Add local server dotenv command

README.md

@@ -122,6 +122,12 @@ clickhousectl local server stop-all                       # Stop all running ser
 
 # Remove a stopped server and its data
 clickhousectl local server remove test
+
+# Write connection env vars to .env file
+clickhousectl local server dotenv                        # From "default" server → .env
+clickhousectl local server dotenv --name dev             # From "dev" server → .env
+clickhousectl local server dotenv --local                # Write to .env.local instead
+clickhousectl local server dotenv --user default --password secret --database mydb  # Include credentials
 ```
 
 **Server naming:** Without `--name`, the first server is called "default". If "default" is already running, a random name is generated (e.g. "bold-crane"). Use `--name` for stable identities you can start/stop repeatedly.

src/local/cli.rs

@@ -214,4 +214,36 @@ CONTEXT FOR AGENTS:
         /// Name of the server to remove
         name: String,
     },
+
+    /// Write ClickHouse connection env vars to a .env file
+    #[command(after_help = "\
+CONTEXT FOR AGENTS:
+  Writes CLICKHOUSE_HOST, CLICKHOUSE_PORT, and CLICKHOUSE_HTTP_PORT into a .env file
+  (or .env.local with --local) based on a running server's actual connection details.
+  Optionally includes CLICKHOUSE_USER, CLICKHOUSE_PASSWORD, and CLICKHOUSE_DATABASE when
+  the corresponding flags are provided.
+  If the file already exists, existing CLICKHOUSE_* vars are replaced in-place. Otherwise the file is created.
+  Useful for configuring apps that read from dotenv files.
+  Related: `clickhousectl local server start` to start a server, `clickhousectl local server list` to see servers.")]
+    Dotenv {
+        /// Server name (default: "default")
+        #[arg(long)]
+        name: Option<String>,
+
+        /// Write to .env.local instead of .env
+        #[arg(long)]
+        local: bool,
+
+        /// Include CLICKHOUSE_USER with this value
+        #[arg(long)]
+        user: Option<String>,
+
+        /// Include CLICKHOUSE_PASSWORD with this value
+        #[arg(long)]
+        password: Option<String>,
+
+        /// Include CLICKHOUSE_DATABASE with this value
+        #[arg(long)]
+        database: Option<String>,
+    },
 }