Add the [global] psuedo-environment for global configuration.

examples/todo/Rocket.toml

@@ -1,8 +1,2 @@
-[dev]
+[global]
-template_dir = "static"
-
-[stage]
-template_dir = "static"
-
-[prod]
 template_dir = "static"

lib/src/config/config.rs

@@ -21,7 +21,7 @@ pub struct Config {
     /// The environment that this configuration corresponds to.
     pub env: Environment,
     session_key: RwLock<Option<String>>,
-    extra: HashMap<String, Value>,
+    extras: HashMap<String, Value>,
     filename: String,
 }
 
@@ -48,7 +48,7 @@ impl Config {
                     port: 8000,
                     log_level: LoggingLevel::Normal,
                     session_key: RwLock::new(None),
-                    extra: HashMap::new(),
+                    extras: HashMap::new(),
                     env: env,
                     filename: filename.to_string(),
                 }
@@ -59,7 +59,7 @@ impl Config {
                     port: 80,
                     log_level: LoggingLevel::Normal,
                     session_key: RwLock::new(None),
-                    extra: HashMap::new(),
+                    extras: HashMap::new(),
                     env: env,
                     filename: filename.to_string(),
                 }
@@ -70,7 +70,7 @@ impl Config {
                     port: 80,
                     log_level: LoggingLevel::Critical,
                     session_key: RwLock::new(None),
-                    extra: HashMap::new(),
+                    extras: HashMap::new(),
                     env: env,
                     filename: filename.to_string(),
                 }
@@ -116,7 +116,7 @@ impl Config {
                                 "log level ('normal', 'critical', 'debug')"))
             };
         } else {
-            self.extra.insert(name.into(), val.clone());
+            self.extras.insert(name.into(), val.clone());
         }
 
         Ok(())
@@ -130,26 +130,26 @@ impl Config {
 
     #[inline(always)]
     pub fn extras<'a>(&'a self) -> impl Iterator<Item=(&'a String, &'a Value)> {
-        self.extra.iter()
+        self.extras.iter()
     }
 
     pub fn get_str<'a>(&'a self, name: &str) -> config::Result<&'a str> {
-        let value = self.extra.get(name).ok_or_else(|| ConfigError::NotFound)?;
+        let value = self.extras.get(name).ok_or_else(|| ConfigError::NotFound)?;
         parse!(self, name, value, as_str, "a string")
     }
 
     pub fn get_int<'a>(&'a self, name: &str) -> config::Result<i64> {
-        let value = self.extra.get(name).ok_or_else(|| ConfigError::NotFound)?;
+        let value = self.extras.get(name).ok_or_else(|| ConfigError::NotFound)?;
         parse!(self, name, value, as_integer, "an integer")
     }
 
     pub fn get_bool<'a>(&'a self, name: &str) -> config::Result<bool> {
-        let value = self.extra.get(name).ok_or_else(|| ConfigError::NotFound)?;
+        let value = self.extras.get(name).ok_or_else(|| ConfigError::NotFound)?;
         parse!(self, name, value, as_bool, "a boolean")
     }
 
     pub fn get_float<'a>(&'a self, name: &str) -> config::Result<f64> {
-        let value = self.extra.get(name).ok_or_else(|| ConfigError::NotFound)?;
+        let value = self.extras.get(name).ok_or_else(|| ConfigError::NotFound)?;
         parse!(self, name, value, as_float, "a float")
     }
 
@@ -191,6 +191,12 @@ impl Config {
         self.env = var;
         self
     }
+
+    #[inline(always)]
+    pub fn extra(mut self, name: &str, value: &Value) -> Self {
+        self.extras.insert(name.into(), value.clone());
+        self
+    }
 }
 
 impl fmt::Debug for Config {
@@ -207,7 +213,7 @@ impl PartialEq for Config {
             && self.port == other.port
             && self.log_level == other.log_level
             && self.env == other.env
-            && self.extra == other.extra
+            && self.extras == other.extras
             && self.filename == other.filename
     }
 }

lib/src/config/environment.rs

@@ -36,6 +36,12 @@ impl Environment {
     pub fn valid() -> &'static str {
         "development, staging, production"
     }
+
+    /// Returns a list of all of the possible environments.
+    #[inline(always)]
+    pub fn all() -> [Environment; 3] {
+        [Development, Staging, Production]
+    }
 }
 
 impl FromStr for Environment {

lib/src/config/error.rs

@@ -58,9 +58,10 @@ impl ConfigError {
                 info_!("{}", reason);
             }
             BadEntry(ref name, ref filename) => {
+                let valid_entries = format!("{}, and global", valid_envs);
                 error!("[{}] is not a known configuration environment", name);
                 info_!("in {}", White.paint(filename));
-                info_!("valid environments are: {}", White.paint(valid_envs));
+                info_!("valid environments are: {}", White.paint(valid_entries));
             }
             BadEnv(ref name) => {
                 error!("'{}' is not a valid ROCKET_ENV value", name);

lib/src/config/mod.rs

@@ -47,11 +47,12 @@
 //! each environment. The file is optional. If it is not present, the default
 //! configuration parameters are used.
 //!
-//! The file must be a series of tables, one for each environment, where each
+//! The file must be a series of tables, at most one for each environment and a
-//! table contains key-value pairs corresponding to configuration parameters for
+//! "global" table, where each table contains key-value pairs corresponding to
-//! that environment. If a configuration parameter is missing, the default value
+//! configuration parameters for that environment. If a configuration parameter
-//! is used. The following is a complete `Rocket.toml` file, where every
+//! is missing, the default value is used. The following is a complete
-//! standard configuration parameter is specified with the default value:
+//! `Rocket.toml` file, where every standard configuration parameter is
+//! specified with the default value:
 //!
 //! ```toml
 //! [development]
@@ -74,6 +75,23 @@
 //! session_key = "adL5fFIPmZBrlyHk2YT4NLV3YCk2gFXz"
 //! ```
 //!
+//! The "global" pseudo-environment can be used to set and/or override
+//! configuration parameters globally. A parameter defined in a `[global]` table
+//! sets, or overrides if already present, that parameter in every environment.
+//! For example, given the following `Rocket.toml` file, the value of `address`
+//! will be `"1.2.3.4"` in every environment:
+//!
+//! ```toml
+//! [global]
+//! address = "1.2.3.4"
+//!
+//! [devolopment]
+//! address = "localhost"
+//!
+//! [production]
+//! address = "0.0.0.0"
+//! ```
+//!
 //! ## Retrieving Configuration Parameters
 //!
 //! Configuration parameters for the currently active configuration environment
@@ -127,6 +145,8 @@ static mut CONFIG: Option<RocketConfig> = None;
 
 const CONFIG_FILENAME: &'static str = "Rocket.toml";
 
+const GLOBAL_ENV_NAME: &'static str = "global";
+
 /// Wraps `std::result` with the error type of
 /// [ConfigError](enum.ConfigError.html).
 pub type Result<T> = ::std::result::Result<T, ConfigError>;
@@ -198,16 +218,14 @@ impl RocketConfig {
             }).collect()
         ))?;
 
-        // Create a config with the defaults, but the set the env to the active
+        // Create a config with the defaults; set the env to the active one.
         let mut config = RocketConfig::active_default(filename)?;
 
+        // Store all of the global overrides, if any, for later use.
+        let mut global = None;
+
         // Parse the values from the TOML file.
         for (entry, value) in toml {
-            // Parse the environment from the table entry name.
-            let env = entry.as_str().parse().map_err(|_| {
-                ConfigError::BadEntry(entry.clone(), filename.into())
-            })?;
-
             // Each environment must be a table.
             let kv_pairs = match value.as_table() {
                 Some(table) => table,
@@ -216,9 +234,25 @@ impl RocketConfig {
                 ))
             };
 
+            if entry.as_str() == GLOBAL_ENV_NAME {
+                global = Some(kv_pairs.clone());
+            } else {
+                // Parse the environment from the table entry name.
+                let env = entry.as_str().parse().map_err(|_| {
+                    ConfigError::BadEntry(entry.clone(), filename.into())
+                })?;
+
                 // Set the environment configuration from the kv pairs.
                 config.set(env, &kv_pairs)?;
             }
+        }
+
+        // Override all of the environments with the global values.
+        if let Some(ref global_kv_pairs) = global {
+            for env in &Environment::all() {
+                config.set(*env, global_kv_pairs)?;
+            }
+        }
 
         Ok(config)
     }
@@ -320,7 +354,7 @@ mod test {
     use std::env;
     use std::sync::Mutex;
 
-    use super::{RocketConfig, ConfigError};
+    use super::{RocketConfig, ConfigError, GLOBAL_ENV_NAME};
     use super::environment::{Environment, CONFIG_ENV};
     use super::Environment::*;
     use super::config::Config;
@@ -678,4 +712,42 @@ mod test {
             session_key = "abcv" = other
         "#.to_string(), TEST_CONFIG_FILENAME).is_err());
     }
+
+    #[test]
+    fn test_global_overrides() {
+        // Take the lock so changing the environment doesn't cause races.
+        let _env_lock = ENV_LOCK.lock().unwrap();
+
+        // Test first that we can override each environment.
+        for env in &Environment::all() {
+            env::set_var(CONFIG_ENV, env.to_string());
+
+            check_config!(RocketConfig::parse(format!(r#"
+                              [{}]
+                              address = "7.6.5.4"
+                          "#, GLOBAL_ENV_NAME), TEST_CONFIG_FILENAME), {
+                              default_config(*env).address(
+                                  "7.6.5.4".into()
+                              )
+                          });
+
+            check_config!(RocketConfig::parse(format!(r#"
+                              [{}]
+                              database = "mysql"
+                          "#, GLOBAL_ENV_NAME), TEST_CONFIG_FILENAME), {
+                              default_config(*env).extra("database",
+                                  &Value::String("mysql".into())
+                              )
+                          });
+
+            check_config!(RocketConfig::parse(format!(r#"
+                              [{}]
+                              port = 3980
+                          "#, GLOBAL_ENV_NAME), TEST_CONFIG_FILENAME), {
+                              default_config(*env).port(
+                                  3980
+                              )
+                          });
+        }
+    }
 }