根据不同开发环境读取不同配置文件

.env

@@ -1,7 +1,5 @@
-WEB.ADDR=0.0.0.0:9527
-
-MYSQL.MAX_CONS=5
-MYSQL.DSN=mysql://root:mysql123!%40%23@127.0.0.1:3306/study
-
 # 日志级别
 RUST_LOG=DEBUG
+
+# 运行模式
+RUN_MODE=dev

config/default.toml

@@ -0,0 +1,6 @@
+[web]
+addr = "0.0.0.0:9527"
+
+[mysql]
+max_cons = 5
+dsn = "mysql://root:mysql123!%40%23@127.0.0.1:3306/study"

src/config.rs

@@ -1,3 +1,5 @@
+use std::env;
+use config::File;
 use serde::Deserialize;
 use crate::{err::Error, Result};
 
@@ -21,9 +23,19 @@ pub struct AppConfig {
 }
 
 impl AppConfig {
-    pub fn from_env() -> Result<Self> {
+    pub fn new() -> Result<Self> {
+        let run_mode = env::var("RUN_MODE").unwrap_or_else(|_| "dev".into());
+
+        // https://github.com/mehcode/config-rs/blob/master/examples/hierarchical-env/settings.rs
         config::Config::builder()
-            .add_source(config::Environment::default())
+            // Start off by merging in the "default" configuration file
+            .add_source(File::with_name("config/default"))
+            // Add in the current environment file
+            // Default to 'dev' env
+            // Note that this file is _optional_
+            .add_source(
+                File::with_name(&format!("config/{}", run_mode)).required(false),
+            )
             .build()
             .map_err(Error::from)?
             .try_deserialize()

src/main.rs

@@ -15,7 +15,7 @@ async fn main() {
 
     tracing_subscriber::fmt::init();
 
-    let cfg = AppConfig::from_env()
+    let cfg = AppConfig::new()
         .map_err(|e| tracing::error!("初始化配置失败：{}", e.to_string()))
         .unwrap();