[mproxy](https://github.com/kevinmcconnell/mproxy) is a custom minimal
proxy designed specifically for Kamal.
It has two big advantages over Traefik:
1. Imperative deployments - we tell it to switch from container A to
container B, and it waits for container B to start then switches. No
need to poll for health checks ourselves or mess around with forcing
health checks to fail.
2. Support for multiple apps - as much as possible, configuration is
supplied at runtime by the deploy command, allowing us to have
multiple apps share an instance of mproxy without conflicting config.
This will allow us to filter for containers that have no destination in
cases where we deploy an empty + a non empty destination to the same
host.
To note:
```
\# Containers with a destination label
$ docker ps --filter label=destination
\# Containers with an empty destination label
$ docker ps --filter label=destination=
```
If no context is specified and we are in a git repo, then we'll build
from a git archive by default. This means we don't need a separate
setting and gives us a safer default build.
Building directly from a checkout will pull in uncommitted files to or
more sneakily files that are git ignored, but not docker ignored.
To avoid this, we'll add an option to build from a git archive of HEAD
instead. Docker doesn't provide a way to build directly from a git
repo, so instead we create a tarball of the current HEAD with git
archive and pipe it into the build command.
When building from a git archive, we'll still display the warning about
uncommitted changes, but we won't add the `_uncommitted_...` suffix to
the container name as they won't be included in the build.
Perhaps this should be the default, but we'll leave that decision for
now.
Secret and clear env variables have different lifecycles. The clear ones
are part of the repo, so it makes sense to always deploy them with the
rest of the repo.
The secret ones are external so we can't be sure that they are up to
date, therefore they require an explicit push via `envify` or `env push`.
We'll keep the env file, but now it just contains secrets. The clear
values are passed directly to `docker run`.
Add an app with roles to the integration tests. We'll deploy two web
containers and one worker. The worker just sleeps, so we are testing
that the container has booted.
If curl is not available to download the docker install script, try
with wget instead.
If neither is available or both fail, return a simple failing script
so that we don't carry on regardless.
Fixes: https://github.com/basecamp/kamal/issues/395
By default we keep 5 containers around for rollback. The containers
don't take much space, but the images for them can.
Make the number of containers to retain configurable, either in the
config with the `retain_containers` setting on the command line
with the `--retain` option.
1. Add Ruby 2.7 specific Gemfile that uses an older version of nokogiri
2. Rails edge doesn't support Ruby 2.7.0, so exclude it.
3. Add Ruby 3.3
4. Update Gemfile.lock to test against Rails 7.1.2 as it's the latest
version.
5. Remove continue-on-error from the matrix and always set to true
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.
Calling `load_envs` again does not load updated env variables, because
Dotenv does not overwrite existing values.
To fix this we'll store the original ENV and reset to it before
reloading.
https://github.com/basecamp/kamal/issues/512
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
Donal McBreen