fabric8:apply

The maven fabric8:apply goal takes the JSON file generated via mvn fabric8:json located at target/classes/kubernetes.json and applies it to the current Kubernetes environment and namespace.

For a summary of the options see the Maven Property Reference

Prerequisites

Note that before trying to apply your Kubernetes JSON you need to make sure your docker image is available to Kubernetes. See the mvn docker:build and mvn docker:push goals.

Also if you are using a local docker registry, make sure it is network accessible to your Kubernetes cluster.

Creating Routes

You can use the maven property fabric8.domain or the environment variable $KUBERNETES_DOMAIN to define the DNS host to expose services automatically using OpenShift Routes

Default Configuration

The Kubernetes environment and authentication is defined by the kubernetes-api environment variables. In particular:

• KUBERNETES_MASTER - the location of the kubernetes master
• KUBERNETES_NAMESPACE - the default namespace used on operations

Defaults from OpenShift

If no configuration is supplied through maven properties or environment variables, the fabric8:apply goal will try to find the current login token and namespace by parsing the users ~/.kube/config file.

This means that if you use the OpenShift command line tool oc you can login and change projects (namespaces in kubernetes speak) and those will be used by default by the fabric8:apply goal. e.g.

oc login
oc project cheese
mvn fabric8:apply

In the above, if there is no KUBERNETES_NAMESPACE environment variable or maven property called fabric8.namespace then the fabric8:apply goal will apply the Kubernetes resources to the cheese namespace.

Example

To apply the kubernetes resources generated by the mvn fabric8:json goal use the following goal:

mvn fabric8:apply

To specify an explicit namespace and domain in recreate mode:

mvn fabric8:apply -Dfabric8.recreate=true \
-Dfabric8.domain=foo.acme.com -Dfabric8.namespace=cheese   

Specifying environments and namespaces

You can use the fabric8.namespace system property to explicitly specify the kubernetes namespace to apply things to...

mvn fabric8:rolling -Dfabric8.namespace=cheese

Or you can use the fabric8.environment system property to refer to a named environment such as Testing, Staging or Production which is then mapped to the physical namespace by using the fabric8.yml file.

mvn fabric8:rolling -Dfabric8.environment=Staging

This lets you keep a level of indirection between the logical environment names for a project and the physical namespaces in kubernetes which probably have team or user prefixes/postfixes. This lets you share the same Jenkinsfiles (Jenkins workflow groovy scripts) across different projects.

e.g. you can have a standard command to apply to the Staging environment and this can be applied to any project which has a fabric8.yml file generated.

Templates

Applying an OpenShift template works the same as a regular List of Kubernetes resources.

One difference is that you may wish to override some of the template parameter values as you apply the template which you can do on the command line via system properties.

mvn fabric8:apply -Dfabric8.apply.FOO=bar

The above will apply the OpenShift template defined in target/classes/kubernetes.json overriding the template parameter FOO with the value bar before processing the template and creating/updating the resources.

Maven Properties

The following maven property values are used to configure the behaviour of the apply goal:

You define the maven properties in the pom.xml file using the <properties> tag such as:

    <properties>
      <fabric8.label.container>java</fabric8.label.container>
      <fabric8.label.group>myapp</fabric8.label.group>
      <fabric8.iconRef>camel</fabric8.iconRef>
    </properties>

If you wish to override or add a property from the command line, you can do this by using Java JVM system properties. A property from the command line will override any existing option configured in the pom.xml file.

mvn fabric8:apply -Dfabric8.recreate=true

There are many options as listed in the following table: