Refactor config printing

src/main.rs

@@ -134,25 +134,29 @@ fn get_config(_opts: &Opts, config_opts: &ConfigOpts) -> Result<(), anyhow::Erro
         ])?
         .into_json()?;
     debug!("config = {:?}", &config);
+
+    write_config(&mut std::io::stdout().lock(), &config, &keys)
+}
+
+fn write_config(
+    output: &mut dyn Write,
+    config: &WireguardConfig,
+    keys: &WireguardKeyPair,
+) -> Result<(), anyhow::Error> {
     let mut endpoint_addrs = config.data.endpoint.to_socket_addrs()?;
     let endpoint_addr = endpoint_addrs
         .next()
         .ok_or_else(|| anyhow::anyhow!("no endpoint address received"))?;
     debug!("endpoint_addr = {:?}", &endpoint_addr);
-    println!(
-        r"[Interface]
-PrivateKey = {private_key}
-Address = {address}
+    writeln!(output, "[Interface]")?;
+    writeln!(output, "PrivateKey = {}", &keys.private_key)?;
+    writeln!(output, "Address = {}", &config.data.address)?;
+
+    writeln!(output, "[Peer]")?;
+    writeln!(output, "PublicKey = {}", &config.data.public_key)?;
+    writeln!(output, "Endpoint = {}", &endpoint_addr)?;
+    writeln!(output, "AllowedIPs = 0.0.0.0/0 #, ::/0")?;
 
-[Peer]
-PublicKey = {public_key}
-Endpoint = {endpoint_addr}
-AllowedIPs = 0.0.0.0/0 #, ::/0",
-        public_key = &config.data.public_key,
-        private_key = &keys.private_key,
-        address = &config.data.address,
-        endpoint_addr = &endpoint_addr,
-    );
     Ok(())
 }