From 2b9cf56f565517b947b0eb71d2086764e9edf2be Mon Sep 17 00:00:00 2001
From: tobi <31960611+tsmethurst@users.noreply.github.com>
Date: Thu, 23 Nov 2023 19:10:51 +0100
Subject: [PATCH] [chore/bugfix] Fix double gzip on prometheus endpoint (#2383)
* [chore] Move "/metrics" into separate API module
* use our own gzip middleware for prom
---
cmd/gotosocial/action/server/server.go | 2 +
cmd/gotosocial/action/testrig/testrig.go | 2 +
internal/api/metrics.go | 66 ++++++++++++++++++++++++
internal/{web => api/metrics}/metrics.go | 39 ++++++++++----
internal/web/web.go | 13 -----
5 files changed, 100 insertions(+), 22 deletions(-)
create mode 100644 internal/api/metrics.go
rename internal/{web => api/metrics}/metrics.go (55%)
diff --git a/cmd/gotosocial/action/server/server.go b/cmd/gotosocial/action/server/server.go
index a9896a81c..3a8965f1e 100644
--- a/cmd/gotosocial/action/server/server.go
+++ b/cmd/gotosocial/action/server/server.go
@@ -293,6 +293,7 @@ func(context.Context, time.Time) {
var (
authModule = api.NewAuth(dbService, processor, idp, routerSession, sessionName) // auth/oauth paths
clientModule = api.NewClient(dbService, processor) // api client endpoints
+ metricsModule = api.NewMetrics() // Metrics endpoints
fileserverModule = api.NewFileserver(processor) // fileserver endpoints
wellKnownModule = api.NewWellKnown(processor) // .well-known endpoints
nodeInfoModule = api.NewNodeInfo(processor) // nodeinfo endpoint
@@ -322,6 +323,7 @@ func(context.Context, time.Time) {
// apply throttling *after* rate limiting
authModule.Route(router, clLimit, clThrottle, gzip)
clientModule.Route(router, clLimit, clThrottle, gzip)
+ metricsModule.Route(router, clLimit, clThrottle, gzip)
fileserverModule.Route(router, fsLimit, fsThrottle)
wellKnownModule.Route(router, gzip, s2sLimit, s2sThrottle)
nodeInfoModule.Route(router, s2sLimit, s2sThrottle, gzip)
diff --git a/cmd/gotosocial/action/testrig/testrig.go b/cmd/gotosocial/action/testrig/testrig.go
index f08bec609..d6bc92215 100644
--- a/cmd/gotosocial/action/testrig/testrig.go
+++ b/cmd/gotosocial/action/testrig/testrig.go
@@ -212,6 +212,7 @@
var (
authModule = api.NewAuth(state.DB, processor, idp, routerSession, sessionName) // auth/oauth paths
clientModule = api.NewClient(state.DB, processor) // api client endpoints
+ metricsModule = api.NewMetrics() // Metrics endpoints
fileserverModule = api.NewFileserver(processor) // fileserver endpoints
wellKnownModule = api.NewWellKnown(processor) // .well-known endpoints
nodeInfoModule = api.NewNodeInfo(processor) // nodeinfo endpoint
@@ -222,6 +223,7 @@
// these should be routed in order
authModule.Route(router)
clientModule.Route(router)
+ metricsModule.Route(router)
fileserverModule.Route(router)
wellKnownModule.Route(router)
nodeInfoModule.Route(router)
diff --git a/internal/api/metrics.go b/internal/api/metrics.go
new file mode 100644
index 000000000..5d97b9610
--- /dev/null
+++ b/internal/api/metrics.go
@@ -0,0 +1,66 @@
+// GoToSocial
+// Copyright (C) GoToSocial Authors admin@gotosocial.org
+// SPDX-License-Identifier: AGPL-3.0-or-later
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Affero General Public License for more details.
+//
+// You should have received a copy of the GNU Affero General Public License
+// along with this program. If not, see .
+
+package api
+
+import (
+ "github.com/gin-gonic/gin"
+ "github.com/superseriousbusiness/gotosocial/internal/api/metrics"
+ "github.com/superseriousbusiness/gotosocial/internal/config"
+ "github.com/superseriousbusiness/gotosocial/internal/middleware"
+ "github.com/superseriousbusiness/gotosocial/internal/router"
+)
+
+type Metrics struct {
+ metrics *metrics.Module
+}
+
+func (mt *Metrics) Route(r *router.Router, m ...gin.HandlerFunc) {
+ if !config.GetMetricsEnabled() {
+ // Noop: metrics
+ // not enabled.
+ return
+ }
+
+ // Create new group on top level "metrics" prefix.
+ metricsGroup := r.AttachGroup("metrics")
+ metricsGroup.Use(m...)
+ metricsGroup.Use(
+ middleware.CacheControl(middleware.CacheControlConfig{
+ // Never cache metrics responses.
+ Directives: []string{"no-store"},
+ }),
+ )
+
+ // Attach basic auth if enabled.
+ if config.GetMetricsAuthEnabled() {
+ var (
+ username = config.GetMetricsAuthUsername()
+ password = config.GetMetricsAuthPassword()
+ accounts = gin.Accounts{username: password}
+ )
+ metricsGroup.Use(gin.BasicAuth(accounts))
+ }
+
+ mt.metrics.Route(metricsGroup.Handle)
+}
+
+func NewMetrics() *Metrics {
+ return &Metrics{
+ metrics: metrics.New(),
+ }
+}
diff --git a/internal/web/metrics.go b/internal/api/metrics/metrics.go
similarity index 55%
rename from internal/web/metrics.go
rename to internal/api/metrics/metrics.go
index eb5530290..d89e56ad5 100644
--- a/internal/web/metrics.go
+++ b/internal/api/metrics/metrics.go
@@ -15,19 +15,40 @@
// You should have received a copy of the GNU Affero General Public License
// along with this program. If not, see .
-package web
+package metrics
import (
+ "net/http"
+
"github.com/gin-gonic/gin"
+ "github.com/prometheus/client_golang/prometheus"
"github.com/prometheus/client_golang/prometheus/promhttp"
)
-const (
- metricsPath = "/metrics"
- metricsUser = "metrics"
-)
-
-func (m *Module) metricsGETHandler(c *gin.Context) {
- h := promhttp.Handler()
- h.ServeHTTP(c.Writer, c.Request)
+type Module struct {
+ handler http.Handler
+}
+
+func New() *Module {
+ // Use our own gzip handler.
+ opts := promhttp.HandlerOpts{
+ DisableCompression: true,
+ }
+
+ // Instrument handler itself.
+ handler := promhttp.InstrumentMetricHandler(
+ prometheus.DefaultRegisterer,
+ promhttp.HandlerFor(prometheus.DefaultGatherer, opts),
+ )
+
+ return &Module{
+ handler: handler,
+ }
+}
+
+func (m *Module) Route(attachHandler func(method string, path string, f ...gin.HandlerFunc) gin.IRoutes) {
+ attachHandler(http.MethodGet, "", func(c *gin.Context) {
+ // Defer all "/metrics" handling to prom.
+ m.handler.ServeHTTP(c.Writer, c.Request)
+ })
}
diff --git a/internal/web/web.go b/internal/web/web.go
index 6a21a754b..86e74d6f8 100644
--- a/internal/web/web.go
+++ b/internal/web/web.go
@@ -110,19 +110,6 @@ func (m *Module) Route(r *router.Router, mi ...gin.HandlerFunc) {
r.AttachHandler(http.MethodGet, domainBlockListPath, m.domainBlockListGETHandler)
r.AttachHandler(http.MethodGet, tagsPath, m.tagGETHandler)
- // Prometheus metrics export endpoint
- if config.GetMetricsEnabled() {
- metricsGroup := r.AttachGroup(metricsPath)
- metricsGroup.Use(mi...)
- // Attach basic auth if enabled
- if config.GetMetricsAuthEnabled() {
- metricsGroup.Use(gin.BasicAuth(gin.Accounts{
- config.GetMetricsAuthUsername(): config.GetMetricsAuthPassword(),
- }))
- }
- metricsGroup.Handle(http.MethodGet, "", m.metricsGETHandler)
- }
-
// Attach redirects from old endpoints to current ones for backwards compatibility
r.AttachHandler(http.MethodGet, "/auth/edit", func(c *gin.Context) { c.Redirect(http.StatusMovedPermanently, userPanelPath) })
r.AttachHandler(http.MethodGet, "/user", func(c *gin.Context) { c.Redirect(http.StatusMovedPermanently, userPanelPath) })