Retry initial client connections

Previously, `corerpc-node` would try to establish a connection via the
given `Auth` cookie, and would panic if it couldn't setup a initial
connection. Only the rest of the initial setup steps would be retried
with time-delay.

This however was race-y, as the auth cookie might not already be synced
to disk on first startup of a fresh `bitcoind` instance (with fresh data
dir), when we try to connect for the first time. Here, we move the
intial connection logic into the retry loop to simply also retry it
instead of panicking.

Author: tnull

node/src/lib.rs

@@ -383,45 +383,61 @@ impl Node {
         thread::sleep(Duration::from_millis(1000));
         assert!(process.stderr.is_none());
 
-        let mut i = 0;
+        let mut tries = 0;
         let auth = Auth::CookieFile(cookie_file.clone());
-        let client_base =
-            Client::new_with_auth(&rpc_url, auth.clone()).expect("failed to create client");
 
         let client = loop {
+            tries += 1;
+
+            if tries > 10 {
+                error!("failed to get a response from bitcoind");
+                return Err(Error::NoBitcoindInstance.into());
+            }
+
+            let client_base = match Client::new_with_auth(&rpc_url, auth.clone()) {
+                Ok(client) => client,
+                Err(e) => {
+                    error!("failed to create client: {}. Retrying!", e);
+                    thread::sleep(Duration::from_millis(1000));
+                    continue;
+                }
+            };
+
             // Just use serde value because changes to the GetBlockchainInfo type make debugging hard.
             let client_result: Result<serde_json::Value, _> =
                 client_base.call("getblockchaininfo", &[]);
 
-            if client_result.is_ok() {
-                let url = match &conf.wallet {
-                    Some(wallet) => {
-                        debug!("trying to create/load wallet: {}", wallet);
-                        // Debugging logic here implicitly tests `into_model` for create/load wallet.
-                        match client_base.create_wallet(wallet) {
-                            Ok(json) => {
-                                debug!("created wallet: {}", json.name());
-                            }
-                            Err(e) => {
-                                debug!("initial create_wallet failed, try load instead: {:?}", e);
-                                let wallet = client_base.load_wallet(wallet)?.name();
-                                debug!("loaded wallet: {}", wallet);
+            match client_result {
+                Ok(_) => {
+                    let url = match &conf.wallet {
+                        Some(wallet) => {
+                            debug!("trying to create/load wallet: {}", wallet);
+                            // Debugging logic here implicitly tests `into_model` for create/load wallet.
+                            match client_base.create_wallet(wallet) {
+                                Ok(json) => {
+                                    debug!("created wallet: {}", json.name());
+                                }
+                                Err(e) => {
+                                    debug!(
+                                        "initial create_wallet failed, try load instead: {:?}",
+                                        e
+                                    );
+                                    let wallet = client_base.load_wallet(wallet)?.name();
+                                    debug!("loaded wallet: {}", wallet);
+                                }
                             }
+                            format!("{}/wallet/{}", rpc_url, wallet)
                         }
-                        format!("{}/wallet/{}", rpc_url, wallet)
-                    }
-                    None => rpc_url,
-                };
-                debug!("creating client with url: {}", url);
-                break Client::new_with_auth(&url, auth)?;
-            }
-
-            thread::sleep(Duration::from_millis(1000));
-
-            i += 1;
-            if i > 10 {
-                error!("failed to get a response from bitcoind");
-                return Err(Error::NoBitcoindInstance.into());
+                        None => rpc_url,
+                    };
+                    debug!("creating client with url: {}", url);
+                    break Client::new_with_auth(&url, auth)?;
+                }
+                Err(e) => {
+                    error!("failed to get a response from bitcoind: {}. Retrying!", e);
+                    thread::sleep(Duration::from_millis(1000));
+                    continue;
+                }
             }
         };