Open Linear issues for expiring SSL certificates

import socket, ssl
from datetime import datetime, timezone
from clickruntime import on_trigger, credentials, http, state, notify

DOMAINS = ["example.com", "app.example.com", "api.example.com"]
TEAM_ID = "your-linear-team-id"

def days_left(host):
    with socket.create_connection((host, 443), timeout=10) as sock:
        with ssl.create_default_context().wrap_socket(sock, server_hostname=host) as s:
            expires = datetime.fromtimestamp(ssl.cert_time_to_seconds(s.getpeercert()["notAfter"]), timezone.utc)
    return (expires - datetime.now(timezone.utc)).days

@on_trigger
def run(event):
    opened = state.get("opened") or {}
    alerts = []
    for host in DOMAINS:
        days = days_left(host)
        if days > 30 or host in opened:
            continue
        query = "mutation($i: IssueCreateInput!) { issueCreate(input: $i) { issue { identifier } } }"
        r = http.post("https://api.linear.app/graphql", headers={"Authorization": credentials.secret("LINEAR_API_KEY")},
                      json={"query": query, "variables": {"i": {"teamId": TEAM_ID, "title": f"Renew SSL certificate for {host} ({days} days left)"}}}).json()
        opened[host] = r["data"]["issueCreate"]["issue"]["identifier"]
        alerts.append(f"{host}: {days} days left ({opened[host]})")
    if alerts:
        notify.slack("SSL certificates expiring soon:\n" + "\n".join(alerts), channel="#ops")
    state.set("opened", opened)
    return {"checked": len(DOMAINS), "new_issues": len(alerts)}