Default WEBHOOKER_ENVIRONMENT to prod (closes #307)

An unset WEBHOOKER_ENVIRONMENT now means prod, not dev. The only
thing dev still changes is CORS, which then answers every origin with
Access-Control-Allow-Origin: *, so an operator who forgets the
variable is no longer silently permissive; dev must be set
explicitly. Cookie Secure and CSRF strictness follow each request's
transport and are unaffected.

The README, comments and tests no longer describe dev as the default:
the deployment checklist asks only that the environment is not dev,
the Docker and nginx examples drop the now-redundant setting, and the
TRUSTED_PROXIES warning gives its real reason for firing in every
environment.

Model: opus-4-8 (implementation); opus-5-5 (rework)

README.md

@@ -44,9 +44,9 @@ make bootstrap
 # Run all checks (test, lint, format check)
 make check
 
-# Run in development mode. DATA_DIR defaults to /var/lib/webhooker in
+# Run the server from the clone. DATA_DIR defaults to
-# every environment, so set it (in .env or the shell) to a writable
+# /var/lib/webhooker in every environment, so set it (in .env or the
-# directory when running from a clone.
+# shell) to a writable directory.
 DATA_DIR=./data make dev
 
 # Build Docker image
@@ -92,7 +92,8 @@ them at once. A variable already present in the real environment wins
 over the file's value for the same name.
 
 The environment is selected by setting `WEBHOOKER_ENVIRONMENT` to `dev`
-or `prod` (default: `dev`). The setting controls exactly one behavior:
+or `prod` (default: `prod`; `dev` must be set explicitly). The setting
+controls exactly one behavior:
 
 | Behavior | `dev`                   | `prod`           |
 | -------- | ----------------------- | ---------------- |
@@ -134,7 +135,7 @@ TTY detection, and security headers are always applied.
 
 | Variable                | Description                         | Default  |
 | ----------------------- | ----------------------------------- | -------- |
-| `WEBHOOKER_ENVIRONMENT` | `dev` or `prod`                     | `dev`    |
+| `WEBHOOKER_ENVIRONMENT` | `dev` or `prod`                     | `prod`   |
 | `PORT`                  | HTTP listen port                    | `8080`   |
 | `BIND_ADDRESS`          | IP address the HTTP listener binds. Loopback by default, so the cleartext listener is not published on every interface. The Docker image ships `0.0.0.0` instead. See [Bind address](#bind-address) | `127.0.0.1` (image: `0.0.0.0`) |
 | `DATA_DIR`              | Directory for all SQLite databases  | `/var/lib/webhooker` |
@@ -399,10 +400,9 @@ the bucket is. See [Rate Limiting](#rate-limiting).
 
 The remedy is to set `TRUSTED_PROXIES` to your reverse proxy's
 address, which restores per-client buckets. webhooker logs a warning
-at startup whenever `TRUSTED_PROXIES` is empty, in every environment —
+at startup whenever `TRUSTED_PROXIES` is empty, in every environment,
-not only when `WEBHOOKER_ENVIRONMENT=prod`, because that variable
+because behind a proxy every client shares one bucket in `dev` and
-defaults to `dev` and an operator who never set it is precisely the
+`prod` alike. The warning is informational when nothing proxies to the
-one at risk. The warning is informational when nothing proxies to the
 process: with no proxy in front, the peer address is the client's own
 and the buckets are already per-client. See
 [Rate Limiting](#rate-limiting) for what each limit shares.
@@ -638,7 +638,6 @@ decision:
 docker run -d \
   -p 127.0.0.1:8080:8080 \
   -v /path/to/data:/var/lib/webhooker \
-  -e WEBHOOKER_ENVIRONMENT=prod \
   -e BIND_ADDRESS=0.0.0.0 \
   webhooker:latest
 ```
@@ -812,17 +811,18 @@ reports.
    serves the admin login form and the unauthenticated receiver with
    no TLS at all, and the proxy in front of it changes nothing about
    that.
-2. **Set `WEBHOOKER_ENVIRONMENT=prod`, and make sure the proxy sends
+2. **Make sure the environment is not `dev` (leave
-   `X-Forwarded-Proto`.** These are two requirements, not one. The
+   `WEBHOOKER_ENVIRONMENT` unset or set it to `prod`), and make sure
-   environment setting decides CORS and nothing else: the default
+   the proxy sends `X-Forwarded-Proto`.** These are two requirements,
+   not one. The environment setting decides CORS and nothing else:
    `dev` answers every origin with `Access-Control-Allow-Origin: *`
    (without credentials), which a server-rendered production
-   deployment has no use for. Cookie `Secure` and the strict
+   deployment has no use for, and `prod` — the default — disables it.
-   Origin/Referer mode are **not** tied to it — they are decided per
+   Cookie `Secure` and the strict Origin/Referer mode are **not** tied
-   request from the transport, which behind a proxy means the
+   to it — they are decided per request from the transport, which
-   `X-Forwarded-Proto` header. The block below sets it; without it
+   behind a proxy means the `X-Forwarded-Proto` header. The block below
-   every request is read as plaintext and cookies ship without
+   sets it; without it every request is read as plaintext and cookies
-   `Secure`. See [Configuration](#configuration).
+   ship without `Secure`. See [Configuration](#configuration).
 3. **Set `TRUSTED_PROXIES` to the proxy's address.** Unset, every rate
    limiter keys on the connecting peer, which behind a proxy is the
    proxy on every request: all clients collapse into one global bucket
@@ -914,7 +914,6 @@ sent — `$scheme` above does.
 With that block, webhooker's environment is:
 
 ```sh
-WEBHOOKER_ENVIRONMENT=prod
 BIND_ADDRESS=127.0.0.1   # the default; stated here to be explicit
 TRUSTED_PROXIES=127.0.0.1
 ```

internal/config/config.go

@@ -585,12 +585,14 @@ func resolveMetricsAuth() (string, string, error) {
 	)
 }
 
-// resolveEnvironment reads WEBHOOKER_ENVIRONMENT, defaulting to
+// resolveEnvironment reads WEBHOOKER_ENVIRONMENT, defaulting to prod
-// dev, and rejects unrecognised values.
+// when it is unset so a deployment that forgets the variable is not
+// silently permissive; dev must be set explicitly. It rejects
+// unrecognised values.
 func resolveEnvironment() (string, error) {
 	environment := os.Getenv("WEBHOOKER_ENVIRONMENT")
 	if environment == "" {
-		environment = EnvironmentDev
+		environment = EnvironmentProd
 	}
 
 	if environment != EnvironmentDev &&
@@ -772,10 +774,8 @@ func (c *Config) warnEgressAllowlist(log *slog.Logger) {
 // everyone else's wrong passwords, and the receiver's limits become
 // service-wide ceilings.
 //
-// The warning is deliberately not gated on WEBHOOKER_ENVIRONMENT. That
+// The warning is deliberately not gated on WEBHOOKER_ENVIRONMENT:
-// variable defaults to dev, so gating on it would silence the warning
+// behind a proxy every client shares one bucket in dev and prod alike.
-// for exactly the operator who forgot to configure the deployment —
-// the case it exists to catch.
 //
 // The default of trusting nobody is deliberate — trusting forwarded
 // headers from arbitrary peers lets any client choose its own bucket —

internal/config/config_test.go

@@ -44,9 +44,9 @@ func TestEnvironmentConfig(t *testing.T) {
 		isProd      bool
 	}{
 		{
-			name:   "default is dev",
+			name:   "default is prod",
-			isDev:  true,
+			isDev:  false,
-			isProd: false,
+			isProd: true,
 		},
 		{
 			name:     "explicit dev",
@@ -848,10 +848,9 @@ func TestEgressAllowlistWarning(t *testing.T) {
 // tells an operator a deployment behind a reverse proxy shares one
 // rate-limit bucket between every client, which turns the receiver
 // limits into service-wide ceilings and collapses login failure
-// counting. It must fire whenever TRUSTED_PROXIES is empty,
+// counting. It must fire whenever TRUSTED_PROXIES is empty, in any
-// in any environment: WEBHOOKER_ENVIRONMENT defaults to dev, so gating
+// environment, because behind a proxy every client shares one bucket
-// on it would silence the warning for exactly the operator who never
+// in dev and prod alike. It stays quiet once proxies are named.
-// configured the deployment. It stays quiet once proxies are named.
 func TestSharedRateLimitBucketWarning(t *testing.T) {
 	tests := []struct {
 		name           string
@@ -871,10 +870,6 @@ func TestSharedRateLimitBucketWarning(t *testing.T) {
 			expectWarning:  false,
 		},
 		{
-			// The default environment. An internet-exposed
-			// deployment whose operator never set
-			// WEBHOOKER_ENVIRONMENT lands here and has exactly
-			// the exposure the warning announces.
 			name:          "dev without trusted proxies warns",
 			environment:   config.EnvironmentDev,
 			expectWarning: true,

internal/middleware/csrf_test.go

@@ -380,9 +380,8 @@ func csrfTookStrictPath(
 
 // TestCSRF_ForwardedProtoSpellingsTakeStrictPath runs the header
 // spellings a real proxy emits through the middleware. The environment
-// is dev -- the DEFAULT when WEBHOOKER_ENVIRONMENT is unset -- to pin
+// is set to dev -- the permissive setting -- to pin that the routing is
-// that the routing is a per-request transport decision and owes
+// a per-request transport decision and owes nothing to configuration.
-// nothing to configuration.
 func TestCSRF_ForwardedProtoSpellingsTakeStrictPath(t *testing.T) {
 	t.Parallel()
 

internal/reqtls/reqtls.go

@@ -5,7 +5,7 @@
 // several packages, by hand, and the answers disagreed. The session
 // cookie's Secure attribute was decided at startup from the configured
 // environment while the CSRF cookie's was decided per-request, so a
-// deployment behind a TLS proxy in the default environment emitted one
+// deployment behind a TLS proxy in the dev environment emitted one
 // Secure cookie and one non-Secure cookie on the same response.
 // Everything kept working, which is exactly why nobody noticed.
 //

internal/session/session.go

@@ -146,8 +146,8 @@ func newStore(key []byte) *sessions.CookieStore {
 //
 // This is decided per-request, not once at startup. Deciding it at
 // startup from the configured environment is what this replaces, and
-// it got the DEFAULT posture wrong: "dev" is the environment when
+// it got the DEFAULT posture wrong: "dev" was then the environment when
-// WEBHOOKER_ENVIRONMENT is unset, so a deployment terminating TLS at a
+// WEBHOOKER_ENVIRONMENT was unset, so a deployment terminating TLS at a
 // proxy without also setting the environment emitted the
 // authentication cookie with no Secure attribute -- silently, and on
 // the same response as a CSRF cookie that did have one.

internal/session/session_test.go

@@ -990,8 +990,8 @@ func sessionCookieFrom(
 
 // TestSave_SecureFollowsRequestTransport is the regression test for
 // the defect this replaces: Secure was fixed at startup from the
-// configured environment, and "dev" is the environment when
+// configured environment, and "dev" was then the environment when
-// WEBHOOKER_ENVIRONMENT is unset. A deployment behind a TLS proxy in
+// WEBHOOKER_ENVIRONMENT was unset. A deployment behind a TLS proxy in
 // that DEFAULT posture shipped the authentication cookie with no
 // Secure attribute and said nothing about it.
 //