feat(docs): add cline thinking notes

Author: lzwjava

notes/2025-03-22-cline-thinking-en.md

@@ -0,0 +1,74 @@
+---
+title: Debugging a Hetzner Cloud Server Snapshot Script
+lang: en
+layout: post
+audio: false
+translated: false
+generated: true
+---
+
+# Debugging and Enhancing a Hetzner Cloud Server Snapshot Script
+
+This article documents the process of troubleshooting and improving a Python script for managing Hetzner Cloud server snapshots and cloning servers.
+
+## The Initial Problem
+
+The script was encountering an error where a 'Server' object had no attribute 'create_snapshot'. The issue was in the `scripts/auto-ss-config/hetzner.py` file, which needed to be fixed to properly create snapshots.
+
+## Step 1: Identifying the Bug
+
+After examining the code, I identified that the error occurred because the script was trying to call `create_snapshot()` directly on a server object, but this method doesn't exist in the hcloud Python library's Server class.
+
+The initial problematic code was:
+
+```python
+snapshot = server.create_snapshot(name=f"{server.name}-snapshot")
+```
+
+## Step 2: First Fix Attempt
+
+The first fix was to use the client's servers API instead:
+
+```python
+snapshot = client.servers.create_snapshot(server, description=f"{server.name}-snapshot")
+```
+
+However, this led to a new error: `'ServersClient' object has no attribute 'create_snapshot'`
+
+## Step 3: Investigating the Correct API
+
+To understand the correct API method, I examined the hcloud Python library. This revealed that I needed to use `client.servers.create_image()` rather than trying to use a non-existent method.
+
+The correct solution was:
+
+```python
+response = client.servers.create_image(server, description=f"{server.name}-snapshot", type="snapshot")
+```
+
+## Step 4: Enhancing the Script
+
+After fixing the initial bug, I enhanced the script to add the ability to create new servers from snapshots. This involved:
+
+1. Waiting for snapshots to be fully available before using them
+2. Adding command-line arguments for flexibility
+3. Improving error handling
+4. Creating a more robust solution for checking snapshot status
+
+## Final Implementation
+
+The enhanced script now supports:
+
+- Creating snapshots with: `python scripts/auto-ss-config/hetzner.py --create-snapshot [--server-name NAME]`
+- Creating a server from an existing snapshot: `python scripts/auto-ss-config/hetzner.py --create-server --snapshot-id ID [--server-name NAME]`
+- Doing both in one command: `python scripts/auto-ss-config/hetzner.py --create-snapshot --create-server [--server-name NAME]`
+
+The script successfully creates snapshots and then uses them to create new server instances with the same specifications (server type, datacenter location) as the original server.
+
+## Key Learnings
+
+1. When working with cloud provider APIs, it's important to use the correct method calls as specified in their documentation
+2. Resources like snapshots often have states (e.g., "creating", "available") that need to be properly handled
+3. Adding command-line arguments improves script flexibility
+4. Proper error handling and waiting mechanisms are essential for robust cloud automation scripts
+
+This debugging process demonstrates how to systematically identify and fix issues in Python scripts that interact with cloud provider APIs.

scripts/auto-ss-config/hetzner.py

@@ -1,5 +1,21 @@
 from hcloud import Client
 import os
+import time
+import argparse
+import sys
+
+# Parse command line arguments
+parser = argparse.ArgumentParser(description='Hetzner Cloud server snapshot and clone tool')
+parser.add_argument('--create-snapshot', action='store_true', help='Create snapshots of servers')
+parser.add_argument('--create-server', action='store_true', help='Create servers from existing snapshots')
+parser.add_argument('--snapshot-id', type=str, help='Specific snapshot ID to use when creating a server')
+parser.add_argument('--server-name', type=str, help='Server name to operate on (optional, all servers if not specified)')
+args = parser.parse_args()
+
+# If no action specified, show help and exit
+if not (args.create_snapshot or args.create_server):
+    parser.print_help()
+    sys.exit(0)
 
 # Get the API token from the environment variable
 api_token = os.environ.get('HERTZNER_API_KEY')
@@ -13,14 +29,90 @@
 
 def create_snapshot(server):
     try:
+        print(f"Creating snapshot for server {server.name}...")
+        # Create the snapshot directly - the API will handle any locking issues
         response = client.servers.create_image(server, description=f"{server.name}-snapshot", type="snapshot")
         print(f"Snapshot created for server {server.name} with ID: {response.image.id}")
+        return response.image
+    except Exception as e:
+        if "locked" in str(e).lower():
+            print(f"Server {server.name} is locked. Please try again later.")
+        else:
+            print(f"Error creating snapshot for server {server.name}: {e}")
+        return None
+
+def create_server_from_snapshot(snapshot_id, source_server, new_name=None):
+    try:
+        if new_name is None:
+            new_name = f"{source_server.name}-clone"
+        
+        # Get the server type and location from the source server
+        server_type = source_server.server_type
+        datacenter = source_server.datacenter
+        
+        print(f"Waiting for snapshot (ID: {snapshot_id}) to be available...")
+        
+        # Wait for the snapshot to be available
+        max_attempts = 20
+        attempts = 0
+        snapshot = None
+        
+        while attempts < max_attempts:
+            try:
+                # Try to get the image
+                snapshot = client.images.get_by_id(snapshot_id)
+                print(f"Snapshot status: {snapshot.status}")
+                
+                # Only proceed when the snapshot is actually available
+                if snapshot.status == "available":
+                    print(f"Snapshot is now fully ready to use")
+                    break
+                    
+                print(f"Snapshot found but status is '{snapshot.status}', waiting for 'available' status...")
+            except Exception as e:
+                print(f"Attempt {attempts+1}/{max_attempts}: Snapshot not accessible yet: {e}")
+            
+            # Increment attempts and wait regardless of error or not-ready status
+            attempts += 1
+            if attempts < max_attempts:
+                sleep_time = 20  # Wait longer between attempts
+                print(f"Waiting {sleep_time} seconds before retrying (attempt {attempts}/{max_attempts})...")
+                time.sleep(sleep_time)
+        
+        if snapshot is None or snapshot.status != "available":
+            print("Failed to get a ready snapshot after multiple attempts")
+            return None
+            
+        print(f"Creating new server '{new_name}' from snapshot (ID: {snapshot_id})")
+        print(f"  - Using server type: {server_type.name}")
+        print(f"  - Using datacenter: {datacenter.name} (location: {datacenter.location.name})")
+        
+        # Create the new server using the snapshot as the image
+        response = client.servers.create(
+            name=new_name,
+            server_type=server_type,
+            image=snapshot,
+            datacenter=datacenter,
+            start_after_create=True
+        )
+        
+        print(f"New server created with ID: {response.server.id}")
+        print(f"Root password: {response.root_password}")
+        return response.server
     except Exception as e:
-        print(f"Error creating snapshot for server {server.name}: {e}")
+        print(f"Error creating server from snapshot: {e}")
+        return None
 
-# List all servers
+# Get all servers
 servers = client.servers.get_all()
 
+# Filter servers if server_name is specified
+if args.server_name:
+    servers = [s for s in servers if s.name == args.server_name]
+    if not servers:
+        print(f"Error: No server found with name '{args.server_name}'")
+        sys.exit(1)
+
 # Print server details
 for server in servers:
     print(f"Server ID: {server.id}")
@@ -31,4 +123,27 @@ def create_snapshot(server):
     print(f"Server Type: {server.server_type.name}")
     print(f"Server Location: {server.datacenter.location.name}")
     print("----------------------------------")
-    create_snapshot(server)
+
+# Create snapshots if requested
+if args.create_snapshot:
+    print("\n=== Creating Snapshots ===\n")
+    for server in servers:
+        snapshot = create_snapshot(server)
+        if snapshot and args.create_server:
+            # Create a new server from the snapshot if both flags are set
+            new_server = create_server_from_snapshot(snapshot.id, server)
+
+# Create servers from existing snapshot if requested
+if args.create_server and args.snapshot_id and not args.create_snapshot:
+    print("\n=== Creating Server from Existing Snapshot ===\n")
+    # Use the first server as template for the new server
+    snapshot = None
+    try:
+        snapshot = client.images.get_by_id(args.snapshot_id)
+        print(f"Found snapshot with ID {args.snapshot_id}")
+    except Exception as e:
+        print(f"Error: Could not find snapshot with ID {args.snapshot_id}: {e}")
+        sys.exit(1)
+        
+    if snapshot and servers:
+        new_server = create_server_from_snapshot(args.snapshot_id, servers[0])