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.
