Simple bash deployment script hangs

[davidebbo]

Issue comes from http://stackoverflow.com/questions/37739407/azure-web-site-kudu-publishing-failing-with-timeout/37740335.

This seems to have regressed with the new git 2.8.x. The repro is quite trivial. Here is a repo: https://github.com/KuduApps/KuduDeployBash

It just has two files. .deployment has:

[config]
command = deploy.sh

And deploy.sh has:

#!/bin/bash
echo "Hello"

Which push to Kudu, it hangs trying to launch the script.

[davidebbo]

Here is the process stack. mintty.exe is spinning non-stop with high CPU.

And the command line of the 3 top processes:

cmd.exe: D:\Windows\system32\cmd.exe /c ""C:\Program Files (x86)\SiteExtensions\Kudu\55.50610.2267\bin\Scripts\starter.cmd" deploy.sh"
git-bash.exe: "D:\Program Files (x86)\Git\git-bash.exe" --no-cd "D:\home\site\repository\deploy.sh"
mintty.exe: usr\bin\mintty.exe -o AppID=GitForWindows.Bash -o RelaunchCommand="D:\Program Files (x86)\Git\git-bash.exe" -o RelaunchDisplayName="Git Bash" -i /mingw32/share/git/git-for-windows.ico /usr/bin/bash --login -i "D:\home\site\repository\deploy.sh"

[davidebbo]

The simplest repro is to just run deploy.sh from Kudu console, which hangs in the same way.

This triggers the .sh extension handler. HKEY_CLASSES_ROOT\sh_auto_file\shell\open\command maps to "D:\Program Files (x86)\Git\git-bash.exe" --no-cd "%L" %*, which is why would end up launching git-bash.exe.

Note that running bash deploy.sh from the command line works fine.

[davidebbo]

I found that if I change the shell reg key to "D:\Program Files (x86)\Git\bin\bash.exe" --no-cd "%L" %*, the issue doesn't happen.

@dscho can you explain the difference between git-bash.exe and bash.exe? Why does one use mintty but not the other?

[dscho]

@davidebbo git-bash.exe is supposed to run a graphical terminal, set up the environment variables appropriately, and then call the real Bash. bin/bash.exe does the same, but without the graphical shell (it is a console program). So it looks like you found the correct solution.

[davidebbo]

Instead of hacking the registry, a simpler change is to run the script shell explicitly instead of relying on Windows shell.

e.g. in .deployment file, instead of:

[config]
command = deploy.sh

We should have:

[config]
command = bash deploy.sh

Users who already generated this file will need to change it, but we should change our KuduScript generator to do it.

[davidebbo]

It turns out that our generator already does the right thing. So only users hitting this probably hand won't their .deployment file, and can easily change that.

So I don't think we need to fix anything here.