Create jenkins JLNP slave programmatically
Posted in development on March 15, 2019 by Adrian Wyssmann ‐ 2 min read
Adding a slave to a Jenkins master always required to add the slave via the GUI and then gather the secret in order to be able to connect the slave. So I was wondering whether a slave could be created programmatically.
My initial search brought me to this Stackoverflow post However, I figured you can also create an agent using the REST API. This is especially useful when having an apache proxy in front (see issue JENKINS-47279) and no direct access to the jenkins otherwise (e.g. in a corporate network) where CLI will not work. I recommend to create an API token for this purpose. Then you can do something like this to create a jenkins slave programatically:
Linux (Bash)
export JENKINS_URL=https://jenkins.intra
export JENKINS_USER=papanito
export JENKINS_API_TOKEN=xxxxxxxxxxxxxxxxxxxxxxxx
export NODE_NAME=testnode
export JSON_OBJECT="{ 'name':+'${NODE_NAME}',+'nodeDescription':+'Linux+slave',+'numExecutors':+'5',+'remoteFS':+'/home/jenkins/agent',+'labelString':+'SLAVE-DOCKER+linux',
+'mode':+'EXCLUSIVE',+'':+['hudson.slaves.JNLPLauncher',+'hudson.slaves.RetentionStrategy\$Always'],
+'launcher':+{'stapler-class':+'hudson.slaves.JNLPLauncher',+'\$class':+'hudson.slaves.JNLPLauncher',
+'workDirSettings':+{'disabled':+true,+'workDirPath':+'',+'internalDir':+'remoting',+'failIfWorkDirIsMissing':+false},
+'tunnel':+'',+'vmargs':+'-Xmx1024m'},+'retentionStrategy':+{'stapler-class':+'hudson.slaves.RetentionStrategy\$Always',
+'\$class':+'hudson.slaves.RetentionStrategy\$Always'},+'nodeProperties':+{'stapler-class-bag':+'true',
+'hudson-slaves-EnvironmentVariablesNodeProperty':+{'env':+[{'key':+'JAVA_HOME',+'value':+'/docker-java-home'},
+{'key':+'JENKINS_HOME',+'value':+'/home/jenkins'}]},
+'hudson-tools-ToolLocationNodeProperty':+{'locations':+[{'key':+'hudson.plugins.git.GitTool\[email protected]',
+'home':+'/usr/bin/git'},+{'key':+'hudson.model.JDK\[email protected]',
+'home':+'/usr/bin/java'},+{'key':+'hudson.tasks.Maven\$MavenInstallation\[email protected]',
+'home':+'/usr/bin/mvn'}]}}}"
curl -L -s -o /dev/null -v -k -w "%{http_code}" -u "${JENKINS_USER}:${JENKINS_API_TOKEN}" -H "Content-Type:application/x-www-form-urlencoded" -X POST -d "json=${JSON_OBJECT}" "${JENKINS_URL}/computer/doCreateItem?name=${NODE_NAME}&type=hudson.slaves.DumbSlave"
In order to get the agent secret via REST API checkout this, which would look something like this:
curl -L -s -u ${JENKINS_USER}:${JENKINS_API_TOKEN} -X GET ${JENKINS_URL}/computer/${NODE_NAME}/slave-agent.jnlp | sed "s/.*<application-desc main-class=\"hudson.remoting.jnlp.Main\"><argument>\([a-z0-9]*\).*/\1/"
Windows (PS)
And here my solution for Windows using Powershell:
$JENKINS_URL="https://jenkins.intra"
$JENKINS_USER="papanito"
$JENKINS_API_TOKEN="xxxxxxxxxxxxxxxxxxxxxxxx"
$NODE_NAME="testnode-ps"
# https://stackoverflow.com/questions/27951561/use-invoke-webrequest-with-a-username-and-password-for-basic-authentication-on-t
$bytes = [System.Text.Encoding]::ASCII.GetBytes("${JENKINS_USER}:${JENKINS_API_TOKEN}")
$base64 = [System.Convert]::ToBase64String($bytes)
$basicAuthValue = "Basic $base64"
$headers = @{ Authorization = $basicAuthValue; }
[email protected]{
name="${NODE_NAME}";
nodeDescription="Linux slave";
numExecutors="5";
remoteFS="/home/jenkins/agent";
labelString="SLAVE-DOCKER linux";
mode="EXCLUSIVE";
""[email protected](
"hudson.slaves.JNLPLauncher";
'hudson.slaves.RetentionStrategy$Always'
);
[email protected]{
"stapler-class"="hudson.slaves.JNLPLauncher";
"\$class"="hudson.slaves.JNLPLauncher";
"workDirSettings"[email protected]{
"disabled"="true";
"workDirPath"="";
"internalDir"="remoting";
"failIfWorkDirIsMissing"="false"
};
"tunnel"="";
"vmargs"="-Xmx1024m"
};
"retentionStrategy"[email protected]{
"stapler-class"= 'hudson.slaves.RetentionStrategy$Always';
'$class'= 'hudson.slaves.RetentionStrategy$Always'
};
"nodeProperties"[email protected]{
"stapler-class-bag"= "true";
"hudson-slaves-EnvironmentVariablesNodeProperty"[email protected]{
"env"[email protected](
@{
"key"="JAVA_HOME";
"value"="/docker-java-home"
};
@{
"key"="JENKINS_HOME";
"value"="/home/jenkins"
}
)
};
"hudson-tools-ToolLocationNodeProperty"[email protected]{
"locations"[email protected](
@{
"key"= '[email protected]';
"home"= "/usr/bin/git"
};
@{
"key"= 'hudson.model.JDK\[email protected]';
"home"= "/usr/bin/java"
};
@{
"key"= '[email protected]';
"home"= "/usr/bin/mvn"
}
)
}
}
}
#https://stackoverflow.com/questions/17929494/powershell-convertto-json-with-embedded-hashtable
$JSON_OBJECT = $hash | convertto-json -Depth 5
$JSON_OBJECT
Invoke-WebRequest -Headers $headers -ContentType "application/x-www-form-urlencoded" -Method POST -Body "json=${JSON_OBJECT}" -Uri "${JENKINS_URL}/computer/doCreateItem?name=${NODE_NAME}&type=hudson.slaves.DumbSlave"
Hope this is useful for you.