509 lines
18 KiB
Markdown
509 lines
18 KiB
Markdown
---
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stage: Enablement
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group: Distribution
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info: To determine the technical writer assigned to the Stage/Group associated with this page, see https://about.gitlab.com/handbook/engineering/ux/technical-writing/#assignments
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type: howto
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---
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# How to install GitLab on OpenShift Origin 3
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WARNING:
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This article is deprecated. Use the official Kubernetes Helm charts for
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installing GitLab to OpenShift. Check out the
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[official installation docs](https://docs.gitlab.com/charts/installation/cloud/openshift.html)
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for details.
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## Introduction
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[OpenShift Origin](https://www.okd.io/) (**Note:** renamed to OKD in Aug 2018) is an open source container application
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platform created by [RedHat](https://www.redhat.com/en), based on [Kubernetes](https://kubernetes.io/) and [Docker](https://www.docker.com). That means
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you can host your own PaaS for free and almost with no hassle.
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In this tutorial, we will see how to deploy GitLab in OpenShift using the GitLab
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official Docker image while getting familiar with the web interface and CLI
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tools that will help us achieve our goal.
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For a video demonstration on installing GitLab on OpenShift, check the article [In 13 minutes from Kubernetes to a complete application development tool](https://about.gitlab.com/blog/2016/11/14/idea-to-production/).
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## Prerequisites
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WARNING:
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This information is no longer up to date, as the current versions
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have changed and products have been renamed.
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OpenShift 3 is not yet deployed on RedHat's offered [Online platform](https://www.openshift.com/),
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so in order to test it, we will use an [all-in-one VirtualBox image](https://www.okd.io/minishift/) that is
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offered by the OpenShift developers and managed by Vagrant. If you haven't done
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already, go ahead and install the following components as they are essential to
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test OpenShift easily:
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- [VirtualBox](https://www.virtualbox.org/wiki/Downloads)
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- [Vagrant](https://www.vagrantup.com/downloads.html)
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- [OpenShift Client](https://docs.okd.io/3.11/cli_reference/get_started_cli.html) (`oc` for short)
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It is also important to mention that for the purposes of this tutorial, the
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latest Origin release is used:
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- **oc** `v1.3.0` (must be [installed](https://github.com/openshift/origin/releases/tag/v1.3.0) locally on your computer)
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- **OpenShift** `v1.3.0` (is pre-installed in the [VM image](https://app.vagrantup.com/openshift/boxes/origin-all-in-one))
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- **Kubernetes** `v1.3.0` (is pre-installed in the [VM image](https://app.vagrantup.com/openshift/boxes/origin-all-in-one))
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NOTE:
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If you intend to deploy GitLab on a production OpenShift cluster, there are some
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limitations to bare in mind. Read on the [limitations](#current-limitations)
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section for more information and follow the linked links for the relevant
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discussions.
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Now that you have all batteries, let's see how easy it is to test OpenShift
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on your computer.
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## Getting familiar with OpenShift Origin
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The environment we are about to use is based on CentOS 7 which comes with all
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the tools needed pre-installed: Docker, Kubernetes, OpenShift, etcd.
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### Test OpenShift using Vagrant
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As of this writing, the all-in-one VM is at version 1.3, and that's
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what we will use in this tutorial.
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In short:
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1. Open a terminal and in a new directory run:
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```shell
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vagrant init openshift/origin-all-in-one
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```
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1. This will generate a Vagrantfile based on the all-in-one VM image
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1. In the same directory where you generated the Vagrantfile
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enter:
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```shell
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vagrant up
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```
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This will download the VirtualBox image and fire up the VM with some preconfigured
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values as you can see in the Vagrantfile. As you may have noticed, you need
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plenty of RAM (5GB in our example), so make sure you have enough.
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Now that OpenShift is set up, let's see how the web console looks like.
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### Explore the OpenShift web console
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Once Vagrant finishes its thing with the VM, you will be presented with a
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message which has some important information. One of them is the IP address
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of the deployed OpenShift platform and in particular `https://10.2.2.2:8443/console/`.
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Open this link with your browser and accept the self-signed certificate in
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order to proceed.
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Let's login as admin with username/password `admin/admin`. This is what the
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landing page looks like:
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![openshift web console](img/web-console.png)
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You can see that a number of [projects](https://docs.okd.io/3.11/dev_guide/projects.html) are already created for testing purposes.
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If you head over the `openshift-infra` project, a number of services with their
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respective pods are there to explore.
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![openshift web console](img/openshift-infra-project.png)
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We are not going to explore the whole interface, but if you want to learn about
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the key concepts of OpenShift, read the [core concepts reference](https://docs.okd.io/3.11/architecture/core_concepts/index.html)
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in the official documentation.
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### Explore the OpenShift CLI
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OpenShift Client (`oc`), is a powerful CLI tool that talks to the OpenShift API
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and performs pretty much everything you can do from the web UI and much more.
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Assuming you have [installed](https://docs.okd.io/3.11/cli_reference/get_started_cli.html) it, let's explore some of its main
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functionalities.
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Let's first see the version of `oc`:
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```shell
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$ oc version
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oc v1.3.0
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kubernetes v1.3.0+52492b4
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```
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With `oc help` you can see the top level arguments you can run with `oc` and
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interact with your cluster, Kubernetes, run applications, create projects and
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much more.
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Let's login to the all-in-one VM and see how to achieve the same results like
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when we visited the web console earlier. The username/password for the
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administrator user is `admin/admin`. There is also a test user with username/
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password `user/user`, with limited access. Let's login as admin for the moment:
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```shell
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$ oc login https://10.2.2.2:8443
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Authentication required for https://10.2.2.2:8443 (openshift)
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Username: admin
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Password:
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Login successful.
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You have access to the following projects and can switch between them with 'oc project <projectname>':
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- cockpit
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- default (current)
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- delete
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- openshift
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- openshift-infra
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- sample
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Using project "default".
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```
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Switch to the `openshift-infra` project with:
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```shell
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oc project openshift-infra
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```
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And finally, see its status:
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```shell
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oc status
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```
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The last command should spit a bunch of information about the statuses of the
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pods and the services, which if you look closely is what we encountered in the
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second image when we explored the web console.
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You can always read more about `oc` in the [OpenShift CLI documentation](https://docs.okd.io/3.11/cli_reference/get_started_cli.html).
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### Troubleshooting the all-in-one VM
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Using the all-in-one VM gives you the ability to test OpenShift whenever you
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want. That means you get to play with it, shutdown the VM, and pick up where
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you left off.
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Occasionally, you may encounter issues, like OpenShift not running when booting
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up the VM. The web UI may not respond, or you may see issues when trying to sign
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in with `oc`, like:
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```plaintext
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The connection to the server 10.2.2.2:8443 was refused - did you specify the right host or port?
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```
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In that case, the OpenShift service might not be running, so in order to fix it:
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1. SSH into the VM by going to the directory where the Vagrantfile is and then
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run:
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```shell
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vagrant ssh
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```
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1. Run `systemctl` and verify by the output that the `openshift` service is not
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running (it will be in red color). If that's the case start the service with:
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```shell
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sudo systemctl start openshift
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```
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1. Verify the service is up with:
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```shell
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systemctl status openshift -l
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```
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You can now sign in by using `oc` (like we did before) and visit the web console.
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## Deploy GitLab
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Now that you got a taste of what OpenShift looks like, let's deploy GitLab!
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### Create a new project
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First, we will create a new project to host our application. You can do this
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either by running the CLI client:
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```shell
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oc new-project gitlab
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```
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or by using the web interface:
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![Create a new project from the UI](img/create-project-ui.png)
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If you used the command line, `oc` automatically uses the new project and you
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can see its status with:
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```shell
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$ oc status
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In project gitlab on server https://10.2.2.2:8443
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You have no services, deployment configs, or build configs.
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Run 'oc new-app' to create an application.
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```
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If you visit the web console, you can now see `gitlab` listed in the projects list.
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The next step is to import the OpenShift template for GitLab.
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### Import the template
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The [template](https://docs.okd.io/3.11/architecture/core_concepts/templates.html) is basically a JSON file which describes a set of
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related object definitions to be created together, as well as a set of
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parameters for those objects.
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The template for GitLab resides in the Omnibus GitLab repository under the
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Docker directory. Let's download it locally with `wget`:
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```shell
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wget https://gitlab.com/gitlab-org/omnibus-gitlab/raw/master/docker/openshift-template.json
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```
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And then let's import it in OpenShift:
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```shell
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oc create -f openshift-template.json -n openshift
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```
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NOTE:
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The `-n openshift` namespace flag is a trick to make the template available to all
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projects. If you recall from when we created the `gitlab` project, `oc` switched
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to it automatically, and that can be verified by the `oc status` command. If
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you omit the namespace flag, the application will be available only to the
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current project, in our case `gitlab`. The `openshift` namespace is a global
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one that the administrators should use if they want the application to be
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available to all users.
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We are now ready to finally deploy GitLab!
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### Create a new application
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The next step is to use the template we previously imported. Head over to the
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`gitlab` project and hit the **Add to Project** button.
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![Add to project](img/add-to-project.png)
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This will bring you to the catalog where you can find all the pre-defined
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applications ready to deploy with the click of a button. Search for `gitlab`
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and you will see the previously imported template:
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![Add GitLab to project](img/add-gitlab-to-project.png)
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Select it, and in the following screen you will be presented with the predefined
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values used with the GitLab template:
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![GitLab settings](img/gitlab-settings.png)
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Notice at the top that there are three resources to be created with this
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template:
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- `gitlab-ce`
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- `gitlab-ce-redis`
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- `gitlab-ce-postgresql`
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While PostgreSQL and Redis are bundled in Omnibus GitLab, the template is using
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separate images as you can see from [this line](https://gitlab.com/gitlab-org/omnibus-gitlab/blob/658c065c8d022ce858dd63eaeeadb0b2ddc8deea/docker/openshift-template.json#L239) in the template.
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The predefined values have been calculated for the purposes of testing out
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GitLab in the all-in-one VM. You don't need to change anything here, hit
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**Create** to start the deployment.
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If you are deploying to production you will want to change the **GitLab instance
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hostname** and use greater values for the volume sizes. If you don't provide a
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password for PostgreSQL, it will be created automatically.
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NOTE:
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The `gitlab.apps.10.2.2.2.nip.io` hostname that is used by default will
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resolve to the host with IP `10.2.2.2` which is the IP our VM uses. It is a
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trick to have distinct FQDNs pointing to services that are on our local network.
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Read more on how this works in <https://nip.io>.
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Now that we configured this, let's see how to manage and scale GitLab.
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## Manage and scale GitLab
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Setting up GitLab for the first time might take a while depending on your
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internet connection and the resources you have attached to the all-in-one VM.
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The GitLab Docker image is quite big (approximately 500 MB), so you'll have to
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wait until it's downloaded and configured before you use it.
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### Watch while GitLab gets deployed
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Navigate to the `gitlab` project at **Overview**. You can notice that the
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deployment is in progress by the orange color. The Docker images are being
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downloaded and soon they will be up and running.
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![GitLab overview](img/gitlab-overview.png)
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Switch to the **Browse > Pods** and you will eventually see all 3 pods in a
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running status. Remember the 3 resources that were to be created when we first
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created the GitLab app? This is where you can see them in action.
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![Running pods](img/running-pods.png)
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You can see GitLab being reconfigured by taking look at the logs in realtime.
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Click on `gitlab-ce-2-j7ioe` (your ID will be different) and go to the **Logs**
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tab.
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![GitLab logs](img/gitlab-logs.png)
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At a point you should see a `gitlab Reconfigured!` message in the logs.
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Navigate back to the **Overview** and hopefully all pods will be up and running.
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![GitLab running](img/gitlab-running.png)
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Congratulations! You can now navigate to your new shinny GitLab instance by
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visiting `http://gitlab.apps.10.2.2.2.nip.io` where you will be asked to
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change the root user password. Login using `root` as username and providing the
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password you just set, and start using GitLab!
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### Scale GitLab with the push of a button
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If you reach to a point where your GitLab instance could benefit from a boost
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of resources, you'd be happy to know that you can scale up with the push of a
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button.
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In the **Overview** page just click the up arrow button in the pod where
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GitLab is. The change is instant and you can see the number of [replicas](https://docs.okd.io/3.11/architecture/core_concepts/deployments.html#replication-controllers) now
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running scaled to 2.
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![GitLab scale](img/gitlab-scale.png)
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Upping the GitLab pods is actually like adding new application servers to your
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cluster. You can see how that would work if you didn't use GitLab with
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OpenShift by following the [HA documentation](../../administration/reference_architectures/index.md) for the application servers.
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Bare in mind that you may need more resources (CPU, RAM, disk space) when you
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scale up. If a pod is in pending state for too long, you can navigate to
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**Browse > Events** and see the reason and message of the state.
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![No resources](img/no-resources.png)
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### Scale GitLab using the `oc` CLI
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Using `oc` is super easy to scale up the replicas of a pod. You may want to
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skim through the [basic CLI operations](https://docs.okd.io/3.11/cli_reference/basic_cli_operations.html) to get a taste how the CLI
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commands are used. Pay extra attention to the object types as we will use some
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of them and their abbreviated versions below.
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In order to scale up, we need to find out the name of the replication controller.
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Let's see how to do that using the following steps.
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1. Make sure you are in the `gitlab` project:
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```shell
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oc project gitlab
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```
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1. See what services are used for this project:
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```shell
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oc get svc
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```
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The output will be similar to:
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```plaintext
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NAME CLUSTER-IP EXTERNAL-IP PORT(S) AGE
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gitlab-ce 172.30.243.177 <none> 22/TCP,80/TCP 5d
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gitlab-ce-postgresql 172.30.116.75 <none> 5432/TCP 5d
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gitlab-ce-redis 172.30.105.88 <none> 6379/TCP 5d
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```
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1. We need to see the replication controllers of the `gitlab-ce` service.
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Get a detailed view of the current ones:
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```shell
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oc describe rc gitlab-ce
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```
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This will return a large detailed list of the current replication controllers.
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Search for the name of the GitLab controller, usually `gitlab-ce-1` or if
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that failed at some point and you spawned another one, it will be named
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`gitlab-ce-2`.
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1. Scale GitLab using the previous information:
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```shell
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oc scale --replicas=2 replicationcontrollers gitlab-ce-2
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```
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1. Get the new replicas number to make sure scaling worked:
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```shell
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oc get rc gitlab-ce-2
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```
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which will return something like:
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```plaintext
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NAME DESIRED CURRENT AGE
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gitlab-ce-2 2 2 5d
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```
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And that's it! We successfully scaled the replicas to 2 using the CLI.
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As always, you can find the name of the controller using the web console. Just
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click on the service you are interested in and you will see the details in the
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right sidebar.
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![Replication controller name](img/rc-name.png)
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### Autoscaling GitLab
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In case you were wondering whether there is an option to autoscale a pod based
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on the resources of your server, the answer is yes, of course there is.
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We will not expand on this matter, but feel free to read the documentation on
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OpenShift's website about [autoscaling](https://docs.okd.io/3.11/dev_guide/pod_autoscaling.html).
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## Current limitations
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As stated in the [all-in-one VM](https://www.okd.io/minishift/) page:
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> By default, OpenShift will not allow a container to run as root or even a
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non-random container assigned userid. Most Docker images in Docker Hub do not
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follow this best practice and instead run as root.
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The all-in-one VM we are using has this security turned off so it will not
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bother us. In any case, it is something to keep in mind when deploying GitLab
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on a production cluster.
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In order to deploy GitLab on a production cluster, you will need to assign the
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GitLab service account to the `anyuid` [Security Context Constraints](https://docs.okd.io/3.11/admin_guide/manage_scc.html).
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For OpenShift v3.0, you will need to do this manually:
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1. Edit the Security Context:
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```shell
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oc edit scc anyuid
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```
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1. Add `system:serviceaccount:<project>:gitlab-ce-user` to the `users` section.
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If you changed the Application Name from the default the user will
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will be `<app-name>-user` instead of `gitlab-ce-user`
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1. Save and exit the editor
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For OpenShift v3.1 and above, you can do:
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```shell
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oc adm policy add-scc-to-user anyuid system:serviceaccount:gitlab:gitlab-ce-user
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```
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## Conclusion
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You should now have an understanding of the basic OpenShift Origin concepts, and
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a sense of how things work using the web console or the CLI.
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Upload a template, create a project, add an application, and you're done. You're
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ready to sign in to your new GitLab instance.
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Remember that this tutorial doesn't address all that Origin is capable of. As
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always, refer to the detailed [documentation](https://docs.okd.io) to learn more
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about deploying your own OpenShift PaaS and managing your applications with
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containers.
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