How can I get msysgit on windows to invoke node.js scripts in hooks? - node.js

Question

I would like to use node.js scripts as my git hook scripts. Currently I'm experimenting on my Windows machine with Bonobo Git HTTP service which is attached to msysgit Git-1.9.0-preview20140217 portable installation. It works fine, tested with copuple pulls and pushes.
I have nodejs up and running but my git update script just fails without any clear reason. It definitely works - it started to always reject pushes as soon as I added it into the hooks folder on the server but there are no any clues in SourceTree output log.
Here is my update script:
#!C:/nodejs/node.exe
console.log('Hello world!');
console.log('Hello world 2!');
I tried back slashes, I tried double forward slashes, I tried quoting the path - no results.
Server response is as follows:
git -c diff.mnemonicprefix=false -c core.quotepath=false push -v --tags origin master:master
Pushing to http://myurl.git
POST git-receive-pack (4686 bytes)
remote: error: hook declined to update refs/heads/master[K
To http://myurl.git
! [remote rejected] master -> master (hook declined)
error: failed to push some refs to 'http://myurl.git'
Completed with errors, see above.
P.S. I don't know where [K comes from, my gusess is that it's corrupted newline character.

Answer 1

I ended up using similar approach to the one I found someone was using for Python.
I created a C# console app as follows:
using System;
using System.Diagnostics;
using System.IO;
namespace GitNodeRunner
{
class Program
{
static int Main(string[] args)
{
if (args == null || args.Length == 0)
{
Console.Error.WriteLine("Path to script file not specified");
return -1;
}
string argString = string.Join(" ", args);
Console.WriteLine("Node.js arguments received: {0}", argString);
string nodePath = Environment.GetEnvironmentVariable("NODE_HOME",
EnvironmentVariableTarget.Machine); // without "Machine" Git's Bash loses it
if (string.IsNullOrWhiteSpace(nodePath))
{
Console.Error.WriteLine("NODE_HOME global envirnoment variable not found");
return -1;
}
nodePath = Path.Combine(nodePath, "node.exe");
ProcessStartInfo start = new ProcessStartInfo
{
UseShellExecute = false,
Arguments = argString,
FileName = nodePath,
RedirectStandardInput = true,
RedirectStandardOutput = true,
RedirectStandardError = true,
CreateNoWindow = true
};
Process process = new Process();
process.StartInfo = start;
process.EnableRaisingEvents = true;
process.OutputDataReceived += process_OutputDataReceived;
process.ErrorDataReceived += process_OutputDataReceived;
process.Start();
process.BeginErrorReadLine();
process.BeginOutputReadLine();
process.WaitForExit();
return process.ExitCode;
}
static void process_OutputDataReceived(object sender, DataReceivedEventArgs e)
{
string s = e.Data;
Console.Out.WriteLine(s);
}
static void process_ErrorDataReceived(object sender, DataReceivedEventArgs e)
{
string s = e.Data;
Console.Error.WriteLine(s);
}
}
}
I compiled it as git-nodejs.exe, put into Git's bin folder, ensured that I have NODE_HOME environment variable defined, and now I can use node.js scripts. As an example, I provide my node.js update hook which rejects pushes with malformed comment messages:
#!/bin/git-nodejs
// bin/git-nodejs is our custom C# programmed node launcher
// the following code is ported from http://git-scm.com/book/en/Customizing-Git-An-Example-Git-Enforced-Policy
// we have some offset from standard Git args here:
// 0 is path to node
// 1 is path to this script
var exec = require('child_process').exec,
refname = process.argv[2],
oldrev = process.argv[3],
newrev = process.argv[4],
regexMatch = /^REF #\d* /; // in my case I require strict start with "REF #number "
console.log("Enforcing policies in branch " + refname + " for commits between revisions " + oldrev + " and " + newrev);
// we have a special case - if this is a new branch, oldrev..newrev will cause git to throw an error,
// that's why we check for empty branch commit ID
var revListCmd = (oldrev === "0000000000000000000000000000000000000000") ?
"git rev-list " + newrev + " --not --branches=*" :
"git rev-list " + oldrev + ".." + newrev;
exec(revListCmd,
function (error, stdout, stderr) {
if (error !== null) {
console.error("Exec error: " + error);
exitError();
}
var missedRevs = stdout.split("\n");
missedRevs.forEach(function(rev){
// there is a redundant empty entry at the end after split()
if (rev.length === 0) {
return;
}
console.log("Verifying policy for revision " + rev);
// | sed '1,/^$/d' does not quite work as expected on Windows
// - it returns all commit details instead of comment
// thus we complete the processing from JavaScript
exec("git cat-file commit " + rev,
function (error, stdout, stderr) {
if (error !== null) {
console.error("Exec error: " + error);
exitError();
}
// we skip the blank line (two sequential newlines) and take everything that follows
// not sure if this is the best solution but "it works on my machine"
var commitMessage = stdout.split("\n\n")[1];
// notice: if commit message missing, git will report it as "no message"
if (commitMessage.match(regexMatch) === null) {
console.error("Commit message '" + commitMessage + "' does not match the required pattern " + regexMatch);
exitError();
}
});
});
});
//////////////////////////
// some helpers
function exitError()
{
// hack for bug https://github.com/joyent/node/issues/3584
// delay exit until stdout on Windows has had some time to flush
setTimeout(function() {
console.error("Exiting with error status 1");
process.exit(1);
}, 1000);
}