Can specify environment variables in client configuration

src/utils/string_utils.rs

@@ -1,3 +1,4 @@
+use lazy_regex::regex_find;
 use rand::distributions::Alphanumeric;
 use rand::Rng;
 
@@ -9,3 +10,24 @@ pub fn rand_str(len: usize) -> String {
         .take(len)
         .collect()
 }
+
+/// Parse environment variables
+pub fn apply_env_vars(val: &str) -> String {
+    let mut val = val.to_string();
+
+    if let Some(varname_with_wrapper) = regex_find!(r#"\$\{[a-zA-Z0-9_-]+\}"#, &val) {
+        let varname = varname_with_wrapper.strip_prefix("${").unwrap().strip_suffix('}').unwrap();
+        let value = match std::env::var(varname) {
+            Ok(v) => v,
+            Err(e) => {
+                log::error!("Failed to find environment variable {}!", varname);
+                eprintln!("Failed to find environment variable! {:?}", e);
+                std::process::exit(2);
+            }
+        };
+
+        val = val.replace(varname_with_wrapper, &value);
+    }
+
+    val
+}