Move envoy concurrency as top level config into consuldp

Author: Chris Chapman

cmd/consul-dataplane/main.go

@@ -3,7 +3,6 @@ package main
 import (
 	"context"
 	"flag"
-	"fmt"
 	"log"
 	"os"
 	"os/signal"
@@ -83,17 +82,6 @@ func validateFlags() {
 	}
 }
 
-func extraEnvoyArguments() []string {
-	extraEnvoyArgs := flag.Args()
-	if extraEnvoyArgs == nil {
-		extraEnvoyArgs = []string{}
-	}
-	concurrency := fmt.Sprintf("--concurrency %v", envoyConcurrency)
-	// to ensure precedence of arguements we prepend before extraArgs so that subsequent params override the
-	// last set value
-	return append([]string{concurrency}, extraEnvoyArgs...)
-}
-
 func main() {
 
 	flag.Parse()
@@ -130,7 +118,8 @@ func main() {
 			AdminBindPort:    adminBindPort,
 			ReadyBindAddress: readyBindAddr,
 			ReadyBindPort:    readyBindPort,
-			ExtraArgs:        extraEnvoyArguments(),
+			EnvoyConcurrency: envoyConcurrency,
+			ExtraArgs:        flag.Args(),
 		},
 		XDSServer: &consuldp.XDSServer{
 			BindAddress: xdsBindAddr,

pkg/consuldp/config.go

@@ -74,6 +74,8 @@ type EnvoyConfig struct {
 	ReadyBindAddress string
 	// ReadyBindPort is the port on which the Envoy readiness probe will be available.
 	ReadyBindPort int
+	// EnvoyConcurrency is the envoy concurrency https://www.envoyproxy.io/docs/envoy/latest/operations/cli#cmdoption-concurrency
+	EnvoyConcurrency int
 	// ExtraArgs are the extra arguments passed to envoy at startup of the proxy
 	ExtraArgs []string
 }

pkg/consuldp/consul_dataplane.go

@@ -177,12 +177,7 @@ func (cdp *ConsulDataplane) Run(ctx context.Context) error {
 	}
 	cdp.logger.Debug("generated envoy bootstrap config", "config", string(cfg))
 
-	proxy, err := envoy.NewProxy(envoy.ProxyConfig{
-		Logger:          cdp.logger,
-		LogJSON:         cdp.cfg.Logging.LogJSON,
-		BootstrapConfig: cfg,
-		ExtraArgs:       cdp.cfg.Envoy.ExtraArgs,
-	})
+	proxy, err := envoy.NewProxy(cdp.envoyProxyConfig(cfg))
 	if err != nil {
 		cdp.logger.Error("failed to create new proxy", "error", err)
 		return fmt.Errorf("failed to create new proxy: %w", err)
@@ -211,3 +206,18 @@ func (cdp *ConsulDataplane) Run(ctx context.Context) error {
 	}()
 	return <-doneCh
 }
+
+func (cdp *ConsulDataplane) envoyProxyConfig(cfg []byte) envoy.ProxyConfig {
+	// Translate the concurrency parameter to the envoy parameter.
+	concurrency := fmt.Sprintf("--concurrency %v", cdp.cfg.Envoy.EnvoyConcurrency)
+	// Prepend so that if the consumer also specifies a concurrency level their specification should take
+	// precedence.
+	extraArgs := append([]string{concurrency}, cdp.cfg.Envoy.ExtraArgs...)
+
+	return envoy.ProxyConfig{
+		Logger:          cdp.logger,
+		LogJSON:         cdp.cfg.Logging.LogJSON,
+		BootstrapConfig: cfg,
+		ExtraArgs:       extraArgs,
+	}
+}