fixes #85 #minor

Add proposed timeout configuration parameters.

README.md

@@ -70,3 +70,5 @@ If the filename ends with `.url` suffix, the content will be processed as an URL
 | `DEFAULT_FILE_MODE` | The default file system permission for every file. Use three digits (e.g. '500', '440', ...) | false | - | string
 | `KUBECONFIG` | if this is given and points to a file or `~/.kube/config` is mounted k8s config will be loaded from this file, otherwise "incluster" k8s configuration is tried. | false | - | string
 |`ENABLE_5XX` | Set to `true` to enable pulling of 5XX response content from config map. Used in case if the filename ends with `.url` suffix (Please refer to the `*.url` feature here.) | false | - | boolean
+| `WATCH_SERVER_TIMEOUT` | polite request to the server, asking it to cleanly close watch connections after this amount of seconds ([#85](https://github.com/kiwigrid/k8s-sidecar/issues/85))| false | `60` | integer
+| `WATCH_CLIENT_TIMEOUT` | If you have a network outage dropping all packets with no RST/FIN, this is how many seconds your client waits on watches before realizing & dropping the connection. You can keep this number low. ([#85](https://github.com/kiwigrid/k8s-sidecar/issues/85)) | false | `66` | integer

sidecar/helpers.py

@@ -19,6 +19,22 @@
 REQ_RETRY_BACKOFF_FACTOR = 1.1 if os.getenv("REQ_RETRY_BACKOFF_FACTOR") is None else float(os.getenv("REQ_RETRY_BACKOFF_FACTOR"))
 REQ_TIMEOUT = 10 if os.getenv("REQ_TIMEOUT") is None else float(os.getenv("REQ_TIMEOUT"))
 
+# Tune default timeouts as outlined in
+# https://github.com/kubernetes-client/python/issues/1148#issuecomment-626184613
+# https://github.com/kubernetes-client/python/blob/master/examples/watch/timeout-settings.md
+# I picked 60 and 66 due to https://github.com/nolar/kopf/issues/847#issuecomment-971651446
+
+# 60 is a polite request to the server, asking it to cleanly close the connection after that.
+# If you have a network outage, this does nothing.
+# You can set this number much higher, maybe to 3600 seconds (1h).
+WATCH_SERVER_TIMEOUT = os.environ.get("WATCH_SERVER_TIMEOUT", 60)
+
+# 66 is a client-side timeout, configuring your local socket.
+# If you have a network outage dropping all packets with no RST/FIN,
+# this is how long your client waits before realizing & dropping the connection.
+# You can keep this number low, maybe 60 seconds.
+WATCH_CLIENT_TIMEOUT = os.environ.get("WATCH_CLIENT_TIMEOUT", 66)
+
 def write_data_to_file(folder, filename, data, data_type=CONTENT_TYPE_TEXT):
     """
     Write text to a file. If the parent folder doesn't exist, create it. If there are insufficient

sidecar/resources.py

@@ -15,7 +15,7 @@
 from urllib3.exceptions import ProtocolError
 
 from helpers import request, write_data_to_file, remove_file, timestamp, unique_filename, CONTENT_TYPE_TEXT, \
-    CONTENT_TYPE_BASE64_BINARY, execute
+    CONTENT_TYPE_BASE64_BINARY, execute, WATCH_SERVER_TIMEOUT, WATCH_CLIENT_TIMEOUT
 
 RESOURCE_SECRET = "secret"
 RESOURCE_CONFIGMAP = "configmap"
@@ -191,7 +191,9 @@ def _watch_resource_iterator(label, label_value, target_folder, request_url, req
     label_selector = f"{label}={label_value}" if label_value else label
 
     additional_args = {
-        'label_selector': label_selector
+        'label_selector': label_selector,
+        'timeout_seconds': WATCH_SERVER_TIMEOUT,
+        '_request_timeout': WATCH_CLIENT_TIMEOUT,
     }
     if namespace != "ALL":
         additional_args['namespace'] = namespace