Buildkite Agent SSH Keys
If your agent needs to clone your repositories using git and SSH, you'll need to configure your agent with a valid SSH key.
Finding your SSH key directory
When the Buildkite Agent runs any git operations, SSH will look for keys in
~/.ssh under whichever user the agent runs as. Each platform’s agent installation documentation specifies the exact location of this directory.
Debugging SSH key issues
To help debug SSH issues, you can enable verbose logging by running your build with the following environment variable set:
Creating a single SSH key
The following shows an example of creating a new “machine user” SSH key for an agent:
$ sudo su buildkite-agent # or whichever user your agent runs as $ mkdir -p ~/.ssh && cd ~/.ssh $ ssh-keygen -t rsa -b 4096 -C "firstname.lastname@example.org" Generating public/private rsa key pair. Enter file in which to save the key (/var/lib/buildkite-agent/.ssh/id_rsa): Enter passphrase (empty for no passphrase): Enter same passphrase again: Your identification has been saved in /var/lib/buildkite-agent/.ssh/id_rsa. Your public key has been saved in /var/lib/buildkite-agent/.ssh/id_rsa.pub. The key fingerprint is: 4b:6f:7b:5f:8e:f7:5b:c1:fa:e3:dd:9a:8e:a8:e8:33 email@example.com The key's randomart image is: +---[RSA 4096]----+ | | | | | | | . | | S o | | . o . .| | . o . o| | E. . o...*=| | .oo..o..oB*O| +-----------------+ $ ls id_rsa id_rsa.pub $ cat id_rsa.pub ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAACAQDELESv1QGfoZ2hECJr.......Yho9hDPoNefDbcdZM4NdKWTVmyNGQo6YTzw== firstname.lastname@example.org
You'd then add this key to the user’s settings on GitHub, Bitbucket, GitLab, etc.
Creating multiple SSH keys
If you need to use multiple SSH keys for different pipelines, we support a special repository hostname format which you can use with your
To use a different key for a given pipeline, first change the repository hostname in your Buildkite pipeline settings from
server.com-mypipeline, add an entry to the SSH config file on your agent machine for the host
server.com-mypipeline, and specify your custom SSH key.
For example, if you had a pipeline repository URL of
email@example.com:org/pipeline-1.git you would change it in your Buildkite repository settings to
firstname.lastname@example.org:org/pipeline-1.git and create the following SSH config file:
Host github.com-pipeline-1 HostName github.com IdentityFile /var/lib/buildkite-agent/.ssh/id_rsa.pipeline-1
The following example shows how to create the corresponding pipeline-specific SSH key:
$ sudo su buildkite-agent # or whichever user your agent runs as $ cd ~/.ssh $ ssh-keygen -t rsa -b 4096 -C "email@example.com" Generating public/private rsa key pair. Enter file in which to save the key (/var/lib/buildkite-agent/.ssh/id_rsa): id_rsa.pipeline-1 Enter passphrase (empty for no passphrase): Enter same passphrase again: Your identification has been saved in id_rsa.pipeline-1. Your public key has been saved in id_rsa.pipeline-1.pub. The key fingerprint is: e4:60:69:a3:a0:63:bb:27:e6:ff:53:d3:4a:06:7f:e4 firstname.lastname@example.org The key's randomart image is: +---[RSA 4096]----+ | | | . | | . * . | | . . = = . | |o. . o S | |... * E | | . + + | | o.. . . | |oo+.... | +-----------------+ $ ls id_rsa.pipeline-1 id_rsa.pipeline-1.pub
Alternatively, you can use a shorter approach to creating multiple SSH keys by adding pipeline-specific environments:
Note that if you are using Elastic Stack, the following approach is redundant as secrets support allows you to specify an SSH key per pipeline as
Add a pipeline-specific environment (for example, by using Elastic Stack's secrets support or by having an Agent environment hook that switches on the repository URL or the pipeline slug):
GIT_SSH_COMMAND="ssh -i ~/.ssh/id_rsa_mypipeline"
Create an identity file at that location:
Add the public key for that identity file to
mypipelineon the git repository provider.
Using multiple keys with ssh-agent
If you need to use multiple keys, or want to use keys with pass-phrases, an alternative to the above hostname method is to use
After starting an
ssh-agent process and adding the keys, ensure the
SSH_AUTH_SOCK environment variable is exported by your
For example, if you set up
ssh-agent like so:
$ sudo su buildkite-agent $ ssh-agent -a ~/.ssh/ssh-agent.sock $ export SSH_AUTH_SOCK=/var/lib/buildkite-agent/.ssh/ssh-agent.sock $ ssh-add ~/.ssh/id_rsa-pipeline-1 Identity added: /var/lib/buildkite-agent/.ssh/id_rsa-pipeline-1 $ ssh-add ~/.ssh/id_rsa-pipeline-2 Identity added: /var/lib/buildkite-agent/.ssh/id_rsa-pipeline-2
will direct your build’s git operations to use the
#!/bin/bash set -eu export SSH_AUTH_SOCK="/var/lib/buildkite-agent/.ssh/ssh-agent.sock"