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.
Setting env variables in the docker arguments requires having them on
the deploy host.
Instead we'll add two new commands `kamal env push` and
`kamal env delete` which will manage copying the environment as .env
files to the remote host.
Docker will pick up the file with `--env-file <path-to-file>`. Env files
will be stored under `<kamal run directory>/env`.
Running `kamal env push` will create env files for each role and
accessory, and traefik if required.
`kamal envify` has been updated to also push the env files.
By avoiding using `kamal envify` and creating the local and remote
secrets manually, you can now avoid accessing secrets needed
for the docker runtime environment locally. You will still need build
secrets.
One thing to note - the Docker doesn't parse the environment variables
in the env file, one result of this is that you can't specify multi-line
values - see https://github.com/moby/moby/issues/12997.
We maybe need to look docker config or docker secrets longer term to get
around this.
Hattip to @kevinmcconnell - this was all his idea.
When stopping or starting Traefik, don't hide important errors.
Docker doesn't return an error when starting a started container or
stopping a stopped container.
When rebooting we want to know about errors during run as we've just
stopped and removed the previous container.
When booting, we want to leave the running container if it exists,
restart a stopped container and run a new one if none exists.
We can implement this with `docker start ... || docker run ...`:
- if the container is started, `docker start` will exit with 0
- if the container is stopped, `docker start` will start it and exit with 0
- if the container doesn't exist, `docker start` will return a non zero
exit code and `docker run` will create a new container. Any errors in
`docker run` will be returned.
Add tests for main, app, accessory, traefik and lock commands.
Other commands are generally covered by the main tests.
Also adds some changes to speed up the integration specs:
- Use a persistent volume for the registry so we can push images to to
reuse between runs (also gets around docker hub rate limits)
- Use persistent volume for mrsk gem install, to avoid re-installing
between tests
- Shorter stop wait time
- Shorter connection timeouts on the load balancer
Takes just over 2 minutes to run all tests locally on an M1 Mac
after docker caches are primed.
