ci(mix): add application mode check

This adds a CI check to ensure that applications and their modes are
in sync between Elixir and Rebar release builds.

.github/workflows/elixir_apps_check.yaml

@@ -0,0 +1,48 @@
+---
+
+name: Check Elixir Release Applications
+
+on: [pull_request]
+
+jobs:
+  elixir_apps_check:
+    runs-on: ubuntu-20.04
+    container: hexpm/elixir:1.13.1-erlang-24.2-alpine-3.15.0
+
+    strategy:
+      fail-fast: false
+      matrix:
+        release_type:
+          - cloud
+          - edge
+        package_type:
+          - bin
+          - pkg
+        edition_type:
+          - community
+          - enterprise
+        exclude:
+          - release_type: edge
+            package_type: bin
+            edition_type: enterprise
+          - release_type: edge
+            package_type: pkg
+            edition_type: enterprise
+
+    steps:
+      - name: install
+        run: apk add make bash curl git
+      - name: Checkout
+        uses: actions/checkout@v2.4.0
+        with:
+          fetch-depth: 0
+      - name: ensure rebar
+        run: ./scripts/ensure-rebar3.sh 3.16.1-emqx-1
+      - name: check applications
+        run: ./scripts/check-elixir-applications.exs
+        env:
+          EMQX_RELEASE_TYPE: ${{ matrix.release_type }}
+          EMQX_PACKAGE_TYPE: ${{ matrix.package_type }}
+          EMQX_EDITION_TYPE: ${{ matrix.edition_type }}
+
+...

mix.exs

@@ -106,7 +106,29 @@ defmodule EMQXUmbrella.MixProject do
           end
 
         [
-          applications: [
+          applications: applications(release_type),
+          skip_mode_validation_for: [
+            :emqx_gateway,
+            :emqx_dashboard,
+            :emqx_resource,
+            :emqx_connector,
+            :emqx_exhook,
+            :emqx_bridge,
+            :emqx_modules,
+            :emqx_management,
+            :emqx_statsd,
+            :emqx_retainer,
+            :emqx_prometheus,
+            :emqx_plugins
+          ],
+          steps: steps
+        ]
+      end
+    ]
+  end
+
+  def applications(release_type) do
+    [
       logger: :permanent,
       crypto: :permanent,
       public_key: :permanent,
@@ -126,6 +148,8 @@ defmodule EMQXUmbrella.MixProject do
       ekka: :load,
       emqx_plugin_libs: :load,
       esasl: :load,
+      observer_cli: :permanent,
+      system_monitor: :permanent,
       emqx_http_lib: :permanent,
       emqx_resource: :permanent,
       emqx_connector: :permanent,
@@ -139,32 +163,20 @@ defmodule EMQXUmbrella.MixProject do
       emqx_modules: :permanent,
       emqx_management: :permanent,
       emqx_dashboard: :permanent,
-            emqx_statsd: :permanent,
       emqx_retainer: :permanent,
+      emqx_statsd: :permanent,
       emqx_prometheus: :permanent,
       emqx_psk: :permanent,
       emqx_slow_subs: :permanent,
       emqx_plugins: :permanent,
       emqx_mix: :none
-          ],
+    ] ++
-          skip_mode_validation_for: [
+      if(enable_quicer?(), do: [quicer: :permanent], else: []) ++
-            :emqx_gateway,
+      if(enable_bcrypt?(), do: [bcrypt: :permanent], else: []) ++
-            :emqx_dashboard,
+      if(release_type == :cloud,
-            :emqx_resource,
+        do: [xmerl: :permanent, observer: :load],
-            :emqx_connector,
+        else: []
-            :emqx_exhook,
+      )
-            :emqx_bridge,
-            :emqx_modules,
-            :emqx_management,
-            :emqx_statsd,
-            :emqx_retainer,
-            :emqx_prometheus,
-            :emqx_plugins
-          ],
-          steps: steps
-        ]
-      end
-    ]
   end
 
   defp read_inputs() do

scripts/check-elixir-applications.exs

@@ -0,0 +1,282 @@
+#!/usr/bin/env elixir
+
+defmodule CheckElixirApplications do
+  @default_applications [:kernel, :stdlib, :sasl]
+
+  def main() do
+    {:ok, _} = Application.ensure_all_started(:mix)
+    inputs = read_inputs()
+    # produce `rebar.config.rendered` to consult
+    profile = profile_of(inputs)
+
+    File.cwd!()
+    |> Path.join("rebar3")
+    |> System.cmd(["as", to_string(profile)],
+      env: [{"DEBUG", "1"}]
+    )
+
+    File.cwd!()
+    |> Path.join("mix.exs")
+    |> Code.compile_file()
+
+    mix_apps = mix_applications(inputs.release_type)
+    rebar_apps = rebar_applications(profile)
+    results = diff_apps(mix_apps, rebar_apps)
+
+    report_discrepancy(
+      results[:missing_apps],
+      "* There are missing applications in the Elixir release",
+      fn %{app: app, mode: mode, after: last_app} ->
+        IO.puts("  * #{app}: #{inspect(mode)} should be placed after #{inspect(last_app)}")
+      end
+    )
+
+    report_discrepancy(
+      results[:different_modes],
+      "* There are applications with different application modes in the Elixir release",
+      fn %{app: app, rebar_mode: rebar_mode, mix_mode: mix_mode} ->
+        IO.puts(
+          "  * #{inspect(app)} should have mode #{inspect(rebar_mode)}, but it has mode #{inspect(mix_mode)}"
+        )
+      end
+    )
+
+    report_discrepancy(
+      results[:different_positions],
+      "* There are applications in the Elixir release in the wrong order",
+      fn %{app: app, mode: mode, after: last_app} ->
+        IO.puts("  * #{app}: #{inspect(mode)} should be placed after #{inspect(last_app)}")
+      end
+    )
+
+    success? =
+      results
+      |> Map.take([:missing_apps, :different_modes, :different_positions])
+      |> Map.values()
+      |> Enum.concat()
+      |> Enum.empty?()
+
+    if not success? do
+      System.halt(1)
+    else
+      IO.puts(
+        IO.ANSI.green() <>
+          "Mix and Rebar applications OK!" <>
+          IO.ANSI.reset()
+      )
+    end
+  end
+
+  defp mix_applications(release_type) do
+    EMQXUmbrella.MixProject.applications(release_type)
+  end
+
+  defp rebar_applications(profile) do
+    {:ok, props} =
+      File.cwd!()
+      |> Path.join("rebar.config.rendered")
+      |> :file.consult()
+
+    props[:profiles][profile][:relx]
+    |> Enum.find(&(elem(&1, 0) == :release))
+    |> elem(2)
+    |> Enum.map(fn
+      app when is_atom(app) ->
+        {app, :permanent}
+
+      {app, mode} ->
+        {app, mode}
+    end)
+    |> Enum.reject(fn {app, _mode} ->
+      # Elixir already includes those implicitly
+      app in @default_applications
+    end)
+  end
+
+  defp profile_of(%{
+         release_type: release_type,
+         package_type: package_type,
+         edition_type: edition_type
+       }) do
+    case {release_type, package_type, edition_type} do
+      {:cloud, :bin, :community} ->
+        :emqx
+
+      {:cloud, :pkg, :community} ->
+        :"emqx-pkg"
+
+      {:cloud, :bin, :enterprise} ->
+        :"emqx-enterprise"
+
+      {:cloud, :pkg, :enterprise} ->
+        :"emqx-enterprise-pkg"
+
+      {:edge, :bin, :community} ->
+        :"emqx-edge"
+
+      {:edge, :pkg, :community} ->
+        :"emqx-edge-pkg"
+    end
+  end
+
+  defp read_inputs() do
+    release_type =
+      read_enum_env_var(
+        "EMQX_RELEASE_TYPE",
+        [:cloud, :edge],
+        :cloud
+      )
+
+    package_type =
+      read_enum_env_var(
+        "EMQX_PACKAGE_TYPE",
+        [:bin, :pkg],
+        :bin
+      )
+
+    edition_type =
+      read_enum_env_var(
+        "EMQX_EDITION_TYPE",
+        [:community, :enterprise],
+        :community
+      )
+
+    %{
+      release_type: release_type,
+      package_type: package_type,
+      edition_type: edition_type
+    }
+  end
+
+  defp read_enum_env_var(env_var, allowed_values, default_value) do
+    case System.fetch_env(env_var) do
+      :error ->
+        default_value
+
+      {:ok, raw_value} ->
+        value =
+          raw_value
+          |> String.downcase()
+          |> String.to_atom()
+
+        if value not in allowed_values do
+          Mix.raise("""
+          Invalid value #{raw_value} for variable #{env_var}.
+          Allowed values are: #{inspect(allowed_values)}
+          """)
+        end
+
+        value
+    end
+  end
+
+  defp diff_apps(mix_apps, rebar_apps) do
+    app_names = Keyword.keys(rebar_apps)
+    mix_apps = Keyword.filter(mix_apps, fn {app, _mode} -> app in app_names end)
+
+    acc = %{
+      mix_apps: mix_apps,
+      missing_apps: [],
+      different_positions: [],
+      different_modes: [],
+      last_app: nil
+    }
+
+    Enum.reduce(
+      rebar_apps,
+      acc,
+      fn
+        {rebar_app, rebar_mode}, acc = %{mix_apps: [], last_app: last_app} ->
+          missing_app = %{
+            app: rebar_app,
+            mode: rebar_mode,
+            after: last_app
+          }
+
+          acc
+          |> Map.update!(:missing_apps, &[missing_app | &1])
+          |> Map.put(:last_app, rebar_app)
+
+        {rebar_app, rebar_mode},
+        acc = %{mix_apps: [{mix_app, mix_mode} | rest], last_app: last_app} ->
+          case {rebar_app, rebar_mode} do
+            {^mix_app, ^mix_mode} ->
+              acc
+              |> Map.put(:mix_apps, rest)
+              |> Map.put(:last_app, rebar_app)
+
+            {^mix_app, _mode} ->
+              different_mode = %{
+                app: rebar_app,
+                rebar_mode: rebar_mode,
+                mix_mode: mix_mode
+              }
+
+              acc
+              |> Map.put(:mix_apps, rest)
+              |> Map.update!(:different_modes, &[different_mode | &1])
+              |> Map.put(:last_app, rebar_app)
+
+            {_app, _mode} ->
+              case Keyword.pop(rest, rebar_app) do
+                {nil, _} ->
+                  missing_app = %{
+                    app: rebar_app,
+                    mode: rebar_mode,
+                    after: last_app
+                  }
+
+                  acc
+                  |> Map.update!(:missing_apps, &[missing_app | &1])
+                  |> Map.put(:last_app, rebar_app)
+
+                {^rebar_mode, rest} ->
+                  different_position = %{
+                    app: rebar_app,
+                    mode: rebar_mode,
+                    after: last_app
+                  }
+
+                  acc
+                  |> Map.update!(:different_positions, &[different_position | &1])
+                  |> Map.put(:last_app, rebar_app)
+                  |> Map.put(:mix_apps, [{mix_app, mix_mode} | rest])
+
+                {mode, rest} ->
+                  different_mode = %{
+                    app: rebar_app,
+                    rebar_mode: rebar_mode,
+                    mix_mode: mode
+                  }
+
+                  different_position = %{
+                    app: rebar_app,
+                    mode: rebar_mode,
+                    after: last_app
+                  }
+
+                  acc
+                  |> Map.put(:mix_apps, [{mix_app, mix_mode} | rest])
+                  |> Map.update!(:different_modes, &[different_mode | &1])
+                  |> Map.update!(:different_positions, &[different_position | &1])
+                  |> Map.put(:last_app, rebar_app)
+              end
+          end
+      end
+    )
+  end
+
+  defp report_discrepancy(diffs, header, line_fn) do
+    unless Enum.empty?(diffs) do
+      IO.puts(IO.ANSI.red() <> header)
+
+      diffs
+      |> Enum.reverse()
+      |> Enum.each(line_fn)
+
+      IO.puts(IO.ANSI.reset())
+    end
+  end
+end
+
+CheckElixirApplications.main()