Read from environment configuration

src/main.rs

@@ -6,8 +6,8 @@ extern crate actix_web;
 // Logging & Console output.
 #[macro_use]
 extern crate log;
-extern crate pretty_env_logger;
 
+use std::process::exit;
 use std::sync::Arc;
 use std::sync::RwLock;
 
@@ -18,15 +18,70 @@ fn into_bool(string: &str) -> bool {
     string.eq_ignore_ascii_case("true") || string.eq_ignore_ascii_case("on")
 }
 */
-
 fn main() {
-//    std::env::set_var("RUST_LOG", "info");
+    // If RUST_LOG is unset, set it to INFO, otherwise keep it as-is.
+    if std::env::var("RUST_LOG").is_err() {
+        std::env::set_var("RUST_LOG", "info");
+    }
     pretty_env_logger::init();
 
-    //TODO Retrieve from environment values, with fall back to defaults if unset.
-    let hostname = "0.0.0.0";
-    let base = "/spatial-search";
-    let port = 8888;
+    if std::env::var("MERCATOR_HOST").is_err() {
+        std::env::set_var("MERCATOR_HOST", "0.0.0.0");
+    }
+
+    if std::env::var("MERCATOR_PORT").is_err() {
+        std::env::set_var("MERCATOR_PORT", "8888");
+    }
+
+    if std::env::var("MERCATOR_BASE").is_err() {
+        std::env::set_var("MERCATOR_BASE", "/spatial-search");
+    }
+
+    if std::env::var("MERCATOR_DATA").is_err() {
+        std::env::set_var("MERCATOR_DATA", ".");
+    }
+    let hostname;
+    let port;
+    let base;
+    let data;
+
+    match std::env::var("MERCATOR_HOST") {
+        Ok(val) => hostname = val,
+        Err(val) => {
+            error!("Invalid environment {} : `{}`", "MERCATOR_HOST", val);
+            exit(1);
+        }
+    };
+
+    match std::env::var("MERCATOR_PORT") {
+        Ok(val) => match val.parse::<u16>() {
+            Ok(v) => port = v,
+            Err(e) => {
+                error!("Could not convert to u16 {} : `{}`", "MERCATOR_PORT", e);
+                exit(1);
+            }
+        },
+        Err(val) => {
+            error!("Could not fetch {} : `{}`", "MERCATOR_PORT", val);
+            exit(1);
+        }
+    };
+
+    match std::env::var("MERCATOR_BASE") {
+        Ok(val) => base = val,
+        Err(val) => {
+            error!("Could not fetch {} : `{}`", "MERCATOR_BASE", val);
+            exit(1);
+        }
+    };
+
+    match std::env::var("MERCATOR_DATA") {
+        Ok(val) => data = val,
+        Err(val) => {
+            error!("Could not fetch {} : `{}`", "MERCATOR_DATA", val);
+            exit(1);
+        }
+    };
 
     rest_api::run(hostname, port, base, Arc::new(RwLock::new(0)));
 }

src/rest_api/mod.rs

@@ -41,13 +41,24 @@ mod spatial_objects;
 
 mod default;
 
-fn get_app(
-    prefix: &'static str,
+// From: https://stackoverflow.com/a/52367953
+fn into_static<S>(s: S) -> &'static str
+where
+    S: Into<String>,
+{
+    Box::leak(s.into().into_boxed_str())
+}
+
+fn get_app<S>(
+    prefix: S,
     state: Arc<RwLock<SharedState>>,
-) -> Vec<Box<HttpHandler<Task = Box<HttpHandlerTask>>>> {
+) -> Vec<Box<HttpHandler<Task = Box<HttpHandlerTask>>>>
+where
+    S: Into<String>,
+{
     vec![
         App::with_state(AppState { shared: state })
-            .prefix(format!("{}", prefix))
+            .prefix(format!("{}", into_static(prefix)))
             // ACTIONS           -------------------------------------------------------------------
             .resource("/health", |r| {
                 r.method(Method::GET).f(actions::health);
@@ -119,15 +130,15 @@ fn get_app(
     ]
 }
 
-pub fn run(
-    host: &'static str,
-    port: u16,
-    prefix: &'static str,
-    state: Arc<RwLock<SharedState>>,
-) -> () {
+pub fn run<S>(host: S, port: u16, prefix: S, state: Arc<RwLock<SharedState>>) -> ()
+where
+    S: Into<String>,
+{
     info!("Initializing server...");
 
     let sys = actix::System::new("spatial-search");
+    let prefix = into_static(prefix);
+    let host = host.into();
 
     server::new(move || get_app(prefix, state.clone()))
         .bind(format!("{}:{}", host, port))