Add a read-only Settings page for the loaded configuration (closes #402)

The page at /settings, behind the login and linked from the
navigation bar, lists every field of the configuration the server
started with: each by its environment variable name, with the
README's description and the value in effect. METRICS_PASSWORD and
SENTRY_DSN show only as set or not set; their values never reach the
template. The handlers now take the loaded Config from the dependency
graph.

Model: opus-5-5

README.md

@@ -145,6 +145,11 @@ TTY detection, and security headers are always applied.
 | `TRUSTED_PROXIES`       | CIDRs whose forwarded headers are trusted (unset: all clients behind a proxy share one rate-limit bucket; a correct login password is never throttled either way) | `""` (none) |
 | `ALLOWED_EGRESS_CIDRS`  | CIDRs that delivery targets may reach despite the SSRF blocklist. Read [Allowing egress to your own network](#allowing-egress-to-your-own-network) before setting it | `""` (none) |
 
+The Settings page of the web UI (`/settings`, behind the login) lists
+every one of these with the value the running server loaded. It is
+read-only, and it shows `METRICS_PASSWORD` and `SENTRY_DSN` only as
+set or not set, never their values.
+
 #### Allowing egress to your own network
 
 By default every delivery target must resolve to a public address. The
@@ -2692,20 +2697,17 @@ abuse limit later; they are tracked as future work.
 
 | Method | Path            | Description |
 | ------ | --------------- | ----------- |
-| `GET`  | `/pages/login`  | Login page (not rate limited). Its `next` parameter names the page to return to after login; anything but a path on this site is replaced with `/` |
-| `POST` | `/pages/login`  | Login form submission. On success, redirects to the form's `next` when it is a path on this site, otherwise to `/`. Credentials are verified before any limit is consulted, so a correct password is never throttled; 5 FAILED attempts per minute per bucket per submitted username, then `429`. `503` if no verification slot frees up within 5s, or immediately if 16 requests are already queued for one (see [Rate Limiting](#rate-limiting)) |
+| `GET`  | `/pages/login`  | Login page (not rate limited) |
+| `POST` | `/pages/login`  | Login form submission. Credentials are verified before any limit is consulted, so a correct password is never throttled; 5 FAILED attempts per minute per bucket per submitted username, then `429`. `503` if no verification slot frees up within 5s, or immediately if 16 requests are already queued for one (see [Rate Limiting](#rate-limiting)) |
 | `POST` | `/pages/logout` | Logout (destroys session) |
 
 #### Authenticated Endpoints
 
-A logged-out `GET` of any of these is redirected to `/pages/login` with
-its path and query as `next`, so logging in returns to the page that was
-asked for.
-
 | Method | Path                     | Description |
 | ------ | ------------------------ | ----------- |
 | `GET`  | `/user/{username}`       | User profile page |
 | `POST` | `/user/{username}/password` | Change the user's password (5 per minute per bucket, then `429`; `503` if no verification slot frees up within 5s, or immediately if 16 requests are already queued for one) |
+| `GET`  | `/settings`              | Read-only list of the configuration the server is running with; `METRICS_PASSWORD` and `SENTRY_DSN` show only as set or not set |
 | `GET`  | `/sources`               | List user's webhooks |
 | `GET`  | `/sources/new`           | Create webhook form |
 | `POST` | `/sources/new`           | Create webhook submission |
@@ -2818,6 +2820,7 @@ webhooker/
 │   │   ├── healthcheck.go     # Health check handler
 │   │   ├── index.go           # Index page handler
 │   │   ├── profile.go         # User profile handler
+│   │   ├── settings.go        # Read-only Settings page handler
 │   │   ├── source_management.go  # Webhook CRUD handlers
 │   │   └── webhook.go         # Webhook receiver handler
 │   ├── healthcheck/

internal/handlers/auth.go

@@ -2,62 +2,19 @@ package handlers
 
 import (
 	"net/http"
-	"net/url"
 	"strconv"
-	"strings"
-	"unicode"
 
 	"sneak.berlin/go/webhooker/internal/database"
 	"sneak.berlin/go/webhooker/internal/logfield"
-	"sneak.berlin/go/webhooker/internal/middleware"
 )
 
-// maxNextBytes bounds the page to return to after login. The login
-// page writes it into its form, and every page is rendered into a
-// buffer first (see executeTemplate), so without a bound a request
-// would choose the size of that buffer.
-const maxNextBytes = 2048
-
-// loginDestination returns where a successful login sends the
-// browser: next when it is a path on this site, otherwise "/", which
-// leads to the webhook list.
-//
-// A browser reads "//host" as another site, reads "\" as "/", and
-// drops tabs and newlines before reading at all. So the value must
-// start with exactly one "/" and hold no "\" or control character
-// anywhere: http.Redirect cleans "/a/../\host" down to "/\host". It
-// is checked after percent-decoding, so an encoded form of any of
-// these is refused too.
-func loginDestination(next string) string {
-	if len(next) > maxNextBytes {
-		return "/"
-	}
-
-	decoded, err := url.PathUnescape(next)
-	if err != nil ||
-		!strings.HasPrefix(decoded, "/") ||
-		strings.HasPrefix(decoded, "//") ||
-		strings.Contains(decoded, `\`) ||
-		strings.ContainsFunc(decoded, unicode.IsControl) {
-		return "/"
-	}
-
-	return next
-}
-
 // HandleLoginPage returns a handler for the login page (GET)
 func (h *Handlers) HandleLoginPage() http.HandlerFunc {
 	return func(w http.ResponseWriter, r *http.Request) {
-		next := loginDestination(
-			r.URL.Query().Get(middleware.NextParam),
-		)
-
 		// Check if already logged in
 		sess, err := h.session.Get(r)
 		if err == nil && h.session.IsAuthenticated(sess) {
-			http.Redirect( //nolint:gosec // checked by loginDestination
-				w, r, next, http.StatusSeeOther,
-			)
+			http.Redirect(w, r, "/", http.StatusSeeOther)
 
 			return
 		}
@@ -65,7 +22,6 @@ func (h *Handlers) HandleLoginPage() http.HandlerFunc {
 		// Render login page
 		data := map[string]any{
 			tmplKeyError: "",
-			tmplKeyNext:  next,
 		}
 
 		h.renderTemplate(w, r, "login.html", data)
@@ -121,13 +77,8 @@ func (h *Handlers) HandleLoginSubmit() http.HandlerFunc {
 			"user_id", user.ID,
 		)
 
-		// The form value is the client's to set, so it is checked
-		// again here rather than trusted from the rendered page.
-		http.Redirect( //nolint:gosec // checked by loginDestination
-			w, r,
-			loginDestination(r.PostFormValue(middleware.NextParam)),
-			http.StatusSeeOther,
-		)
+		// Redirect to home page
+		http.Redirect(w, r, "/", http.StatusSeeOther)
 	}
 }
 
@@ -140,9 +91,6 @@ func (h *Handlers) renderLoginError(
 ) {
 	data := map[string]any{
 		tmplKeyError: msg,
-		tmplKeyNext: loginDestination(
-			r.PostFormValue(middleware.NextParam),
-		),
 	}
 
 	w.WriteHeader(status)

internal/handlers/auth_test.go

@@ -454,151 +454,6 @@ func TestLogin_SuccessCreatesSession(t *testing.T) {
 	)
 }
 
-// TestLogin_ReturnsOnlyToAPathOnThisSite is the security half of
-// https://git.eeqj.de/sneak/webhooker/issues/384: the page a login
-// returns to is client-chosen, so anything that is not a path on this
-// site, plain or percent-encoded, must land on "/", the webhook list.
-func TestLogin_ReturnsOnlyToAPathOnThisSite(t *testing.T) {
-	t.Parallel()
-
-	var (
-		h  *handlers.Handlers
-		db *database.Database
-	)
-
-	app := newTestApp(t, &h, &db)
-	app.RequireStart()
-
-	t.Cleanup(app.RequireStop)
-
-	seedOperator(t, db)
-
-	cases := []struct{ next, want string }{
-		{"/source/abc/logs?page=2", "/source/abc/logs?page=2"},
-		{"", "/"},
-		{"https://evil.example/", "/"},
-		{"https%3A%2F%2Fevil.example%2F", "/"},
-		{"//evil.example/", "/"},
-		{"%2F%2Fevil.example/", "/"},
-		{"/%2Fevil.example/", "/"},
-		{`/\evil.example/`, "/"},
-		{"%2F%5Cevil.example/", "/"},
-		{"/%5Cevil.example/", "/"},
-		{`/a/../\evil.example/`, "/"},
-		{"/\t/evil.example/", "/"},
-		{"/%09/evil.example/", "/"},
-		{"/" + strings.Repeat("a", 4096), "/"},
-	}
-
-	for _, c := range cases {
-		form := url.Values{}
-		form.Set("username", operatorUser)
-		form.Set("password", operatorPassword)
-		form.Set("next", c.next)
-
-		req := httptest.NewRequestWithContext(
-			context.Background(),
-			http.MethodPost,
-			"/pages/login",
-			strings.NewReader(form.Encode()),
-		)
-		req.Header.Set(
-			"Content-Type", "application/x-www-form-urlencoded",
-		)
-		req.RemoteAddr = sharedProxyPeer
-
-		w := httptest.NewRecorder()
-		h.HandleLoginSubmit().ServeHTTP(w, req)
-
-		assert.Equal(t, http.StatusSeeOther, w.Code, "next %q", c.next)
-		assert.Equal(
-			t, c.want, w.Header().Get("Location"), "next %q", c.next,
-		)
-	}
-}
-
-// loginPageGet renders the login page as a GET with the given next
-// value and cookies.
-func loginPageGet(
-	h *handlers.Handlers, next string, cookies []*http.Cookie,
-) *httptest.ResponseRecorder {
-	req := httptest.NewRequestWithContext(
-		context.Background(), http.MethodGet,
-		"/pages/login?"+url.Values{"next": {next}}.Encode(), nil,
-	)
-
-	for _, c := range cookies {
-		req.AddCookie(c)
-	}
-
-	w := httptest.NewRecorder()
-	h.HandleLoginPage().ServeHTTP(w, req)
-
-	return w
-}
-
-// TestLoginPage_CarriesOnlyAPathOnThisSite covers the login page
-// itself: its form carries the requested page only when it is a path
-// on this site, and a browser already logged in goes straight there,
-// or to "/" when it is not.
-func TestLoginPage_CarriesOnlyAPathOnThisSite(t *testing.T) {
-	t.Parallel()
-
-	var (
-		h    *handlers.Handlers
-		sess *session.Session
-	)
-
-	app := newTestApp(t, &h, &sess)
-	app.RequireStart()
-
-	t.Cleanup(app.RequireStop)
-
-	assert.Contains(
-		t, loginPageGet(h, "/source/abc", nil).Body.String(),
-		`name="next" value="/source/abc"`,
-	)
-	assert.Contains(
-		t, loginPageGet(h, "//evil.example/", nil).Body.String(),
-		`name="next" value="/"`,
-	)
-
-	cookies := authenticatedCookies(t, sess, "test-user-id", "testuser")
-
-	cases := []struct{ next, want string }{
-		{"/source/abc", "/source/abc"},
-		{"//evil.example/", "/"},
-		{`/\evil.example/`, "/"},
-	}
-
-	for _, c := range cases {
-		w := loginPageGet(h, c.next, cookies)
-
-		assert.Equal(t, http.StatusSeeOther, w.Code, "next %q", c.next)
-		assert.Equal(
-			t, c.want, w.Header().Get("Location"), "next %q", c.next,
-		)
-	}
-}
-
-// TestLoginPage_HasNoLinkToItself: the navigation bar on the login
-// page offers no link to the login page.
-func TestLoginPage_HasNoLinkToItself(t *testing.T) {
-	t.Parallel()
-
-	var h *handlers.Handlers
-
-	app := newTestApp(t, &h)
-	app.RequireStart()
-
-	t.Cleanup(app.RequireStop)
-
-	w := loginPageGet(h, "", nil)
-
-	require.Equal(t, http.StatusOK, w.Code)
-	assert.NotContains(t, w.Body.String(), `href="/pages/login"`)
-}
-
 // TestLogin_UsernameAtLimitCanLogIn shows that a username of exactly
 // database.MaxUsernameBytes still fits in the session cookie. Past
 // what the cookie can carry, a correct login answers 500.

internal/handlers/handlers.go

@@ -13,6 +13,7 @@ import (
 	"sync/atomic"
 
 	"go.uber.org/fx"
+	"sneak.berlin/go/webhooker/internal/config"
 	"sneak.berlin/go/webhooker/internal/database"
 	"sneak.berlin/go/webhooker/internal/delivery"
 	"sneak.berlin/go/webhooker/internal/globals"
@@ -36,9 +37,6 @@ const (
 	tmplKeyError = "Error"
 	// tmplKeyWebhook is the template data key for a webhook.
 	tmplKeyWebhook = "Webhook"
-	// tmplKeyNext is the template data key for the page to return
-	// to after login.
-	tmplKeyNext = "Next"
 )
 
 // errInvalidPassword is returned when a password does not match.
@@ -56,6 +54,7 @@ type HandlersParams struct {
 
 	Logger       *logger.Logger
 	Globals      *globals.Globals
+	Config       *config.Config
 	Database     *database.Database
 	WebhookDBMgr *database.WebhookDBManager
 	Healthcheck  *healthcheck.Healthcheck
@@ -132,6 +131,7 @@ func New(
 	s.templates = map[string]*template.Template{
 		"login.html":         parsePageTemplate("login.html"),
 		"profile.html":       parsePageTemplate("profile.html"),
+		"settings.html":      parsePageTemplate("settings.html"),
 		"sources_list.html":  parsePageTemplate("sources_list.html"),
 		"sources_new.html":   parsePageTemplate("sources_new.html"),
 		"source_detail.html": parsePageTemplate("source_detail.html"),

internal/handlers/handlers_test.go

@@ -83,16 +83,25 @@ func newTestApp(
 ) *fxtest.App {
 	t.Helper()
 
+	return newTestAppWithConfig(
+		t, &config.Config{DataDir: t.TempDir()}, targets...,
+	)
+}
+
+// newTestAppWithConfig is newTestApp over a caller-supplied Config.
+func newTestAppWithConfig(
+	t *testing.T,
+	cfg *config.Config,
+	targets ...any,
+) *fxtest.App {
+	t.Helper()
+
 	return fxtest.New(
 		t,
 		fx.Provide(
 			globals.New,
 			logger.New,
-			func() *config.Config {
-				return &config.Config{
-					DataDir: t.TempDir(),
-				}
-			},
+			func() *config.Config { return cfg },
 			database.New,
 			database.NewWebhookDBManager,
 			healthcheck.New,

internal/handlers/profile_test.go

@@ -88,8 +88,6 @@ func TestHandleProfile_OwnProfile_OK(t *testing.T) {
 	h.HandleProfile().ServeHTTP(w, req)
 
 	assert.Equal(t, http.StatusOK, w.Code)
-	assert.Contains(t, w.Body.String(), "Account Information")
-	assert.NotContains(t, w.Body.String(), "Account Type")
 }
 
 func TestHandleProfile_OtherProfile_Forbidden(t *testing.T) {
@@ -160,10 +158,7 @@ func TestUserRoute_Unauthenticated_RedirectedByMiddleware(t *testing.T) {
 		"handler must not be reached for unauthenticated request",
 	)
 	assert.Equal(t, http.StatusSeeOther, w.Code)
-	assert.Equal(
-		t, "/pages/login?next=%2Fuser%2Ftestuser",
-		w.Header().Get("Location"),
-	)
+	assert.Equal(t, "/pages/login", w.Header().Get("Location"))
 }
 
 // passwordChangeRequest builds a POST request to the password-change

internal/handlers/settings.go

@@ -0,0 +1,130 @@
+package handlers
+
+import (
+	"net/http"
+	"net/netip"
+	"strconv"
+	"strings"
+
+	"sneak.berlin/go/webhooker/internal/config"
+)
+
+// notSet is what the Settings page shows for a value that is empty.
+const notSet = "not set"
+
+// settingRow is one line of the Settings page: an environment
+// variable, what it controls, and the value the server loaded for it.
+type settingRow struct {
+	Name        string
+	Description string
+	Value       string
+}
+
+// HandleSettings returns a handler for the read-only Settings page,
+// which lists the configuration the server started with.
+func (h *Handlers) HandleSettings() http.HandlerFunc {
+	return func(w http.ResponseWriter, r *http.Request) {
+		h.renderTemplate(w, r, "settings.html", map[string]any{
+			"Settings": settingRows(h.params.Config),
+		})
+	}
+}
+
+// settingRows lists every field of cfg under the environment variable
+// it is read from, in the order of the README's configuration table.
+// METRICS_PASSWORD and SENTRY_DSN are credentials, so their values
+// never reach the page: only whether they are set.
+func settingRows(cfg *config.Config) []settingRow {
+	metricsUsername := cfg.MetricsUsername
+	if metricsUsername == "" {
+		metricsUsername = notSet
+	}
+
+	return []settingRow{
+		{"WEBHOOKER_ENVIRONMENT", "dev or prod", cfg.Environment},
+		{"PORT", "HTTP listen port", strconv.Itoa(cfg.Port)},
+		{
+			"BIND_ADDRESS",
+			"IP address the HTTP listener binds",
+			cfg.BindAddress,
+		},
+		{
+			"DATA_DIR",
+			"Directory for all SQLite databases",
+			cfg.DataDir,
+		},
+		{
+			"DEBUG",
+			"Enable debug logging",
+			strconv.FormatBool(cfg.Debug),
+		},
+		{
+			"MAINTENANCE_MODE",
+			"Report maintenanceMode: true in the healthcheck JSON. " +
+				"It does not change how any request is served",
+			strconv.FormatBool(cfg.MaintenanceMode),
+		},
+		{
+			"METRICS_USERNAME",
+			"Basic auth username for /metrics",
+			metricsUsername,
+		},
+		{
+			"METRICS_PASSWORD",
+			"Basic auth password for /metrics",
+			setOrNotSet(cfg.MetricsPassword),
+		},
+		{
+			"SENTRY_DSN",
+			"Error reporting DSN. Unset leaves error reporting off",
+			setOrNotSet(cfg.SentryDSN),
+		},
+		{
+			"RETENTION_SWEEP_INTERVAL",
+			"How often the retention reaper and archive sweeper run",
+			cfg.RetentionSweepInterval.String(),
+		},
+		{
+			"SESSION_IDLE_TIMEOUT",
+			"Idle session timeout. Zero or negative disables idle " +
+				"expiry",
+			cfg.SessionIdleTimeout.String(),
+		},
+		{
+			"RECEIVER_RATE_LIMIT",
+			"Receiver requests per minute per IP per entrypoint " +
+				"(10x that per IP across the route)",
+			strconv.Itoa(cfg.ReceiverRateLimit),
+		},
+		{
+			"TRUSTED_PROXIES",
+			"CIDRs whose forwarded headers are trusted",
+			cidrList(cfg.TrustedProxies),
+		},
+		{
+			"ALLOWED_EGRESS_CIDRS",
+			"CIDRs that delivery targets may reach despite the " +
+				"SSRF blocklist",
+			cidrList(cfg.AllowedEgressCIDRs),
+		},
+	}
+}
+
+// setOrNotSet is how the Settings page shows a credential: whether it
+// has a value, never the value itself.
+func setOrNotSet(value string) string {
+	if value == "" {
+		return notSet
+	}
+
+	return "set"
+}
+
+// cidrList renders a CIDR list setting for the Settings page.
+func cidrList(prefixes []netip.Prefix) string {
+	if len(prefixes) == 0 {
+		return "none"
+	}
+
+	return strings.Join(config.PrefixStrings(prefixes), ", ")
+}

internal/handlers/settings_test.go

@@ -0,0 +1,130 @@
+package handlers_test
+
+import (
+	"context"
+	"html"
+	"net/http"
+	"net/http/httptest"
+	"net/netip"
+	"regexp"
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	"sneak.berlin/go/webhooker/internal/config"
+	"sneak.berlin/go/webhooker/internal/handlers"
+	"sneak.berlin/go/webhooker/internal/session"
+)
+
+// settingsShown renders the Settings page over cfg as a logged-in user
+// and returns the value it shows for each variable name, plus the
+// whole page.
+func settingsShown(
+	t *testing.T, cfg *config.Config,
+) (map[string]string, string) {
+	t.Helper()
+
+	var h *handlers.Handlers
+
+	var sess *session.Session
+
+	app := newTestAppWithConfig(t, cfg, &h, &sess)
+	app.RequireStart()
+
+	t.Cleanup(app.RequireStop)
+
+	req := httptest.NewRequestWithContext(
+		context.Background(), http.MethodGet, "/settings", nil,
+	)
+	for _, c := range authenticatedCookies(t, sess, "id", "admin") {
+		req.AddCookie(c)
+	}
+
+	w := httptest.NewRecorder()
+	h.HandleSettings().ServeHTTP(w, req)
+	require.Equal(t, http.StatusOK, w.Code)
+
+	body := w.Body.String()
+
+	row := regexp.MustCompile(
+		`<code[^>]*>([A-Z_]+)</code>\s*<code[^>]*>([^<]*)</code>`,
+	)
+
+	shown := map[string]string{}
+	for _, match := range row.FindAllStringSubmatch(body, -1) {
+		shown[match[1]] = html.UnescapeString(match[2])
+	}
+
+	return shown, body
+}
+
+func TestSettingsPageShowsLoadedConfiguration(t *testing.T) {
+	t.Parallel()
+
+	const (
+		metricsPassword = "metrics-password-1f9a"
+		sentryKey       = "dsnkey7c2e"
+		sentryDSN       = "https://" + sentryKey + "@errors.example.com/42"
+	)
+
+	cfg := &config.Config{
+		DataDir:                t.TempDir(),
+		Debug:                  true,
+		MaintenanceMode:        true,
+		Environment:            config.EnvironmentDev,
+		MetricsUsername:        "scraper",
+		MetricsPassword:        metricsPassword,
+		Port:                   9123,
+		SentryDSN:              sentryDSN,
+		BindAddress:            "192.0.2.10",
+		RetentionSweepInterval: 17 * time.Minute,
+		SessionIdleTimeout:     3 * time.Hour,
+		ReceiverRateLimit:      77,
+		TrustedProxies: []netip.Prefix{
+			netip.MustParsePrefix("10.1.0.0/16"),
+		},
+		AllowedEgressCIDRs: []netip.Prefix{
+			netip.MustParsePrefix("192.168.5.0/24"),
+			netip.MustParsePrefix("fd00::/8"),
+		},
+	}
+
+	shown, body := settingsShown(t, cfg)
+
+	assert.Equal(t, map[string]string{
+		"WEBHOOKER_ENVIRONMENT":    "dev",
+		"PORT":                     "9123",
+		"BIND_ADDRESS":             "192.0.2.10",
+		"DATA_DIR":                 cfg.DataDir,
+		"DEBUG":                    "true",
+		"MAINTENANCE_MODE":         "true",
+		"METRICS_USERNAME":         "scraper",
+		"METRICS_PASSWORD":         "set",
+		"SENTRY_DSN":               "set",
+		"RETENTION_SWEEP_INTERVAL": "17m0s",
+		"SESSION_IDLE_TIMEOUT":     "3h0m0s",
+		"RECEIVER_RATE_LIMIT":      "77",
+		"TRUSTED_PROXIES":          "10.1.0.0/16",
+		"ALLOWED_EGRESS_CIDRS":     "192.168.5.0/24, fd00::/8",
+	}, shown)
+
+	assert.NotContains(t, body, metricsPassword)
+	assert.NotContains(t, body, sentryKey)
+	assert.Contains(
+		t, body, `href="/settings"`,
+		"the navigation bar links to the page",
+	)
+}
+
+func TestSettingsPageShowsUnsetValues(t *testing.T) {
+	t.Parallel()
+
+	shown, _ := settingsShown(t, &config.Config{DataDir: t.TempDir()})
+
+	assert.Equal(t, "not set", shown["METRICS_USERNAME"])
+	assert.Equal(t, "not set", shown["METRICS_PASSWORD"])
+	assert.Equal(t, "not set", shown["SENTRY_DSN"])
+	assert.Equal(t, "none", shown["TRUSTED_PROXIES"])
+	assert.Equal(t, "none", shown["ALLOWED_EGRESS_CIDRS"])
+}

internal/middleware/middleware.go

@@ -6,7 +6,6 @@ import (
 	"log/slog"
 	"net"
 	"net/http"
-	"net/url"
 	"sync"
 	"time"
 
@@ -367,24 +366,6 @@ func (s *Middleware) CORS() func(http.Handler) http.Handler {
 	}
 }
 
-// NextParam is the query parameter on the login redirect, and the
-// login form field, that holds the page to return to after login.
-const NextParam = "next"
-
-// loginURL is the login page RequireAuth redirects to. A GET carries
-// its own path and query in NextParam so that logging in returns to
-// it; HandleLoginSubmit decides whether that value is safe to follow.
-// Other methods carry nothing, since a redirect cannot repeat them.
-func loginURL(r *http.Request) string {
-	if r.Method != http.MethodGet {
-		return "/pages/login"
-	}
-
-	return "/pages/login?" + url.Values{
-		NextParam: {r.URL.RequestURI()},
-	}.Encode()
-}
-
 // RequireAuth returns middleware that checks for a valid session.
 // Unauthenticated users are redirected to the login page.
 func (s *Middleware) RequireAuth() func(http.Handler) http.Handler {
@@ -400,7 +381,7 @@ func (s *Middleware) RequireAuth() func(http.Handler) http.Handler {
 					"error", err,
 				)
 				http.Redirect(
-					w, r, loginURL(r), http.StatusSeeOther,
+					w, r, "/pages/login", http.StatusSeeOther,
 				)
 
 				return
@@ -428,7 +409,7 @@ func (s *Middleware) RequireAuth() func(http.Handler) http.Handler {
 					),
 				)
 				http.Redirect(
-					w, r, loginURL(r), http.StatusSeeOther,
+					w, r, "/pages/login", http.StatusSeeOther,
 				)
 
 				return

internal/middleware/middleware_test.go

@@ -338,42 +338,6 @@ func TestRequireAuth_NoSession_RedirectsToLogin(t *testing.T) {
 			"unauthenticated request",
 	)
 	assert.Equal(t, http.StatusSeeOther, w.Code)
-	assert.Equal(
-		t, "/pages/login?next=%2Fdashboard", w.Header().Get("Location"),
-	)
-}
-
-// TestRequireAuth_LoginRedirectCarriesOnlyAGet pins what the login
-// redirect carries: a GET's path and query, so logging in can return
-// there, and nothing for a POST, which a redirect cannot repeat.
-func TestRequireAuth_LoginRedirectCarriesOnlyAGet(t *testing.T) {
-	t.Parallel()
-
-	m, _ := testMiddleware(t, config.EnvironmentDev)
-
-	handler := m.RequireAuth()(http.HandlerFunc(
-		func(_ http.ResponseWriter, _ *http.Request) {},
-	))
-
-	get := httptest.NewRequestWithContext(
-		context.Background(),
-		http.MethodGet, "/source/abc/logs?page=2", nil,
-	)
-	w := httptest.NewRecorder()
-	handler.ServeHTTP(w, get)
-
-	assert.Equal(
-		t, "/pages/login?next=%2Fsource%2Fabc%2Flogs%3Fpage%3D2",
-		w.Header().Get("Location"),
-	)
-
-	post := httptest.NewRequestWithContext(
-		context.Background(),
-		http.MethodPost, "/source/abc/delete", nil,
-	)
-	w = httptest.NewRecorder()
-	handler.ServeHTTP(w, post)
-
 	assert.Equal(t, "/pages/login", w.Header().Get("Location"))
 }
 
@@ -479,9 +443,7 @@ func TestRequireAuth_UnauthenticatedSession_RedirectsToLogin(
 			"unauthenticated session",
 	)
 	assert.Equal(t, http.StatusSeeOther, w.Code)
-	assert.Equal(
-		t, "/pages/login?next=%2Fdashboard", w.Header().Get("Location"),
-	)
+	assert.Equal(t, "/pages/login", w.Header().Get("Location"))
 }
 
 // --- RequireAuth Session Expiry Tests ---
@@ -579,9 +541,7 @@ func TestRequireAuth_IdleExpiredSession_RedirectsToLogin(
 		"handler should not run for an idle-expired session",
 	)
 	assert.Equal(t, http.StatusSeeOther, w.Code)
-	assert.Equal(
-		t, "/pages/login?next=%2Fdashboard", w.Header().Get("Location"),
-	)
+	assert.Equal(t, "/pages/login", w.Header().Get("Location"))
 	assert.Empty(
 		t, sessionCookies(w),
 		"an expired session must not be refreshed",

internal/server/routes.go

@@ -141,6 +141,7 @@ func (s *Server) setupRoutes() {
 
 	s.setupPageRoutes()
 	s.setupUserRoutes()
+	s.setupSettingsRoutes()
 	s.setupSourceRoutes()
 	s.setupWebhookRoutes()
 }
@@ -181,6 +182,21 @@ func (s *Server) setupUserRoutes() {
 	})
 }
 
+// setupSettingsRoutes serves the Settings page. It is GET only:
+// configuration comes from the environment and nothing here changes
+// it.
+func (s *Server) setupSettingsRoutes() {
+	s.router.Route("/settings", func(r chi.Router) {
+		// MaxBodySize precedes CSRF and RequireAuth deliberately;
+		// see maxFormBodySize for why, and for what it costs.
+		r.Use(s.mw.MaxBodySize(maxFormBodySize))
+		r.Use(s.mw.CSRF())
+		r.Use(s.mw.NoCache())
+		r.Use(s.mw.RequireAuth())
+		r.Get("/", s.h.HandleSettings())
+	})
+}
+
 func (s *Server) setupSourceRoutes() {
 	s.router.Route("/sources", func(r chi.Router) {
 		// MaxBodySize precedes CSRF and RequireAuth deliberately;

internal/server/routes_test.go

@@ -680,44 +680,6 @@ func TestPagesLogin_CookiesFromAnEarlierDatabase(t *testing.T) {
 	)
 }
 
-// TestPagesLogin_ReturnsToTheRequestedPage is
-// https://git.eeqj.de/sneak/webhooker/issues/384: a page opened while
-// logged out leads to the login page, and logging in from there lands
-// on that page, query included.
-func TestPagesLogin_ReturnsToTheRequestedPage(t *testing.T) {
-	t.Parallel()
-
-	const (
-		username = "operator"
-		password = "correct-horse-battery-staple"
-	)
-
-	env := newTestEnv(t)
-	userID, _ := env.seedUser(t, username, password)
-	asked := "/source/" + env.seedWebhook(t, userID).ID + "/logs?page=2"
-
-	bounced := env.get(asked, nil)
-	require.Equal(t, http.StatusSeeOther, bounced.Code)
-
-	loginPage := bounced.Header().Get("Location")
-
-	match := regexp.MustCompile(`name="next" value="([^"]*)"`).
-		FindStringSubmatch(env.get(loginPage, nil).Body.String())
-	require.Len(t, match, 2, "the login form must carry the page")
-
-	token, cookies := env.csrfFrom(t, loginPage, nil)
-
-	form := url.Values{}
-	form.Set("csrf_token", token)
-	form.Set("username", username)
-	form.Set("password", password)
-	form.Set("next", html.UnescapeString(match[1]))
-
-	w := env.post("/pages/login", form, cookies)
-	require.Equal(t, http.StatusSeeOther, w.Code)
-	assert.Equal(t, asked, w.Header().Get("Location"))
-}
-
 // --- /user/{username} group ---
 
 // TestPasswordChange_OversizeBody_RejectedAndPasswordUnchanged
@@ -868,10 +830,7 @@ func TestSourceLogsBody_OtherUser404s(t *testing.T) {
 
 	anon := env.get(path, nil)
 	assert.Equal(t, http.StatusSeeOther, anon.Code)
-	assert.Equal(
-		t, "/pages/login?next="+url.QueryEscape(path),
-		anon.Header().Get("Location"),
-	)
+	assert.Equal(t, "/pages/login", anon.Header().Get("Location"))
 }
 
 // TestDeliveryReplay_PostOnlyAndCSRFProtected walks the replay action

internal/server/settings_test.go

@@ -0,0 +1,22 @@
+package server_test
+
+import (
+	"net/http"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestSettingsPageIsBehindLogin(t *testing.T) {
+	t.Parallel()
+
+	env := newTestEnv(t)
+
+	w := env.get("/settings", nil)
+	assert.Equal(t, http.StatusSeeOther, w.Code)
+	assert.Equal(t, "/pages/login", w.Header().Get("Location"))
+
+	w = env.get("/settings", env.authCookies(t, "id", "admin"))
+	assert.Equal(t, http.StatusOK, w.Code)
+	assert.Contains(t, w.Body.String(), "WEBHOOKER_ENVIRONMENT")
+}

templates/login.html

@@ -24,7 +24,6 @@
 
             <form method="POST" action="/pages/login" class="space-y-6">
                 <input type="hidden" name="csrf_token" value="{{.CSRFToken}}">
-                <input type="hidden" name="next" value="{{.Next}}">
                 <div class="form-group">
                     <label for="username" class="label">Username</label>
                     <input

templates/navbar.html

@@ -6,19 +6,18 @@
         </div>
 
         <!-- Mobile menu button -->
-        {{if .User}}
         <button @click="open = !open" class="md:hidden p-2 rounded-md text-gray-500 hover:bg-gray-100">
             <svg class="w-6 h-6" fill="none" stroke="currentColor" viewBox="0 0 24 24">
                 <path x-show="!open" stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M4 6h16M4 12h16M4 18h16"/>
                 <path x-show="open" x-cloak stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M6 18L18 6M6 6l12 12"/>
             </svg>
         </button>
-        {{end}}
 
         <!-- Desktop navigation -->
         <div class="hidden md:flex items-center gap-4">
             {{if .User}}
             <a href="/sources" class="btn-text">Webhooks</a>
+            <a href="/settings" class="btn-text">Settings</a>
             <a href="/user/{{.User.Username}}" class="btn-text">
                 <svg class="w-5 h-5 mr-1" fill="currentColor" viewBox="0 0 16 16">
                     <path d="M11 6a3 3 0 1 1-6 0 3 3 0 0 1 6 0z"/>
@@ -30,6 +29,8 @@
                 <input type="hidden" name="csrf_token" value="{{.CSRFToken}}">
                 <button type="submit" class="btn-text">Logout</button>
             </form>
+            {{else}}
+            <a href="/pages/login" class="btn-primary">Login</a>
             {{end}}
         </div>
     </div>
@@ -39,11 +40,14 @@
         <div class="flex flex-col gap-2">
             {{if .User}}
             <a href="/sources" class="btn-text w-full text-left">Webhooks</a>
+            <a href="/settings" class="btn-text w-full text-left">Settings</a>
             <a href="/user/{{.User.Username}}" class="btn-text w-full text-left">Profile</a>
             <form method="POST" action="/pages/logout">
                 <input type="hidden" name="csrf_token" value="{{.CSRFToken}}">
                 <button type="submit" class="btn-text w-full text-left">Logout</button>
             </form>
+            {{else}}
+            <a href="/pages/login" class="btn-primary w-full">Login</a>
             {{end}}
         </div>
     </div>

templates/profile.html

@@ -41,6 +41,10 @@
                     <dt class="w-32 text-sm font-medium text-gray-500">Username</dt>
                     <dd class="text-sm text-gray-900">{{.User.Username}}</dd>
                 </div>
+                <div class="flex">
+                    <dt class="w-32 text-sm font-medium text-gray-500">Account Type</dt>
+                    <dd class="text-sm text-gray-900">Standard User</dd>
+                </div>
             </dl>
         </div>
     </div>

templates/settings.html

@@ -0,0 +1,24 @@
+{{template "base" .}}
+
+{{define "title"}}Settings - Webhooker{{end}}
+
+{{define "content"}}
+<div class="max-w-6xl mx-auto px-6 py-8">
+    <h1 class="text-2xl font-medium text-gray-900">Settings</h1>
+    <p class="text-sm text-gray-500 mt-1 mb-6">The configuration this server started with. It is set in the server's environment and cannot be changed here.</p>
+
+    <div class="card">
+        <div class="divide-y divide-gray-100">
+            {{range .Settings}}
+            <div class="p-4">
+                <div class="flex justify-between items-start gap-4">
+                    <code class="text-sm font-medium text-gray-900">{{.Name}}</code>
+                    <code class="text-sm text-gray-900 break-all">{{.Value}}</code>
+                </div>
+                <p class="text-sm text-gray-500 mt-1">{{.Description}}</p>
+            </div>
+            {{end}}
+        </div>
+    </div>
+</div>
+{{end}}