Support Elixir language

[meysholdt]

Add support for https://elixir-lang.org/

source for request: here

[svenefftinge]

https://github.com/JakeBecker/elixir-ls

[jehrhardt]

Would love to use for my open source Elixir / Phoenix project: https://github.com/technology-ebay-de/werkstatt

If you need anyone for testing it, just ping me.

[svenefftinge]

You can subscribe to this #433
It will allow to install the elixir VS Code extension.

[lemol]

@svenefftinge , following #433 now I was able to install the elixir extension, but cannot figure out how to run elixir (nor mix) command.
Is it be possible to build elixir app on gitpod?

[lemol]

Following the docs in https://www.gitpod.io/docs/42_config_docker/ I figured out how to make install elixir on my workspace, I just add the installation step on the Dockerfile .gitpod.Dockerfile:

FROM gitpod/workspace-full

USER root

ENV DEBIAN_FRONTEND noninteractive

RUN wget https://packages.erlang-solutions.com/erlang-solutions_1.0_all.deb \
    && dpkg -i erlang-solutions_1.0_all.deb \
    && apt-get update \
    && apt-get install esl-erlang -y \
    && apt-get install elixir -y

[svenefftinge]

@lemol awesome! Thanks for looking into it. Do you have a public repository that can be used as an example?

[lemol]

Sure!
I also included the elixir vs extension and it works nicely: https://github.com/lemol/guess_elixir

[sntran]

For Phoenix, there are a few additions:

FROM gitpod/workspace-postgres

USER root

ENV DEBIAN_FRONTEND noninteractive

# Install Erlang, Elixir, Hex and Rebar
RUN wget https://packages.erlang-solutions.com/erlang-solutions_1.0_all.deb \
    && dpkg -i erlang-solutions_1.0_all.deb \
    && apt-get update \
    && apt-get install esl-erlang -y \
    && apt-get install elixir -y \
    && apt-get install inotify-tools -y \
    && mix local.hex --force \
    && mix local.rebar --force \
    && apt-get clean && rm -rf /var/cache/apt/* && rm -rf /var/lib/apt/lists/* && rm -rf /tmp/*

.gitpod.yml

image:
  file: .gitpod.Dockerfile

# List the ports you want to expose and what to do when they are served. See https://www.gitpod.io/docs/43_config_ports/
ports:
- port: 4000

# List the start up tasks. You can start them in parallel in multiple terminals. See https://www.gitpod.io/docs/44_config_start_tasks/
tasks:
# Install front-end assets
- init: cd apps/mkfifo/assets && npm install && node node_modules/webpack/bin/webpack.js --mode development
# Install dependencies
- init: psql --command "CREATE USER postgres WITH SUPERUSER PASSWORD 'postgres';" && mix deps.get && mix ecto.create
  command: iex -S mix phx.server

vscode:
  extensions:
    - JakeBecker.elixir-ls@0.2.25:X1tqg5Hmluq055QJpf0/7A==
    - mjmcloug.vscode-elixir@1.1.0:w8GjsJyyhVFmCZmBc2Ws7A==

There are still some confusions for me with .gitpod.yml, as I am trying to create the postgres user for Phoenix, and somehow one terminal does not see the postgres user being created. Would love to see some improvement.

[jankeromnes]

Hi @sntran, thanks a lot for sharing this configuration!

There are still some confusions for me with .gitpod.yml, as I am trying to create the postgres user for Phoenix, and somehow one terminal does not see the postgres user being created.

I can help you debug this.

Firstly, I tried to import your config into https://github.com/jankeromnes/test-phoenix, but I'm obviously missing some files, because I get error like cd: apps/mkfifo/assets: No such file or directory and please ensure you are running Mix in a directory with a mix.exs file. If your repository is public, could you please share its URL here?

But I can make a few guesses:

somehow one terminal does not see the postgres user being created

maybe this terminal checks for the postgres user too early? (Both init tasks will run in parallel, and thus race each other.)

If that's the case, the fix is to use synchronization, e.g. with gp sync-await and gp sync-done:

tasks:
  - init: gp sync-await pguser && # ... (user 'postgres' should exist here)
  - init: >
      psql --command "CREATE USER postgres WITH SUPERUSER PASSWORD 'postgres';" && \
      gp sync-done pguser # (notify we're done creating the user)

Another potential problem I see is that PostgreSQL data isn't persistant across workspace instances. Thus, if you stop a workspace and restart it, the postgres user you created may be gone. (This won't be a problem if your init task runs in your current workspace instance, but if you enable prebuilt workspaces, or if you restart a stopped workspace, or if you share a workspace snapshot, the init task will have completed in a previous instance, but since the PostgreSQL data isn't saved inside /workspace, the data will be lost.)

A way to prevent this is to have an initialization script that runs on every workspace start (e.g. in a command or in before task), and which checks whether the PostgreSQL data needs to be pre-filled or not.

[sntran]

Thanks for looking into this @jankeromnes . I have submitted a PR for the test repo with full Phoenix application for you to test.

What I'm trying to achieve is to have the postgres user always available after the workspace is created (from cloning). The gitpod/workspace-postgres Docker image sets up Postgres for gitpod user, but Phoenix defaults to postgres.

[jgchristopher]

I just started playing around with gitpod and Elixir/Phoenix.

I have an example repo working. https://github.com/jgchristopher/rumbl

[svenefftinge]

I just started playing around with gitpod and Elixir/Phoenix.

I have an example repo working. https://github.com/jgchristopher/rumbl

Awesome, just tried it and it seems to work nicely. You might want to add

ports:
  - port: 4000
    onOpen: open-preview

So the preview opens when the server is up.