Explanation
By default, the kubernetes plugin uses the jenkins/inbound-agent public image.
In CloudBees CI:
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Prior to version 2.204.1.3, the Kubernetes plugin default is used across all controllers.
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Since version 2.204.1.3, the default image is set to cloudbees/cloudbees-core-agent by default across all controllers.
However, enterprises might need to:
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Use a Private Docker Registry
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Use a different default JNLP image
In CloudBees Core - Modern cloud platforms, there are different approaches for changing the default jnlp container image for an instance:
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(Recommended) Specify the default image via a system property
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Define a default parent template (also known as "Default Provider Template") to the Kubernetes Cloud(s)
Resolution
System Property Approach
The default jnlp container image can be set by adding the system property org.csanchez.jenkins.plugins.kubernetes.pipeline.PodTemplateStepExecution.defaultImage=<fullImageNameAndTag> on startup. In fact, since version 2.204.1.3 CloudBees CI adds the system property org.csanchez.jenkins.plugins.kubernetes.pipeline.PodTemplateStepExecution.defaultImage=cloudbees/cloudbees-core-agent:<version> as a controller Global Java Options to enforce cloudbees/cloudbees-core-agent:<version> as the default jnlp container image to all controllers. And also provides a solution to change it.
With Helm
The default agent jnlp image can be set via the .Agents.Image.dockerImage attribute:
Agents: Image: # Change the following with full image name and tag such as `my.registry.com/cloudbees/cloudbees-core-agent:2.163.1.2` dockerImage: "<fullImageNameAndTag>"
Upon Operations Center restart, redeploy existing Managed controllers to apply the change.
With Helm prior to 2.204.1.3
For versions prior to 2.204.1.3, add -Dorg.csanchez.jenkins.plugins.kubernetes.pipeline.PodTemplateStepExecution.defaultImage=<fullImageNameAndTag> to the value of .controller.JavaOpts. Upon Operations Center restart, redeploy existing Managed controllers to apply the change.
With .yaml modifications
Add -Dorg.csanchez.jenkins.plugins.kubernetes.pipeline.PodTemplateStepExecution.defaultImage=<fullImageNameAndTag> to the MASTER_GLOBAL_JAVA_OPTIONS environment variable. Upon Operations Center restart, redeploy existing Managed controllers to apply the change.
Default Provider Template Approach
In a Kubernetes Cloud, there is an option called Defaults Provider Template Name, which provides a way of using this template as a parent to all other pod templates for that cloud. This can be used to customize the default jnlp container (not only the image). Here is an example:
When defining a Defaults Provider Template Name in the kubernetes shared cloud in Operations Center, most templates defined in the Managed controllers inherits this parent template.
There are considerations to this approach:
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the
Defaults Provider Template Namein the kubernetes shared cloud applies to all pod templates defined under or inside pipelines for the cloud named "kubernetes". It does not apply to templates defined in a local controller Kubernetes cloud - i.e. a Kubernetes Cloud that is configured in the Managed controller global configuration. Each cloud has its own "Default Provider Template". -
this approach relies on Pod Template inheritance that must be understood. Especially around how YAML merge works
Due to those considerations, this is NOT the preferred approach. It may be a viable option in cases where a controller has different Kubernetes Clouds configured, and those clouds need different defaults for the jnlp container.
Further Notes
To disable the enforcement of the default jnlp container image in CloudBees CI Modern, the .Agents.Image.dockerImage attribute may be left empty. With this configuration, the kubernetes plugin defaults will be used:
Agents: Image: dockerImage:
Upon Operations Center restart, redeploy existing Managed controllers to apply the change.