Add support for CleverCloud environment variables

Cargo.lock

@@ -1,3 +1,5 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
 [[package]]
 name = "actix"
 version = "0.7.9"

post_build.sh

@@ -0,0 +1,4 @@
+#!/bin/sh
+
+[ -x ./bin/diesel ] || cargo install diesel_cli --no-default-features --features postgres --root .
+./bin/diesel setup --database-url "$POSTGRESQL_ADDON_URI"

src/bin/callmeback.rs

@@ -15,12 +15,21 @@ pub fn main() {
     env_logger::init();
 
     dotenv().ok();
-    let database_url = env::var("DATABASE_URL").expect("DATABASE_URL must be set");
+    let database_url = env::var("POSTGRESQL_ADDON_URI")
+        .or(env::var("DATABASE_URL"))
+        .expect("DATABASE_URL must be set");
+    let port = env::var("PORT").unwrap_or("3000".to_string());
 
     let mut listenfd = ListenFd::from_env();
     let sys = actix::System::new("callmeback");
 
-    let addr = SyncArbiter::start(3, move || DbExecutor::new(&database_url));
+    let addr = SyncArbiter::start(
+        env::var("DATABASE_CONNECTION_COUNT")
+            .unwrap_or("1".to_string())
+            .parse()
+            .unwrap_or(1),
+        move || DbExecutor::new(&database_url),
+    );
 
     let mut server = HttpServer::new(move || {
         callmeback::configure_app(App::with_state(callmeback::AppState { db: addr.clone() }))
@@ -31,7 +40,7 @@ pub fn main() {
     server = if let Some(l) = listenfd.take_tcp_listener(0).unwrap() {
         server.listen(l)
     } else {
-        server.bind("127.0.0.1:3000").unwrap()
+        server.bind(format!("0.0.0.0:{}", port)).unwrap()
     };
     server.start();
 

src/db.rs

@@ -10,10 +10,10 @@ impl Actor for DbExecutor {
 
 impl DbExecutor {
     pub fn new(database_url: &str) -> Self {
-        DbExecutor(
-            PgConnection::establish(database_url)
-                .unwrap_or_else(|_| panic!("Error connecting to {}", database_url)),
-        )
+        DbExecutor(match PgConnection::establish(database_url) {
+            Err(e) => panic!("Error connecting to {}: {}", database_url, e),
+            Ok(c) => c,
+        })
     }
 }