fabric8:create-env

The maven fabric8:create-env goal queries all the Services in the current namespace along with looking at the JSON file generated via mvn fabric8:json (located at target/classes/kubernetes.json) and generates a list of environment variables that would be required to simulate running a process inside Kubernetes.

This makes it easy to run, say, Java programs in your IDE as if it was running inside a Kubernetes environment; discovering all the services available in the namespace and setting all the same environment variables that are defined inside your pods or replication controllers

For a summary of the options see the Maven Property Reference

Generated files

The goal generates the following files:

• target/docker-run.sh to start a docker container with specific environment variables, volumes and container ports (obtained from kubernetes.json)
• target/env.sh you can source in a shell to setup your environment together
• target/env.properties file you can process easily with Java code or ideally your IDE can accept in its UI for running applications or test cases

Accessing services

Note that your local machine may not be able to see services using the PortalIP address of the service (depending on how your networking is setup).

So the service environment variables like FOO_SERVICE_HOST will use the host names on any defined OpenShift Routes instead which allow access to services from outside of the Kubernetes cluster.

If you do not have OpenShift Routes setup for your services then you can either:

• apply them via fabric8:apply so that it creates the routes by specifying the maven property fabric8.domain or the environment variable $KUBERNETES_DOMAIN to specify to the DNS/host domain you wish to expose the services on.
• use fabric8:create-routes to generate any missing OpenShift Routes for the current services using the maven property fabric8.domain or the environment variable $KUBERNETES_DOMAIN to specify to the DNS/host domain you wish to expose the services on.

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:create-env 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:create-env goal. e.g.

oc login
oc project cheese
mvn fabric8:create-env

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

Example

To setup your shell as if its running inside a Kubernetes environment container:

mvn fabric8:create-env
source target/env.sh

To specify an explicit namespace:

mvn fabric8:create-env -Dfabric8.namespace=cheese

It is also possible to specify an environment variable value. Suppose you want to set the value of environment variable FOO:

mvn fabric8:create-env -Dfabric8.create-env.FOO=bar

Every time the fabric8:create-env goal will find the ${FOO} variable, it will expand it with value bar.

Maven Properties

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