add restart signals to other machines

main.py

@@ -1,4 +1,5 @@
 import os
+import re
 import time
 
 import requests
@@ -6,7 +7,7 @@ import requests
 SIDECAR_URL = os.getenv("SIDECAR_URL", "http://sidecar:80")
 DB_URL = os.getenv("DB_CONTROLLER_URL", "http://sidecar:8081")
 TABLE = "host_session"
-UPTIME, CPU, RAM, DISK = 63, 21, 22, 23
+SIGNALS_FILE = "/app/signals.yml"
 MINUTE_MS = 60000
 HOUR_MS = 60 * MINUTE_MS
 LOOKBACK_MS = 60 * 24 * HOUR_MS
@@ -18,7 +19,29 @@ def read_history(signals, start_ms, end_ms, resolution):
     path = f"/api/history/?signals={names}&start={int(start_ms)}&end={int(end_ms)}&resolution={resolution}"
     response = requests.get(SIDECAR_URL + path, timeout=(5, 80))
     response.raise_for_status()
-    return {item["signalId"]: item for item in response.json()["data"]["series"]}
+    return {item["name"]: item for item in response.json()["data"]["series"]}
+
+
+def signal_hosts():
+    with open(SIGNALS_FILE) as file:
+        names = re.findall(r"name:\s*'([^']+)'", file.read())
+    return sorted(name[: -len("-uptime")] for name in names if name.endswith("-uptime"))
+
+
+def owns(host, now_ms):
+    path = f"/api/history/?signals={host}-uptime&start={int(now_ms - MINUTE_MS)}&end={int(now_ms)}&resolution=1min"
+    status = requests.get(SIDECAR_URL + path, timeout=(5, 80)).status_code
+    if status not in (200, 403):
+        raise RuntimeError(f"history probe for {host} answered {status}")
+    return status == 200
+
+
+def own_host():
+    now_ms = time.time() * 1000
+    host = next((name for name in signal_hosts() if owns(name, now_ms)), None)
+    if host is None:
+        raise RuntimeError("no uptime signal of this gateway is listed in signals.yml")
+    return host
 
 
 def samples(series):
@@ -39,14 +62,15 @@ def current_boot_ms():
     return int(time.time() * 1000 - uptime_s * 1000)
 
 
-def previous_session(boot_ms):
-    hours = last_samples(UPTIME, boot_ms - LOOKBACK_MS, boot_ms, "1hr")
+def previous_session(host, boot_ms):
+    uptime = f"{host}-uptime"
+    hours = last_samples(uptime, boot_ms - LOOKBACK_MS, boot_ms, "1hr")
     if not hours:
         return None
-    minutes = last_samples(UPTIME, hours[-1][0], min(hours[-1][0] + HOUR_MS, boot_ms), "1min")
+    minutes = last_samples(uptime, hours[-1][0], min(hours[-1][0] + HOUR_MS, boot_ms), "1min")
     if not minutes:
         return None
-    seconds = last_samples(UPTIME, minutes[-1][0], min(minutes[-1][0] + MINUTE_MS, boot_ms), "1s")
+    seconds = last_samples(uptime, minutes[-1][0], min(minutes[-1][0] + MINUTE_MS, boot_ms), "1s")
     end_ms, uptime_s = (seconds or minutes)[-1]
     return int(end_ms - uptime_s * 1000), int(end_ms)
 
@@ -88,21 +112,22 @@ def coverage(series, start_ms, end_ms):
     return min(1.0, present / total)
 
 
-def build_row(start_ms, end_ms):
-    history = read_history([CPU, RAM, DISK], start_ms, end_ms, "1min")
+def build_row(host, start_ms, end_ms):
+    cpu, ram, disk = f"{host}-cpu", f"{host}-ram", f"{host}-disk"
+    history = read_history([cpu, ram, disk], start_ms, end_ms, "1min")
     row = {"start_time": start_ms, "end_time": end_ms, "duration_s": (end_ms - start_ms) // 1000}
-    for prefix, signal in (("cpu", CPU), ("ram", RAM), ("disk", DISK)):
+    for prefix, signal in (("cpu", cpu), ("ram", ram), ("disk", disk)):
         row[f"{prefix}_mean"], row[f"{prefix}_max"] = mean_max(history[signal], start_ms, end_ms)
-    row["coverage"] = coverage(history[CPU], start_ms, end_ms)
+    row["coverage"] = coverage(history[cpu], start_ms, end_ms)
     return row
 
 
-def close_previous(rows, boot_ms):
-    session = previous_session(boot_ms)
+def close_previous(host, rows, boot_ms):
+    session = previous_session(host, boot_ms)
     if session is None:
         print("no previous session in the uptime history", flush=True)
         return
-    row = build_row(*session)
+    row = build_row(host, *session)
     stored = find_row(rows, session[0])
     if stored is None:
         print("previous session stored", db_call("POST", f"/api/db/{TABLE}/", row), row, flush=True)
@@ -116,9 +141,9 @@ def main():
     rows = stored_rows()
     if find_row(rows, boot_ms) is not None:
         return
-    close_previous(rows, boot_ms)
+    close_previous(own_host(), rows, boot_ms)
     print("current session opened", db_call("POST", f"/api/db/{TABLE}/", open_row(boot_ms)), flush=True)
 
 
 if __name__ == "__main__":
-    main()
+    main()