使い方
- インストールコマンドをコピーし、自分の環境へ導入する前にソースを確認します。
- 必要なツール、認証情報、対応環境を原文で確認します。
- 入力と成果物を指定し、出力を資料と照合します。
npx skills add https://github.com/affaan-m/ecc --skill netmiko-ssh-automation開始前の確認
- 導入にはモデル契約、API枠、ファイルへのアクセス許可は含まれません。
- スター数や導入数は活動の指標であり、独立した品質・安全性試験ではありません。
リポジトリの原文
見出し、例、コード、表、リンク、参照画像を含む原文を表示しています。
Netmiko SSH Automation
Use this skill when writing or reviewing Python automation that connects to network devices with Netmiko. Keep the default path read-only; config changes need a separate change window, peer review, and rollback plan.
When to Use
- Collecting
showcommand output across routers, switches, or firewalls. - Building a small audit script for interface, routing, or config evidence.
- Adding timeouts and exception handling to network SSH scripts.
- Parsing command output with TextFSM when a template exists.
- Reviewing automation before it touches production devices.
Safety Defaults
- Start with read-only
send_command()collection. - Keep inventory small and explicit; do not sweep whole address ranges.
- Use environment variables, a vault, or
getpass; never hardcode credentials. - Set connection and read timeouts.
- Limit concurrency so older devices are not overloaded.
- Require an explicit operator flag before
send_config_set(). - Do not call
save_config()until the change has been verified and approved.
Read-Only Connection Pattern
python
import os
from getpass import getpass
from netmiko import ConnectHandler
from netmiko.exceptions import (
NetmikoAuthenticationException,
NetmikoTimeoutException,
ReadTimeout,
)
device = {
"device_type": "cisco_ios",
"host": "192.0.2.10",
"username": os.environ.get("NETMIKO_USERNAME") or input("Username: "),
"password": os.environ.get("NETMIKO_PASSWORD") or getpass("Password: "),
"secret": os.environ.get("NETMIKO_ENABLE_SECRET"),
"conn_timeout": 10,
"auth_timeout": 20,
"banner_timeout": 15,
"read_timeout_override": 30,
}
try:
with ConnectHandler(**device) as conn:
if device.get("secret") and not conn.check_enable_mode():
conn.enable()
output = conn.send_command("show ip interface brief", read_timeout=30)
print(output)
except NetmikoAuthenticationException:
print("Authentication failed")
except NetmikoTimeoutException:
print("SSH connection timed out")
except ReadTimeout:
print("Command read timed out")Use placeholder addresses from documentation ranges in examples. Keep real inventory in an ignored local file or a secrets-managed system.
Batch Collection
python
from concurrent.futures import ThreadPoolExecutor, as_completed
from typing import Any
def collect_show(device: dict[str, Any], command: str) -> dict[str, Any]:
host = device["host"]
try:
with ConnectHandler(**device) as conn:
output = conn.send_command(command, read_timeout=45)
return {"host": host, "ok": True, "output": output}
except (NetmikoAuthenticationException, NetmikoTimeoutException, ReadTimeout) as exc:
return {"host": host, "ok": False, "error": type(exc).__name__}
results = []
with ThreadPoolExecutor(max_workers=8) as pool:
futures = [pool.submit(collect_show, device, "show version") for device in devices]
for future in as_completed(futures):
results.append(future.result())Keep max_workers low unless the device estate and AAA systems are known to handle higher connection volume.
Structured Parsing
Netmiko can ask TextFSM, TTP, or Genie to parse supported command output. Treat parser output as an optimization, not the only evidence path.
python
with ConnectHandler(**device) as conn:
parsed = conn.send_command(
"show ip interface brief",
use_textfsm=True,
raise_parsing_error=False,
read_timeout=30,
)
if isinstance(parsed, str):
print("No parser template matched; store raw output for review")
else:
for row in parsed:
print(row)If parsing drives a blocking decision, keep the raw command output alongside the parsed result so an operator can inspect mismatches.
Guarded Config Pattern
python
import os
commands = [
"interface GigabitEthernet0/1",
"description CHANGE-1234 UPLINK-TO-CORE",
]
apply_changes = os.environ.get("APPLY_NETWORK_CHANGES") == "1"
if not apply_changes:
print("Dry run only. Candidate commands:")
print("\n".join(commands))
else:
with ConnectHandler(**device) as conn:
conn.enable()
before = conn.send_command("show running-config interface GigabitEthernet0/1")
output = conn.send_config_set(commands)
after = conn.send_command("show running-config interface GigabitEthernet0/1")
print(before)
print(output)
print(after)
print("Verify behavior before saving startup config.")Saving the config is a separate approval step. In production, include a rollback snippet and capture before/after evidence in the change record.
Review Checklist
- Does the script identify an explicit inventory source?
- Are credentials absent from source, logs, and exception messages?
- Are
conn_timeout,auth_timeout, and commandread_timeoutset? - Are failures reported per device without stopping the whole batch?
- Does the script avoid broad scans and unbounded concurrency?
- Are config changes behind a dry-run or explicit operator flag?
- Is
save_config()separate from the initial push and tied to verification?
Anti-Patterns
- Hardcoding passwords, enable secrets, or private keys in source.
- Sending config commands as the default code path.
- Running automation against a CIDR range instead of a reviewed inventory.
- Logging full running configs to shared systems without sanitization.
- Treating parser success as proof that the device state is correct.
See Also
- Skill:
cisco-ios-patterns - Skill:
network-config-validation - Skill:
network-interface-health
