Cache content with OpenStack/Swift storage

Sometimes it is desirable to cache swift storage objects inside the charm for faster processing and reducing the number of requests to the swift server. This also allows you to have a different hostname than the one from the Swift service.

This guide will demonstrate how to deploy this charm along with OpenStack/Swift storage.

First, connect to your openstack instance with your credentials, sourcing an .rc file:

source myfile.rc

if you don’t have any credentials check here for more information. The openstack container you are going to work with has to be globally readable. check that property:

swift stat <container_name>

And if it’s not globally readable yet, change that with:

swift post <container_name> --read-acl ".r:*"

Then list all the objects on the openstack container in debug mode and get the url of the swift connection:

openstack object list <container_name> -vv 2>&1 | grep "^REQ: curl" | grep AUTH | cut -d'"' -f2 | cut -d'?' -f1

After obtaining the URL, configure the charm to use that url as our charm’s backend. Assuming the charm has been deployed as content-cache-k8s, run:

juju config content-cache-k8s backend="http://<swift_conn_url>"

Once configured, you can use swift commands to push or download objects. More details about swift commands here

You can check everything is working by executing

curl <swift_conn_url>

And also add a relation to the nginx-ingress-integrator charm:

juju deploy nginx-ingress-integrator

If your cluster has RBAC enabled, you’ll be prompted to run the following:

juju trust nginx-ingress-integrator --scope cluster

The deployed application name will need to resolve to the IP of your ingress controller. A great way of testing this is to upload an index.html file into the openstack container and confirm that that content is reachable when they browse to this URL now.