Regarding GitHub collaboration and SSH certification in Jenkins

We are installing jenkins on the rental server and trying to build a development environment using virtual machines.

However, when you log in to the virtual machine with ssh from jenkins and git pull to github, the job hardens.

Development laptops
Debian GNU/LINUX 8.0

Guest virtual machines in laptops
VMs:VirtualBox 4.3.30
OS:CentOS 6.6
mem —512MB
HDD: 8.0GB Host only adapter for host communication ->eth1192.168.56.10
NAT (for Internet use)
working users:vagrant

jenkins server (rental VPS, fixed IP, root privileges)
OS:CentOS 6.6
mem: 1GB
HDD: 50GB working users:jenkins

Supplementary

The host PC and guest virtual machines do not have static IP, so the connection to the jenkins server is tunneling using ssh forward.This tunnel has successfully secured communication.

The Jenkins server and github have been configured to work together and have been able to confirm their cooperation (when pushed to github, jenkins jobs can be invoked).

Successfully logged in to the guest virtual machine from the jenkins server through the ssh plug-in in jenkins.

The github key registers the jenkins server and guest virtual machines separately and has a private key.

I want to code and develop on the host laptop and automatically pull from the github via jenkins when I push to the github.

• Source Code Management and other items are configured appropriately
• Set the build trigger to "Build when a change is pushed to -GitHub" with the github plug-in

• In the build environment, insert the ssh plug-in and select Run Shell on Remote Host.Guest virtual machines can be logged in as vagrant@localhost:10022 using a private key (with pty enabled)

• Configured Shell Script

  cd/var/www/html/hoge
git pull

For the build environment, insert the ssh plug-in and select Run Shell on Remote Host.Guest virtual machines can be logged in as vagrant@localhost:10022 using a private key (with pty enabled)

Configured Shell Script

cd/var/www/html/hoge
git pull

When I originally started the job in this state, the play job failed because the private key passphrase to enter the github was not included.

jenkins console output

~(some omitted)
~~
cd/var/www/html/force
git pull
Permission denied (publickey).
fatal —The remote end hang up unexpectedly
SSH exit-status: 1
Finished—FAILURE

Using ssh-agent

So I started ssh-agent on the guest virtual machine, registered the key passphrase with ssh-add in advance, and started the job again, but it didn't play, but the job hardened. (The round and round mark keeps moving)

Manually Successful

Enter the guest virtual machine directly from the development laptop or from the jenkins server (after logging in to the jenkins server as a jenkins user from the development laptop with ssh) with SSH and git pull will succeed.

In my understanding

Development Laptop ->github ->jenkins Server ->Guest Virtual Machine ->github

and so on, eventually logging in to github using the guest virtual machine's private key.

I think the problem this time is probably about how to insert the key passphrase, but I have little experience and have not been able to solve it.

I'm sure some of you may think that this configuration is strange, but personally, I will need to build a development environment using ssh forward in the future, so I would like to tell you how to solve it now.

Thank you for your cooperation.

Add

I searched on the web and found that I could enter a passphrase with the command expect.

I immediately created a shell script with expect, and the passphrase was successful and pull succeeded.

#!/usr/bin/expect
expect-c" 
set timeout5
spawn git pull
expect\"Enter passphrase for key'/home/vagrant/.ssh/id_rsa':\"
send\"Passphrase\n\"
interact 
"

As a result, the job was successful, but expect requires a passphrase in the shell script and does not seem to be in a very favorable condition.

If possible, I would like to do it in a way that makes sense for security.

Thank you for your continued support.