mprymek · November 25, 2015 21:29 · Aug 5, 2014 · Aug 5, 2014 · Aug 5, 2014 · Aug 5, 2014
diff --git a/elixir → auth_plug.ex b/elixir → auth_plug.ex
@@ -1,11 +1,11 @@
-Simple Phoenix authentication plug
+# Simple Phoenix authentication plug
+#
+# - based on Plug's session store
+# - redirects unauthenticated requests to login page "/login/<request url>"
+# - /static/... requests are not authenticated 
+# - authentication is valid as long as session is valid (you can change this behaviour easily)
 
-- based on Plug's session store
-- redirects unauthenticated requests to login page "/login/<request url>"
-- /static/... requests are not authenticated 
-- authentication is valid as long as session is valid (you can change this behaviour easily)
-
-Because we need session to be fetched BEFORE this plug, we must put this to router.ex:
+# Because we need session to be fetched BEFORE this plug, we must put this to router.ex:
 
 #----------------------------
   # copied from https://github.com/phoenixframework/phoenix/blob/master/lib/phoenix/router.ex
@@ -19,7 +19,7 @@ Because we need session to be fetched BEFORE this plug, we must put this to rout
   # here put your other plugs...
 #----------------------------
 
-Auth plug code:
+# Auth plug code:
 
 #----------------------------
 defmodule WebApp.Plugs.Auth do
@@ -57,7 +57,7 @@ defmodule WebApp.Plugs.Auth do
 end
 #----------------------------
 
-Login page in router.ex:
+# Login page in router.ex:
 
 #----------------------------
   get  "/login/*src", WebApp.LoginController, :login
@@ -66,7 +66,7 @@ Login page in router.ex:
 #----------------------------
 
 
-Login page controller:
+# Login page controller:
 
 #----------------------------
 defmodule WebApp.LoginController do

diff --git a/gistfile1.txt → elixir b/gistfile1.txt → elixir
diff --git a/gistfile1.txt b/gistfile1.txt
@@ -72,12 +72,12 @@ Login page controller:
 defmodule WebApp.LoginController do
   use Phoenix.Controller
 
-  def login(conn, _) do
+  def login(conn, _, messages\\[]) do
     if WebApp.Plugs.Auth.authenticated?(conn) do
        # already logged in
        redirect conn, "/#{conn.params["src"]}"
     else
-       render conn, "login"
+       render conn, "login", [messages: messages]
     end
   end
 

diff --git a/gistfile1.txt b/gistfile1.txt
@@ -0,0 +1,105 @@
+Simple Phoenix authentication plug
+
+- based on Plug's session store
+- redirects unauthenticated requests to login page "/login/<request url>"
+- /static/... requests are not authenticated 
+- authentication is valid as long as session is valid (you can change this behaviour easily)
+
+Because we need session to be fetched BEFORE this plug, we must put this to router.ex:
+
+#----------------------------
+  # copied from https://github.com/phoenixframework/phoenix/blob/master/lib/phoenix/router.ex
+  key    = Phoenix.Config.router!(__MODULE__, [:session_key])
+  secret = Phoenix.Config.router!(__MODULE__, [:session_secret])
+  plug Plug.Session, store: :cookie, key: key, secret: secret
+  plug Phoenix.Plugs.SessionFetcher
+
+  # auth plug now
+  plug WebApp.Plugs.Auth, []
+  # here put your other plugs...
+#----------------------------
+
+Auth plug code:
+
+#----------------------------
+defmodule WebApp.Plugs.Auth do
+  require Logger
+
+  def init(opts), do: opts
+
+  def call(conn, _opts) do
+    cond do
+      skip?(conn.path_info) ->
+        conn
+      authenticated?(conn) ->
+        conn
+      true ->
+        Logger.debug "AUTH for #{inspect conn.path_info}"
+        url = "/#{Enum.join(conn.path_info,"/")}"
+        Phoenix.Controller.Connection.redirect(conn,"/login#{url}")
+        Phoenix.Controller.Connection.halt!(conn)
+    end
+  end
+
+  defp skip?(["static"|_]), do: true
+  defp skip?(["login"|_]), do: true
+  #
+  # you can insert any unauthenticated pages here...
+  #
+  defp skip?(_), do: false
+
+  def authenticated?(conn) do
+    # BEWARE!
+    # User is authenticated as long as session is valid!
+    # You probably want to check if user still exists and is authorized here.
+    Plug.Conn.get_session(conn, :user) != nil
+  end
+end
+#----------------------------
+
+Login page in router.ex:
+
+#----------------------------
+  get  "/login/*src", WebApp.LoginController, :login
+  post "/login/*src", WebApp.LoginController, :login_post
+  get  "/logout",     WebApp.LoginController, :logout
+#----------------------------
+
+
+Login page controller:
+
+#----------------------------
+defmodule WebApp.LoginController do
+  use Phoenix.Controller
+
+  def login(conn, _) do
+    if WebApp.Plugs.Auth.authenticated?(conn) do
+       # already logged in
+       redirect conn, "/#{conn.params["src"]}"
+    else
+       render conn, "login"
+    end
+  end
+
+  def login_post(conn, _) do
+    passwd = conn.params["password"]
+    user = conn.params["username"]
+    case WebApp.Auth.auth(user,passwd) do
+       nil ->
+          login(conn,[{:error,"Login failed."}])
+       group ->
+          conn = conn
+                 |> Plug.Conn.put_session(:user, String.to_atom(user))
+                 |> Plug.Conn.put_session(:group, group)
+          redirect conn, "/#{conn.params["src"]}"
+    end
+  end
+
+  def logout(conn, _) do
+     conn = conn
+            |> Plug.Conn.delete_session(:user)
+            |> Plug.Conn.delete_session(:group)
+     redirect conn, "/login"
+  end
+end
+#----------------------------