Set up SSL for Rancher Server

One issue you will probably run across if you start to use Rancher to manage your Docker containers is that it doesn’t serve pages over an encrypted connection by default.  If you are looking to put Rancher in to a production scenario, it is a good idea to serve encrypted pages.  HA is another topic, but at this point I have not attempted to set it up yet because it is a much more complicated process currently.  The Rancher folks are working on making HA easier in the near future (if you know an easy way to do it I would love to hear about it).  I would argue though that if you can set up SSL for your Rancher server you are over half way to a full production set up.

The process of getting Rancher to proxy through an encrypted connection is straight forward, assuming you already have some certs to use.  If you don’t already have any official certificates issued *I think* you should be okay with self signed certs, but you won’t get that green lock that everybody loves.  Definitely if you are just testing this set up you should be fine to start out with some self signed certs.  Here is a reference for creating some certs for Nginx to test with.

Another important thing to be aware of is that these instructions are specific to the Nginx method outline above.  I have not tried the Apache method, though I would guess it should be very easy to adapt.

Take a look at the Rancher docs as a starting point for getting started, they are very good and will get you most of the way there.  However, when I went through this process there were a few pieces of information that I had to piece together myself, which is the bulk of what I will be sharing today.

The first step is to adapt the configuration in the docs in to a full Nginx config that can be dropped in to the official Nginx image from Dockerhub.  Here is the config I used.

upstream rancher {
    server rancher-server:8080;

server {
    listen 443 ssl;
    ssl_certificate /etc/rancher/;
    ssl_certificate_key /etc/rancher/;

    access_log /var/log/nginx/access.log;
    error_log  /var/log/nginx/error.log;

    location / {
        proxy_set_header Host $host;
        proxy_set_header X-Forwarded-Proto $scheme;
        proxy_set_header X-Forwarded-Port $server_port;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_pass http://rancher;
        proxy_http_version 1.1;
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection "upgrade";
        # This allows the ability for the execute shell window to remain open for up to 15 minutes. Without this parameter, the default is 1 minute and will automatically close.
        proxy_read_timeout 900s;

server {
    listen 80;
    return 301 https://$server_name$request_uri;

There are a few important things to note about this config.   One is naming the upstream the same name as what the rancher server container is named, in this case rancher-server.

Note that I have used as the server name and so the certs and names are all reflective of that value.  Obviously that will need to be updated with your own values.

Finally, we have added an additional logging section to the config that will pipe the logs to stdout/stderr so we can easily look at the requests from the host OS via the “docker logs” command.

To get the following Docker run command to work correctly you will want to create a directory called /etc/rancher or something easy to remember, and place this config (named as rancher-nginx.conf), along with the certs you have created in to this location.  Alternately you can modify the Docker run command and simply have the volume mounts pointed at the location you store the configuration and certs.  For me, it makes the most sense to group these items together in /etc/rancher.

docker run -d --restart=always --name nginx 
    -v /etc/rancher/rancher-nginx.conf:/etc/nginx/conf.d/default.conf
    -v /etc/rancher/
    -v /etc/rancher/
    -p 80:80 -p 443:443 --link=rancher-server nginx

This will mount in the correct configuration and certificates to the Nginx docker container, expose port 80 and 443 for web traffic (make sure to adjust any firewall rules you need to get traffic to pass through these ports), and link to the rancher-server container so that the traffic can be proxied.

Additionally, you will need to update any reference to the old address that was using http://<rancher-name>:8080/ to point to https://<rancher-name>/.  Namely the host registration configuration in the Rancher server, but if you were relying on any other outside tools to hit that endpoint they will also need to be updated to use https instead.

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Josh Reichardt

Josh is the creator of this blog, a system administrator and a contributor to other technology communities such as /r/sysadmin and Ops School. You can also find him on Twitter and Facebook.