Elixir (for Phoenix w/ Postgres) Deployment on Gitpod using ASDF and Dockerfile

.gitpod.elixir_init.sh

#!/bin/bash

# These should be done in order and before mix deps.get and mix compile

# Verify postgres database credentials because if docker image starts `FROM gitpod/workspace-postgres`, 
# then it seems to use `gitpod` as the default owner on the postgres DB setup

# Check if the user exists
user_exists=$(psql -U gitpod -c "SELECT usename FROM pg_user WHERE usename='postgres';" -t)

if [[ -z "$user_exists" ]]; then
  echo "Creating postgres user to be compatible with default Elixir dev config..."
  
  # Create the user
  psql -U gitpod -c "CREATE USER postgres SUPERUSER;ALTER USER postgres PASSWORD 'postgres';"
  psql -U gitpod -c "ALTER DATABASE postgres OWNER TO postgres;"
  psql -U gitpod -c "GRANT ALL PRIVILEGES ON DATABASE postgres TO gitpod;"
  echo "'postgres' user created successfully and made owner of 'postgres' db!"
else
  echo "'postgres' user already exists."
fi;

# check if HEX v2.x.x installed via asdf, and if not install
# Run mix hex to see if exists, $MIX_HOME is set in .gitpod.ElixirDockerfile
echo "Checking Hex version in $MIX_HOME...";

if echo $(mix hex) | grep -q "Hex v2."; then
  echo "Hex package manager is already installed."
else
  echo "Hex package manager is not installed. Installing...";
  mix local.hex --force;

  if [ $? -eq 0 ]; then
    echo "Hex package manager installed successfully."
  else
    echo "Failed to install Hex package manager."
  fi;
fi;

# Determine is if Rebar3 was installed properly using asdf
mix_path=$(asdf which mix)
mix_directory=$(dirname "$mix_path")
mix_directory=${mix_directory%/bin}  # Remove '/bin' from the end of the path

#Parsing to dermine the path of asdf install dir
elixir_version=$(elixir --version | grep -oE "Elixir [0-9]+\.[0-9]+\.[0-9]+" | awk '{print $2}')
major_version=$(echo "$elixir_version" | cut -d "." -f 1)
minor_version=$(echo "$elixir_version" | cut -d "." -f 2)
internal_mix_path="$mix_directory/.mix/elixir/$major_version-$minor_version"

rebar_bin_path="$internal_mix_path/rebar3"
rebar_info=$($rebar_bin_path -v)

if echo "$rebar_info" | grep -q "rebar 3."; then
  echo "Rebar3 package manager is already installed."
else
  echo "Rebar3 package manager is not installed. Installing..."
  mix local.rebar --force

  if [ $? -eq 0 ]; then
    echo "Rebar3 package manager installed successfully."
  else
    echo "Failed to install Rebar3 package manager."
  fi
fi
# the .gitpod.yml uses --if-missing flags for mix local.hex & mix local.rebar and makes these install checks redundant however, 
# dynamically determining the Elixir version asdf path routes might be useful for other deployment scenarios like umbrellas

# This adds support for elixir-lsp.elixir-ls and victorbjorklund.phoenix extensions 
# (in theory, but in practice the extensions themselves are somewhat unreliable in vscode-remote IDE)
# so in short, this configuration and extension setup *needs work*

json_file="/workspace/.vscode-remote/data/Machine/settings.json"
# Read the JSON file and add the new key-value pair
updated_json=$(jq '. + { "emmet.includeLanguages": { "phoenix-heex": "html", "html-eex": "html" } }' "$json_file")
# Write the updated JSON back to the file
echo "$updated_json" > "$json_file"

.gitpod.ElixirDockerfile

FROM gitpod/workspace-postgres

ENV DEBIAN_FRONTEND noninteractive
ENV ASDF_BRANCH v0.12.0
ENV ERLANG_V 25.2
ENV ELIXIR_V 1.14.2-otp-25
ENV KERL_BUILD_DOCS yes

USER root
# install dependencies here
RUN apt-get clean && apt-get update && apt-get -y install --no-install-recommends \
    inotify-tools jq xsltproc libncurses-dev automake autoconf xsltproc fop \
    && rm -rf /var/lib/apt/lists/*

USER gitpod
SHELL ["/bin/bash", "-lc"]

RUN git config --global advice.detachedHead false
RUN git clone https://github.com/asdf-vm/asdf.git ~/.asdf --branch ${ASDF_BRANCH}

RUN sed -i '1s;^;source $HOME/.asdf/asdf.sh\nsource $HOME/.asdf/completions/asdf.bash\n;' ~/.bashrc

RUN asdf plugin add erlang https://github.com/asdf-vm/asdf-erlang.git && \
    asdf plugin-add elixir https://github.com/asdf-vm/asdf-elixir.git && \
    asdf install erlang ${ERLANG_V} && \
    asdf install elixir ${ELIXIR_V}
RUN asdf global erlang ${ERLANG_V} && \
    asdf global elixir ${ELIXIR_V}

ENV MIX_HOME "$HOME/.asdf/installs/elixir/${ELIXIR_V}/.mix"

.gitpod.yml

image:
  file: .gitpod.ElixirDockerfile

# List the start up tasks. Learn more https://www.gitpod.io/docs/config-start-tasks/
# --if-missing flag is only available for Elixir >= v1.13.0
tasks:
  - name: phx 
    before: mix local.hex --if-missing --force && mix local.rebar --force --if-missing
    init: bash .gitpod.elixir_init.sh && mix deps.get && mix compile
    command: mix ecto.create && mix ecto.migrate && iex -S mix phx.server

# List the ports to expose. Learn more https://www.gitpod.io/docs/config-ports/
ports:
  - port: 4000
    onOpen: open-preview
  - port: 5432
    onOpen: ignore

vscode:
  extensions:
    - bradlc.vscode-tailwindcss 
    - elixir-lsp.elixir-ls 
    - victorbjorklund.phoenix 
    - benvp.vscode-hex-pm-intellisense