Merge pull request #54 from lobbyboy-ssh/is-available

Add a `Provider.is_available` method

lobbyboy/contrib/provider/footloose.py

@@ -2,6 +2,7 @@
 from pathlib import Path
 from dataclasses import dataclass
 import subprocess
+import sys
 from typing import List
 
 from paramiko import Channel
@@ -27,17 +28,15 @@ class FootlooseConfig(LBConfigProvider):
 class FootlooseProvider(BaseProvider):
     config = FootlooseConfig
 
-    # TODO add to pre hook
-    def check_footloose_executable(self):
-        process = subprocess.run(["footloose", "-h"])
-        if process.returncode != 0:
-            raise FootlooseException(
-                (
-                    "footloose executable is not exist! "
-                    "Please install footloose via "
-                    "`GO111MODULE=on go get github.com/weaveworks/footloose`"
-                )
+    def is_available(self) -> bool:
+        if not self.check_command(["footloose", "-h"]):
+            print(
+                "footloose executable is not exist! "
+                "Please install footloose via "
+                "`GO111MODULE=on go get github.com/weaveworks/footloose`",
+                file=sys.stderr,
             )
+            return False
         return True
 
     def create_server(self, channel: Channel) -> LBServerMeta:

lobbyboy/contrib/provider/ignite.py

@@ -1,6 +1,7 @@
 import logging
 from pathlib import Path
 import subprocess
+import sys
 from typing import List
 from dataclasses import dataclass
 
@@ -30,17 +31,15 @@ class IgniteConfig(LBConfigProvider):
 class IgniteProvider(BaseProvider):
     config = IgniteConfig
 
-    # TODO add to pre hook
-    def check_ignite_executable(self):
-        process = subprocess.run(["ignite", "-h"])
-        if process.returncode != 0:
-            raise IgniteException(
-                (
-                    "ignite executable is not exist! "
-                    "Please install ignite via the instrution on "
-                    "https://ignite.readthedocs.io/en/stable/installation/"
-                )
+    def is_available(self) -> bool:
+        if not self.check_command(["ignite", "-h"]):
+            print(
+                "ignite executable is not exist! "
+                "Please install ignite via the instrution on "
+                "https://ignite.readthedocs.io/en/stable/installation/",
+                file=sys.stderr,
             )
+            return False
         return True
 
     def create_server(self, channel: Channel) -> LBServerMeta:

lobbyboy/contrib/provider/multipass.py

@@ -2,6 +2,7 @@
 import json
 from pathlib import Path
 import subprocess
+import sys
 from typing import List
 from dataclasses import dataclass
 
@@ -32,13 +33,12 @@ class MultipassConfig(LBConfigProvider):
 class MultipassProvider(BaseProvider):
     config = MultipassConfig
 
-    # TODO add to pre hook
-    def check_multipass_executable(self):
-        process = subprocess.run(["multipass", "-h"])
-        if process.returncode != 0:
-            raise MultipassException(
-                ("multipass executable is not exist! " "Please install it via `snap install multipass`")
+    def is_available(self) -> bool:
+        if not self.check_command(["multipass", "-h"]):
+            print(
+                "multipass executable is not exist! " "Please install it via `snap install multipass`", file=sys.stderr
             )
+            return False
         return True
 
     def create_server(self, channel: Channel) -> LBServerMeta:

lobbyboy/main.py

@@ -56,7 +56,9 @@ def load_providers(provider_configs: Dict[str, LBConfigProvider], head_workspace
 
         module = importlib.import_module(module_path)
         provider_cls = getattr(module, classname)
-        _providers[name] = provider_cls(name=name, config=config, workspace=head_workspace.joinpath(name))
+        provider = provider_cls(name=name, config=config, workspace=head_workspace.joinpath(name))
+        if provider.is_available():
+            _providers[name] = provider
 
     logger.info(f"{len(_providers)} providers loaded: {_providers.keys()}")
     return _providers

lobbyboy/provider.py

@@ -4,6 +4,7 @@
 from datetime import datetime
 from pathlib import Path
 import logging
+import subprocess
 import time
 from typing import List, Dict, Callable
 
@@ -102,6 +103,13 @@ def load_raw_server(server_workspace: Path):
             logger.debug(f"load server data from {_path}")
             return json.load(f)
 
+    def is_available(self) -> bool:
+        """
+        Returns:
+            bool: True if this provider is available, False to disable it
+        """
+        return True
+
     @abstractmethod
     def create_server(self, channel: Channel) -> LBServerMeta:
         """
@@ -167,3 +175,10 @@ def ssh_server_command(self, meta: LBServerMeta, pri_key_path: Path = None) -> L
 
     def get_bill(self):
         ...
+
+    def check_command(self, command: List[str]) -> bool:
+        try:
+            process = subprocess.run(command, capture_output=True)
+        except FileNotFoundError:
+            return False
+        return process.returncode == 0

readme.md

@@ -31,6 +31,7 @@
     * [DigitalOcean Provider](#digitalocean-provider)
     * [Linode Provider](#linode-provider)
     * [Ignite(Firecracker) Provider](#ignitefirecracker-provider)
+    * [Multipass Provider](#multipass-provider)
   * [Write Your Own Providers](#write-your-own-providers)
   * [Publish Your Own Providers](#publish-your-own-providers)
 * [FAQ](#faq)
@@ -260,6 +261,15 @@ To make a new Provider work, you need to extend base class
 `lobbyboy.provider.BaseProvider``, implement 2 methods:
 
 ```python
+    def is_available(self) -> bool:
+        """
+        Override this method to check for requirements of this provider
+
+        Returns:
+            bool: True if this provider is available, False to disable it
+        """
+        return True
+
     def create_server(self, channel: Channel) -> LBServerMeta:
         """
         Args: