cluster: rewrite debug ports consistently

When debug flags are passed to clustered applications, the debug port is rewritten for each worker process to avoid collisions. Prior to this commit, each debug flag would get a unique value. This commit reworks the logic to assign the same port value to all debug flags for a single worker. PR-URL: #7050 Reviewed-By: Ben Noordhuis <[email protected]> Reviewed-By: Santiago Gimeno <[email protected]>

Author: cjihrig

lib/cluster.js

@@ -286,6 +286,7 @@ function masterInit(){
 functioncreateWorkerProcess(id,env){
 varworkerEnv=util._extend({},process.env);
 varexecArgv=cluster.settings.execArgv.slice();
+vardebugPort=0;
 
 workerEnv=util._extend(workerEnv,env);
 workerEnv.NODE_UNIQUE_ID=''+id;
@@ -294,8 +295,11 @@ function masterInit(){
 varmatch=execArgv[i].match(/^(--debug|--debug-(brk|port))(=\d+)?$/);
 
 if(match){
-constdebugPort=process.debugPort+debugPortOffset;
-++debugPortOffset;
+if(debugPort===0){
+debugPort=process.debugPort+debugPortOffset;
+++debugPortOffset;
+}
+
 execArgv[i]=match[1]+'='+debugPort;
 }
 }

test/parallel/test-cluster-debug-port.js

@@ -23,6 +23,11 @@ if (cluster.isMaster){
 portSet: process.debugPort+1
 }).on('exit',checkExitCode);
 
+cluster.setupMaster({
+execArgv: [`--debug-port=${process.debugPort}`,
+`--debug=${process.debugPort}`]
+});
+
 console.log('forked worker should have --debug-port, with offset = 2');
 cluster.fork({
 portSet: process.debugPort+2