Lab 1.2 Run a Container on Docker

See also

This is only a very basic introduction to docker. For everything else see Docker Documentation

1. Continuing from where we left off on the jumpbox go back to the kube-master1 session.

2. Now that docker is up and running and confirmed to be working lets deploy the latest Apache web server.

   Note

   The docker run command will first look for a local cache of the container httpd, and upon comparing that copy to the latest instance, decide to either download an update or use the local copy. Since there is no local copy, docker will download the container httpd to your local cache. This can take a few seconds (or longer), depending on container size and your bandwidth. Docker will chunk this into parts called a pull.

   --rm “tells docker to remove the container after stopping”

   --name “give the container a memorable name”

   -d “tells docker to run detached. Without this the container would run in foreground and stop upon exit”

   -it “this allows for interactive process, like shell, used together in order to allocate a tty for the container process”

   -P “tells docker to auto assign any required ephemeral port and map it to the container”

   docker run --rm --name "myapache" -d -it -P httpd:latest
   

3. If everything is working properly you should see your container running.

   Note

   -f “lets us filter on key:pair”

   docker ps -f name=myapache
   

   

   Note

   The “PORTS” section shows the container mapping. In this case the nodes local IP and port 32768 are mapped to the container. We can use this info to connect to the container in the next step.

4. The httpd container “myapache, is running on kube-master1 (10.1.10.21) and port 32768. To test, connect to the webserver via chrome.

   http://ip:port
   

   

Attention

That’s it, you installed docker, downloaded a container, ran the Hello World container, ran a web server container, and accessed your web server container via the browser.