chore: configuration for publishing library to Hex.pm (#9)

.github/actions/erlang-publish.yml

@@ -0,0 +1,110 @@
+on:
+  workflow_call:
+    inputs:
+      otp-version:
+        type: string
+        description: >
+          OTP version to install on the runner.
+          See https://github.com/erlef/setup-beam/
+      rebar3-version:
+        type: string
+        default: ""
+        description: >
+          A rebar3 version to install on the runner.
+          See
+      version-file:
+        type: string
+        default: ""
+        description: >
+          A versions file (e.g. as used by `asdf`), which defines inputs
+          See https://github.com/erlef/setup-beam/
+      runs-on:
+        required: false
+        type: string
+        default: "k8s-medium"
+        description: "T-Shirt dimension of the runner ( k8s-small | k8s-medium | k8s-large )"
+      mix-env:
+        required: false
+        type: string
+        default: "dev"
+        description: "Elixir mix environment"
+      mix-working-directory:
+        required: false
+        type: string
+        default: .
+        description: "Elixir Mix project directory"
+    secrets:
+      GHA_SSH_DEPLOY_KEY:
+        description: "SSH deploy key with read permissions on private deps repos, passed from the caller workflow"
+        required: false
+      HEX_KEY:
+        description: "API Key for hex package publish on hex.pm"
+        required: false
+
+env:
+  MIX_ENV: ${{ inputs.mix-env }}
+  HEX_HOME: ./_build/.hex
+
+jobs:
+  secrets_check:
+    name: Secrets Check
+    runs-on: ${{ inputs.runs-on }}
+    outputs:
+      gha_ssh_deploy_key_available: ${{ steps.secrets_check.outputs.gha_ssh_deploy_key_available }}
+    steps:
+      - name: Check for Secret availability
+        id: secrets_check
+        # secrets are not available as if condition on GHA
+        # perform secret check & put boolean result as an output
+        shell: bash
+        run: |
+          if [ "${{ secrets.GHA_SSH_DEPLOY_KEY }}" != '' ]; then
+            echo "gha_ssh_deploy_key_available=true" >> $GITHUB_OUTPUT;
+          else
+            echo "gha_ssh_deploy_key_available=false" >> $GITHUB_OUTPUT;
+          fi
+
+  erlang_publish:
+    name: Erlang library publish to Hex
+    defaults:
+      run:
+        working-directory: ${{ inputs.mix-working-directory }}
+    runs-on: ${{ inputs.runs-on }}
+    permissions:
+      id-token: write
+      contents: read
+    steps:
+      - name: Checkout project source
+        uses: actions/checkout@v4
+      - name: Install Beam/OTP/Elixir
+        uses: erlef/setup-beam@v1
+        id: setup-erlang
+        with:
+          otp-version: ${{inputs.otp-version}}
+          rebar3-version: ${{inputs.rebar3-version}}
+          version-file: ${{inputs.version-file}}
+          version-type: ${{inputs.version-file && 'strict' || 'loose'}}
+      - name: Configure known_hosts for github.com
+        run: |
+          # $HOME directory is /home/runner but the user may not be runner
+          # if it's root /home should not be there
+          # since it's impossible to know if we are running in a container or not we configure known_hosts always
+          [ "$(id -u)" -eq 0 ] && SSH_HOME=/root/.ssh || SSH_HOME="/home/$(id -un)/.ssh"
+          mkdir "$SSH_HOME" || :
+          cat > "$SSH_HOME/known_hosts" << EOF || :
+          ${{ vars.KNOWN_HOSTS_GITHUB }}
+          EOF
+      - uses: webfactory/ssh-agent@dc588b651fe13675774614f8e6a936a468676387 # v0.9.0
+        if: ${{ needs.secrets_check.outputs.gha_ssh_deploy_key_available == 'true' }}
+        with:
+          ssh-private-key: ${{ secrets.GHA_SSH_DEPLOY_KEY }}
+      - name: Login to hex.pm
+        run: rebar3 hex organization auth prima --key ${{ secrets.HEX_KEY }}
+      - name: Install dependencies
+        run: rebar3 update; rebar3 deps
+      - name: Publish to Hex.pm
+        run: rebar3 hex publish -r hexpm:${{ inputs.hex-organization }}
+        env:
+          HEX_API_KEY: ${{ secrets.HEX_KEY }}
+    needs:
+      - secrets_check

.github/workflows/publish.yml

@@ -0,0 +1,14 @@
+name: Publish to Hex
+
+on:
+  release:
+    types: [published]
+
+jobs:
+  elixir-ci:
+    uses: ./.github/actions/erlang-publish.yml
+    with:
+      rebar3-version: 3.24.0
+      otp-version: 26.0
+    secrets:
+      HEX_KEY: ${{ secrets.HEX_KEY }}

rebar.config

@@ -1,4 +1,5 @@
 {deps, [{erlsom, "1.4.2"}]}.
+{plugins, [rebar3_hex]}.
 
 {erl_opts, [debug_info]}.