Content-cache-docs - Tutorial

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Deploy content-cache

The content-cache charm makes deploying and managing a static web content cache with nginx easy with the help of Juju charm.

What you’ll do

  • Deploy the Content Cache charm.
  • Deploy the Content Cache Backends Config charm.
  • Integrate the two charms.

Requirements

  • A workstation, e.g. a laptop, with amd64 architecture.
  • Juju 3 installed and bootstrapped to a LXD controller. You can accomplish this process by using a Multipass VM as outlined in this guide: Set up / Tear down your test environment

Steps

  • Pack the Content Cache charm. Run the following command at the root of the git repository. The version of the charm is an unreleased rewrite of the charm. In the future, it will be available on charmhub.
charmcraft pack
  • Deploy the Content Cache charm.
juju deploy ./content-cache_amd64.charm cache
  • Deploy the Content Cache Backends Config charm, and configure the application.
juju deploy content-cache-backends-config --channel=latest/edge --revision=5 backends
juju config backends backends=185.125.90.20 hostname=ubuntu.com protocol=https

The backends takes a comma-separated list of IP addresses, and protocol can be set to http or https. The above configuration ask the nginx to cache the content from https://185.125.90.20. The configuration can be changed to point to a different server. The Juju machine hosting the Content Cache charm needs to be able to access the server, for the charm to work. Whether the Juju machine is able to access to server can be tested by juju ssh into the Juju machine and use curl to test access.

  • Integrate the two charms, and wait until the charms are in active state.
juju integrate cache backends
juju status --watch 5s
  • Test the Content Cache with cURL.
curl http://<IP of the juju machine> -H "Host: ubuntu.com"

Right now https://185.125.90.20 is responding with the following content:

<!DOCTYPE html>
<html>
    <head>
        <meta charset="UTF-8" />
        <meta http-equiv="refresh" content="0;url=https://ubuntu.com/login" />

        <title>Redirecting to https://ubuntu.com/login</title>
    </head>
    <body>
        Redirecting to <a href="https://ubuntu.com/login">https://ubuntu.com/login</a>.
    </body>
</html>%

Cleanup

  • Remove the charms.
juju remove-application cache backends