Next steps: From NGINX WordPress and MySQL running on Docker, to Kubernetes

This website running this blog has been running in Docker containers on a small-ish 4GB VPS for the past 9 months pretty much issue free. You can follow by journey to migrate this site to Docker in posts here and here.

Since I’ve been spending time recently getting up to speed with Kubernetes, the next logic step would be to deploy to a Kubernetes cluster, which would give me an opportunity to find out what it takes to run Kubernetes. I’ve looked at managed offerings on Google and AWS, but the cost for a few small personal projects is a little more than I want to spend.

I have a 8GB VPS ready to go, so far installed with Docker and Kubernetes running as a single node cluster, and I’m starting to plan my strategy for migrating to this new server. The first thing I’ve been thinking about is whether I should take my existing Docker images and just deploy to Kubernetes as is. Where I’ve got stuck so far is I don’t know enough about how to run NGINX with WordPress and MySQL in multiple pods, so I think I might install the WordPress Chart using Helm and for the time being not worry about how to do this myself.

The next thing I’ve been looking at is how to configure an Ingress to access different deployed services via different urls. I’ve been looking at setting up Traefik as the Ingress Controller to do this, and will be sharing a post about that config shortly. What I’m interested in is being able to deploy a number of different projects, including my WordPress site, and have them accessed via different urls, and it looks like Traefik will handle this fine.

I plan on writing some further posts as I make this transition over the next couple of weeks.

Running GitLab in a Docker container on a different port

Gitlab by default runs on port 80. GitLab in a Docker container runs the same as a when natively installed, but to change the port you need to change the config, and change the exposed ports on the container.

First, per steps here, start the container with:

docker run --detach \	
--hostname gitlab.example.com \
--publish host-https-port:container-https-port
--publish host-http-port:container-http-port
--publish 22:22 \
--name gitlab \
--restart always \
--volume /srv/gitlab/config:/etc/gitlab \
--volume /srv/gitlab/logs:/var/log/gitlab \
--volume /srv/gitlab/data:/var/opt/gitlab \
gitlab/gitlab-ce:latest

By default host-http-port and container-http-port are 80, and host-https-port container-https-port are 443. Change these to be whatever port you want to run on, but keep each pair the same (e.g. host-http-port and container-http-port = 8090)

When the container is up, start a shell into the running container:

docker exec -it containerid sh

and then edit the config file:

vi /etc/gitlab/gitlab.rb

and add line (at the top is ok):

external_url 'http://localhost:your-new-port-here

setting your-new-port-here to the new port.

Reconfigure the server:

gitlab-ctl reconfigure
gitlab-ctl restart

Done!

Updating rke created Kubernetes cluster from 1.11.3 to 1.11.5

There was a vulnerability found today in some older Kubernetes versions. There are already patched versions available. If you have 1.11.3 installed from rke, you can update to 1.11.5 by editing your cluster.yml, replacing the kubernetes image:

kubernetes: rancher/hyperkube:v1.11.3-rancher1

with

kubernetes: rancher/hyperkube:v1.11.5-rancher1

And then run ‘rke up’ again.

This is from this Github ticket.

Rancher RKE Kubernetes install notes

Rancher’s RKE is a Kubernetes cluster installer – see more here.

Pre-reqs:

  • Docker must be running on the client machine where you are going to run the rke setup tool
  • The docs are not obvious, but the rke tool is run on a client machine to provision your cluster, it is not run on any of the target cluster nodes 

Notes using Ubuntu 16.04 server.

Remove prior Docker installs:

sudo apt-get remove docker docker-engine docker.io

Create docker group and add user to docker group:

sudo groupadd docker
usermod -aG docker <user_name>

Install per Docker CE install steps here, or use the Rancher provider install script here

Supported Docker versions for RKE (as of Dec 2018) are: 1.11.x 1.12.x 1.13.x 17.03.x

Configure Docker daemon to listen for incoming requests on 2376, as per steps here.

Using ‘rke config’ with the default/minimal cluster.yml here, and then install/setup with ‘rke up’

If you didn’t change the name of the cluster.yml file, after the install is complete, you’ll have a kube_config_cluster.yml file in the same dir which you can use with kubectl to interact with you cluster, or add it into your existing ~/.kube/config file