feat(volume): add the possibilty to mount local directory into the container (like docker volume)

README.md

@@ -46,6 +46,10 @@ mc session create --driver goose
 # Create a session with environment variables
 mc session create -e VAR1=value1 -e VAR2=value2
 
+# Mount custom volumes (similar to Docker's -v flag)
+mc session create -v /local/path:/container/path
+mc session create -v ~/data:/data -v ./configs:/etc/app/config
+
 # Shorthand for creating a session with a project repository
 mc github.com/username/repo
 ```

mcontainer/cli.py

@@ -109,6 +109,9 @@ def create_session(
     env: List[str] = typer.Option(
         [], "--env", "-e", help="Environment variables (KEY=VALUE)"
     ),
+    volume: List[str] = typer.Option(
+        [], "--volume", "-v", help="Mount volumes (LOCAL_PATH:CONTAINER_PATH)"
+    ),
     name: Optional[str] = typer.Option(None, "--name", "-n", help="Session name"),
     no_connect: bool = typer.Option(
         False, "--no-connect", help="Don't automatically connect to the session"
@@ -139,6 +142,29 @@ def create_session(
                 f"[yellow]Warning: Ignoring invalid environment variable format: {var}[/yellow]"
             )
 
+    # Parse volume mounts
+    volume_mounts = {}
+    for vol in volume:
+        if ":" in vol:
+            local_path, container_path = vol.split(":", 1)
+            # Convert to absolute path if relative
+            if not os.path.isabs(local_path):
+                local_path = os.path.abspath(local_path)
+
+            # Validate local path exists
+            if not os.path.exists(local_path):
+                console.print(
+                    f"[yellow]Warning: Local path '{local_path}' does not exist. Volume will not be mounted.[/yellow]"
+                )
+                continue
+
+            # Add to volume mounts
+            volume_mounts[local_path] = {"bind": container_path, "mode": "rw"}
+        else:
+            console.print(
+                f"[yellow]Warning: Ignoring invalid volume format: {vol}. Use LOCAL_PATH:CONTAINER_PATH.[/yellow]"
+            )
+
     with console.status(f"Creating session with driver '{driver}'..."):
         session = container_manager.create_session(
             driver_name=driver,
@@ -146,6 +172,7 @@ def create_session(
             environment=environment,
             session_name=name,
             mount_local=not no_mount and user_config.get("defaults.mount_local", True),
+            volumes=volume_mounts,
         )
 
     if session:
@@ -284,6 +311,9 @@ def quick_create(
     env: List[str] = typer.Option(
         [], "--env", "-e", help="Environment variables (KEY=VALUE)"
     ),
+    volume: List[str] = typer.Option(
+        [], "--volume", "-v", help="Mount volumes (LOCAL_PATH:CONTAINER_PATH)"
+    ),
     name: Optional[str] = typer.Option(None, "--name", "-n", help="Session name"),
     no_connect: bool = typer.Option(
         False, "--no-connect", help="Don't automatically connect to the session"
@@ -303,6 +333,7 @@ def quick_create(
         driver=driver,
         project=project,
         env=env,
+        volume=volume,
         name=name,
         no_connect=no_connect,
         no_mount=no_mount,

mcontainer/container.py

@@ -125,6 +125,7 @@ class ContainerManager:
         environment: Optional[Dict[str, str]] = None,
         session_name: Optional[str] = None,
         mount_local: bool = True,
+        volumes: Optional[Dict[str, Dict[str, str]]] = None,
     ) -> Optional[Session]:
         """Create a new MC session
 
@@ -134,6 +135,7 @@ class ContainerManager:
             environment: Optional environment variables
             session_name: Optional session name
             mount_local: Whether to mount the current directory to /app
+            volumes: Optional additional volumes to mount (dict of {host_path: {"bind": container_path, "mode": mode}})
         """
         try:
             # Validate driver exists
@@ -178,25 +180,46 @@ class ContainerManager:
                 self.client.images.pull(driver.image)
 
             # Set up volume mounts
-            volumes = {}
+            session_volumes = {}
+
             # If project URL is provided, don't mount local directory (will clone into /app)
             # If no project URL and mount_local is True, mount local directory to /app
             if not project and mount_local:
                 # Mount current directory to /app in the container
                 current_dir = os.getcwd()
-                volumes[current_dir] = {"bind": "/app", "mode": "rw"}
+                session_volumes[current_dir] = {"bind": "/app", "mode": "rw"}
                 print(f"Mounting local directory {current_dir} to /app")
             elif project:
                 print(
                     f"Project URL provided - container will clone {project} into /app during initialization"
                 )
 
+            # Add user-specified volumes
+            if volumes:
+                for host_path, mount_spec in volumes.items():
+                    container_path = mount_spec["bind"]
+                    # Check for conflicts with /app mount
+                    if container_path == "/app" and not project and mount_local:
+                        print(
+                            "[yellow]Warning: Volume mount to /app conflicts with automatic local directory mount. User-specified mount takes precedence.[/yellow]"
+                        )
+                        # Remove the automatic mount if there's a conflict
+                        if current_dir in session_volumes:
+                            del session_volumes[current_dir]
+
+                    # Add the volume
+                    session_volumes[host_path] = mount_spec
+                    print(f"Mounting volume: {host_path} -> {container_path}")
+
             # Set up persistent project configuration
             project_config_path = self._get_project_config_path(project)
             print(f"Using project configuration directory: {project_config_path}")
 
             # Mount the project configuration directory
-            volumes[str(project_config_path)] = {"bind": "/mc-config", "mode": "rw"}
+            session_volumes[str(project_config_path)] = {
+                "bind": "/mc-config",
+                "mode": "rw",
+            }
 
             # Add environment variables for config path
             env_vars["MC_CONFIG_DIR"] = "/mc-config"
@@ -230,7 +253,7 @@ class ContainerManager:
                 tty=True,
                 stdin_open=True,
                 environment=env_vars,
-                volumes=volumes,
+                volumes=session_volumes,
                 labels={
                     "mc.session": "true",
                     "mc.session.id": session_id,