Jenkins unable to fetch repo - code 255 permission denied

Question

I'm trying to set up Jenkins to work with git webhooks. So far I have

• Jenkins running
• Created an ssh key pair under the jenkins user
• Added the key to git deploy keys
• Added the git plugin
• Configured the project to use git with the repo
• Set the branch to */develop to only watch the dev branch
• Set the custom workspace directory to /data/www/<site>
• Added the ubunutu group to the jenkins user (see below)

And when trying to build the project, I get this error:

Started by user anonymous
Building in workspace /data/www/<site>
 > git rev-parse --is-inside-work-tree # timeout=10
Fetching changes from the remote Git repository
 > git config remote.jenkins.url [email protected]:<repo_url> # timeout=10
ERROR: Error fetching remote repo 'jenkins'
hudson.plugins.git.GitException: Failed to fetch from [email protected]:<repo_url>
    at hudson.plugins.git.GitSCM.fetchFrom(GitSCM.java:735)
    at hudson.plugins.git.GitSCM.retrieveChanges(GitSCM.java:983)
    at hudson.plugins.git.GitSCM.checkout(GitSCM.java:1016)
    at hudson.scm.SCM.checkout(SCM.java:485)
    at hudson.model.AbstractProject.checkout(AbstractProject.java:1276)
    at hudson.model.AbstractBuild$AbstractBuildExecution.defaultCheckout(AbstractBuild.java:610)
    at jenkins.scm.SCMCheckoutStrategy.checkout(SCMCheckoutStrategy.java:86)
    at hudson.model.AbstractBuild$AbstractBuildExecution.run(AbstractBuild.java:532)
    at hudson.model.Run.execute(Run.java:1744)
    at hudson.model.FreeStyleBuild.run(FreeStyleBuild.java:43)
    at hudson.model.ResourceController.execute(ResourceController.java:98)
    at hudson.model.Executor.run(Executor.java:374)
Caused by: hudson.plugins.git.GitException: Command "git config remote.jenkins.url [email protected]:<repo_url>" returned status code 255:
stdout: 
stderr: error: could not lock config file .git/config: Permission denied

    at org.jenkinsci.plugins.gitclient.CliGitAPIImpl.launchCommandIn(CliGitAPIImpl.java:1591)
    at org.jenkinsci.plugins.gitclient.CliGitAPIImpl.launchCommandIn(CliGitAPIImpl.java:1567)
    at org.jenkinsci.plugins.gitclient.CliGitAPIImpl.launchCommandIn(CliGitAPIImpl.java:1563)
    at org.jenkinsci.plugins.gitclient.CliGitAPIImpl.launchCommand(CliGitAPIImpl.java:1249)
    at org.jenkinsci.plugins.gitclient.CliGitAPIImpl.launchCommand(CliGitAPIImpl.java:1261)
    at org.jenkinsci.plugins.gitclient.CliGitAPIImpl.setRemoteUrl(CliGitAPIImpl.java:961)
    at hudson.plugins.git.GitAPI.setRemoteUrl(GitAPI.java:160)
    at hudson.plugins.git.GitSCM.fetchFrom(GitSCM.java:723)
    ... 11 more
ERROR: Error fetching remote repo 'jenkins'

The repo has already been pulled by a different user (in this case, ubuntu:ubuntu) in the /data/www/<site> directory, so initially I thought adding the ubunutu group to jenkins would fix the problem, but no luck. I've also tried logging in as the jenkins user and pulling the repo, which I can do successfully.

I've tried googling everything I can think of, but most searches point to people who are having key problems, rather than config file permission problems. At this point I'm out of ideas.

Edit:

ls -la in the .git dir:

drwxrwxr-x   2 ubuntu  ubuntu   4096 Mar  5 12:13 branches
-rw-rw-r--   1 ubuntu  ubuntu     15 Mar  5 18:09 COMMIT_EDITMSG
-rw-rw-r--   1 jenkins jenkins   318 Jun  1 14:55 config
-rw-rw-r--   1 ubuntu  ubuntu     73 Mar  5 12:13 description
-rw-rw-r--   1 ubuntu  ubuntu     88 May 29 12:50 FETCH_HEAD
-rw-rw-r--   1 ubuntu  ubuntu     24 May 28 13:21 HEAD
drwxrwxr-x   2 ubuntu  ubuntu   4096 May 28 13:49 hooks
-rw-rw-r--   1 ubuntu  ubuntu  36480 May 29 12:50 index
drwxrwxr-x   2 ubuntu  ubuntu   4096 Mar  5 12:13 info
drwxrwxr-x   3 ubuntu  ubuntu   4096 Mar  5 12:13 logs
drwxrwxr-x 260 ubuntu  ubuntu   4096 Apr 10 10:40 objects
-rw-rw-r--   1 jenkins jenkins    41 May 29 11:53 ORIG_HEAD
-rw-rw-r--   1 ubuntu  ubuntu    179 Mar  5 12:13 packed-refs
drwxrwxr-x   5 ubuntu  ubuntu   4096 Mar  5 12:13 refs

ls -la from the parent dir (it's a Laravel 5 app):

drwxrwxr-x 13 ubuntu   ubuntu    4096 Apr  3 11:07 app
-rwxrwxr-x  1 ubuntu   ubuntu    2452 Mar  5 12:13 artisan
drwxrwxr-x  2 ubuntu   ubuntu    4096 Mar 11 08:18 bootstrap
-rwxrwxr-x  1 ubuntu   ubuntu    1094 Mar 11 08:16 composer.json
-rw-rw-r--  1 ubuntu   ubuntu   79004 Mar 11 08:17 composer.lock
-rwxrwxr-x  1 ubuntu   ubuntu     146 Mar  5 12:13 CONTRIBUTING.md
drwxrwxr-x  8 ubuntu   ubuntu    4096 May  6 09:45 frontend
drwxrwxr-x  8 ubuntu   ubuntu    4096 Jun  1 14:56 .git
-rwxrwxr-x  1 ubuntu   ubuntu      12 Mar  5 12:13 .gitattributes
-rwxrwxr-x  1 ubuntu   ubuntu     160 Mar  5 12:13 .gitignore
-rwxrwxr-x  1 ubuntu   ubuntu     567 Mar  5 12:13 phpunit.xml
drwxrwxr-x  7 www-data www-data  4096 Mar  5 17:13 public
-rwxrwxr-x  1 ubuntu   ubuntu    2051 Mar  5 12:13 readme.md
-rwxrwxr-x  1 ubuntu   ubuntu     519 Mar  5 12:13 server.php
drwxrwxr-x 29 ubuntu   ubuntu    4096 Mar 11 08:18 vendor

Groups:

$ cat /etc/group | grep jenkins
ubuntu:x:1000:jenkins
jenkins:x:113:

$ cat /etc/group | grep ubuntu
adm:x:4:syslog,ubuntu
dialout:x:20:ubuntu
cdrom:x:24:ubuntu
floppy:x:25:ubuntu
sudo:x:27:ubuntu
audio:x:29:ubuntu
dip:x:30:ubuntu
video:x:44:ubuntu
plugdev:x:46:ubuntu
netdev:x:102:ubuntu
ubuntu:x:1000:jenkins

Answer 1

This works pretty nice form me:

1 - Find the git config.lock file, inside the jenkins folder run:

find . -type f -name "config.lock"

2 - Delete the config.lock file founded.

Thats it!

Answer 2

Check the owner / permissions of the .git/config file in the jenkins workspace. It's probably still owned by the ubuntu user. Change the owner to the jenkins user.