Lp: replacement issue using LxD vm as a Jenkins slave

LXD
1

I am using images:ubuntu/bionic/cloud to create vm, and jnlp slave connected to Jenkins master.
By initiating the LxD vm, I am using cloud-init to write a file into “/root/.gitconfig” with content as followed.

[user]
	email = username@canonical.com
        name = username

[url "git+ssh://username@git.launchpad.net/"]
        insteadof = lp:

But when I run Jenkins configuration with “git clone lp:~project-team/project/+git/repository”, it shows the following error.

**14:06:18** ssh: Could not resolve hostname lp: Temporary failure in name resolution 
**14:06:18** fatal: Could not read from remote repository.

I printed out with whoami, and the user shows “root”.

2

Maybe Jenkins somehow isn’t using .gitconfig when calling git?

You could probably strace the jenkins agent to see exactly what it’s calling and what files are read.

3

I tried git config --global and got this

23:01:25 + git config --global user.email ****@canonical.com
23:01:25 fatal: $HOME not set

I think the main cause is $HOME not been set.
I didn’t hit this when using Vagrant VM as the JNLP slave.
The only difference I can guess is when using LxD vm I use “root” as the user to connect.
Keep investigating.

4

Investigate the issue by 2 changes.

  1. Put agent.jar elsewhere than /root [This has been prove NOT relevant]
    Original:
    java -jar /root/agent.jar -jnlpUrl http://jenkins.ip.:8080/computer/oem-iot-focal-1/slave-agent.jnlp -secret xxxxxx -workDir "/home/user"
    Updated:
    java -jar /home/user/agent.jar -jnlpUrl http://jenkins.ip.:8080/computer/oem-iot-focal-1/slave-agent.jnlp -secret xxxxxx -workDir "/home/user"

This solve the issue $HOME not been set, and now it shows /root as home but it comes another issue.

**09:46:14** + git clone 'lp:~project-team/project/+git/oem-repo' 
**09:46:14** fatal: open /dev/null or dup failed: No such file or directory
  1. To solve this, create /dev/null in LxD vm
    mknod /dev/null c 1 3
    chmod 666 /dev/null

Step 1. proved that manually run JNLP connect works well.

5

$HOME not been set issue still exists when I use cloud-init to make this a systemd service and start when LxD vm boot up.

java -jar /home/user/agent.jar -jnlpUrl http://jenkins.ip.:8080/computer/oem-iot-focal-1/slave-agent.jnlp -secret xxxxxx -workDir "/home/user"

I think it is not because agent.jar under /root, but because of using systemd to run jnlp connect.
When I use manual run, it works well.

6

Instead of creating a systemd service to run another bash script (with & to run in background), I re-write the systemd service following the guidance of this

And it solves my issue 100%.