Allow applications to be deployed without needing to set up a repository
in a remote Docker registry.
If the registry server starts with `localhost`, Kamal will start a local
docker registry on that port and push the app image to it.
Then when pulling the image onto the servers, we use net-ssh to forward
the that port from the app server to the deployment server.
This will allow the deployment server to pull the image from the
registry as if it were local, meaning we don't need to set up a cert.
1. Update to kamal-proxy 0.4.0 which creates and chowns
/home/kamal-proxy/.config/kamal-proxy to kamal-proxy
2. Use a docker volume rather than mapping in a directory, so docker
keeps it owned by the correct user
By default only the primary role runs the proxy. To disable the proxy
for that role, you can set `proxy: false` under it.
For other roles they default to not running the proxy, but you can
enable it by setting `proxy: true` for the role, or alternatively
setting a proxy configuration.
The proxy configuration will be merged into the root proxy configuration.
Remove `stop_wait_time` and `readiness_timeout` from the root config
and remove `deploy_timeout` and `drain_timeout` from the proxy config.
Instead we'll just have `deploy_timeout` and `drain_timeout` in the
root config.
For roles that run the proxy, they are passed to the kamal-proxy deploy
command. Once that returns we can assume the container is ready to
shut down.
For other roles, we'll use the `deploy_timeout` when polling the
container to see if it is ready and the `drain_timeout` when stopping
the container.
Adds:
- `kamal upgrade` to upgrade all app hosts and accessory hosts
- `kamal proxy upgrade` to upgrade the proxy on all hosts
- `kamal accessory upgrade [name]` to upgrade accessories on all hosts
Upgrade takes rolling and confirmed options and calls `proxy upgrade`
and `accessory upgrade` in turn.
To just upgrade a single host add -h [host] to the command. But the
upgrade should run on all hosts, not just those running the proxy.
Calling upgrade on a host that has already been upgraded should work ok.
Upgrading hosts causes downtime but you can avoid if you run multiple
hosts by:
1. Implementing the pre-proxy-reboot and post-proxy-reboot hooks to
remove the host from external load balancers
2. Running the upgrade with the --rolling option
**kamal proxy upgrade**
1. Creates a `kamal` network if required
2. Stops and removes the old proxy (whether Traefik or kamal-proxy)
3. Starts a kamal-proxy container in the `kamal` network
4. Reboots the app containers in the `kamal` network
**kamal accessory upgrade [name]**
1. Creates a `kamal` network if required
2. Reboots the accessory containers in the `kamal` network
A matching `downgrade` command will be added to Kamal 1.9.
