From 44e681dd13859927b13213b3da5a4fa3f3534b82 Mon Sep 17 00:00:00 2001
From: Abel Luck <abel@guardianproject.info>
Date: Sun, 5 Nov 2023 20:59:15 +0100
Subject: [PATCH] appease the linter

---
 tailscalesd/main.py | 26 ++++++++++++--------------
 1 file changed, 12 insertions(+), 14 deletions(-)

diff --git a/tailscalesd/main.py b/tailscalesd/main.py
index 63a5ed5..f3a78cd 100644
--- a/tailscalesd/main.py
+++ b/tailscalesd/main.py
@@ -6,9 +6,8 @@ from ipaddress import ip_address
 from typing import Dict, List
 
 import httpx
+import json_logging  # type: ignore
 import uvicorn
-
-import json_logging
 from fastapi import FastAPI
 from pydantic import Field, SecretStr
 from pydantic_settings import BaseSettings, SettingsConfigDict
@@ -20,7 +19,8 @@ log.setLevel(logging.DEBUG if debug else logging.INFO)
 log.addHandler(logging.StreamHandler(sys.stdout))
 
 
-def filter_ipv6(addresses):
+def ipv4_only(addresses) -> List[str]:
+    """Given a list of ip addresses, returns only the ipv4 ones"""
     return list(filter(lambda a: ip_address(a).version == 4, addresses))
 
 
@@ -55,7 +55,7 @@ async def tailscale_devices() -> List:
             return r.json()["devices"]
         except Exception as e:
             log.error(
-                f"Polling tailscale devices failed!",
+                "Polling tailscale devices failed!",
                 exc_info=e,
             )
             return []
@@ -70,7 +70,7 @@ def group_by_type(input_list):
     return result
 
 
-def tailscale_labels(device) -> Dict:
+def tailscale_labels(device) -> Dict[str, str]:
     return {
         "__meta_tailscale_device_client_version": device["clientVersion"],
         "__meta_tailscale_device_hostname": device["hostname"],
@@ -83,7 +83,7 @@ def tailscale_labels(device) -> Dict:
 
 
 async def matrix_node_sd(device) -> Dict:
-    ipv4 = filter_ipv6(device["addresses"])[0]
+    ipv4 = ipv4_only(device["addresses"])[0]
     async with httpx.AsyncClient() as client:
         r = await client.get(f"http://{ipv4}:8081/")
         data = r.json()
@@ -93,7 +93,7 @@ async def matrix_node_sd(device) -> Dict:
 def matrix_workers_to_sd(device, workers) -> List:
     if len(workers) == 0:
         return []
-    ipv4 = filter_ipv6(device["addresses"])[0]
+    ipv4 = ipv4_only(device["addresses"])[0]
     target_groups = []
     for worker_type, workers in workers.items():
         targets = []
@@ -131,7 +131,7 @@ async def matrix_sd(devices) -> List:
                 f"Failed parsing matrix node sd for device={device['hostname']}",
                 exc_info=e,
             )
-            workers = []
+            workers = {}
         targets = matrix_workers_to_sd(device, workers)
         if targets:
             sd.append(targets)
@@ -141,11 +141,9 @@ async def matrix_sd(devices) -> List:
 def plain_devices_sd(devices) -> List:
     sd = []
     for device in devices:
-        service = {}
-        service["targets"] = filter_ipv6(device["addresses"])
-        service["labels"] = tailscale_labels(device)
-
-        sd.append(service)
+        targets = ipv4_only(device["addresses"])
+        labels = tailscale_labels(device)
+        sd.append({"labels": labels, "targets": targets})
 
     return sd
 
@@ -161,7 +159,7 @@ async def poll_sd():
             await asyncio.sleep(settings.interval)
         except Exception as e:
             log.error(
-                f"service discovery poller failed",
+                "Service Discovery poller failed",
                 exc_info=e,
             )