Implement log fetching

[smlx]

This feature allows users who can ssh into a pod to instead gather container logs from the pod to be returned via the SSH connection.

Features:

• Select service, and optionally container to retrieve logs from.
• Select number of log lines to return.
• Optionally stream logs live from the service (i.e. "follow").
• Select all pods in a service and seamlessly handle scaling up/down (pods being added/removed from service).
• Timestamp and pod/container prefix on all log lines, with format matching kubectl log.

How to use:

ssh $PROJECT-$ENVIRONMENT@$SSH_PORTAL_HOSTNAME service=$SERVICE [container=$CONTAINER] logs=tailLines=$LINES[,follow]

This feature is disabled by default. Enable it via the LOG_ACCESS_ENABLED=true environment variable, or by the --log-access-enabled CLI flag.

Closes: #149

[smlx]

Here's an experimental branch on lagoon-cli that adds a logs command. The branch is just a PoC because it doesn't handle follow correctly due to buffering output.

https://github.com/uselagoon/lagoon-cli/tree/logs

[smlx]

This outstanding PR is blocking other work, so I'm merging it now. The feature is disabled by default, and not yet part of any chart release.

[shreddedbacon]

This outstanding PR is blocking other work, so I'm merging it now. The feature is disabled by default, and not yet part of any chart release.

Sorry, haven't had time to review it properly with everything else going on at the moment. Quick 👀 seems fine though, disabled by default is 🆗