feat: pprof is always on (#4951)

cli/agent.go

@@ -4,7 +4,7 @@ import (
 	"context"
 	"fmt"
 	"net/http"
-	_ "net/http/pprof" //nolint: gosec
+	"net/http/pprof"
 	"net/url"
 	"os"
 	"path/filepath"
@@ -28,7 +28,6 @@ import (
 func workspaceAgent() *cobra.Command {
 	var (
 		auth         string
-		pprofEnabled bool
 		pprofAddress string
 		noReap       bool
 	)
@@ -82,15 +81,11 @@ func workspaceAgent() *cobra.Command {
 			// Set a reasonable timeout so requests can't hang forever!
 			client.HTTPClient.Timeout = 10 * time.Second
 
-			if pprofEnabled {
+			// Enable pprof handler
-				srvClose := serveHandler(cmd.Context(), logger, nil, pprofAddress, "pprof")
+			// This prevents the pprof import from being accidentally deleted.
-				defer srvClose()
+			_ = pprof.Handler
-			} else {
+			pprofSrvClose := serveHandler(cmd.Context(), logger, nil, pprofAddress, "pprof")
-				// If pprof wasn't enabled at startup, allow a
+			defer pprofSrvClose()
-				// `kill -USR1 $agent_pid` to start it (on Unix).
-				srvClose := agentStartPPROFOnUSR1(cmd.Context(), logger, pprofAddress)
-				defer srvClose()
-			}
 
 			// exchangeToken returns a session token.
 			// This is abstracted to allow for the same looping condition
@@ -177,7 +172,6 @@ func workspaceAgent() *cobra.Command {
 	}
 
 	cliflag.StringVarP(cmd.Flags(), &auth, "auth", "", "CODER_AGENT_AUTH", "token", "Specify the authentication type to use for the agent")
-	cliflag.BoolVarP(cmd.Flags(), &pprofEnabled, "pprof-enable", "", "CODER_AGENT_PPROF_ENABLE", false, "Enable serving pprof metrics on the address defined by --pprof-address.")
 	cliflag.BoolVarP(cmd.Flags(), &noReap, "no-reap", "", "", false, "Do not start a process reaper.")
 	cliflag.StringVarP(cmd.Flags(), &pprofAddress, "pprof-address", "", "CODER_AGENT_PPROF_ADDRESS", "127.0.0.1:6060", "The address to serve pprof.")
 	return cmd

cli/agent_unix.go

@@ -1,38 +0,0 @@
-//go:build !windows
-
-package cli
-
-import (
-	"context"
-	"os"
-	"os/signal"
-	"syscall"
-
-	"cdr.dev/slog"
-)
-
-func agentStartPPROFOnUSR1(ctx context.Context, logger slog.Logger, pprofAddress string) (srvClose func()) {
-	ctx, cancel := context.WithCancel(ctx)
-
-	usr1 := make(chan os.Signal, 1)
-	signal.Notify(usr1, syscall.SIGUSR1)
-	go func() {
-		defer close(usr1)
-		defer signal.Stop(usr1)
-
-		select {
-		case <-usr1:
-			signal.Stop(usr1)
-			srvClose := serveHandler(ctx, logger, nil, pprofAddress, "pprof")
-			defer srvClose()
-		case <-ctx.Done():
-			return
-		}
-		<-ctx.Done() // Prevent defer close until done.
-	}()
-
-	return func() {
-		cancel()
-		<-usr1 // Wait until usr1 is closed, ensures srvClose was run.
-	}
-}

cli/agent_windows.go

@@ -1,12 +0,0 @@
-package cli
-
-import (
-	"context"
-
-	"cdr.dev/slog"
-)
-
-// agentStartPPROFOnUSR1 is no-op on Windows (no SIGUSR1 signal).
-func agentStartPPROFOnUSR1(ctx context.Context, logger slog.Logger, pprofAddress string) (srvClose func()) {
-	return func() {}
-}