refactor: remove metrics functionality and simplify sandbox lifecycle

BREAKING CHANGE: Removed metrics functionality from Python and Rust SDKs

- Removed metrics.py and related functionality from Python SDK
- Removed metrics.rs and related functionality from Rust SDK
- Simplified sandbox lifecycle management in both SDKs
- Updated dotenv loading to be more resilient
- Removed metrics examples and documentation
- Updated dependencies in Rust SDK
- Simplified error handling and command execution

Author: appcypher

README.md

@@ -85,16 +85,15 @@ npm install microsandbox
 pip install microsandbox
 ```
 
-<!--
 ##### Rust
 
 ```sh
 cargo add microsandbox
 ```
--->
 
 > [!NOTE]
 > There are [SDKs](./sdk) for other languages as well! Join us in expanding support for your favorite language.
+
 <!--
 >
 > <div align="left">
@@ -167,7 +166,6 @@ async def main():
 asyncio.run(main())
 ```
 
-<!--
 ##### Rust
 
 ```rs
@@ -187,7 +185,6 @@ async fn main() -> Result<(), Box<dyn std::error::Error>> {
     Ok(())
 }
 ```
--->
 
 > [!NOTE]
 >

sdk/python/README.md

@@ -68,35 +68,6 @@ async def main():
 asyncio.run(main())
 ```
 
-### Retrieving Sandbox Metrics
-
-```python
-import asyncio
-from microsandbox import PythonSandbox
-
-async def main():
-    async with PythonSandbox.create() as sandbox:
-        # Get current sandbox metrics
-        metrics = await sandbox.metrics.get()
-
-        # Access specific metrics
-        print(f"Sandbox running: {metrics.running}")
-        print(f"CPU usage: {metrics.cpu_usage:.2f}%")
-        print(f"Memory usage: {metrics.memory_usage_mb:.2f} MB")
-        print(f"Disk usage: {metrics.disk_usage_mb:.2f} MB")
-
-        # Access all raw metrics data
-        print(f"Raw metrics: {metrics.raw_data}")
-
-        # Monitor sandbox performance over time
-        for _ in range(5):
-            metrics = await sandbox.metrics.get()
-            print(f"CPU: {metrics.cpu_usage:.2f}%, Memory: {metrics.memory_usage_mb:.2f} MB")
-            await asyncio.sleep(1)
-
-asyncio.run(main())
-```
-
 ## Requirements
 
 - Python 3.8+
@@ -115,7 +86,6 @@ Check out the [examples directory](./examples) for sample scripts that demonstra
 - Create and use sandboxes
 - Run code in sandbox environments
 - Execute shell commands in the sandbox
-- Monitor sandbox metrics and resource usage
 - Handle execution output and error handling
 
 ## License

sdk/python/examples/metrics.py

@@ -10,7 +10,6 @@
 from .command import Command
 from .command_execution import CommandExecution
 from .execution import Execution
-from .metrics import Metrics, SandboxMetrics
 from .node_sandbox import NodeSandbox
 from .python_sandbox import PythonSandbox
 

sdk/python/microsandbox/__init__.py

@@ -40,7 +40,13 @@ def __init__(
             name: Optional name for the sandbox. If not provided, a random name will be generated.
             api_key: API key for Microsandbox server authentication. If not provided, it will be read from MSB_API_KEY environment variable.
         """
-        load_dotenv()
+        # Only try to load .env if MSB_API_KEY is not already set
+        if "MSB_API_KEY" not in os.environ:
+            # Ignore errors if .env file doesn't exist
+            try:
+                load_dotenv()
+            except Exception:
+                pass
 
         self._server_url = server_url or os.environ.get(
             "MSB_SERVER_URL", "http://127.0.0.1:5555"
@@ -82,6 +88,14 @@ async def create(
         Returns:
             An instance of the sandbox ready for use
         """
+        # Only try to load .env if MSB_API_KEY is not already set
+        if "MSB_API_KEY" not in os.environ:
+            # Ignore errors if .env file doesn't exist
+            try:
+                load_dotenv()
+            except Exception:
+                pass
+
         sandbox = cls(
             server_url=server_url,
             namespace=namespace,