	}
-}
-
 // HandleDeliveryReplay re-sends a finished delivery's event to its
 // target.
 //
@@ -140,14 +105,14 @@ func (h *Handlers) replayDelivery(
 	}
 
 	if !original.Status.Terminal() {
-		h.finishReplay(w, r, webhook, replayNotTerminal)
+		redirectToEventLog(w, r, webhook, replayNotTerminal)
 
 		return
 	}
 
 	target, code := h.replayTarget(webhook.ID, original.TargetID)
 	if target == nil {
-		h.finishReplay(w, r, webhook, code)
+		redirectToEventLog(w, r, webhook, code)
 
 		return
 	}
@@ -200,7 +165,7 @@ func (h *Handlers) queueReplay(
 	}
 
 	if inFlight > 0 {
-		h.finishReplay(w, r, webhook, replayInFlight)
+		redirectToEventLog(w, r, webhook, replayInFlight)
 
 		return
 	}
@@ -238,7 +203,7 @@ func (h *Handlers) queueReplay(
 		"delivery_id", task.DeliveryID,
 	)
 
-	h.finishReplay(w, r, webhook, replayQueued)
+	redirectToEventLog(w, r, webhook, replayQueued)
 }
 
 // replayTarget loads the delivery's target as it stands now.
@@ -251,7 +216,7 @@ func (h *Handlers) queueReplay(
 // with the returned code saying why.
 func (h *Handlers) replayTarget(
 	webhookID, targetID string,
-) (*database.Target, replayOutcomeCode) {
+) (*database.Target, noticeCode) {
 	var target database.Target
 
 	err := h.db.DB().Unscoped().Where(
@@ -361,17 +326,16 @@ func replayBody(body string) *string {
 	return &body
 }
 
-// finishReplay redirects back to the event log the replay was
-// triggered from, carrying the outcome code the page turns into a
-// banner and the page number the form submitted.
-func (h *Handlers) finishReplay(
+// redirectToEventLog redirects a replay or resubmit back to the event
+// log it was triggered from, carrying the outcome as its notice and
+// the page number the form submitted.
+func redirectToEventLog(
 	w http.ResponseWriter,
 	r *http.Request,
 	webhook database.Webhook,
-	code replayOutcomeCode,
+	code noticeCode,
 ) {
-	dest := "/hook/" + webhook.ID + "/events?" +
-		replayOutcomeParam + "=" + string(code)
+	dest := withNotice("/hook/"+webhook.ID+"/events", code)
 
 	// The page is read from the form rather than the query string:
 	// this is a POST, and its query string is what logs and Referer

internal/handlers/delivery_replay_test.go

@@ -212,7 +212,7 @@ func TestHandleDeliveryReplay_AppendsDeliveryAndLeavesOriginal(
 	require.Equal(t, http.StatusSeeOther, w.Code)
 	assert.Equal(
 		t,
-		"/hook/"+wh.ID+"/events?replay=queued",
+		"/hook/"+wh.ID+"/events?notice=replay-queued",
 		w.Header().Get("Location"),
 	)
 
@@ -362,7 +362,7 @@ func TestHandleDeliveryReplay_RefusesDeletedTarget(t *testing.T) {
 	require.Equal(t, http.StatusSeeOther, w.Code)
 	assert.Equal(
 		t,
-		"/hook/"+wh.ID+"/events?replay=target-deleted",
+		"/hook/"+wh.ID+"/events?notice=replay-target-deleted",
 		w.Header().Get("Location"),
 	)
 
@@ -390,7 +390,7 @@ func TestHandleDeliveryReplay_RefusesDeletedTarget(t *testing.T) {
 	require.Equal(t, http.StatusSeeOther, missing.Code)
 	assert.Equal(
 		t,
-		"/hook/"+wh.ID+"/events?replay=target-missing",
+		"/hook/"+wh.ID+"/events?notice=replay-target-missing",
 		missing.Header().Get("Location"),
 	)
 }
@@ -431,7 +431,7 @@ func TestHandleDeliveryReplay_RefusesWhileEarlierReplayInFlight(
 	require.Equal(t, http.StatusSeeOther, first.Code)
 	require.Equal(
 		t,
-		"/hook/"+wh.ID+"/events?replay=queued",
+		"/hook/"+wh.ID+"/events?notice=replay-queued",
 		first.Header().Get("Location"),
 	)
 
@@ -439,7 +439,7 @@ func TestHandleDeliveryReplay_RefusesWhileEarlierReplayInFlight(
 	require.Equal(t, http.StatusSeeOther, second.Code)
 	assert.Equal(
 		t,
-		"/hook/"+wh.ID+"/events?replay=in-flight",
+		"/hook/"+wh.ID+"/events?notice=replay-in-flight",
 		second.Header().Get("Location"),
 	)
 
@@ -465,7 +465,7 @@ func TestHandleDeliveryReplay_RefusesWhileEarlierReplayInFlight(
 	require.Equal(t, http.StatusSeeOther, pending.Code)
 	assert.Equal(
 		t,
-		"/hook/"+wh.ID+"/events?replay=not-terminal",
+		"/hook/"+wh.ID+"/events?notice=replay-not-terminal",
 		pending.Header().Get("Location"),
 	)
 }
@@ -509,7 +509,7 @@ func TestHandleSourceLogs_RendersReplayControlAndBanner(t *testing.T) {
 	assert.Contains(t, body, ">Replay<")
 
 	refused := renderSourceLogsPageWithQuery(
-		t, h, sess, wh.ID, "?replay=target-deleted",
+		t, h, sess, wh.ID, "?notice=replay-target-deleted",
 	)
 
 	assert.Contains(t, refused, "alert-error")
@@ -517,7 +517,7 @@ func TestHandleSourceLogs_RendersReplayControlAndBanner(t *testing.T) {
 
 	// An outcome code nobody issued renders no banner at all.
 	unknown := renderSourceLogsPageWithQuery(
-		t, h, sess, wh.ID, "?replay=made-up",
+		t, h, sess, wh.ID, "?notice=made-up",
 	)
 
 	assert.NotContains(t, unknown, "alert-error")

internal/handlers/event_resubmit.go

@@ -3,7 +3,6 @@ package handlers
 import (
 	"errors"
 	"net/http"
-	"strconv"
 
 	"github.com/go-chi/chi"
 	"github.com/google/uuid"
@@ -11,43 +10,19 @@ import (
 	"sneak.berlin/go/webhooker/internal/database"
 )
 
-// resubmitOutcomeParam is the query parameter the resubmit POST
-// redirects with and the event log page reads its banner from.
-const resubmitOutcomeParam = "resubmit"
-
-// resubmitOutcomeCode is the outcome of a resubmit POST. The redirect
-// carries one of these fixed codes rather than a message, so nothing a
-// client submits can reach the rendered page through it.
-type resubmitOutcomeCode string
-
+// The outcomes of a resubmit POST, as the notice codes its redirect
+// carries. noticeFor holds the line each one shows.
 const (
 	// resubmitQueued reports that a new event was stored and its
 	// deliveries handed to the delivery engine.
-	resubmitQueued resubmitOutcomeCode = "queued"
+	resubmitQueued noticeCode = "resubmit-queued"
 
 	// resubmitNoTargets reports a source with no active targets. The
 	// new event is stored either way, exactly as a received event
 	// with no targets is.
-	resubmitNoTargets resubmitOutcomeCode = "no-targets"
+	resubmitNoTargets noticeCode = "resubmit-no-targets"
 )
 
-// resubmitOutcome returns the banner the event log page shows for an
-// outcome code, and whether the resubmit was queued. An unrecognised
-// code yields no banner.
-func resubmitOutcome(code string) (string, bool) {
-	switch resubmitOutcomeCode(code) {
-	case resubmitQueued:
-		return "Resubmitted: a new event was created from the stored " +
-			"one and queued to every active target.", true
-	case resubmitNoTargets:
-		return "Resubmitted: a new event was created, but this " +
-				"source has no active targets, so nothing was queued.",
-			true
-	default:
-		return "", false
-	}
-}
-
 // resubmitSource is the stored event a resubmit copies. Its body is
 // read as bytes rather than as a string so the copy is byte-identical
 // to what was received, whatever the payload's encoding.
@@ -245,29 +220,5 @@ func (h *Handlers) queueResubmit(
 		code = resubmitNoTargets
 	}
 
-	h.finishResubmit(w, r, webhook, code)
-}
-
-// finishResubmit redirects back to the event log the resubmit was
-// triggered from, carrying the outcome code the page turns into a
-// banner and the page number the form submitted.
-func (h *Handlers) finishResubmit(
-	w http.ResponseWriter,
-	r *http.Request,
-	webhook database.Webhook,
-	code resubmitOutcomeCode,
-) {
-	dest := "/hook/" + webhook.ID + "/events?" +
-		resubmitOutcomeParam + "=" + string(code)
-
-	// The page is read from the form rather than the query string:
-	// this is a POST, and its query string is what logs and Referer
-	// headers record.
-	if page := pageOrFirst(
-		r.PostFormValue("page"),
-	); page > 1 {
-		dest += "&page=" + strconv.Itoa(page)
-	}
-
-	http.Redirect(w, r, dest, http.StatusSeeOther)
+	redirectToEventLog(w, r, webhook, code)
 }

internal/handlers/event_resubmit_test.go

@@ -154,7 +154,7 @@ func TestHandleEventResubmit_DeliversToTargetCreatedAfterTheEvent(
 	require.Equal(t, http.StatusSeeOther, w.Code)
 	assert.Equal(
 		t,
-		"/hook/"+wh.ID+"/events?resubmit=queued",
+		"/hook/"+wh.ID+"/events?notice=resubmit-queued",
 		w.Header().Get("Location"),
 	)
 
@@ -282,7 +282,7 @@ func TestHandleEventResubmit_IsRepeatable(t *testing.T) {
 		require.Equal(t, http.StatusSeeOther, w.Code)
 		assert.Equal(
 			t,
-			"/hook/"+wh.ID+"/events?resubmit=queued",
+			"/hook/"+wh.ID+"/events?notice=resubmit-queued",
 			w.Header().Get("Location"),
 			"a resubmit must not be refused while an earlier "+
 				"one is in flight",
@@ -436,7 +436,7 @@ func TestHandleEventResubmit_SkipsInactiveTarget(t *testing.T) {
 	require.Equal(t, http.StatusSeeOther, w.Code)
 	assert.Equal(
 		t,
-		"/hook/"+wh.ID+"/events?resubmit=queued",
+		"/hook/"+wh.ID+"/events?notice=resubmit-queued",
 		w.Header().Get("Location"),
 		"an inactive target is skipped, not an error",
 	)
@@ -482,7 +482,7 @@ func TestHandleEventResubmit_NoActiveTargetsStillStoresEvent(
 	require.Equal(t, http.StatusSeeOther, w.Code)
 	assert.Equal(
 		t,
-		"/hook/"+wh.ID+"/events?resubmit=no-targets",
+		"/hook/"+wh.ID+"/events?notice=resubmit-no-targets",
 		w.Header().Get("Location"),
 	)
 

internal/handlers/handlers.go

@@ -97,10 +97,10 @@ type Handlers struct {
 
 // parsePageTemplate parses a page-specific template set from the
 // embedded FS. Each page template is combined with the shared
-// base, htmlheader, and navbar templates, and with any further files
-// the page includes. The page file must be listed first so that its
-// root action ({{template "base" .}}) becomes the template set's entry
-// point.
+// base, htmlheader, navbar and notice templates, and with any further
+// files the page includes. The page file must be listed first so that
+// its root action ({{template "base" .}}) becomes the template set's
+// entry point.
 func parsePageTemplate(
 	pageFile string, included ...string,
 ) *template.Template {
@@ -109,6 +109,7 @@ func parsePageTemplate(
 		"base.html",
 		"htmlheader.html",
 		"navbar.html",
+		"notice.html",
 	}, included...)
 
 	return template.Must(
@@ -209,11 +210,13 @@ func (s *Handlers) renderError(
 	// served outside the routes where NoCache runs.
 	w.Header().Set("Cache-Control", "no-store")
 
+	// No notice: one would say an action worked above a page saying
+	// the request failed.
 	data := s.pageData(r, map[string]any{
 		"Status":     status,
 		"StatusText": http.StatusText(status),
 		"Message":    errorPageText(status),
-	})
+	}, nil)
 
 	var buf bytes.Buffer
 
@@ -267,6 +270,7 @@ type templateDataWrapper struct {
 	User      *UserInfo
 	CSRFToken string
 	Version   string
+	Notice    *notice
 	Data      any
 }
 
@@ -311,12 +315,15 @@ func (s *Handlers) renderTemplate(
 		return
 	}
 
-	s.executeTemplate(w, r, tmpl, s.pageData(r, data))
+	s.executeTemplate(w, r, tmpl, s.pageData(r, data, noticeFor(r)))
 }
 
 // pageData adds the fields the shared layout renders to a page's own
-// data.
-func (s *Handlers) pageData(r *http.Request, data any) any {
+// data. The layout shows the notice, when there is one, above the
+// page.
+func (s *Handlers) pageData(
+	r *http.Request, data any, pageNotice *notice,
+) any {
 	userInfo := s.getUserInfo(r)
 	csrfToken := middleware.CSRFToken(r)
 
@@ -330,6 +337,7 @@ func (s *Handlers) pageData(r *http.Request, data any) any {
 		m["User"] = userInfo
 		m["CSRFToken"] = csrfToken
 		m["Version"] = version
+		m["Notice"] = pageNotice
 
 		return m
 	}
@@ -338,6 +346,7 @@ func (s *Handlers) pageData(r *http.Request, data any) any {
 		User:      userInfo,
 		CSRFToken: csrfToken,
 		Version:   version,
+		Notice:    pageNotice,
 		Data:      data,
 	}
 }

internal/handlers/notice.go

@@ -0,0 +1,109 @@
+package handlers
+
+import "net/http"
+
+// noticeParam is the query parameter an action's redirect carries its
+// notice code in.
+const noticeParam = "notice"
+
+// noticeCode names one of the fixed lines noticeFor knows. An action
+// redirects with the code rather than the line, so nothing a client
+// puts in the URL reaches the page: a code noticeFor does not know
+// shows nothing.
+type noticeCode string
+
+// The codes of the actions on the webhook pages and of signing out.
+// Replay's codes, with the reasons a replay can be refused, and
+// resubmit's codes are defined beside those actions.
+const (
+	webhookCreated        noticeCode = "webhook-created"
+	webhookSaved          noticeCode = "webhook-saved"
+	webhookDeleted        noticeCode = "webhook-deleted"
+	entrypointAdded       noticeCode = "entrypoint-added"
+	entrypointDeleted     noticeCode = "entrypoint-deleted"
+	entrypointActivated   noticeCode = "entrypoint-activated"
+	entrypointDeactivated noticeCode = "entrypoint-deactivated"
+	targetAdded           noticeCode = "target-added"
+	targetSaved           noticeCode = "target-saved"
+	targetDeleted         noticeCode = "target-deleted"
+	targetActivated       noticeCode = "target-activated"
+	targetDeactivated     noticeCode = "target-deactivated"
+	signedOut             noticeCode = "signed-out"
+)
+
+// notice is the line templates/notice.html shows above a page to say
+// what an action did.
+type notice struct {
+	Text string
+
+	// Failed shows the line as an error: the action was refused.
+	Failed bool
+}
+
+// noticeFor returns the notice the request's URL names, or nil when it
+// names none or an unknown code.
+func noticeFor(r *http.Request) *notice {
+	n, ok := map[noticeCode]notice{
+		webhookCreated:        {Text: "Webhook created."},
+		webhookSaved:          {Text: "Webhook saved."},
+		webhookDeleted:        {Text: "Webhook deleted."},
+		entrypointAdded:       {Text: "Entrypoint added."},
+		entrypointDeleted:     {Text: "Entrypoint deleted."},
+		entrypointActivated:   {Text: "Entrypoint activated."},
+		entrypointDeactivated: {Text: "Entrypoint deactivated."},
+		targetAdded:           {Text: "Target added."},
+		targetSaved:           {Text: "Target saved."},
+		targetDeleted:         {Text: "Target deleted."},
+		targetActivated:       {Text: "Target activated."},
+		targetDeactivated:     {Text: "Target deactivated."},
+		signedOut:             {Text: "Signed out."},
+
+		replayQueued: {
+			Text: "Replay queued: a new delivery was created " +
+				"against the target's current configuration.",
+		},
+		replayTargetDeleted: {
+			Text: "Not replayed: the target this delivery was for " +
+				"has been deleted. Recreate the target, then replay.",
+			Failed: true,
+		},
+		replayTargetMissing: {
+			Text: "Not replayed: the target this delivery was for " +
+				"no longer exists.",
+			Failed: true,
+		},
+		replayTargetInactive: {
+			Text: "Not replayed: the target this delivery was for " +
+				"is deactivated. Activate it, then replay.",
+			Failed: true,
+		},
+		replayNotTerminal: {
+			Text:   "Not replayed: this delivery has not finished yet.",
+			Failed: true,
+		},
+		replayInFlight: {
+			Text: "Not replayed: a delivery of this event to this " +
+				"target is already in flight.",
+			Failed: true,
+		},
+
+		resubmitQueued: {
+			Text: "Resubmitted: a new event was created from the " +
+				"stored one and queued to every active target.",
+		},
+		resubmitNoTargets: {
+			Text: "Resubmitted: a new event was created, but this " +
+				"source has no active targets, so nothing was queued.",
+		},
+	}[noticeCode(r.URL.Query().Get(noticeParam))]
+	if !ok {
+		return nil
+	}
+
+	return &n
+}
+
+// withNotice returns path with code added as its notice.
+func withNotice(path string, code noticeCode) string {
+	return path + "?" + noticeParam + "=" + string(code)
+}

internal/handlers/source_delete_test.go

@@ -411,7 +411,9 @@ func TestHandleSourceDelete_RemovesConfigAndEventDatabase(
 	h.HandleSourceDelete().ServeHTTP(w, req)
 
 	require.Equal(t, http.StatusSeeOther, w.Code)
-	assert.Equal(t, "/hooks", w.Header().Get("Location"))
+	assert.Equal(
+		t, "/hooks?notice=webhook-deleted", w.Header().Get("Location"),
+	)
 
 	assert.Equal(
 		t, int64(0),

internal/handlers/source_management.go

@@ -322,7 +322,8 @@ func (h *Handlers) createWebhookWithEntrypoint(
 	)
 
 	http.Redirect(
-		w, r, "/hook/"+webhook.ID, http.StatusSeeOther,
+		w, r, withNotice("/hook/"+webhook.ID, webhookCreated),
+		http.StatusSeeOther,
 	)
 }
 
@@ -579,7 +580,8 @@ func (h *Handlers) applyWebhookEdit(
 	}
 
 	http.Redirect(
-		w, r, "/hook/"+webhook.ID, http.StatusSeeOther,
+		w, r, withNotice("/hook/"+webhook.ID, webhookSaved),
+		http.StatusSeeOther,
 	)
 }
 
@@ -662,7 +664,9 @@ func (h *Handlers) deleteWebhookResources(
 		return
 	}
 
-	http.Redirect(w, r, "/hooks", http.StatusSeeOther)
+	http.Redirect(
+		w, r, withNotice("/hooks", webhookDeleted), http.StatusSeeOther,
+	)
 }
 
 // commitWebhookDeletion soft-deletes a webhook's entrypoints,
@@ -841,31 +845,16 @@ func (h *Handlers) HandleSourceLogs() http.HandlerFunc {
 			totalPages++
 		}
 
-		// The banner a replay or resubmit POST redirected back
-		// with. The message comes from a fixed set keyed by the
-		// outcome code, never from the query string itself.
-		replayMsg, replayOK := replayOutcome(
-			r.URL.Query().Get(replayOutcomeParam),
-		)
-
-		resubmitMsg, resubmitOK := resubmitOutcome(
-			r.URL.Query().Get(resubmitOutcomeParam),
-		)
-
 		data := map[string]any{
-			tmplKeyWebhook:    &webhook,
-			"Events":          evts,
-			"ReplayMessage":   replayMsg,
-			"ReplayQueued":    replayOK,
-			"ResubmitMessage": resubmitMsg,
-			"ResubmitQueued":  resubmitOK,
-			"Page":            page,
-			"TotalPages":      totalPages,
-			"TotalEvents":     total,
-			"HasPrev":         page > 1,
-			"HasNext":         page < totalPages,
-			"PrevPage":        page - 1,
-			"NextPage":        page + 1,
+			tmplKeyWebhook: &webhook,
+			"Events":       evts,
+			"Page":         page,
+			"TotalPages":   totalPages,
+			"TotalEvents":  total,
+			"HasPrev":      page > 1,
+			"HasNext":      page < totalPages,
+			"PrevPage":     page - 1,
+			"NextPage":     page + 1,
 		}
 
 		h.renderTemplate(w, r, "source_logs.html", data)
@@ -1254,7 +1243,8 @@ func (h *Handlers) HandleEntrypointCreate() http.HandlerFunc {
 		}
 
 		http.Redirect(
-			w, r, "/hook/"+webhook.ID, http.StatusSeeOther,
+			w, r, withNotice("/hook/"+webhook.ID, entrypointAdded),
+			http.StatusSeeOther,
 		)
 	}
 }
@@ -1365,7 +1355,8 @@ func (h *Handlers) processTargetCreate(
 	}
 
 	http.Redirect(
-		w, r, "/hook/"+webhook.ID, http.StatusSeeOther,
+		w, r, withNotice("/hook/"+webhook.ID, targetAdded),
+		http.StatusSeeOther,
 	)
 }
 
@@ -1569,10 +1560,11 @@ func (h *Handlers) validateTargetURL(
 		msg := "Invalid target URL: " + err.Error()
 
 		// Only a private or reserved address's refusal says how
-		// to allow it. Metadata refusals never do: link-local and
-		// the other unconditional metadata addresses cannot be
-		// opened, and the default blocklist's public addresses,
-		// which listing does open, hand out credentials.
+		// to allow it. Other refusals never do: link-local, the
+		// unspecified addresses and the unconditional metadata
+		// addresses cannot be opened, and the default
+		// blocklist's public addresses, which listing does open,
+		// hand out credentials.
 		if errors.Is(err, delivery.ErrBlockedPrivateOrReservedIP) {
 			msg += ". Private and reserved addresses are refused " +
 				"by default; the server's ALLOWED_EGRESS_CIDRS " +
@@ -1643,6 +1635,7 @@ func (h *Handlers) HandleEntrypointDelete() http.HandlerFunc {
 		"entrypointID", &database.Entrypoint{},
 		"failed to delete entrypoint",
 		nil,
+		entrypointDeleted,
 	)
 }
 
@@ -1655,18 +1648,21 @@ func (h *Handlers) HandleTargetDelete() http.HandlerFunc {
 		"targetID", &database.Target{},
 		"failed to delete target",
 		h.evictArchiveWriterIfUnused,
+		targetDeleted,
 	)
 }
 
 // deleteChildResource returns a handler that deletes a child
 // resource (entrypoint or target) belonging to a webhook. The
 // optional afterDelete hook runs with the webhook's id once the
-// delete has succeeded, before the redirect.
+// delete has succeeded, before the redirect, which carries done as
+// its notice.
 func (h *Handlers) deleteChildResource(
 	idParam string,
 	model any,
 	errMsg string,
 	afterDelete func(webhookID string),
+	done noticeCode,
 ) http.HandlerFunc {
 	return func(w http.ResponseWriter, r *http.Request) {
 		userID, ok := h.getUserID(r)
@@ -1708,7 +1704,7 @@ func (h *Handlers) deleteChildResource(
 
 		http.Redirect(
 			w, r,
-			"/hook/"+webhook.ID,
+			withNotice("/hook/"+webhook.ID, done),
 			http.StatusSeeOther,
 		)
 	}
@@ -1719,7 +1715,7 @@ func (h *Handlers) deleteChildResource(
 func (h *Handlers) HandleEntrypointToggle() http.HandlerFunc {
 	return h.toggleChildResource(
 		"entrypointID",
-		func(webhookID, childID string) error {
+		func(webhookID, childID string) (bool, error) {
 			var ep database.Entrypoint
 
 			err := h.db.DB().Where(
@@ -1727,14 +1723,15 @@ func (h *Handlers) HandleEntrypointToggle() http.HandlerFunc {
 				childID, webhookID,
 			).First(&ep).Error
 			if err != nil {
-				return err
+				return false, err
 			}
 
 			ep.Active = !ep.Active
 
-			return h.db.DB().Save(&ep).Error
+			return ep.Active, h.db.DB().Save(&ep).Error
 		},
 		"failed to toggle entrypoint",
+		entrypointActivated, entrypointDeactivated,
 	)
 }
 
@@ -1742,7 +1739,7 @@ func (h *Handlers) HandleEntrypointToggle() http.HandlerFunc {
 func (h *Handlers) HandleTargetToggle() http.HandlerFunc {
 	return h.toggleChildResource(
 		"targetID",
-		func(webhookID, childID string) error {
+		func(webhookID, childID string) (bool, error) {
 			var tgt database.Target
 
 			err := h.db.DB().Where(
@@ -1750,23 +1747,27 @@ func (h *Handlers) HandleTargetToggle() http.HandlerFunc {
 				childID, webhookID,
 			).First(&tgt).Error
 			if err != nil {
-				return err
+				return false, err
 			}
 
 			tgt.Active = !tgt.Active
 
-			return h.db.DB().Save(&tgt).Error
+			return tgt.Active, h.db.DB().Save(&tgt).Error
 		},
 		"failed to toggle target",
+		targetActivated, targetDeactivated,
 	)
 }
 
 // toggleChildResource returns a handler that toggles the active
-// state of a child resource belonging to a webhook.
+// state of a child resource belonging to a webhook. toggleFn returns
+// the new state, and the redirect carries activated or deactivated as
+// its notice to match.
 func (h *Handlers) toggleChildResource(
 	idParam string,
-	toggleFn func(webhookID, childID string) error,
+	toggleFn func(webhookID, childID string) (bool, error),
 	errMsg string,
+	activated, deactivated noticeCode,
 ) http.HandlerFunc {
 	return func(w http.ResponseWriter, r *http.Request) {
 		userID, ok := h.getUserID(r)
@@ -1792,16 +1793,21 @@ func (h *Handlers) toggleChildResource(
 			return
 		}
 
-		err = toggleFn(webhook.ID, childID)
+		active, err := toggleFn(webhook.ID, childID)
 		if err != nil {
 			h.serverError(w, r, errMsg, err)
 
 			return
 		}
 
+		done := deactivated
+		if active {
+			done = activated
+		}
+
 		http.Redirect(
 			w, r,
-			"/hook/"+webhook.ID,
+			withNotice("/hook/"+webhook.ID, done),
 			http.StatusSeeOther,
 		)
 	}

internal/handlers/target_edit.go

@@ -161,7 +161,8 @@ func (h *Handlers) applyTargetEdit(
 	}
 
 	http.Redirect(
-		w, r, "/hook/"+webhook.ID, http.StatusSeeOther,
+		w, r, withNotice("/hook/"+webhook.ID, targetSaved),
+		http.StatusSeeOther,
 	)
 }
 

internal/server/error_page_test.go

@@ -83,6 +83,22 @@ func TestErrorPage_DeletedTarget(t *testing.T) {
 	assertErrorPage(t, w, http.StatusNotFound, backToWebhooks)
 }
 
+// TestErrorPage_ShowsNoNotice pins that a notice code in the URL of a
+// page that fails is not shown above the error.
+func TestErrorPage_ShowsNoNotice(t *testing.T) {
+	t.Parallel()
+
+	env := newTestEnv(t)
+
+	userID, _ := env.seedUser(t, "owner", "somepassword")
+	cookies := env.authCookies(t, userID, "owner")
+
+	w := env.get("/hook/no-such-webhook?notice=webhook-saved", cookies)
+
+	assertErrorPage(t, w, http.StatusNotFound, backToWebhooks)
+	assert.NotContains(t, w.Body.String(), "Webhook saved.")
+}
+
 func TestErrorPage_UnknownPath(t *testing.T) {
 	t.Parallel()
 

internal/server/routes_test.go

@@ -263,6 +263,24 @@ func (e *testEnv) urlFrom(
 	return html.UnescapeString(match[1])
 }
 
+// requireNotice requires w to redirect to dest carrying the notice
+// code, then renders that page and requires it to show text.
+func (e *testEnv) requireNotice(
+	t *testing.T,
+	w *httptest.ResponseRecorder,
+	dest, code, text string,
+	cookies []*http.Cookie,
+) {
+	t.Helper()
+
+	require.Equal(t, http.StatusSeeOther, w.Code)
+	require.Equal(t, dest+"?notice="+code, w.Header().Get("Location"))
+
+	page := e.get(w.Header().Get("Location"), cookies)
+	require.Equal(t, http.StatusOK, page.Code)
+	assert.Contains(t, page.Body.String(), text)
+}
+
 // authCookies forges an authenticated session for the given user.
 func (e *testEnv) authCookies(
 	t *testing.T,
@@ -741,6 +759,31 @@ func TestPagesLogin_ReturnsToTheRequestedPage(t *testing.T) {
 	assert.Equal(t, asked, w.Header().Get("Location"))
 }
 
+// TestPagesLogout_SaysSignedOut signs out with the navbar's form and
+// lands on the sign-in page, which says so.
+func TestPagesLogout_SaysSignedOut(t *testing.T) {
+	t.Parallel()
+
+	env := newTestEnv(t)
+
+	userID, _ := env.seedUser(t, "leaver", "somepassword")
+	token, cookies := env.csrfFrom(
+		t, "/hooks", env.authCookies(t, userID, "leaver"),
+	)
+
+	form := url.Values{}
+	form.Set("csrf_token", token)
+
+	w := env.post(
+		env.urlFrom(t, "/hooks", `action="(/pages/logout)"`, cookies),
+		form, cookies,
+	)
+
+	// The sign-in page is requested without the session cookie, which
+	// the logout told the browser to delete.
+	env.requireNotice(t, w, "/pages/login", "signed-out", "Signed out.", nil)
+}
+
 // --- /user/{username} group ---
 
 // TestPasswordChange_OversizeBody_RejectedAndPasswordUnchanged
@@ -858,9 +901,9 @@ func TestHooks_ListAndNewWebhookForm(t *testing.T) {
 	require.NoError(t,
 		env.db.DB().Where("name = ?", "created").First(&created).Error,
 	)
-	assert.Equal(
-		t, "/hook/"+created.ID, w.Header().Get("Location"),
-		"creating a webhook should redirect to its page",
+	env.requireNotice(
+		t, w, "/hook/"+created.ID, "webhook-created", "Webhook created.",
+		cookies,
 	)
 }
 
@@ -891,8 +934,7 @@ func TestHook_EditFormAndDelete(t *testing.T) {
 		env.urlFrom(t, editPage, `action="(/hook/[^/"]+/edit)"`, cookies),
 		form, cookies,
 	)
-	require.Equal(t, http.StatusSeeOther, w.Code)
-	assert.Equal(t, page, w.Header().Get("Location"))
+	env.requireNotice(t, w, page, "webhook-saved", "Webhook saved.", cookies)
 
 	var edited database.Webhook
 
@@ -906,16 +948,17 @@ func TestHook_EditFormAndDelete(t *testing.T) {
 		env.urlFrom(t, page, `action="(/hook/[^/"]+/delete)"`, cookies),
 		form, cookies,
 	)
-	require.Equal(t, http.StatusSeeOther, w.Code)
-	assert.Equal(t, "/hooks", w.Header().Get("Location"))
+	env.requireNotice(
+		t, w, "/hooks", "webhook-deleted", "Webhook deleted.", cookies,
+	)
 	assert.Equal(
 		t, http.StatusNotFound, env.get(page, cookies).Code,
 		"a deleted webhook's page should be gone",
 	)
 }
 
-// TestHook_EntrypointActions adds, deactivates and deletes an
-// entrypoint with the forms on the webhook page, each submitted to
+// TestHook_EntrypointActions adds, deactivates, activates and deletes
+// an entrypoint with the forms on the webhook page, each submitted to
 // the action and with the token the page rendered.
 func TestHook_EntrypointActions(t *testing.T) {
 	t.Parallel()
@@ -933,16 +976,19 @@ func TestHook_EntrypointActions(t *testing.T) {
 	form.Set("csrf_token", token)
 
 	// submit posts the webhook page's form whose action pattern
-	// captures, and requires the redirect back to that page.
-	submit := func(pattern string) {
+	// captures, and requires the redirect back to that page with the
+	// notice code, and the page to show text.
+	submit := func(pattern, code, text string) {
 		t.Helper()
 
 		w := env.post(env.urlFrom(t, page, pattern, cookies), form, cookies)
-		require.Equal(t, http.StatusSeeOther, w.Code)
-		require.Equal(t, page, w.Header().Get("Location"))
+		env.requireNotice(t, w, page, code, text, cookies)
 	}
 
-	submit(`action="(/hook/[^/"]+/entrypoints)"`)
+	toggle := `action="(/hook/[^/"]+/entrypoints/[^/"]+/toggle)"`
+
+	submit(`action="(/hook/[^/"]+/entrypoints)"`,
+		"entrypoint-added", "Entrypoint added.")
 
 	var added database.Entrypoint
 
@@ -951,7 +997,7 @@ func TestHook_EntrypointActions(t *testing.T) {
 	)
 	require.True(t, added.Active)
 
-	submit(`action="(/hook/[^/"]+/entrypoints/[^/"]+/toggle)"`)
+	submit(toggle, "entrypoint-deactivated", "Entrypoint deactivated.")
 
 	var toggled database.Entrypoint
 
@@ -960,7 +1006,10 @@ func TestHook_EntrypointActions(t *testing.T) {
 	)
 	assert.False(t, toggled.Active, "the toggle should deactivate it")
 
-	submit(`action="(/hook/[^/"]+/entrypoints/[^/"]+/delete)"`)
+	submit(toggle, "entrypoint-activated", "Entrypoint activated.")
+
+	submit(`action="(/hook/[^/"]+/entrypoints/[^/"]+/delete)"`,
+		"entrypoint-deleted", "Entrypoint deleted.")
 
 	var left int64
 
@@ -971,8 +1020,8 @@ func TestHook_EntrypointActions(t *testing.T) {
 
 // TestHook_TargetActions adds a target with the form on the webhook
 // page, follows its Edit link to the target edit form and submits
-// it, then deactivates and deletes it, every URL and token taken from
-// the rendered pages.
+// it, then deactivates, activates and deletes it, every URL and token
+// taken from the rendered pages.
 func TestHook_TargetActions(t *testing.T) {
 	t.Parallel()
 
@@ -987,27 +1036,29 @@ func TestHook_TargetActions(t *testing.T) {
 
 	// submit posts form, with the token, to the action pattern
 	// captures on the page at from, and requires the redirect back to
-	// the webhook page.
-	submit := func(from, pattern string, form url.Values) {
+	// the webhook page with the notice code, and that page to show
+	// text.
+	submit := func(from, pattern string, form url.Values, code, text string) {
 		t.Helper()
 
 		form.Set("csrf_token", token)
 
 		w := env.post(env.urlFrom(t, from, pattern, cookies), form, cookies)
-		require.Equal(t, http.StatusSeeOther, w.Code)
-		require.Equal(t, page, w.Header().Get("Location"))
+		env.requireNotice(t, w, page, code, text, cookies)
 	}
 
+	toggle := `action="(/hook/[^/"]+/targets/[^/"]+/toggle)"`
+
 	submit(page, `action="(/hook/[^/"]+/targets)"`, url.Values{
 		"name": {"added"},
 		"type": {string(database.TargetTypeLog)},
-	})
+	}, "target-added", "Target added.")
 
 	editPage := env.urlFrom(
 		t, page, `href="(/hook/[^/"]+/targets/[^/"]+/edit)"`, cookies,
 	)
 	submit(editPage, `action="(/hook/[^/"]+/targets/[^/"]+/edit)"`,
-		url.Values{"name": {"renamed"}})
+		url.Values{"name": {"renamed"}}, "target-saved", "Target saved.")
 
 	var edited database.Target
 
@@ -1017,8 +1068,8 @@ func TestHook_TargetActions(t *testing.T) {
 	assert.Equal(t, "renamed", edited.Name)
 	require.True(t, edited.Active)
 
-	submit(page, `action="(/hook/[^/"]+/targets/[^/"]+/toggle)"`,
-		url.Values{})
+	submit(page, toggle, url.Values{},
+		"target-deactivated", "Target deactivated.")
 
 	var toggled database.Target
 
@@ -1027,8 +1078,11 @@ func TestHook_TargetActions(t *testing.T) {
 	)
 	assert.False(t, toggled.Active, "the toggle should deactivate it")
 
+	submit(page, toggle, url.Values{},
+		"target-activated", "Target activated.")
+
 	submit(page, `action="(/hook/[^/"]+/targets/[^/"]+/delete)"`,
-		url.Values{})
+		url.Values{}, "target-deleted", "Target deleted.")
 
 	var left int64
 
@@ -1064,9 +1118,9 @@ func TestHook_ResubmitFromEventLog(t *testing.T) {
 		env.urlFrom(t, logsPath, `action="(/hook/[^"]+/resubmit)"`, cookies),
 		form, cookies,
 	)
-	require.Equal(t, http.StatusSeeOther, w.Code)
-	assert.Equal(
-		t, logsPath+"?resubmit=no-targets", w.Header().Get("Location"),
+	env.requireNotice(
+		t, w, logsPath, "resubmit-no-targets",
+		"this source has no active targets", cookies,
 	)
 
 	webhookDB, err := env.dbMgr.GetDB(wh.ID)
@@ -1302,10 +1356,8 @@ func TestDeliveryReplay_PostOnlyAndCSRFProtected(t *testing.T) {
 		html.UnescapeString(action[1]), form, cookies,
 	)
 
-	require.Equal(t, http.StatusSeeOther, w.Code)
-	assert.Equal(
-		t, logsPath+"?replay=queued",
-		w.Header().Get("Location"),
+	env.requireNotice(
+		t, w, logsPath, "replay-queued", "Replay queued:", cookies,
 	)
 	assert.Equal(
 		t, int64(2), env.countDeliveries(t, wh.ID),

templates/base.html

@@ -7,6 +7,7 @@
 <body class="bg-gray-50 min-h-screen flex flex-col">
     <div class="flex-grow">
         {{template "navbar" .}}
+        {{template "notice" .}}
         {{block "content" .}}{{end}}
     </div>
     {{template "footer" .}}

templates/notice.html

@@ -0,0 +1,7 @@
+{{define "notice"}}
+{{with .Notice}}
+<div class="max-w-6xl mx-auto px-6 pt-4">
+    <div class="{{if .Failed}}alert-error{{else}}alert-success{{end}}">{{.Text}}</div>
+</div>
+{{end}}
+{{end}}

templates/source_logs.html

@@ -12,14 +12,6 @@
         </div>
     </div>
 
-    {{if .ReplayMessage}}
-    <div class="{{if .ReplayQueued}}alert-success{{else}}alert-error{{end}}">{{.ReplayMessage}}</div>
-    {{end}}
-
-    {{if .ResubmitMessage}}
-    <div class="{{if .ResubmitQueued}}alert-success{{else}}alert-error{{end}}">{{.ResubmitMessage}}</div>
-    {{end}}
-
     <div class="card">
         <div class="divide-y divide-gray-100">
             {{range .Events}}