Log the server / cluster logfile on error.

This allows us to find errors that aren't visible
in stdout/stderr.

Author: nihohit

redis/tests/support/cluster.rs

@@ -216,8 +216,12 @@ impl RedisCluster {
                                     out.read_to_string(&mut str).unwrap();
                                     str
                                 });
+
+                                let log_file_index = cmd.get_args().position(|arg|arg == "--logfile").unwrap() + 1;
+                                let log_file_path = cmd.get_args().nth(log_file_index).unwrap();
+                                let log_file_contents = std::fs::read_to_string(log_file_path).unwrap();
                                 let err =
-                                    format!("redis server creation failed with status {status:?}.\nstdout: `{stdout}`.\nstderr: `{stderr}`");
+                                    format!("redis server creation failed with status {status:?}.\nstdout: `{stdout}`.\nstderr: `{stderr}`\nlog file: {log_file_contents}");
                                 if cur_attempts == max_attempts {
                                     panic!("{err}");
                                 }

redis/tests/support/mod.rs

@@ -142,6 +142,7 @@ pub enum Module {
 pub struct RedisServer {
     pub process: process::Child,
     tempdir: tempfile::TempDir,
+    log_file: PathBuf,
     addr: redis::ConnectionAddr,
     pub(crate) tls_paths: Option<TlsFilePaths>,
 }
@@ -174,6 +175,10 @@ impl RedisServer {
         RedisServer::with_modules(&[], true)
     }
 
+    pub fn log_file_contents(&self) -> String {
+        std::fs::read_to_string(self.log_file.clone()).unwrap()
+    }
+
     pub fn get_addr(port: u16) -> ConnectionAddr {
         let server_type = ServerType::get_intended();
         match server_type {
@@ -270,7 +275,8 @@ impl RedisServer {
             .prefix("redis")
             .tempdir()
             .expect("failed to create tempdir");
-        redis_cmd.arg("--logfile").arg(Self::log_file(&tempdir));
+        let log_file = Self::log_file(&tempdir);
+        redis_cmd.arg("--logfile").arg(log_file.clone());
         match addr {
             redis::ConnectionAddr::Tcp(ref bind, server_port) => {
                 redis_cmd
@@ -281,6 +287,7 @@ impl RedisServer {
 
                 RedisServer {
                     process: spawner(&mut redis_cmd),
+                    log_file,
                     tempdir,
                     addr,
                     tls_paths: None,
@@ -320,6 +327,7 @@ impl RedisServer {
 
                 RedisServer {
                     process: spawner(&mut redis_cmd),
+                    log_file,
                     tempdir,
                     addr,
                     tls_paths: Some(tls_paths),
@@ -333,6 +341,7 @@ impl RedisServer {
                     .arg(path);
                 RedisServer {
                     process: spawner(&mut redis_cmd),
+                    log_file,
                     tempdir,
                     addr,
                     tls_paths: None,
@@ -410,15 +419,27 @@ impl TestContext {
     }
 
     pub fn with_tls(tls_files: TlsFilePaths, mtls_enabled: bool) -> TestContext {
+        Self::with_modules_and_tls(&[], mtls_enabled, Some(tls_files))
+    }
+
+    pub fn with_modules(modules: &[Module], mtls_enabled: bool) -> TestContext {
+        Self::with_modules_and_tls(modules, mtls_enabled, None)
+    }
+
+    fn with_modules_and_tls(
+        modules: &[Module],
+        mtls_enabled: bool,
+        tls_files: Option<TlsFilePaths>,
+    ) -> Self {
         let redis_port = get_random_available_port();
         let addr = RedisServer::get_addr(redis_port);
 
         let server = RedisServer::new_with_addr_tls_modules_and_spawner(
             addr,
             None,
-            Some(tls_files),
+            tls_files,
             mtls_enabled,
-            &[],
+            modules,
             |cmd| {
                 cmd.spawn()
                     .unwrap_or_else(|err| panic!("Failed to run {cmd:?}: {err}"))
@@ -442,51 +463,16 @@ impl TestContext {
                         sleep(millisecond);
                         retries += 1;
                         if retries > 100000 {
-                            panic!("Tried to connect too many times, last error: {err}");
-                        }
-                    } else {
-                        panic!("Could not connect: {err}");
-                    }
-                }
-                Ok(x) => {
-                    con = x;
-                    break;
-                }
-            }
-        }
-        redis::cmd("FLUSHDB").execute(&mut con);
-
-        TestContext {
-            server,
-            client,
-            protocol: use_protocol(),
-        }
-    }
-
-    pub fn with_modules(modules: &[Module], mtls_enabled: bool) -> TestContext {
-        let server = RedisServer::with_modules(modules, mtls_enabled);
-
-        #[cfg(feature = "tls-rustls")]
-        let client =
-            build_single_client(server.connection_info(), &server.tls_paths, mtls_enabled).unwrap();
-        #[cfg(not(feature = "tls-rustls"))]
-        let client = redis::Client::open(server.connection_info()).unwrap();
-
-        let mut con;
-
-        let millisecond = Duration::from_millis(1);
-        let mut retries = 0;
-        loop {
-            match client.get_connection() {
-                Err(err) => {
-                    if err.is_connection_refusal() {
-                        sleep(millisecond);
-                        retries += 1;
-                        if retries > 100000 {
-                            panic!("Tried to connect too many times, last error: {err}");
+                            panic!(
+                                "Tried to connect too many times, last error: {err}, logfile: {}",
+                                server.log_file_contents()
+                            );
                         }
                     } else {
-                        panic!("Could not connect: {err}");
+                        panic!(
+                            "Could not connect: {err}, logfile: {}",
+                            server.log_file_contents()
+                        );
                     }
                 }
                 Ok(x) => {