fix(env): Retro-compatible precedence order for variables with defaults set in Dockerfile

- `BLOCK_NSA` has precedence over `BLOCK_SURVEILLANCE`
- `HEALTH_OPENVPN_DURATION_ADDITION` has precedence over `HEALTH_VPN_DURATION_ADDITION`
- `HEALTH_OPENVPN_DURATION_INITIAL` has precendence over `HEALTH_VPN_DURATION_INITIAL`
- Chain of precedence: `PROXY` > `TINYPROXY` > `HTTPPROXY`
- Chain of precedence: `PROXY_LOG_LEVEL` > `TINYPROXY_LOG` > `HTTPPROXY_LOG`
- `PROTOCOL` has precendence over `OPENVPN_PROTOCOL`
- `IP_STATUS_FILE` has precendence over `PUBLICIP_FILE`
- `SHADOWSOCKS_PORT` has precedence over `SHADOWSOCKS_LISTENING_ADDRESS`
- `SHADOWSOCKS_METHOD` has precedence over `SHADOWSOCKS_CIPHER`

internal/configuration/sources/env/shadowsocks.go

@@ -25,11 +25,6 @@ func (r *Reader) readShadowsocks() (shadowsocks settings.Shadowsocks, err error)
 }
 
 func (r *Reader) readShadowsocksAddress() (address string) {
-	address = os.Getenv("SHADOWSOCKS_LISTENING_ADDRESS")
-	if address != "" {
-		return address
-	}
-
 	// Retro-compatibility
 	portString := os.Getenv("SHADOWSOCKS_PORT")
 	if portString != "" {
@@ -37,18 +32,16 @@ func (r *Reader) readShadowsocksAddress() (address string) {
 		return ":" + portString
 	}
 
-	return ""
+	return os.Getenv("SHADOWSOCKS_LISTENING_ADDRESS")
 }
 
 func (r *Reader) readShadowsocksCipher() (cipher string) {
-	cipher = os.Getenv("SHADOWSOCKS_CIPHER")
-	if cipher != "" {
-		return cipher
-	}
 	// Retro-compatibility
 	cipher = os.Getenv("SHADOWSOCKS_METHOD")
 	if cipher != "" {
 		r.onRetroActive("SHADOWSOCKS_METHOD", "SHADOWSOCKS_CIPHER")
-	}
 	return cipher
+	}
+
+	return os.Getenv("SHADOWSOCKS_CIPHER")
 }