Deployment Strategies with Akd

Once an elixir app is working, it's ready to be deployed, but deploying an elixir application takes a lot of setup and customization. This is where akd comes to the rescue. Akd integrates with elixir deployment packages (like distillery) and combines it with custom generators and DSLs which make elixir deployments painless. Akd is inspired by the ruby package capistrano, in the way that it provides a similar way of interacting with the deployment servers.

In this document, we will be talking about different ways to deploy an elixir application and how akd makes it easy to adopt either of those strategies.

Remote Distillery build + Deliver to production

This is the recommended way to deploy an elixir application. Distillery is a widely adopted elixir deployment tool. It produces a "distilled form of your raw application's components; a single package which can be deployed anywhere." , which is why Akd is built in support for distillery.

Pros

• Do not have to put your code on the production server.
• Deployments are reproducible.
• Less vulnerable to security attacks.
• Distillery takes advantage of erlang's script and appup files which utlize OTP's features of no-downtime upgrades and how to stratup an application.
• Distillery is widely used, so a good amount of support is available.

Cons

• Build server has access to your code.
• Build server should have access to all the dependencies. (For mix deps.get)
• Build server's state should be close (or identical) to production's state, which means if production gets a major upgrade, so should the build server.

Setps to setup this workflow

• Install asdf on a trusted build server which has similar configurations as the production server (same OS, similar packages etc)
• Use distillery to build the code on the build server.
• Copy the distillery release to the production server.

Using Akd with Distillery

• TODO

Local Distillery build w/ ERTS + Deliver to production

• TODO

Asdf on production

One of the deployment strategies is to deploy the app as a Mix project (with the source code) to the destination. This is the simplest way to deploying an elixir application without needing to configure or initialize another package.

Pros

• This is the simplest way to deploy an elixir application.
• Easy to setup.
• Easy to uprade elixir/OTP versions.

Cons

• Installing/Maintaining asdf or other elixir/erlang version manager on the production server.
• Production server and the final build has access to your code.
• Deployments are not reproducible.
• More Vulnerable to security attacks.
• Doesn't utilize OTP's abilities.

Steps to adopt this strategy

• Install asdf on your local environment and the production environment.
• Copy the code on the final destination and start a mix phx.server or a mix run --no-halt with MIX_ENV=prod.

How akd does it

• TODO