Use dynamic app info plug

README.md

@@ -1,25 +1,25 @@
-[![Coverage Status](https://coveralls.io/repos/github/heyorbit/metadata_plugs/badge.svg?branch=master)](https://coveralls.io/github/heyorbit/metadata_plugs?branch=master)
+[![Coverage Status](https://coveralls.io/repos/github/qgadrian/metadata_plugs/badge.svg?branch=master)](https://coveralls.io/github/qgadrian/metadata_plugs?branch=master)
 [![Hex version](https://img.shields.io/hexpm/v/sippet.svg "Hex version")](https://hex.pm/packages/metadata_plugs)
 [![Hex Docs](https://img.shields.io/badge/hex-docs-9768d1.svg)](https://hexdocs.pm/metadata_plugs)
-[![Build Status](https://travis-ci.org/heyorbit/metadata_plugs.svg?branch=master)](https://travis-ci.org/heyorbit/metadata_plugs)
-[![Deps Status](https://beta.hexfaktor.org/badge/all/github/heyorbit/metadata_plugs.svg)](https://beta.hexfaktor.org/github/heyorbit/metadata_plugs)
+[![Build Status](https://travis-ci.org/qgadrian/metadata_plugs.svg?branch=master)](https://travis-ci.org/qgadrian/metadata_plugs)
+[![Deps Status](https://beta.hexfaktor.org/badge/all/github/qgadrian/metadata_plugs.svg)](https://beta.hexfaktor.org/github/qgadrian/metadata_plugs)
 
 # MetadataPlugs
 
 Collection of plugs to provide different metadata information.
 
-Plugs included:
+[Plugs included](#plugs):
 
-* Health
-* App version
+* [Health](#health)
+* [Info](#info)
 
 ## Installation
 
 Add to dependencies
 
 ```elixir
 def deps do
-  [{:metadata_plugs, "~> 0.1.0"}]
+  [{:metadata_plugs, "~> 0.2.0"}]
 end
 ```
 
@@ -29,19 +29,32 @@ Install dependencies
 mix deps.get
 ```
 
-## Usage
+## Plugs
 
-Add the desired plugs to the endpoint file
+### Health
+
+Just add the plug to the endpoint file
 
 ```elixir
 plug(MetadataPlugs.Health)
-plug(MetadataPlugs.Info)
 ```
 
-You can configure the path for the endpoints, for example
+You can configure the path for the endpoint
 
 ```elixir
-plug(MetadataPlugs.Health, health_path: "/healthz")
+plug(MetadataPlugs.Health, path: "/healthz")
 ```
 
-Check [documentation](https://hexdocs.pm/metadata_plugs) for more options
+### Info
+
+Add the plug to the endpoint file with the desired environment variables to get the info from.
+
+```elixir
+plug(MetadataPlugs.Info, env_vars: ["APP_VERSION", "ENVIRONMENT"])
+```
+
+You can configure the path for the endpoint
+
+```elixir
+plug(MetadataPlugs.Info, path: "/infoz")
+```

lib/info_plug.ex

@@ -0,0 +1,55 @@
+defmodule MetadataPlugs.Info do
+  @behaviour Plug
+  import Plug.Conn
+
+  @path "/info"
+
+  @typedoc """
+  - `:env_vars` -- String list of environment variables names to get the value from (default: []).
+  - `:path` -- (Optional) Info endpoint path (default: `/info`).
+  """
+
+  @type opts :: [
+          path: String.t(),
+          env_vars: list(String.t())
+        ]
+
+  @spec init(opts :: opts) :: map
+  def init(opts) do
+    default_opts = [
+      path: @path,
+      env_vars: []
+    ]
+
+    Keyword.merge(default_opts, opts)
+  end
+
+  @doc """
+  Resolves a health request
+  """
+  @spec call(Plug.Conn.t(), map) :: Plug.Conn.t()
+  def call(conn, opts) do
+    if conn.request_path == opts[:path] and conn.method == "GET" do
+      send_info(conn, opts[:env_vars])
+    else
+      conn
+    end
+  end
+
+  @spec send_info(Plug.Conn.t(), list(String.t())) :: Plug.Conn.t()
+  defp send_info(conn, env_vars) do
+    conn
+    |> put_resp_content_type("application/json")
+    |> send_resp(200, info_response(env_vars))
+  end
+
+  @spec info_response(list(String.t())) :: Map.t()
+  defp info_response(env_vars) do
+    env_vars
+    |> Enum.reduce(%{}, fn env_var, acc ->
+      env_var_value = System.get_env(env_var) || ""
+      Map.put(acc, env_var, env_var_value)
+    end)
+    |> Poison.encode!()
+  end
+end

mix.exs

@@ -4,7 +4,7 @@ defmodule MetadataPlug.MixProject do
   def project do
     [
       app: :metadata_plugs,
-      version: "0.1.0",
+      version: "0.2.0",
       elixir: "~> 1.6",
       start_permanent: Mix.env() == :prod,
       deps: deps(),

test/plugs/health_plug_test.exs

@@ -17,4 +17,12 @@ defmodule MetadataPlugs.HealthTest do
     assert conn.status == 200
     assert conn.resp_body == "{\"status\":\"up\"}"
   end
+
+  test "when the conn does not match with the plug then the conn is returned" do
+    another_conn = conn(:get, "/whatever")
+
+    conn = MetadataPlugs.Health.call(another_conn, @opts)
+
+    assert(conn == another_conn)
+  end
 end

test/plugs/info_plug_test.exs

@@ -0,0 +1,37 @@
+defmodule MetadataPlugs.InfoTest do
+  use ExUnit.Case
+  use Plug.Test
+
+  doctest MetadataPlugs.Info
+
+  @path "/info"
+  @env_vars ["APP_VERSION", "TEST_VAR"]
+
+  @opts MetadataPlugs.Info.init(info_path: @path, env_vars: @env_vars)
+
+  test "Given a list of env variables when call the info endpoint then value of the variables is returned" do
+    Enum.each(@env_vars, &System.put_env(&1, "#{&1}_value"))
+
+    expected_env_vars_response =
+      @env_vars
+      |> Enum.reduce(%{}, fn env_var, acc -> Map.put(acc, env_var, "#{env_var}_value") end)
+      |> Poison.encode!()
+
+    conn =
+      :get
+      |> conn(@path)
+      |> MetadataPlugs.Info.call(@opts)
+
+    assert conn.state == :sent
+    assert conn.status == 200
+    assert conn.resp_body == expected_env_vars_response
+  end
+
+  test "when the conn does not match with the plug then the conn is returned" do
+    another_conn = conn(:get, "/whatever")
+
+    conn = MetadataPlugs.Info.call(another_conn, @opts)
+
+    assert(conn == another_conn)
+  end
+end