kaffa/haproxy-mcp
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feat: Add bulk operations, wildcard support, and stability improvements

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1. Add timeout to HAProxy response wait
   - Use select() for non-blocking recv with 30s timeout
   - Prevents indefinite blocking on slow/hung HAProxy

2. Log warnings for failed server clears
   - haproxy_remove_domain now logs warnings instead of silent pass
   - Helps debugging without breaking cleanup flow

3. Add HAPROXY_CONTAINER environment variable
   - Container name now configurable (default: "haproxy")
   - Used in reload_haproxy() and haproxy_check_config()

4. Add haproxy_add_servers() for bulk operations
   - Add multiple servers in single call
   - Accepts JSON array of server configs
   - More efficient than multiple haproxy_add_server calls

5. Add wildcard domain support in haproxy_list_domains()
   - New include_wildcards parameter (default: false)
   - Shows .domain entries with (wildcard) label when enabled

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
This commit is contained in:
kaffa
2026-02-01 13:43:05 +00:00
parent 4c4ec24848
commit eebb1ca8df
1 changed files with 188 additions and 16 deletions
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192
mcp/server.py
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@@ -24,6 +24,7 @@ import re
import json
import logging
import os
import select
import tempfile
import time
import fcntl
@@ -60,6 +61,9 @@ SERVERS_FILE: str = os.getenv("HAPROXY_SERVERS_FILE", "/opt/haproxy/conf/servers
POOL_COUNT: int = int(os.getenv("HAPROXY_POOL_COUNT", "100"))
MAX_SLOTS: int = int(os.getenv("HAPROXY_MAX_SLOTS", "10"))
# Container configuration
HAPROXY_CONTAINER: str = os.getenv("HAPROXY_CONTAINER", "haproxy")
# Validation patterns - compiled once for performance
DOMAIN_PATTERN = re.compile(
r'^[a-zA-Z0-9]([a-zA-Z0-9\-]{0,61}[a-zA-Z0-9])?'
@@ -77,6 +81,7 @@ SUBPROCESS_TIMEOUT = 30 # seconds
STARTUP_RETRY_COUNT = 10 # HAProxy ready check retries
STATE_MIN_COLUMNS = 19 # Minimum columns in HAProxy server state output
SOCKET_TIMEOUT = 5 # seconds for HAProxy socket connection
SOCKET_RECV_TIMEOUT = 30 # seconds for HAProxy socket recv loop
class HaproxyError(Exception):
@@ -119,7 +124,7 @@ def haproxy_cmd(command: str) -> str:
The response from HAProxy
Raises:
HaproxyError: If connection fails or response exceeds size limit
HaproxyError: If connection fails, times out, or response exceeds size limit
"""
try:
with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as s:
@@ -127,14 +132,30 @@ def haproxy_cmd(command: str) -> str:
s.connect(HAPROXY_SOCKET)
s.sendall(f"{command}\n".encode())
s.shutdown(socket.SHUT_WR)
# Set socket to non-blocking for select-based recv loop
s.setblocking(False)
response = b""
start_time = time.time()
while True:
# Check for overall timeout
elapsed = time.time() - start_time
if elapsed >= SOCKET_RECV_TIMEOUT:
raise HaproxyError(f"Response timeout after {SOCKET_RECV_TIMEOUT} seconds")
# Wait for data with timeout (remaining time)
remaining = SOCKET_RECV_TIMEOUT - elapsed
ready, _, _ = select.select([s], [], [], min(remaining, 1.0))
if ready:
data = s.recv(8192)
if not data:
break
response += data
if len(response) > MAX_RESPONSE_SIZE:
raise HaproxyError(f"Response exceeded {MAX_RESPONSE_SIZE} bytes limit")
return response.decode().strip()
except socket.timeout:
raise HaproxyError("Connection timeout")
@@ -156,14 +177,14 @@ def reload_haproxy() -> Tuple[bool, str]:
"""
try:
validate = subprocess.run(
["podman", "exec", "haproxy", "haproxy", "-c", "-f", "/usr/local/etc/haproxy/haproxy.cfg"],
["podman", "exec", HAPROXY_CONTAINER, "haproxy", "-c", "-f", "/usr/local/etc/haproxy/haproxy.cfg"],
capture_output=True, text=True, timeout=SUBPROCESS_TIMEOUT
)
if validate.returncode != 0:
return False, f"Config validation failed:\n{validate.stderr}"
result = subprocess.run(
["podman", "kill", "--signal", "USR2", "haproxy"],
["podman", "kill", "--signal", "USR2", HAPROXY_CONTAINER],
capture_output=True, text=True, timeout=SUBPROCESS_TIMEOUT
)
if result.returncode != 0:
@@ -595,11 +616,16 @@ def restore_servers_from_config() -> int:
@mcp.tool()
def haproxy_list_domains() -> str:
def haproxy_list_domains(include_wildcards: bool = False) -> str:
"""List all configured domains with their backend servers.
Shows all domains mapped in HAProxy with their pool backend and configured servers.
Args:
include_wildcards: If True, also show wildcard domain mappings (entries starting
with '.', e.g., '.example.com' which matches '*.example.com').
Default is False to show only explicit domain mappings.
Returns:
List of domains in format: domain -> pool_N (pool): server=ip:port
@@ -607,6 +633,10 @@ def haproxy_list_domains() -> str:
# Output:
# • api.example.com -> pool_1 (pool): pool_1_1=10.0.0.1:8080, pool_1_2=10.0.0.2:8080
# • web.example.com -> pool_2 (pool): pool_2_1=10.0.0.3:80
# With include_wildcards=True:
# • api.example.com -> pool_1 (pool): pool_1_1=10.0.0.1:8080
# • .api.example.com -> pool_1 (wildcard): pool_1_1=10.0.0.1:8080
"""
try:
domains = []
@@ -624,16 +654,22 @@ def haproxy_list_domains() -> str:
f"{parts[StateField.SRV_NAME]}={parts[StateField.SRV_ADDR]}:{parts[StateField.SRV_PORT]}"
)
# Read from domains.map (skip wildcard entries starting with .)
# Read from domains.map
seen_domains: Set[str] = set()
for domain, backend in get_map_contents():
if domain.startswith("."):
# Skip wildcard entries unless explicitly requested
if domain.startswith(".") and not include_wildcards:
continue
if domain in seen_domains:
continue
seen_domains.add(domain)
servers = server_map.get(backend, ["(none)"])
backend_type = "pool" if backend.startswith("pool_") else "static"
if domain.startswith("."):
backend_type = "wildcard"
elif backend.startswith("pool_"):
backend_type = "pool"
else:
backend_type = "static"
domains.append(f"• {domain} -> {backend} ({backend_type}): {', '.join(servers)}")
return "\n".join(domains) if domains else "No domains configured"
@@ -755,8 +791,12 @@ def haproxy_remove_domain(domain: str) -> str:
try:
haproxy_cmd(f"set server {backend}/{server} state maint")
haproxy_cmd(f"set server {backend}/{server} addr 0.0.0.0 port 0")
except HaproxyError:
pass # Ignore errors for individual servers
except HaproxyError as e:
logger.warning(
"Failed to clear server %s/%s for domain %s: %s",
backend, server, domain, e
)
# Continue with remaining cleanup
return f"Domain {domain} removed from {backend}"
@@ -863,6 +903,138 @@ def haproxy_add_server(domain: str, slot: int, ip: str, http_port: int = 80) ->
return f"Error: {e}"
@mcp.tool()
def haproxy_add_servers(domain: str, servers: str) -> str:
"""Add multiple servers to a domain's backend at once.
More efficient than calling haproxy_add_server multiple times.
All servers are validated before any are added.
Args:
domain: The domain name to add servers to
servers: JSON array of server configs. Each object can have:
- slot (required): Server slot number (1-10)
- ip (required): IP address of the server
- http_port (optional): HTTP port (default: 80)
Example: '[{"slot":1,"ip":"10.0.0.1","http_port":80},{"slot":2,"ip":"10.0.0.2"}]'
Returns:
Summary of added servers or errors for each failed server
Example:
haproxy_add_servers("api.example.com", '[{"slot":1,"ip":"10.0.0.1"},{"slot":2,"ip":"10.0.0.2"}]')
# Output: Added 2 servers to api.example.com (pool_1):
# • slot 1: 10.0.0.1:80
# • slot 2: 10.0.0.2:80
"""
if not validate_domain(domain):
return "Error: Invalid domain format"
# Parse JSON array
try:
server_list = json.loads(servers)
except json.JSONDecodeError as e:
return f"Error: Invalid JSON - {e}"
if not isinstance(server_list, list):
return "Error: servers must be a JSON array"
if not server_list:
return "Error: servers array is empty"
# Validate all servers first before adding any
validated_servers = []
validation_errors = []
for i, srv in enumerate(server_list):
if not isinstance(srv, dict):
validation_errors.append(f"Server {i+1}: must be an object")
continue
# Extract and validate slot
slot = srv.get("slot")
if slot is None:
validation_errors.append(f"Server {i+1}: missing 'slot' field")
continue
try:
slot = int(slot)
except (ValueError, TypeError):
validation_errors.append(f"Server {i+1}: slot must be an integer")
continue
if not (1 <= slot <= MAX_SLOTS):
validation_errors.append(f"Server {i+1}: slot must be between 1 and {MAX_SLOTS}")
continue
# Extract and validate IP
ip = srv.get("ip")
if not ip:
validation_errors.append(f"Server {i+1}: missing 'ip' field")
continue
if not validate_ip(ip):
validation_errors.append(f"Server {i+1}: invalid IP address '{ip}'")
continue
# Extract and validate port
http_port = srv.get("http_port", 80)
try:
http_port = int(http_port)
except (ValueError, TypeError):
validation_errors.append(f"Server {i+1}: http_port must be an integer")
continue
if not (1 <= http_port <= 65535):
validation_errors.append(f"Server {i+1}: port must be between 1 and 65535")
continue
validated_servers.append({"slot": slot, "ip": ip, "http_port": http_port})
# Return validation errors if any
if validation_errors:
return "Validation errors:\n" + "\n".join(f" • {e}" for e in validation_errors)
# Check for duplicate slots
slots = [s["slot"] for s in validated_servers]
if len(slots) != len(set(slots)):
return "Error: Duplicate slot numbers in servers array"
# Get backend info
try:
backend, server_prefix = get_backend_and_prefix(domain)
except ValueError as e:
return f"Error: {e}"
# Add all servers
added = []
errors = []
for srv in validated_servers:
slot = srv["slot"]
ip = srv["ip"]
http_port = srv["http_port"]
try:
for suffix, port in get_server_suffixes(http_port):
server = f"{server_prefix}{suffix}_{slot}"
haproxy_cmd(f"set server {backend}/{server} addr {ip} port {port}")
haproxy_cmd(f"set server {backend}/{server} state ready")
# Save to persistent config
add_server_to_config(domain, slot, ip, http_port)
added.append(f"slot {slot}: {ip}:{http_port}")
except (HaproxyError, IOError) as e:
errors.append(f"slot {slot}: {e}")
# Build result message
result_parts = []
if added:
result_parts.append(f"Added {len(added)} servers to {domain} ({backend}):")
result_parts.extend(f" • {s}" for s in added)
if errors:
result_parts.append(f"Failed to add {len(errors)} servers:")
result_parts.extend(f" • {e}" for e in errors)
return "\n".join(result_parts) if result_parts else "No servers added"
@mcp.tool()
def haproxy_remove_server(domain: str, slot: int) -> str:
"""Remove a server from a domain's backend at specified slot.
@@ -1293,7 +1465,7 @@ def haproxy_check_config() -> str:
"""
try:
result = subprocess.run(
["podman", "exec", "haproxy", "haproxy", "-c", "-f", "/usr/local/etc/haproxy/haproxy.cfg"],
["podman", "exec", HAPROXY_CONTAINER, "haproxy", "-c", "-f", "/usr/local/etc/haproxy/haproxy.cfg"],
capture_output=True, text=True, timeout=SUBPROCESS_TIMEOUT
)
if result.returncode == 0: