Provide pre and post reboot hooks for Traefik, that can be used to
remove/add to an external load balancer to prevent requests from being
sent during the reboot.
Works best with the --rolling setting, where each hook is called once
per host.
If the app container is down or not responding then traefik will return
a 404 response code. This is not ideal as it suggests a client rather
than a server problem.
To fix this, we'll define a catch all route that always returns a 502.
This is not ideal as this route would take priority over a shorter route
with priorty 1.
TODO: up the priority of the app route.
The env check is not needded anymore as all the commands rely on the
env files having already been created remotely.
The only place the env is needed is when running `kamal env push` and
that will still raise an apropriate error.
When calling `kamal app exec` for new non interactive containers, run
the command per role on each server and include the role config
including the environment.
Fixes: https://github.com/basecamp/kamal/issues/492
Adding -T to the copy command ensures that the files are copied at the
same level into the target directory whether it exists or not.
That allows us to drop the `/*` which was not picking up hidden files.
Fixes: https://github.com/basecamp/kamal/issues/465
Kamal needs images to have the service label so it can track them for
pruning. Images built by Kamal will have the label, but externally built
ones may not.
Without it images will build up over time. The worst case is an outage
if all the hosts disks fill up at the same time.
We'll add a check for the label and halt if it is not there.
If you always want to use a destination, and have a base deploy.yml file
that doesn't specify any hosts, then if you forget to specific the
destination you will get a cryptic error.
Add a "require_destination" setting you can use to avoid this.
An interrupted deployment can leave older containers lying around. To
ensure they are cleaned up subsequently, stop stale containers during
deployments instead of just reporting them.
