I created this environment so that I could have a self contained environment to use, from development through production, and not have to worry about conflicts between different versions of software on my host and/or production environment.
The environment uses .dev/Dockerfile along with .dev/docker-compose.yml
files to create an environment that lets you use Docker to generate a Docker
container and run the container on the host OS. Once the container is up and
running you can use mix as you normally would to generate a project inside the
container. The project is created in the app/ directory in the container and
written to the coresponding volume located in the src/ directory on the host.
Having the src/ directory in the root of the poject makes it easy to make
changes. You simply edit the files and use mix commands as normal. Because the
container port 4000 is mapped to the host port 4000 you can also view the
project on the host browser at localhost:4000. In short, once the container is
built your workflow is the same as if you were working in a project built and
running on the host with the execpetion of starting the server, which uses the
docker-compose up command and deployment, which is done with an interactive
terminal in the Docker container. But, I'll get to those details in a bit.
After pulling down the environment by either forking or cloning it into a
folder on your local computer there are a few steps you need to take to get it
ready for use. First, you should remove the src/ directory which contains a
very simple example application. After that you should change the git remote
to point to the git repository for the poject you're creating. Next you need to
run $ source .dev/.env in the host terminal file order to create the alias'
for running the commands that execute the functionality of the environment.
Sorcing the .dev/.env file makes it so any mix commands you run in the
development terminal will be executed against the Elixir code running in the
container. This step needs to be done for all terminals you are using for
development. Finally, you need to build the docker image that will create
your container. Here are the commands to do that.
$ rm -rf src/
$ git remote set-url origin [email protected]:USERNAME/REPOSITORY.git
$ source .dev/.env
$ build
Now, in order to develope your application the work flow is nearly identical to
working on an app generated on your localhost. You use mix commands in the same
way you normally would with the execption of starting the server. Additionally,
you will need to change the owner of the src/ dirctory from root:root to
user:user where user is your username. Finally, you need to make two changes
in the src/config/dev.ex: change the database host name from localhost to db and change your ip from http: [ip: {127, 0, 0, 1}, port: 4000] to http: [ip: {0, 0, 0, 0}, port: 4000]. Lets do that now.
$ mix phx.new . --app <application_name> [ options ]
$ sudo chown -R user:user src/
$ mix ecto.create
To run your sever you need to run docker-compose up against the container.
Similarly to stop the server you docker-compose down. One thing that can be a
little bit surprising is if you decide to remove the pgdata/ directory
for any reason you need to stop the container first because otherwise the
container running the db service will simply recreate it. If you don't intend to
use the db service you can simply comment it out in the
.dev/docker-compose.yml So, to stop and start the containers used by this
project simply run the following commands.
Start the Container
$ up
Stop the Container
$ down
As is normally the case, you can run the Phoenix server in either the normal mode or in an interactive terminal. First you need to bring the container up as described above. Once that is done open a second terminal and source .dev/.env again. Now start the interactive terminal with the it alias which will change the command prompt to look something like root@7b4690bb39fd:/app#. Finally you need start the server with eiter mix phx.server or iex -S mix phx.server Here are the commands in the order that they should be run in.
$ up
$ it run in second terminal after $ . .dev/.env
root@7b4690bb39fd:/app# mix phx.server pr
root@7b4690bb39fd:/app# iex -S mix.iex
Deploy to fly.io
The container that creates this environment includes the fly.io CLI. The
deployment process for fly.io is about as simple as it gets and there docs are
quite thorough so I will not receate them here. That said, you do need to run
the fly CLI command in an interactive terminal inside the container. Again, this is done with $ it. Once you're in the container terminal you will use the fly CLI commands. Fly.io uses fly launch to initialially build and deploy the app and fly deploy to push updates to the running application. But, before you can use those commands you have to login using the fly auth login command. Here are the commands to login, launch and push updates to your project on fly.
root@ad578a95b7db:/app# fly auth login
root@ad578a95b7db:/app# fly launch
You will be presented with a message similar to
failed opening browser. Copy the url (https://fly.io/app/auth/cli/4490b6fe0c93e612af90738423bc7985) into a browser and continue
Opening https://fly.io/app/auth/cli/4490b6fe0c93e612af90738423bc7985 ...
Waiting for session...
Copy the link into your host browser address bar. Once you get the interactive terminal prompt root@ad578a95b7db:/app# back your project has been deployed. Typing the comand open will again return an error like this. Again copy the link to your host browser and you will be taken to your production application.
Error failed opening http://summer-dream-8993.fly.dev: exec: "xdg-open": executable file not found in $PATH
Finally use the fly deploy command in the interactive terminal to push updates.
root@ad578a95b7db:/app# fly launch