Refactor volume mount configuration and add shared mount

Use separate classes for each volume mount type.
Added support for shared filesystem volume mounts.
The base VolumeMount class now serves as an abstract base,
and specific volume mount types like ScratchMount, SecretMount,
MemoryMount, and SharedFilesystemMount inherit from it.

Author: tamirse

datacrunch/containers/containers.py

@@ -43,6 +43,7 @@ class VolumeMountType(str, Enum):
     SCRATCH = "scratch"
     SECRET = "secret"
     MEMORY = "memory"
+    SHARED = "shared"
 
 
 class ContainerRegistryType(str, Enum):
@@ -119,25 +120,85 @@ class EnvVar:
 @dataclass_json(undefined=Undefined.EXCLUDE)
 @dataclass
 class VolumeMount:
-    """Volume mount configuration for containers.
+    """Base class for volume mount configurations.
 
     Attributes:
         type: Type of volume mount.
         mount_path: Path where the volume should be mounted in the container.
-        size_in_mb: Size of the memory volume in megabytes, only used for memory volume mounts
     """
 
     type: VolumeMountType
     mount_path: str
-    size_in_mb: Optional[int] = None
 
 
-@dataclass_json
+@dataclass_json(undefined=Undefined.EXCLUDE)
 @dataclass
-class SecretMount:
-    mount_path: str
+class ScratchMount(VolumeMount):
+    """Scratch volume mount configuration.
+    """
+
+    def __init__(self, mount_path: str):
+        """Initialize a scratch volume mount.
+
+        Args:
+            mount_path: Path where the volume should be mounted in the container.
+        """
+        super().__init__(type=VolumeMountType.SCRATCH, mount_path=mount_path)
+
+
+@dataclass_json(undefined=Undefined.EXCLUDE)
+@dataclass
+class SecretMount(VolumeMount):
+    """Secret volume mount configuration.
+
+    A secret volume mount allows mounting secret files into the container.
+
+    Attributes:
+        secret_name: Name of the fileset secret to mount
+        file_names: List of file names that are part of the fileset secret
+    """
+
     secret_name: str
-    type: VolumeMountType = VolumeMountType.SECRET
+    file_names: Optional[List[str]] = None
+
+    def __init__(self, mount_path: str, secret_name: str, file_names: Optional[List[str]] = None):
+        super().__init__(type=VolumeMountType.SECRET, mount_path=mount_path)
+        self.secret_name = secret_name
+        self.file_names = file_names
+
+
+@dataclass_json(undefined=Undefined.EXCLUDE)
+@dataclass
+class MemoryMount(VolumeMount):
+    """Memory volume mount configuration.
+
+    A memory volume mount provides high-speed, ephemeral in-memory storage inside your container.
+    The mount path is currently hardcoded to /dev/shm and cannot be changed.
+
+    Attributes:
+        size_in_mb: Size of the memory volume in megabytes.
+    """
+
+    size_in_mb: int
+
+    def __init__(self, size_in_mb: int):
+        super().__init__(type=VolumeMountType.MEMORY, mount_path='/dev/shm')
+        self.size_in_mb = size_in_mb
+
+
+@dataclass_json(undefined=Undefined.EXCLUDE)
+@dataclass
+class SharedFilesystemMount(VolumeMount):
+    """Shared filesystem volume mount configuration.
+
+    A shared filesystem volume mount allows mounting a shared filesystem into the container.
+    """
+
+    volume_id: str  # The ID of the shared filesystem volume to mount, needs to be created first
+
+    def __init__(self, mount_path: str, volume_id: str):
+        super().__init__(type=VolumeMountType.SHARED, mount_path=mount_path)
+        self.volume_id = volume_id
 
 
 @dataclass_json