OpenShift "oc cluster up" Wrapper script

oc cluster as the internal tool.

What it provides

This script provides the following enhancements:

• cluster profiles

• cluster management lifecycle

• convenience methods for working with persistent volumes

• convenience methods for adding common software to your cluster (This will be rewritten to be a plugin like mechanism)

Cluster profiles

As a developer, you do not always want to work on the same project, with the same code. Sometimes you need to be able to switch between different clusters. For that, we provide a profile concept. How does this work? To learn how this works, see the following example:

oc-cluster up                 # Brings up a <default> cluster
oc-cluster down
oc-cluster up java-cluster    # Brings up a cluster named java-cluster
oc-cluster down
oc-cluster up workshop        # Brings up a cluster named workshop
oc-cluster down
oc-cluster up java-cluster    # Brings up the previous java-cluster with all the info from the previous running cluster with the same name
oc-cluster down

As you’ve realized the clusters by default are persistent. That means that you can create as many clusters (profiles) as you want, and bring them up and down at will. But what do I do once I’m finished with a cluster? For that there is a cluster management lifecycle.

Cluster management lifecycle

Again, we’ll use some examples to ilustrate:

$ oc-cluster up example
oc cluster up --public-hostname 127.0.0.1 --host-data-dir /Users/jmorales/.oc/profiles/example/data
              --host-config-dir /Users/jmorales/.oc/profiles/example/config
              --use-existing-config
-- Checking OpenShift client ... OK
-- Checking Docker client ... OK
-- Checking Docker version ... OK
-- Checking for existing OpenShift container ... OK
-- Checking for openshift/origin:v1.3.0 image ... OK
-- Checking Docker daemon configuration ... OK
-- Checking for available ports ... OK
-- Checking type of volume mount ...
   Using Docker shared volumes for OpenShift volumes
-- Creating host directories ... OK
-- Finding server IP ...
   Using public hostname IP 127.0.0.1 as the host IP
   Using 127.0.0.1 as the server IP
-- Starting OpenShift container ...
   Creating initial OpenShift configuration
   Starting OpenShift using container 'origin'
   Waiting for API server to start listening
   OpenShift server started
-- Installing registry ... OK
-- Installing router ... OK
-- Importing image streams ... OK
-- Importing templates ... OK
-- Login to server ... OK
-- Creating initial project "myproject" ... OK
-- Server Information ...
   OpenShift server started.
   The server is accessible via web console at:
       https://127.0.0.1:8443

   You are logged in as:
       User:     developer
       Password: developer

   To login as administrator:
       oc login -u system:admin

Any user is sudoer. They can execute commands with '--as=system:admin'

Now, let’s work with the cluster:

$ oc new-project example
$ oc new-app wildfly~https://github.com/OpenShiftDemos/os-sample-java-web.git

I’m gone for a while, I need to know if my cluster is running:

$ oc-cluster status
oc cluster running. Current profile <example>

I need to get some information on my clusters:

$ oc-cluster list
Profiles:
- example
- roadshow
- test

$ oc-cluster console
https://127.0.0.1:8443/console

I need to log in to the origin container, to check something:

$ oc-cluster ssh
Going into the Origin Container
[root@moby origin]# pwd
/var/lib/origin

I’m done, let’s get rid of this cluster:

$ oc-cluster destroy
Are you sure you want to destroy cluster with profile <example> (y/n)? y
Removing profile example
Bringing the cluster down

Removing /Users/jmorales/.oc/profiles/example

How this works?

For the profiles to work, by default a subdirectory will be created in $HOME/.oc/profiles with the profile name. A file called $HOME/.oc/active_profile will hold also the name of the active profile, if there is a cluster up. Removing the cluster will remove the subdirectory holding all the profile data.

We’re using --host-data-config and --host-data-dir to retain the configuration of the cluster, as we understand this is basic for daily use of the tool. And we use --keep-config to retain this information.

We’re also binding the cluster to 127.0.0.1 as this is the way to make the cluster secure, and reproducible, as the ip address changes when you move from network to network. Also, anyone can log into your running cluster if you had a cluster up, since it’s using AnyPasswd identity provider.

We also do two really convenient things for developers:

• We create an admin/admin user that will be a cluster-admin, so you can login as admin from the web console

• We add the sudoer role to system:authenticated so that any user can impersonate cluster-admin without needing to change user profiles

Convenience methods for working with persistent volumes

Most users will need to work with persistent services, so we have added two convenience methods for working with volumes. One for cluster-specific volumes, and another for shared volumes (similating NFS server behaviors).

• oc-cluster create-volume volumeName [size|10Gi] [path|/Users/jmorales/.oc/profiles/<profile>/volumes/<volumeName>]

• oc-cluster create-shared-volume project/volumeName [size|10Gi] [path|/Users/jmorales/.oc/volumes/<volumeName>]

oc-cluster create-volume

This command will create a volume in the cluster’s profile. That means that if the cluster is removed, the volume and the data stored in the volume will be removed as well. This will create a PV of type hostPath, with the specified size (or 10Gi by default), on the specified path (or the default for the profile) and a Retain policy for the data.

oc-cluster create-shared-volume

This command will create a volume in a shared location. That means that every cluster will have access to the data, and the data will not be removed if the cluster is removed. For the applications to be able to use this data, the created PV will be prebound to a specific project/namespace, with the same name for the volume as for the claim. This will create a PV of type hostPath, with the specified size (or 10Gi by default), on the specified path (or the default for the profile). With this second mechanism, we can, as an example, share the storage for our nexus deployment between all our clusters, and use nexus for java dependency management in a very convenient way.

Conenience methods for adding common software to your cluster (This will be rewritten to be a plugin like mechanism in the future)

Right now, as this tool is created to boost my productivity (and one of my colleagues), we have some additional methods (that we will convert into plugins) to deploy commons stuff that we use in most of our clusters. In this way, we have a method to deploy nexus in a project called ci, and soon we will have one for gitlab, workshops, etc…​

$ oc-cluster deploy-nexus
Created project ci
persistentvolume "nexus-data" created
Volume created in /Users/jmorales/.oc/volumes/nexus-data
service "nexus" created
route "nexus" created
deploymentconfig "nexus" created
persistentvolumeclaim "nexus-data" created
Project ci has been created and shared with you. It has a nexus instance that has shared storage with other clusters

Bind to a reproducible IP

In systems like linux or mac, you can create a link-local interface, with a static ip, that you can reuse in any place you go. There’s a system environment variable that you can define to use this ip to bind the cluster to. Otherwise it will default to 127.0.0.1

Example:

export OC_CLUSTER_BIND_IP=11.2.2.2

Prerequisites

If you can run oc cluster up you can run this tool. This works anywhere that oc cluster up runs, so any limitation really will be more a oc cluster limitation than this tool’s.

Note	This tool assumes you run oc cluster with Docker native and not docker-machine.

ROADMAP

Find here a list of things we would like to include in the tool. These will be tracked via issues to allow for feature discussion (https://github.com/openshift-evangelists/oc-cluster-wrapper/labels/enhancement):

• RFE #26 Allow for login user and keep a KUBECONFIG in the profile. This is a feature that will allow to have multiple profiles using same clsuter ip, that will probably have different certificates, and different users. With a new "oc-cluster login" you’ll be able to login with current certificates created on first boot.

• RFE #9 Allow to execute upstream images (--image=registry.access.redhat.com/openshift3/ose)

• RFE #22 Use upstream command "status". openshift/origin#11171

• RFE #21 Allow for profile snapshot/restore. This way you can create a cluster, provision it, use it, screw it, and restore to a safe point. There will be potential image conflicts, but will be assumable.

• RFE #23 Ability to enable technology-preview features (like pipelines)

• RFE #20 Make additional commands via "plugins". Additional scripts in the same dir as cluster-up will provide additional provisioning capabilities. Installing nexus, gitlab, imagestreams, tech-preview,…​

• RFE #19 Allow to use htpasswd identity provider and create users

• RFE #17 Provide basic bash completion

• RFE #25 Add support for TimeZone

• RFE #24 Add support for proxies

Any idea you might have, share it with us.

Contributing

Pull Request, and issues to make the tool are welcome. Please help us make this tool better by contributing your use cases. Once we have the plugin mechanism, this will be easier to do. Also, we would love all of these use cases to be in official oc cluster tool but until that happens, we will keep using and maintaining this tool.

This work is done by the OpenShift Evangelist team