Conveniently deploy a bunch of Phoenix apps
The main goal of Gatling is to make it very easy, cheap, and convenient to deploy Phoenix apps.
Gatling is essentially a collection of mix tasks that (from a Git push) automatically create a Distillery release and launches/upgrades it on your server.
For more information see the detailed changelog.
As you read through the instructions, keep in mind that both Distillery and
Nginx have tons of options you can configure outside of Gatling. Gatling's goal
is to offer an out-of-the-box solution that keeps out of the way of your custom
deployment strategy. For example, Distillery requires a configuration file in
./rel/config.exs
of your project. There is a
lot you can do with this
but if you decide not to install this yourself, Gatling will generate a basic
one for you.
Please see the Distillery docs to unlock the full power of your releases. Gatling simply triggers them in a convenient way.
This has been tested on an Ubuntu 16.04 x64 server on Ec2 and Digital Ocean.
Install Elixir, Nginx, and the Gatling archive on your server:
$ ssh server.address
Follow instructions here to install Elixir.
$ sudo apt-get install nginx git
$ mix archive.install https://github.com/hashrocket/gatling_archives/raw/master/gatling.ez
If needed, install hex and rebar:
mix local.hex
mix local.rebar
For a brand new project, SSH into your server and run the following:
$ mix gatling.load {mix project name}
This only creates git repository on your server. Remember, when pushing to this
repository, it would be remote_server_username@address.to_server:<project name>
e.g. for a Digital Ocean box, you would push to
root@xx.xx.xx.xx:sample_project
Ensure your Elixir project can build a production release with Distillery.
Add a file to the root of your project named domains
and list all domains
that will point to this project. See an example
here.
In your config/prod.exs
, ensure your port
configuration uses an
environment variable called PORT
(Gatling will set this for you
automatically):
config :my_app, MyApp.Endpoint, [
http: [port: {:system, "PORT"}],
# root: ".", # add if using Phoenix
# server: true, # add if using Phoenix
# url: [host: "www.yourdomain.com"], # add if using Phoenix
]
config :phoenix, :serve_endpoints, true # uncomment if your using Phoenix
Setup your Git remote and push to your server:
$ git remote add production user_with_root_access@<address.to.server>:<project_name>
$ git push production master
SSH back into your server and ensure you have your secret.exs
file(s)
installed if needed.
Set your environment to prod
by adding the following to /etc/environment
:
$ MIX_ENV=prod
For the initial deploy, run $ sudo --preserve-env mix gatling.deploy {project_name}
and Gatling
will do the following:
distillery
release and put all the parts in the right placeinit.d
file so your app will boot if/when your server restartsOnce your app is running do the following:
git push path.to.remote:project
And that's it! You'll see the new version being deployed with no downtime!
In your project root, create a file called deploy.exs
. Define any of the
following functions to wrap the Gatling deployment actions:
defmodule SampleProject.DeployCallbacks do
import Gatling.Bash
def before_mix_deps_get(env)
def after_mix_deps_get(env)
def before_mix_compile(env)
def after_mix_compile(env)
def before_mix_digest(env)
def after_mix_digest(env)
def before_mix_release_init(env)
def after_mix_release_init(env)
def before_mix_release(env)
def after_mix_release(env)
def before_make_deploy_dir(env)
def after_make_deploy_dir(env)
def before_copy_release_to_deploy(env)
def after_copy_release_to_deploy(env)
def before_expand_release(env)
def after_expand_release(env)
def before_install_init_script(env)
def after_install_init_script(env)
def before_mix_ecto_setup(env)
def after_mix_ecto_setup(env)
def before_start_service(env)
def after_start_service(env)
def before_configure_nginx(env)
def after_configure_nginx(env)
end
Note: the env
is passed to every function. It is a READ only struct you
can use. Returning env
from a callback function will have no effect on the
rest of the deployment process. Here is an example of the
env
that is passed in.
In your project root, create a file called upgrade.exs
. Define any of the
following functions to to wrap the Gatling upgrade actions:
defmodule SampleProject.UpgradeCallbacks do
import Gatling.Bash
def before_mix_deps_get(env)
def after_mix_deps_get(env)
def before_mix_compile(env)
def after_mix_compile(env)
def before_mix_digest(env)
def after_mix_digest(env)
def before_mix_release_init(env)
def after_mix_release_init(env)
def before_mix_release(env)
def after_mix_release(env)
def before_make_upgrade_dir(env)
def after_make_upgrade_dir(env)
def before_copy_release_to_upgrade(env)
def after_copy_release_to_upgrade(env)
def before_upgrade_service(env)
def after_upgrade_service(env)
end
Note: the env
is passed to every function. It is a READ only struct you
can use. Returning env
from a callback function will have no effect on the
rest of the upgrade process.
Here is an example of the env
that is passed in.
While implementing your callback functions. If you are going to use
System.cmd/3
, you can instead add import Gatling.Bash
to the top of your
module and use bash/3
to get a more transparent output.
Say I want to install wget before my dependencies are installed in the deploy
task.
Also I want to avoid complaints about the priv/static
directory not existing.
I would create a file in my project called ./deploy.exs
with the following:
defmodule SampleProject.DeployCallbacks do
import Gatling.Bash
def before_mix_deps_get(_env) do
bash("sudo", ~w[apt-get install wget])
end
def before_mix_digest(env) do
# optional: release may complain about this directory not existing
bash("mkdir", ~w[-p priv/static], cd: env.build_dir)
# you might also want to add the asset compiling here.
# see the upgrade example below for details.
end
end
This wget install function will be called right before mix deps get
and the
mkdir
will happen before mix phoenix.digest
.
Say I want the server to run npm install
and recompile assets as well as
migrate on upgrade:
defmodule SampleProject.UpgradeCallbacks do
import Gatling.Bash
def before_mix_digest(env) do
bash("npm", ~w[install], cd: env.build_dir)
bash("npm", ~w[run deploy], cd: env.build_dir)
end
def before_upgrade_service(env) do
bash("mix", ~w[ecto.migrate], cd: env.build_dir)
end
end
$ git clone https://github.com/hashrocket/gatling.git
$ cd gatling
$ mix deps.get
# Clone the archives repo
$ git clone https://github.com/hashrocket/gatling_archives.git
To create a new release, take the following steps:
mix.exs
git add . && git commit -m 'Bump to v<version>'
$ MIX_ENV=prod mix do compile, build
$ cd gatling_archives
$ git add .
$ git commit -m "Release v<version>" && git tag v<version>
$ git push origin master && git push origin --tags
$ cd ../ && git tag v<version>
$ git push origin master && git push origin --tags
Gatling is supported by the team gatling_archives Hashrocket, a multidisciplinary design and development consultancy. If you'd like to work with us or join our team, don't hesitate to get in touch.