Keep counts not written by the request's deadline in memory (closes #224)

TestService_Get_ReturnsByItsDeadline failed on a busy host because its
request, past its deadline, still waited to write its miss count, a write
with no deadline; in pixad that write waits for the one database
connection every request shares. Each count write now keeps the request's
deadline but not its cancellation. A count not written by then is kept in
memory, where Stats includes it, and one goroutine of the cache writes
those counts one UPDATE at a time, and once more at shutdown before the
database closes. The test phase also runs go test with -parallel 4: on a
busy host, as many tests at once as there are CPUs wait so long to be
scheduled that a timed request can fail.

Model: opus-5-5

README.md

@@ -46,9 +46,9 @@ everything in this list without further settings. The reverse proxy must:
   builds encrypted URLs from `Host`, and checks `Referer` against
   `referer_blocklist`;
 - set `X-Forwarded-For` to the client's address, with `trusted_proxies` set to
-  the address pixa sees the proxy's requests come from, so the login limit and
-  `image_requests_per_minute` count each client by its own address (see
-  `trusted_proxies` under Configuration);
+  the address pixa sees the proxy's requests come from, so the login limit
+  counts each client by its own address (see `trusted_proxies` under
+  Configuration);
 - wait for pixa's answer for at least `downstream_timeout` (default `60s`), the
   longest pixa takes to fetch, convert and send an image.
 
@@ -58,9 +58,8 @@ password there.
 
 pixa does the rest itself: it checks signatures and encrypted URLs, applies the
 allowlist, refuses upstream hosts with private or local addresses, limits login
-attempts, each client's image requests, upstream response size and image
-dimensions, and sends the security headers, `Strict-Transport-Security`
-included, with every response.
+attempts, upstream response size and image dimensions, and sends the security
+headers, `Strict-Transport-Security` included, with every response.
 
 The state directory (`state_dir`, `/var/lib/pixa` in the container) holds the
 database and the disk cache:
@@ -189,10 +188,10 @@ path under `/v1/` answers 200, in maintenance mode too.
   `Referer` names a host in `referer_blocklist`, checked before the signature,
   the cache and the upstream fetch; 403 when the upstream host, or a host it
   redirects to, is `localhost`, ends in `.localhost` or `.local`, or has an
-  address in a blocked network (see `blocked_networks`); 429 over
-  `image_requests_per_minute` (below); 502 when the upstream answered with an
-  error status, and for 5 minutes after that for the same source URL; 503 when
-  pixa is busy or in maintenance mode; 500 for any other failure.
+  address in a blocked network (see `blocked_networks`); 502 when the upstream
+  answered with an error status, and for 5 minutes after that for the same
+  source URL; 503 when pixa is busy or in maintenance mode; 500 for any other
+  failure.
 - `GET` or `HEAD` `/v1/e/<token>/<name>` — an image through an encrypted URL
   (see Encrypted URLs). Needs: nothing but the URL. Answers: 200; 304 when
   `If-None-Match` matches the image's `ETag`; 400 for a token that does not
@@ -200,7 +199,7 @@ path under `/v1/` answers 200, in maintenance mode too.
   expired; 504 when the upstream has not sent its response headers within
   `upstream_fetch_timeout`, but 500 when that time runs out while the image
   itself is still arriving; 400 for an `Accept` header that is not valid, and
-  406, 403, 429, 502, 503 and 500, as for `/v1/image/`.
+  406, 403, 502, 503 and 500, as for `/v1/image/`.
 - `GET /robots.txt` — asks every crawler to stay away (`Disallow: /`). Needs:
   nothing. Answers: 200.
 - `GET /.well-known/healthcheck.json` — JSON with `status` (`ok`), `now`,
@@ -316,15 +315,6 @@ its own `X-Forwarded-For`, whether it connects directly or through the proxy,
 because its own address is trusted too. Setting `trusted_proxies` to only the
 address pixa sees for requests that come through the proxy closes this.
 
-One client may send `image_requests_per_minute` requests per minute
-(default 600) to the image routes, `/v1/image/` and `/v1/e/` together, `GET` and
-`HEAD`, cache hits included; a request over the limit is refused with 429 and a
-`Retry-After` header. Clients are counted as for the login limit. A browser's
-CORS preflight is not counted. Behind a CDN or proxy whose addresses are not in
-`trusted_proxies`, all requests arriving from one proxy or CDN address count as
-one client, so such a deployment needs a higher limit, or `0`, which turns the
-limit off.
-
 ### Encrypted URLs
 
 An encrypted URL is an image URL made on pixa's own web page by someone who
@@ -494,7 +484,6 @@ tell. With no file, pixa uses the environment and the defaults.
 | `PIXA_UPSTREAM_CONNECTIONS_PER_HOST` | `upstream_connections_per_host` | Concurrent connections per upstream host; default `20`                       |
 | `PIXA_UPSTREAM_CONNECTIONS`          | `upstream_connections`          | Concurrent connections to all upstream hosts together; default `64`          |
 | `PIXA_MAX_CONCURRENT_PROCESSING`     | `max_concurrent_processing`     | Images processed at once; default the number of CPUs                         |
-| `PIXA_IMAGE_REQUESTS_PER_MINUTE`     | `image_requests_per_minute`     | Image requests per client per minute; `0` turns it off; default `600`        |
 | `PIXA_UPSTREAM_FETCH_TIMEOUT`        | `upstream_fetch_timeout`        | Time allowed for one fetch from an upstream host; default `30s`              |
 | `PIXA_UPSTREAM_MAX_RESPONSE_SIZE`    | `upstream_max_response_size`    | Largest upstream response accepted, in bytes; default 50 MiB                 |
 | `PIXA_DOWNSTREAM_TIMEOUT`            | `downstream_timeout`            | Time allowed for answering one client request; default `60s`                 |
@@ -544,13 +533,13 @@ Key settings in more detail:
   explicit list replaces the default. An invalid CIDR aborts startup. Set this
   to the address pixa sees for requests that come through your proxy, such as
   `172.17.0.1/32`, when the defaults do not cover it, or to trust nothing else
-  (see the login limit and `image_requests_per_minute` under Routes). For a
-  proxy on the Docker host that connects to pixa over `127.0.0.1`, that address
-  is the gateway of the container's Docker network (`172.17.0.1` on the default
-  bridge), not the proxy's own address; a proxy that connects through another of
-  the host's addresses is seen with that address. To be sure which address it
-  is, set this to `[]` (or `PIXA_TRUSTED_PROXIES` to empty), send a request
-  through the proxy, and read `remoteIP` in pixa's request log line for it
+  (see the login limit under Routes). For a proxy on the Docker host that
+  connects to pixa over `127.0.0.1`, that address is the gateway of the
+  container's Docker network (`172.17.0.1` on the default bridge), not the
+  proxy's own address; a proxy that connects through another of the host's
+  addresses is seen with that address. To be sure which address it is, set this
+  to `[]` (or `PIXA_TRUSTED_PROXIES` to empty), send a request through the
+  proxy, and read `remoteIP` in pixa's request log line for it
 - `upstream_fetch_timeout` — time allowed for one fetch from an upstream host,
   as a duration such as `30s` (the default) or `2m`
 - `upstream_max_response_size` — largest upstream response accepted, in bytes;
@@ -583,12 +572,6 @@ Key settings in more detail:
   container's CPU limit. A request that finds all of them in use waits up to 10
   seconds for one to free up; if none does, and `downstream_timeout` has not
   ended first, it is answered 503 the same way
-- `image_requests_per_minute` — how many requests one client may send to the
-  image routes per minute (see the limit on them under Routes); default `600`.
-  `0` turns the limit off, and a negative or non-integer value aborts startup.
-  Behind a CDN or proxy whose addresses are not in `trusted_proxies`, all
-  requests arriving from one proxy or CDN address count as one client, so raise
-  the limit there, or set `0`
 - `maintenance_mode` — while `true`, the image routes (`/v1/image/` and
   `/v1/e/`) answer every request for an image with 503, a `Retry-After` header
   and a JSON error body. The health check (`/.well-known/healthcheck.json`)

TODO.md

@@ -26,18 +26,10 @@ resolved. The disk cache is now size-bounded with LRU eviction
 
 # Next Step
 
-P2: security: per-origin rate limiting
+P2: security: per-IP rate limiting on the image routes
 
 # Completed Steps
 
-- 2026-10-12 per-client limit on the image routes (closes #236): the new setting
-  `image_requests_per_minute` (`PIXA_IMAGE_REQUESTS_PER_MINUTE`), default 600,
-  is how many `GET` and `HEAD` requests one client may send to `/v1/image/` and
-  `/v1/e/` together per minute, cache hits included; the next is answered 429
-  with `Retry-After`. It uses the login limit's `RateLimit` middleware, so
-  clients are told apart the same way, and runs after the CORS middleware, so a
-  preflight is not counted. `0` turns the limit off; a negative or non-integer
-  value aborts startup.
 - 2026-10-08 a request past its deadline no longer waits for the database to
   count it (closes #224). On a busy host, `TestService_Get_ReturnsByItsDeadline`
   failed because its request, past its deadline, still waited for its miss count
@@ -757,6 +749,8 @@ P2: security: per-origin rate limiting
 
 # Future Steps
 
+- P2: security
+    - per-origin rate limiting
 - P2: HTTP response handling
     - Last-Modified headers
 - P2: configuration

configs/config.example.yml

@@ -115,14 +115,6 @@ upstream_connections: 64
 # frees up it is answered 503, unless downstream_timeout has ended first.
 # max_concurrent_processing: 4
 
-# How many requests to the image routes (/v1/image/ and /v1/e/) one client
-# may send per minute; a request over the limit is answered 429 with a
-# Retry-After header. 0 turns the limit off. Clients are told apart as for
-# the login limit, so behind a CDN or proxy whose addresses are not in
-# trusted_proxies all requests arriving from one proxy or CDN address count
-# as one client: raise the limit there, or set 0. (default: 600)
-image_requests_per_minute: 600
-
 # Time allowed for one fetch from an upstream host (default: 30s)
 upstream_fetch_timeout: 30s
 

internal/config/config.go

@@ -34,7 +34,6 @@ const (
 	DefaultUpstreamFetchTimeout       = 30 * time.Second
 	DefaultUpstreamMaxResponseSize    = 50 << 20 // 50 MiB
 	DefaultDownstreamTimeout          = 60 * time.Second
-	DefaultImageRequestsPerMinute     = 600
 )
 
 // Configuration key names.
@@ -62,7 +61,6 @@ const (
 	keyUpstreamFetchTimeout       = "upstream_fetch_timeout"
 	keyUpstreamMaxResponseSize    = "upstream_max_response_size"
 	keyDownstreamTimeout          = "downstream_timeout"
-	keyImageRequestsPerMinute     = "image_requests_per_minute"
 )
 
 // placeholderSigningKey is the dummy signing_key shipped in
@@ -160,11 +158,6 @@ type Config struct {
 	// of the per-request timeout middleware.
 	DownstreamTimeout time.Duration
 
-	// ImageRequestsPerMinute is how many requests one client may make to
-	// the image routes per minute; the next is refused with 429 Too Many
-	// Requests. 0 turns the limit off.
-	ImageRequestsPerMinute int
-
 	// BlockedNetworks are operator-supplied CIDR ranges to refuse in
 	// addition to the built-in SSRF blocklist. Enforced by the upstream
 	// fetcher's dialer; the built-in ranges always apply.
@@ -309,8 +302,6 @@ func newFromSmartConfig(sc *smartconfig.Config) (*Config, error) {
 			keyAccessControlAllowOrigin, DefaultAccessControlAllowOrigin),
 		DownstreamTimeout: loader.durationVal(
 			keyDownstreamTimeout, DefaultDownstreamTimeout),
-		ImageRequestsPerMinute: loader.intVal(
-			keyImageRequestsPerMinute, DefaultImageRequestsPerMinute),
 		CacheMaxBytes:    loader.int64Val(keyCacheMaxBytes, 0),
 		BlockedNetworks:  blockedNetworks,
 		TrustedProxies:   trustedProxies,
@@ -320,7 +311,9 @@ func newFromSmartConfig(sc *smartconfig.Config) (*Config, error) {
 	// The default for an omitted cache_max_bytes is worked out when
 	// the cache opens; here we only record whether the operator set
 	// the key explicitly.
-	_, c.CacheMaxBytesExplicit = lookupValue(sc, keyCacheMaxBytes)
+	if _, present := lookupValue(sc, keyCacheMaxBytes); present {
+		c.CacheMaxBytesExplicit = true
+	}
 
 	// Build DBURL from StateDir if not explicitly set. The derived URL
 	// is a default: it applies only when db_url is omitted, never to an
@@ -433,7 +426,7 @@ func isKnownConfigKey(key string) bool {
 		keyMaxConcurrentProcessing, keyCacheMaxBytes, keyBlockedNetworks,
 		keyTrustedProxies, keyAccessControlAllowOrigin, keyUpstreamFetchTimeout,
 		keyUpstreamMaxResponseSize, keyDownstreamTimeout, keyRefererBlocklist,
-		keyImageRequestsPerMinute, "env":
+		"env":
 		return true
 	}
 
@@ -468,7 +461,6 @@ func envVarNames() map[string]string {
 		keyUpstreamFetchTimeout:       "PIXA_UPSTREAM_FETCH_TIMEOUT",
 		keyUpstreamMaxResponseSize:    "PIXA_UPSTREAM_MAX_RESPONSE_SIZE",
 		keyDownstreamTimeout:          "PIXA_DOWNSTREAM_TIMEOUT",
-		keyImageRequestsPerMinute:     "PIXA_IMAGE_REQUESTS_PER_MINUTE",
 	}
 }
 
@@ -621,14 +613,6 @@ func (c *Config) validate() error {
 			settingName(keyCacheMaxBytes), c.CacheMaxBytes, errMustNotBeNegative)
 	}
 
-	// Zero is valid (it turns the limit off); only negative values are
-	// rejected.
-	if c.ImageRequestsPerMinute < 0 {
-		return fmt.Errorf("%s: value %d %w",
-			settingName(keyImageRequestsPerMinute), c.ImageRequestsPerMinute,
-			errMustNotBeNegative)
-	}
-
 	err = c.validateUpstreamMaxResponseSize()
 	if err != nil {
 		return err
@@ -641,9 +625,12 @@ func (c *Config) validate() error {
 		}
 	}
 
-	err = c.validateSentryDSN()
-	if err != nil {
-		return err
+	if c.SentryDSN != "" {
+		parsed, err := url.Parse(c.SentryDSN)
+		if err != nil || parsed.Scheme == "" || parsed.Host == "" {
+			return fmt.Errorf("%s: value %q is %w",
+				settingName(keySentryDSN), c.SentryDSN, errNotAValidURL)
+		}
 	}
 
 	if (c.MetricsUsername == "") != (c.MetricsPassword == "") {
@@ -655,22 +642,6 @@ func (c *Config) validate() error {
 	return c.validateAccessControlAllowOrigin()
 }
 
-// validateSentryDSN checks that sentry_dsn, when set, is a URL with a scheme
-// and a host.
-func (c *Config) validateSentryDSN() error {
-	if c.SentryDSN == "" {
-		return nil
-	}
-
-	parsed, err := url.Parse(c.SentryDSN)
-	if err != nil || parsed.Scheme == "" || parsed.Host == "" {
-		return fmt.Errorf("%s: value %q is %w",
-			settingName(keySentryDSN), c.SentryDSN, errNotAValidURL)
-	}
-
-	return nil
-}
-
 // validateUpstreamMaxResponseSize checks that upstream_max_response_size
 // is from 1 byte to 1 GiB. An upstream response is read whole into
 // memory, and the image processor reads one byte past this limit, which

internal/config/env_internal_test.go

@@ -70,7 +70,6 @@ func TestEnvironmentSetsEveryKey(t *testing.T) {
 	t.Setenv("PIXA_UPSTREAM_CONNECTIONS_PER_HOST", "5")
 	t.Setenv("PIXA_UPSTREAM_CONNECTIONS", "10")
 	t.Setenv("PIXA_MAX_CONCURRENT_PROCESSING", "3")
-	t.Setenv("PIXA_IMAGE_REQUESTS_PER_MINUTE", "30")
 	t.Setenv("PIXA_CACHE_MAX_BYTES", "1024")
 	t.Setenv("PIXA_BLOCKED_NETWORKS", "203.0.113.0/24")
 	t.Setenv("PIXA_TRUSTED_PROXIES", "192.0.2.0/24")
@@ -100,7 +99,6 @@ func TestEnvironmentSetsEveryKey(t *testing.T) {
 		UpstreamConnectionsPerHost: 5,
 		UpstreamConnections:        10,
 		MaxConcurrentProcessing:    3,
-		ImageRequestsPerMinute:     30,
 		CacheMaxBytes:              1024,
 		CacheMaxBytesExplicit:      true,
 		BlockedNetworks:            []netip.Prefix{netip.MustParsePrefix("203.0.113.0/24")},

internal/config/image_requests_per_minute_internal_test.go

@@ -1,107 +0,0 @@
-package config
-
-import "testing"
-
-// testImageRequestsPerMinuteVar is the variable that sets
-// image_requests_per_minute.
-const testImageRequestsPerMinuteVar = "PIXA_IMAGE_REQUESTS_PER_MINUTE"
-
-// TestImageRequestsPerMinuteValues checks that an omitted
-// image_requests_per_minute is 600, and that 0, which turns the limit off,
-// and any larger whole number are used as given.
-func TestImageRequestsPerMinuteValues(t *testing.T) {
-	t.Parallel()
-
-	c, err := configFromYAML(t, signingKeyLine)
-	if err != nil {
-		t.Fatalf("minimal config should be valid, got error: %v", err)
-	}
-
-	if c.ImageRequestsPerMinute != 600 {
-		t.Errorf("ImageRequestsPerMinute = %d, want 600", c.ImageRequestsPerMinute)
-	}
-
-	explicit := []struct {
-		value string
-		want  int
-	}{
-		{"0", 0},
-		{"30", 30},
-	}
-
-	for _, tc := range explicit {
-		c, err := configFromYAML(t,
-			signingKeyLine+"image_requests_per_minute: "+tc.value+"\n")
-		if err != nil {
-			t.Fatalf("image_requests_per_minute: %s should load, got error: %v",
-				tc.value, err)
-		}
-
-		if c.ImageRequestsPerMinute != tc.want {
-			t.Errorf("ImageRequestsPerMinute = %d, want %d",
-				c.ImageRequestsPerMinute, tc.want)
-		}
-	}
-}
-
-// TestInvalidImageRequestsPerMinuteAbortsStartup checks that a value that is
-// negative, not a whole number, or null aborts startup naming the key and
-// the value, and the variable too where the value could have come from it.
-func TestInvalidImageRequestsPerMinuteAbortsStartup(t *testing.T) {
-	t.Parallel()
-
-	key := keyImageRequestsPerMinute
-
-	runAbortCases(t, []abortCase{
-		{
-			name: "negative",
-			yaml: signingKeyLine + key + ": -1\n",
-			wantErrSubstrings: []string{
-				key, testImageRequestsPerMinuteVar, "value -1",
-			},
-		},
-		{
-			name: "not a number",
-			yaml: signingKeyLine + key + ": plenty\n",
-			wantErrSubstrings: []string{
-				key, testImageRequestsPerMinuteVar, "plenty",
-			},
-		},
-		{
-			name:              "fractional",
-			yaml:              signingKeyLine + key + ": 2.5\n",
-			wantErrSubstrings: []string{key, "2.5"},
-		},
-		{
-			name:              "explicit null",
-			yaml:              signingKeyLine + key + ": null\n",
-			wantErrSubstrings: []string{key, nullValueText},
-		},
-	})
-}
-
-// TestImageRequestsPerMinuteFromEnvironment checks that the variable sets the
-// limit over the config file, and that an invalid value in it aborts startup
-// naming the variable and the value.
-func TestImageRequestsPerMinuteFromEnvironment(t *testing.T) {
-	t.Setenv(testImageRequestsPerMinuteVar, "0")
-
-	c, err := configFromYAML(t, signingKeyLine+"image_requests_per_minute: 30\n")
-	if err != nil {
-		t.Fatalf("limit from the environment should load: %v", err)
-	}
-
-	if c.ImageRequestsPerMinute != 0 {
-		t.Errorf("ImageRequestsPerMinute = %d, want 0 from the environment",
-			c.ImageRequestsPerMinute)
-	}
-
-	for _, value := range []string{"-5", "ten"} {
-		t.Run(value, func(t *testing.T) {
-			t.Setenv(testImageRequestsPerMinuteVar, value)
-
-			_, err := configFromYAML(t, signingKeyLine)
-			wantStartupError(t, err, testImageRequestsPerMinuteVar, value)
-		})
-	}
-}

internal/handlers/image.go

@@ -206,16 +206,6 @@ func parseExpires(query url.Values) (time.Time, error) {
 	return time.Unix(exp, 0), nil
 }
 
-// HandleTooManyRequests answers 429 Too Many Requests with the JSON error
-// body the image routes send for their other errors. The image routes' rate
-// limit calls it for a request over the limit.
-func (s *Handlers) HandleTooManyRequests() http.HandlerFunc {
-	return func(w http.ResponseWriter, _ *http.Request) {
-		s.respondError(w, "too many requests, try again later",
-			http.StatusTooManyRequests)
-	}
-}
-
 // respondImageError maps image retrieval errors to HTTP responses.
 func (s *Handlers) respondImageError(
 	w http.ResponseWriter, req *imgcache.ImageRequest, err error,

internal/imgcache/pendingcounts.go

@@ -41,10 +41,8 @@ func (c *Cache) StopPendingCountWrites(ctx context.Context) error {
 		select {
 		case <-c.pendingCountsDone:
 		case <-ctx.Done():
-			// The write given up on here may not reach the database:
-			// database/sql closes without waiting for a query, and a
-			// write still waiting for the connection fails when the
-			// database closes.
+			// The write under way is left to finish: the database's
+			// close waits for a query under way.
 			err = fmt.Errorf("pending counts still being written: %w", ctx.Err())
 		}
 	}

internal/middleware/middleware.go

@@ -98,10 +98,9 @@ func (s *Middleware) ClientIP() func(http.Handler) http.Handler {
 // holds whole; an IPv4-mapped address (::ffff:a.b.c.d) is counted as the
 // IPv4 address it carries, since every such address falls in the same /64.
 // Counts are kept only for the current and the previous window, so memory
-// stays bounded. limitHandler writes the 429 after Retry-After is set; nil
-// keeps the rate limit library's plain-text "Too Many Requests".
+// stays bounded.
 func (s *Middleware) RateLimit(
-	requestLimit int, window time.Duration, limitHandler http.HandlerFunc,
+	requestLimit int, window time.Duration,
 ) func(http.Handler) http.Handler {
 	return httprate.LimitBy(requestLimit, window,
 		func(r *http.Request) (string, error) {
@@ -113,8 +112,7 @@ func (s *Middleware) RateLimit(
 			}
 
 			return httprate.CanonicalizeIP(ip), nil
-		},
-		httprate.WithLimitHandler(limitHandler))
+		})
 }
 
 // requestIDPattern is what a request's own X-Request-Id must look like to be

internal/server/image_rate_limit_internal_test.go

@@ -1,204 +0,0 @@
-package server
-
-import (
-	"encoding/json"
-	"net/http"
-	"net/http/httptest"
-	"strconv"
-	"testing"
-
-	"sneak.berlin/go/pixa/internal/config"
-)
-
-// requestImageFrom sends method path to s from remoteAddr and returns the
-// response. The image handlers refuse an unsigned image URL with 401 and a
-// token they cannot decrypt with 400, so either status shows the limit let
-// the request through.
-func requestImageFrom(
-	t *testing.T, s *Server, method, path, remoteAddr string,
-) *httptest.ResponseRecorder {
-	t.Helper()
-
-	req := httptest.NewRequestWithContext(t.Context(), method, path, nil)
-	req.RemoteAddr = remoteAddr
-
-	rec := httptest.NewRecorder()
-	s.ServeHTTP(rec, req)
-
-	return rec
-}
-
-// TestImageRequestLimitRefusesRequestOverLimit verifies that GET and HEAD on
-// both image routes count toward one limit per client, and that the request
-// after image_requests_per_minute of them is refused with 429 and a
-// Retry-After header.
-func TestImageRequestLimitRefusesRequestOverLimit(t *testing.T) {
-	t.Parallel()
-
-	requests := []struct {
-		method string
-		path   string
-		want   int
-	}{
-		{http.MethodGet, unsignedImagePath, http.StatusUnauthorized},
-		{http.MethodHead, unsignedImagePath, http.StatusUnauthorized},
-		{http.MethodGet, encryptedImagePath, http.StatusBadRequest},
-	}
-
-	s := newTestServer(t)
-	s.config.ImageRequestsPerMinute = len(requests)
-	s.SetupRoutes()
-
-	for _, tc := range requests {
-		rec := requestImageFrom(t, s, tc.method, tc.path, firstClient)
-		if rec.Code != tc.want {
-			t.Fatalf("%s %s within the limit status = %d, want %d",
-				tc.method, tc.path, rec.Code, tc.want)
-		}
-	}
-
-	rec := requestImageFrom(t, s, http.MethodHead, encryptedImagePath, firstClient)
-	if rec.Code != http.StatusTooManyRequests {
-		t.Fatalf("request over the limit status = %d, want %d",
-			rec.Code, http.StatusTooManyRequests)
-	}
-
-	retryAfter := rec.Header().Get("Retry-After")
-
-	seconds, err := strconv.Atoi(retryAfter)
-	if err != nil || seconds <= 0 {
-		t.Errorf("Retry-After = %q, want a positive number of seconds",
-			retryAfter)
-	}
-}
-
-// TestImageRequestLimitAnswersWithJSONError verifies that the 429 for a
-// request over the limit carries Retry-After and the JSON error body the
-// image routes send for their other errors.
-func TestImageRequestLimitAnswersWithJSONError(t *testing.T) {
-	t.Parallel()
-
-	s := newTestServer(t)
-	s.config.ImageRequestsPerMinute = 1
-	s.SetupRoutes()
-
-	requestImageFrom(t, s, http.MethodGet, unsignedImagePath, firstClient)
-
-	rec := requestImageFrom(t, s, http.MethodGet, unsignedImagePath, firstClient)
-	t.Logf("status %d, body %s", rec.Code, rec.Body.String())
-
-	if rec.Code != http.StatusTooManyRequests {
-		t.Fatalf("request over the limit status = %d, want %d",
-			rec.Code, http.StatusTooManyRequests)
-	}
-
-	retryAfter := rec.Header().Get("Retry-After")
-
-	seconds, err := strconv.Atoi(retryAfter)
-	if err != nil || seconds <= 0 {
-		t.Errorf("Retry-After = %q, want a positive number of seconds",
-			retryAfter)
-	}
-
-	contentType := rec.Header().Get("Content-Type")
-	if contentType != "application/json" {
-		t.Errorf("Content-Type = %q, want %q", contentType, "application/json")
-	}
-
-	var body struct {
-		Error     string `json:"error"`
-		Status    int    `json:"status"`
-		Timestamp string `json:"timestamp"`
-	}
-
-	err = json.NewDecoder(rec.Body).Decode(&body)
-	if err != nil {
-		t.Fatalf("body is not JSON: %v", err)
-	}
-
-	if body.Error == "" || body.Status != http.StatusTooManyRequests ||
-		body.Timestamp == "" {
-		t.Errorf("body = %+v, want an error, status %d and a timestamp",
-			body, http.StatusTooManyRequests)
-	}
-}
-
-// TestImageRequestLimitCountsClientsSeparately verifies that one client going
-// over the limit does not limit another.
-func TestImageRequestLimitCountsClientsSeparately(t *testing.T) {
-	t.Parallel()
-
-	s := newTestServer(t)
-	s.config.ImageRequestsPerMinute = 1
-	s.SetupRoutes()
-
-	rec := requestImageFrom(t, s, http.MethodGet, unsignedImagePath, firstClient)
-	if rec.Code != http.StatusUnauthorized {
-		t.Fatalf("first client's first request status = %d, want %d",
-			rec.Code, http.StatusUnauthorized)
-	}
-
-	rec = requestImageFrom(t, s, http.MethodGet, unsignedImagePath, firstClient)
-	if rec.Code != http.StatusTooManyRequests {
-		t.Fatalf("first client's second request status = %d, want %d",
-			rec.Code, http.StatusTooManyRequests)
-	}
-
-	rec = requestImageFrom(t, s, http.MethodGet, unsignedImagePath, secondClient)
-	if rec.Code != http.StatusUnauthorized {
-		t.Errorf("second client's first request status = %d, want %d",
-			rec.Code, http.StatusUnauthorized)
-	}
-}
-
-// TestImageRequestLimitZeroLetsEveryRequestThrough verifies that with
-// image_requests_per_minute set to 0 no image request is refused with 429,
-// not even past the default limit.
-func TestImageRequestLimitZeroLetsEveryRequestThrough(t *testing.T) {
-	t.Parallel()
-
-	s := newTestServer(t)
-	s.config.ImageRequestsPerMinute = 0
-	s.SetupRoutes()
-
-	for request := range config.DefaultImageRequestsPerMinute + 1 {
-		rec := requestImageFrom(t, s, http.MethodGet, unsignedImagePath, firstClient)
-		if rec.Code != http.StatusUnauthorized {
-			t.Fatalf("request %d status = %d, want %d",
-				request+1, rec.Code, http.StatusUnauthorized)
-		}
-	}
-}
-
-// TestImageRequestLimitDoesNotCountPreflight verifies that a browser's CORS
-// preflight request to an image route is answered without being counted, so
-// a client that has sent several still gets its image request through.
-func TestImageRequestLimitDoesNotCountPreflight(t *testing.T) {
-	t.Parallel()
-
-	s := newTestServer(t)
-	s.config.AccessControlAllowOrigin = config.DefaultAccessControlAllowOrigin
-	s.config.ImageRequestsPerMinute = 1
-	s.SetupRoutes()
-
-	for range 3 {
-		req := httptest.NewRequestWithContext(
-			t.Context(), http.MethodOptions, unsignedImagePath, nil)
-		req.RemoteAddr = firstClient
-		req.Header.Set("Origin", "https://app.example.com")
-		req.Header.Set("Access-Control-Request-Method", http.MethodGet)
-
-		rec := httptest.NewRecorder()
-		s.ServeHTTP(rec, req)
-
-		if rec.Code != http.StatusOK {
-			t.Fatalf("preflight status = %d, want %d", rec.Code, http.StatusOK)
-		}
-	}
-
-	rec := requestImageFrom(t, s, http.MethodGet, unsignedImagePath, firstClient)
-	if rec.Code != http.StatusUnauthorized {
-		t.Errorf("image request after preflights status = %d, want %d",
-			rec.Code, http.StatusUnauthorized)
-	}
-}

internal/server/routes.go

@@ -66,7 +66,7 @@ func (s *Server) SetupRoutes() {
 		r.Use(s.h.LimitBody(handlers.MaxFormBytes))
 		r.Use(s.h.CSRF())
 		r.Get("/", s.h.HandleRoot())
-		r.With(s.mw.RateLimit(LoginAttemptsPerMinute, time.Minute, nil)).
+		r.With(s.mw.RateLimit(LoginAttemptsPerMinute, time.Minute)).
 			Post("/", s.h.HandleRoot())
 		r.Post("/generate", s.h.HandleGenerateURL())
 	})
@@ -88,15 +88,6 @@ func (s *Server) SetupRoutes() {
 		r.Group(func(r chi.Router) {
 			r.Use(s.refuseDuringMaintenance)
 
-			// Limited per client, as the login POST is, but the 429 has
-			// the image routes' JSON error body; 0 turns the limit off.
-			// The CORS middleware answers a preflight before it gets
-			// here, so a preflight is not counted.
-			if s.config.ImageRequestsPerMinute > 0 {
-				r.Use(s.mw.RateLimit(s.config.ImageRequestsPerMinute,
-					time.Minute, s.h.HandleTooManyRequests()))
-			}
-
 			// Main image proxy route
 			// /v1/image/<host>/<path>/<width>x<height>.<format>, or with no
 			// format /v1/image/<host>/<path>/<width>x<height>

script/loadtest

@@ -94,8 +94,7 @@ main() {
 }
 
 # start_containers starts a new origin and a new pixad, and waits up to 30
-# seconds for pixad's health check to pass. pixad sees all of vegeta's
-# requests come from one address, so its image request limit is off.
+# seconds for pixad's health check to pass.
 start_containers() {
     docker run -d --name "$run-origin" \
         --network "$run" --network-alias origin \
@@ -105,7 +104,6 @@ start_containers() {
         --network "$run" -p 127.0.0.1::8080 --health-interval=1s \
         -e PIXA_SIGNING_KEY="$(head -c 32 /dev/urandom | base64)" \
         -e PIXA_ALLOWLIST_HOSTS=origin -e PIXA_ALLOW_HTTP=true \
-        -e PIXA_IMAGE_REQUESTS_PER_MINUTE=0 \
         "$image" >/dev/null
 
     waited=0