State what the default blocklist covers (closes #244)

The default blocklist covers private and reserved space, plus public
addresses that serve cloud credentials. A provider's other services on
public addresses, such as IBM Cloud's 161.26.0.0/16 and 166.8.0.0/14,
are deliberately not on it: they serve no credentials, reaching them
can be legitimate, and every cloud has some, so a partial list would
promise coverage it does not give.

The README's egress section and the comment above blockedNetworks now
state this rule, so nobody infers wider coverage and a future candidate
can be accepted or refused against it. No list change.

Model: opus-5-5

Dockerfile

@@ -88,9 +88,7 @@ RUN CGO_ENABLED=1 make build VERSION="$VERSION" GO_LDFLAGS='-extldflags "-static
 # alpine:3.21, 2026-03-17
 FROM alpine:3.21@sha256:c3f8e73fdb79deaebaa2037150150191b9dcbfba68b4a46d70103204c53f4709
 
-# su-exec 0.2-r3 (Alpine 3.21), 2026-09-29: the entrypoint runs the app
-# as webhooker with it.
-RUN apk --no-cache add ca-certificates su-exec=0.2-r3
+RUN apk --no-cache add ca-certificates
 
 # Create non-root user
 RUN addgroup -g 1000 -S webhooker && \
@@ -101,17 +99,13 @@ WORKDIR /app
 # Copy binary from builder
 COPY --from=builder /build/bin/webhooker /app/webhooker
 
-# Not under /app, which belongs to webhooker: this script runs as root.
-COPY deploy/docker-entrypoint.sh /usr/local/bin/docker-entrypoint.sh
-
 # Create data directory for all SQLite databases (main app DB +
 # per-webhook event DBs). DATA_DIR defaults to /var/lib/webhooker.
 RUN mkdir -p /var/lib/webhooker
 
 RUN chown -R webhooker:webhooker /app /var/lib/webhooker
 
-# No USER: the entrypoint starts as root to make the data directory
-# webhooker's, then runs the app as webhooker.
+USER webhooker
 
 EXPOSE 8080
 
@@ -130,5 +124,4 @@ ENV BIND_ADDRESS=0.0.0.0
 HEALTHCHECK --interval=30s --timeout=3s --start-period=5s --retries=3 \
     CMD wget --no-verbose --tries=1 --spider http://localhost:8080/.well-known/healthcheck || exit 1
 
-ENTRYPOINT ["/usr/local/bin/docker-entrypoint.sh"]
 CMD ["/app/webhooker"]

README.md

@@ -162,6 +162,14 @@ public cloud metadata addresses: currently only `168.63.129.16`, Azure's
 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: private and reserved space,
+plus public addresses that serve cloud credentials. A cloud provider's
+other services on public addresses are not refused — IBM Cloud's
+`161.26.0.0/16` and `166.8.0.0/14`, for example, which carry its DNS
+resolvers, time servers and package mirrors. They serve no credentials,
+reaching them 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
 network. A container on the same Docker network, a box on `10.x`, a
@@ -552,9 +560,8 @@ printf '%s' "$NEW_PASSWORD" | \
     DATA_DIR=/var/lib/webhooker webhooker resetpw admin
 ```
 
-In a container it is the same binary. The image's `CMD` is
-`/app/webhooker`, and a command given to `docker run` replaces all of
-it, so the whole command has to be given:
+In a container it is the same binary, which the image sets as `CMD`
+rather than `ENTRYPOINT`, so the whole command has to be given:
 
 ```bash
 docker run --rm -v webhooker-data:/var/lib/webhooker \
@@ -691,22 +698,38 @@ those three values rather than trusting the figure. Measured at 65s on
 Docker 29.7.2.) A container `unhealthy` with `connection refused` in
 its health log, or a published port that resets connections, is this.
 
-The app runs as a non-root user (`webhooker`, UID 1000), exposes port
-8080, and includes a health check against `/.well-known/healthcheck`.
-The `/var/lib/webhooker` volume holds all SQLite databases: the main
-application database (`webhooker.db`), the per-webhook event databases
-(`events-{uuid}.db`), and any archive databases written by `database`
-targets (`archive-{uuid}.db`). Mount this as a persistent volume to
-preserve data across container restarts.
+The container runs as a non-root user (`webhooker`, UID 1000), exposes
+port 8080, and includes a health check against
+`/.well-known/healthcheck`. The `/var/lib/webhooker` volume holds all
+SQLite databases: the main application database (`webhooker.db`), the
+per-webhook event databases (`events-{uuid}.db`), and any archive
+databases written by `database` targets (`archive-{uuid}.db`). Mount
+this as a persistent volume to preserve data across container
+restarts.
 
-**The container sets its data directory's owner and mode itself
-before the app starts**, so a host directory can be mounted as it is,
-whoever owns it. The image's `ENTRYPOINT`,
-`deploy/docker-entrypoint.sh`, starts as root, creates `DATA_DIR` if
-it is missing, gives the directory and anything in it that belongs to
-another user to `webhooker`, sets the directory to `0750`, and only
-then runs the app as `webhooker`. Started with `--user`, it changes
-nothing and runs the app as that user.
+**The bind-mounted directory must be owned by UID 1000, or the
+container does not start.** Docker creates a `-v` source path that
+does not exist yet as `root:root`, and the process runs as UID 1000,
+so it cannot take its `DATA_DIR` lock:
+
+```
+webhooker: locking data directory /var/lib/webhooker: open
+/var/lib/webhooker/webhooker.lock: permission denied
+```
+
+It exits non-zero at that point, before opening any database. Create
+the directory ahead of the first `docker run`:
+
+```bash
+mkdir -p /path/to/data
+chown 1000:1000 /path/to/data
+chmod 750 /path/to/data
+```
+
+The same `chown` is what a restore needs — see step 4 of
+[Restore](#restore). A **named volume** does not have this problem:
+Docker copies the image's ownership onto a volume it initializes, and
+the image creates `/var/lib/webhooker` owned by `webhooker`.
 
 **The file modes are not yours to set, and do not depend on the
 directory.** `webhooker.db` holds target configuration in plaintext —
@@ -714,10 +737,13 @@ bearer tokens, API keys, Slack webhook URLs — along with the session
 encryption key, so webhooker creates every SQLite file it owns `0600`:
 each database and both of its `-wal` and `-shm` sidecars, across all
 three tiers. Files an earlier build left `0644` are tightened when
-they are opened. The directory's `0750` is defence in depth — it stops
-other local users listing the directory and learning your webhook
-UUIDs from the `events-{uuid}.db` filenames — not the barrier
-protecting the credentials.
+they are opened. A `DATA_DIR` webhooker creates itself is `0750`, but
+a bind mount supplies its own directory and Docker's default for one
+it creates is `0755`; the `0600` files hold there regardless. The
+`chmod 750` above is defence in depth — it stops other local users
+listing the directory and learning your webhook UUIDs from the
+`events-{uuid}.db` filenames — not the barrier protecting the
+credentials.
 
 ### Running under upaas
 
@@ -733,6 +759,17 @@ repository's `Dockerfile` and runs it. The app needs:
   app name, port `8080`. Leave `PORT` unset: the image's health check
   probes `8080`.
 - **Volume:** one host directory mounted at `/var/lib/webhooker`.
+  upaas bind-mounts the host path it is given and does not create it,
+  and the container does not start unless UID 1000 owns it (see
+  [Running with Docker](#running-with-docker)). Create it before the
+  first deploy:
+
+    ```bash
+    mkdir -p /path/to/data
+    chown 1000:1000 /path/to/data
+    chmod 750 /path/to/data
+    ```
+
 - **Environment variables:**
     - `WEBHOOKER_ENVIRONMENT=prod`
     - `TRUSTED_PROXIES`: your reverse proxy's address on that Docker
@@ -991,12 +1028,12 @@ done
 `.backup` reads through the WAL and writes a single consistent file with
 no sidecars of its own, so the destination is complete as it stands.
 Two caveats. First, the runtime image is `alpine:3.21` with only
-`ca-certificates` and `su-exec` added — the `sqlite3` CLI is **not** in
-it, so run this on the host against the volume path, or from a
-throwaway container that mounts the volume. Second, each file is
-captured at its own instant, so a webhook created or an event delivered
-between two files being copied lands in one and not the other. If you
-need the whole set coherent as of a single moment, stop the service.
+`ca-certificates` added — the `sqlite3` CLI is **not** in it, so run
+this on the host against the volume path, or from a throwaway container
+that mounts the volume. Second, each file is captured at its own
+instant, so a webhook created or an event delivered between two files
+being copied lands in one and not the other. If you need the whole set
+coherent as of a single moment, stop the service.
 
 Note that `sqlite3 <db> .dump` is **not** one of these procedures: it is
 an export, it holds a read transaction open for as long as it runs, and
@@ -1050,11 +1087,21 @@ with any `-wal`/`-shm` beside it, or wait until there are none.
    archive not opened since a crash. A copy salvaged from a crashed
    instance has them for everything, and needs all of them.
 
-4. Start the service. The container gives the directory and the
-   restored files to the `webhooker` user before the app starts,
-   whoever restored them (see
-   [Running with Docker](#running-with-docker)). `AutoMigrate` runs
-   against each restored database as it is opened.
+4. **Fix ownership.** The container runs as the non-root `webhooker`
+   user, UID 1000 / GID 1000. Restored files must be owned by (or
+   writable by) that UID, and so must the directory itself — SQLite
+   creates the `-wal` and `-shm` sidecars beside the database, so a
+   writable file inside a directory it cannot write is not enough:
+
+    ```bash
+    chown -R 1000:1000 /path/to/data
+    ```
+
+    Restoring as `root` on the host and forgetting this step is the
+    usual way a restore fails.
+
+5. Start the service. `AutoMigrate` runs against each restored database
+   as it is opened.
 
 ### Upgrades
 
@@ -2682,7 +2729,7 @@ abuse limit later; they are tracked as future work.
 | ------ | --------------------------- | ----------- |
 | `GET`  | `/`                         | Root redirect, 303 (authenticated → `/sources`, unauthenticated → `/pages/login`) |
 | `GET`  | `/.well-known/healthcheck`  | Health check (JSON: `status`, `now`, `uptimeSeconds`, `uptimeHuman`, `version`, `appname`, `maintenanceMode`) |
-| `GET`, `HEAD` | `/s/*`              | Static file serving (embedded CSS, JS). `GET` and `HEAD` only — `POST`, `PUT`, `PATCH`, `DELETE`, `OPTIONS`, `TRACE` and `CONNECT` are answered `405 Method Not Allowed` with `Allow: GET, HEAD`. Any other method (such as `PROPFIND`) is refused by chi before it reaches this route, and gets `405` without an `Allow` header. Pinned by `TestStaticServesOnlyGetAndHead` |
+| any    | `/s/*`                      | Static file serving (embedded CSS, JS). Mounted for every method, not just `GET`/`HEAD`: chi's `Mount` registers all methods and `http.FileServer` special-cases only `HEAD` (by omitting the body), so a `POST` or `DELETE` to an asset is answered `200` with the file. Pinned by `TestStaticServesEveryMethod` |
 | `POST` | `/webhook/{uuid}`           | Webhook receiver endpoint. `POST` only — every other method is answered `405 Method Not Allowed` with `Allow: POST`. Rate limited (see [Rate Limiting](#rate-limiting)) |
 
 #### Authentication Endpoints
@@ -3032,9 +3079,7 @@ check, see [The login endpoint](#the-login-endpoint).
 - Prometheus metrics behind basic auth
 - Static assets embedded in binary (no filesystem access needed at
   runtime)
-- The app runs as a non-root user (UID 1000) in the container; only
-  the `ENTRYPOINT` script that sets the data directory's owner runs as
-  root, before the app starts
+- Container runs as non-root user (UID 1000)
 - GORM soft deletes on every entity that carries `BaseModel`, which is
   all of them but `Setting` (data preserved for audit)
 
@@ -3161,13 +3206,10 @@ version is fixed independently of the compiler's:
    `GO_LDFLAGS`, so neither can drop the `-X` that stamps the version.
    The version arrives as the `VERSION` build arg, since the context
    has no `.git` (see [Version stamping](#version-stamping)).
-3. **Runtime stage** (`alpine:3.21`) — copies the static binary and
-   `deploy/docker-entrypoint.sh`, creates the `/var/lib/webhooker`
-   directory for all SQLite databases, exposes port 8080, and includes
-   a health check against `/.well-known/healthcheck`. It sets no
-   `USER`: the `ENTRYPOINT` script starts as root, sets the data
-   directory's owner and mode, and runs the app as the non-root
-   `webhooker` user (UID 1000) through `su-exec`.
+3. **Runtime stage** (`alpine:3.21`) — copies the static binary,
+   creates the `/var/lib/webhooker` directory for all SQLite databases,
+   runs as the non-root `webhooker` user (UID 1000), exposes port 8080,
+   and includes a health check against `/.well-known/healthcheck`.
 
 The lint stage invokes `golangci-lint` directly rather than `make lint`:
 it is already the pinned linter image, and `make lint` builds

deploy/docker-entrypoint.sh

@@ -1,22 +0,0 @@
-#!/bin/sh
-# deploy/docker-entrypoint.sh: the image's ENTRYPOINT. A bind-mounted
-# data directory keeps its owner from the host, often root, and the app
-# could not write to it. Started as root, this creates DATA_DIR if
-# needed, gives it and everything in it to webhooker, sets its mode, and
-# runs the command as webhooker, so the app never runs as root. Started
-# as another user, it only runs the command.
-set -eu
-
-main() {
-    if [ "$(id -u)" != 0 ]; then
-        exec "$@"
-    fi
-
-    dir="${DATA_DIR:-/var/lib/webhooker}"
-    mkdir -p "$dir"
-    find "$dir" ! -user webhooker -exec chown -h webhooker:webhooker {} +
-    chmod 750 "$dir"
-    exec su-exec webhooker "$@"
-}
-
-main "$@"

internal/delivery/ssrf.go

@@ -43,6 +43,12 @@ var (
 // permit specific blocks out of this set with
 // ALLOWED_EGRESS_CIDRS; see Guard.
 //
+// A public address belongs here only if it serves cloud
+// credentials; a provider's other services on public addresses,
+// such as its DNS resolvers or package mirrors, stay out, since
+// reaching them can be legitimate and no list of them could be
+// complete.
+//
 //nolint:gochecknoglobals // package-level network list is appropriate here
 var blockedNetworks []*net.IPNet
 

internal/server/routes.go

@@ -92,25 +92,11 @@ func (s *Server) setupGlobalMiddleware() {
 func (s *Server) setupRoutes() {
 	s.router.Get("/", s.h.HandleIndex())
 
-	// Static assets answer GET and HEAD only. chi's default 405
-	// carries no Allow header, so this group supplies its own.
-	staticFiles := http.StripPrefix(
-		"/s", http.FileServer(http.FS(static.Static)),
+	s.router.Mount(
+		"/s",
+		http.StripPrefix("/s", http.FileServer(http.FS(static.Static))),
 	)
 
-	s.router.Route("/s", func(r chi.Router) {
-		r.MethodNotAllowed(func(w http.ResponseWriter, _ *http.Request) {
-			w.Header().Set("Allow", "GET, HEAD")
-			http.Error(
-				w,
-				"Method Not Allowed",
-				http.StatusMethodNotAllowed,
-			)
-		})
-		r.Method(http.MethodGet, "/*", staticFiles)
-		r.Method(http.MethodHead, "/*", staticFiles)
-	})
-
 	s.router.Route("/api/v1", func(_ chi.Router) {
 		// API routes will be added here.
 	})

internal/server/routes_test.go

@@ -396,15 +396,13 @@ func (e *testEnv) storedHash(t *testing.T, username string) string {
 
 // --- /s static group ---
 
-// TestStaticServesOnlyGetAndHead pins the methods the static group
-// answers: GET and HEAD are served the asset, and the other methods
-// chi routes (POST, PUT, DELETE and the rest) are refused with 405
-// and an Allow header naming those two. A method chi does not route,
-// such as PROPFIND, is refused with 405 by the top-level router
-// before it reaches the static group, so it gets no Allow header.
-// The README documents this; the test is what keeps the two from
-// drifting.
-func TestStaticServesOnlyGetAndHead(t *testing.T) {
+// TestStaticServesEveryMethod pins what the static mount actually
+// answers. chi's Mount registers the handler for all methods and
+// http.FileServer only special-cases HEAD (by suppressing the body),
+// so a POST or a DELETE to an asset is served the file rather than
+// refused. The README documents this; the test is what keeps the two
+// from drifting.
+func TestStaticServesEveryMethod(t *testing.T) {
 	t.Parallel()
 
 	env := newTestEnv(t)
@@ -419,7 +417,6 @@ func TestStaticServesOnlyGetAndHead(t *testing.T) {
 		http.MethodPost,
 		http.MethodPut,
 		http.MethodDelete,
-		"PROPFIND",
 	} {
 		t.Run(method, func(t *testing.T) {
 			t.Parallel()
@@ -431,38 +428,18 @@ func TestStaticServesOnlyGetAndHead(t *testing.T) {
 			w := httptest.NewRecorder()
 			env.router.ServeHTTP(w, req)
 
-			switch method {
-			case http.MethodGet:
-				assert.Equal(t, http.StatusOK, w.Code)
-				assert.Equal(t, body, w.Body.Bytes(),
-					"the asset itself is returned")
-			case http.MethodHead:
-				assert.Equal(t, http.StatusOK, w.Code)
+			assert.Equal(t, http.StatusOK, w.Code,
+				"static mount answers every method")
+
+			if method == http.MethodHead {
 				assert.Empty(t, w.Body.Bytes(),
 					"HEAD must not carry a body")
-			case "PROPFIND":
-				assert.Equal(
-					t, http.StatusMethodNotAllowed, w.Code,
-				)
-				assert.Empty(t, w.Header().Get("Allow"),
-					"chi refuses a method it does not route "+
-						"before the static group runs")
-				assert.NotContains(
-					t, w.Body.String(), string(body),
-					"a refused method must not get the asset",
-				)
-			default:
-				assert.Equal(
-					t, http.StatusMethodNotAllowed, w.Code,
-				)
-				assert.Equal(
-					t, "GET, HEAD", w.Header().Get("Allow"),
-				)
-				assert.NotContains(
-					t, w.Body.String(), string(body),
-					"a refused method must not get the asset",
-				)
+
+				return
 			}
+
+			assert.Equal(t, body, w.Body.Bytes(),
+				"the asset itself is returned")
 		})
 	}
 }