Add configuration for heroku deployment of the example app

Dockerfile

@@ -0,0 +1,33 @@
+FROM heroku/heroku:18-build
+
+# Update system and install stack
+ENV DEBIAN_FRONTEND noninteractive
+ENV LANG   C.UTF-8
+ENV LC_ALL C.UTF-8
+RUN apt-get update \
+  && apt-get install sudo haskell-stack \
+  && apt-get clean
+
+# Create user "testuser"
+RUN useradd -m -d /home/testuser -s /bin/bash testuser
+RUN mkdir -p /etc/sudoers.d \
+  && echo "testuser ALL=(ALL) NOPASSWD: ALL" > /etc/sudoers.d/testuser \
+  && chmod 0440 /etc/sudoers.d/testuser
+ENV HOME /home/testuser
+WORKDIR /home/testuser
+USER testuser
+COPY --chown=testuser package.yaml app
+COPY --chown=testuser stack.yaml app
+
+# Update stack and cache dependencies and app in stages
+ENV PATH="/home/testuser/.local/bin:${PATH}"
+RUN stack upgrade
+RUN cd app && stack setup
+RUN cd app && stack build --only-dependencies Cabal
+RUN cd app && stack build --only-dependencies yesod
+
+COPY --chown=testuser . app
+RUN cd app && stack install --flag yesod-auth-oauth2:example
+WORKDIR /home/testuser/app
+
+CMD yesod-auth-oauth2-example

example/Main.hs

@@ -26,13 +26,13 @@ import Data.Aeson.Encode.Pretty
 import Data.ByteString.Lazy (fromStrict, toStrict)
 import qualified Data.Map as M
 import Data.Maybe (fromJust)
-import Data.Text (Text)
+import Data.Text (Text, pack)
 import qualified Data.Text as T
 import Data.Text.Encoding (decodeUtf8)
 import LoadEnv
 import Network.HTTP.Conduit
 import Network.Wai.Handler.Warp (runEnv)
-import System.Environment (getEnv)
+import System.Environment (getEnv, lookupEnv)
 import Yesod
 import Yesod.Auth
 import Yesod.Auth.OAuth2.BattleNet
@@ -50,6 +50,7 @@ import Yesod.Auth.OAuth2.Upcase
 data App = App
     { appHttpManager :: Manager
     , appAuthPlugins :: [AuthPlugin App]
+    , appAppRoot :: Text
     }
 
 mkYesod "App" [parseRoutes|
@@ -59,7 +60,7 @@ mkYesod "App" [parseRoutes|
 
 instance Yesod App where
     -- see https://github.com/thoughtbot/yesod-auth-oauth2/issues/87
-    approot = ApprootStatic "http://localhost:3000"
+    approot = ApprootMaster appAppRoot
 
 instance YesodAuth App where
     type AuthId App = Text
@@ -146,6 +147,12 @@ mkFoundation = do
         , loadPlugin oauth2Upcase "UPCASE"
         ]
 
+    appAppRoot <- do
+      root <- lookupEnv "APPROOT"
+      return $ pack $ case root of
+        Nothing -> "http://localhost:3000"
+        Just url -> url
+
     return App {..}
   where
     loadPlugin f prefix = do

heroku.yml

@@ -0,0 +1,5 @@
+build:
+  docker:
+    web: Dockerfile
+run:
+  web: yesod-auth-oauth2-example