feat: Parameterize config paths. Fixes #12911.

Author: emmanuel

internal/ingress/controller/nginx.go

@@ -704,7 +704,7 @@ func (n *NGINXController) OnUpdate(ingressCfg ingress.Configuration) error {
 	}
 
 	if klog.V(2).Enabled() {
-		src, err := os.ReadFile(cfgPath)
+		src, err := os.ReadFile(cfgPath())
 		if err != nil {
 			return err
 		}
@@ -719,7 +719,7 @@ func (n *NGINXController) OnUpdate(ingressCfg ingress.Configuration) error {
 				return err
 			}
 			//nolint:gosec //Ignore G204 error
-			diffOutput, err := exec.Command("diff", "-I", "'# Configuration.*'", "-u", cfgPath, tmpfile.Name()).CombinedOutput()
+			diffOutput, err := exec.Command("diff", "-I", "'# Configuration.*'", "-u", cfgPath(), tmpfile.Name()).CombinedOutput()
 			if err != nil {
 				if exitError, ok := err.(*exec.ExitError); ok {
 					ws, ok := exitError.Sys().(syscall.WaitStatus)
@@ -740,7 +740,7 @@ func (n *NGINXController) OnUpdate(ingressCfg ingress.Configuration) error {
 		}
 	}
 
-	err = os.WriteFile(cfgPath, content, file.ReadWriteByUser)
+	err = os.WriteFile(cfgPath(), content, file.ReadWriteByUser)
 	if err != nil {
 		return err
 	}
@@ -1105,7 +1105,7 @@ func (n *NGINXController) createLuaConfig(cfg *ngx_config.Configuration) error {
 	if err != nil {
 		return err
 	}
-	return os.WriteFile(luaCfgPath, jsonCfg, file.ReadWriteByUser)
+	return os.WriteFile(luaCfgPath(), jsonCfg, file.ReadWriteByUser)
 }
 
 func cleanTempNginxCfg() error {

internal/ingress/controller/util.go

@@ -98,9 +98,7 @@ func rlimitMaxNumFiles() int {
 }
 
 const (
-	defBinary  = "/usr/bin/nginx"
-	cfgPath    = "/etc/nginx/nginx.conf"
-	luaCfgPath = "/etc/nginx/lua/cfg.json"
+	defBinary = "/usr/bin/nginx"
 )
 
 // NginxExecTester defines the interface to execute
@@ -115,6 +113,22 @@ type NginxCommand struct {
 	Binary string
 }
 
+func luaCfgPath() string {
+	cfgPath := os.Getenv("NGINX_LUA_CONFIG_PATH")
+	if cfgPath == "" {
+		return "/etc/nginx/lua/cfg.json"
+	}
+	return cfgPath
+}
+
+func cfgPath() string {
+	cfgPath := os.Getenv("NGINX_CONFIG_PATH")
+	if cfgPath == "" {
+		return "/etc/nginx/nginx.conf"
+	}
+	return cfgPath
+}
+
 // NewNginxCommand returns a new NginxCommand from which path
 // has been detected from environment variable NGINX_BINARY or default
 func NewNginxCommand() NginxCommand {
@@ -134,7 +148,7 @@ func NewNginxCommand() NginxCommand {
 func (nc NginxCommand) ExecCommand(args ...string) *exec.Cmd {
 	cmdArgs := []string{}
 
-	cmdArgs = append(cmdArgs, "-c", cfgPath)
+	cmdArgs = append(cmdArgs, "-c", cfgPath())
 	cmdArgs = append(cmdArgs, args...)
 	//nolint:gosec // Ignore G204 error
 	return exec.Command(nc.Binary, cmdArgs...)