[IMP] healthcheck: implement timeouts for healthchecks

this should help if ports are/become firewalled for healthcheck to be
able to mark container as unhealthy

README.md

@@ -58,6 +58,13 @@ Default: `http://$TARGET/`
 Url to use in [`HTTP_HEALTHCHECK`](#http_healthcheck) if enabled. `$TARGET` gets
 replaced inside the url by the configured [`TARGET`](#target).
 
+### `HTTP_HEALTHCHECK_TIMEOUT_MS`
+
+Default: `2000`
+
+Timeout in milliseconds for http healthcheck. This is used as a timeout for connecting
+and receiving an answer. You may end up with twice the time spend.
+
 ### `MODE`
 
 Default: `tcp`
@@ -143,6 +150,13 @@ Default: `HELP`
 Enables changing the healthcheck command for servers that do not support `HELP` (e.g.
 for [MailHog](https://github.com/mailhog/MailHog) you can use `QUIT`)
 
+### `SMTP_HEALTHCHECK_TIMEOUT_MS`
+
+Default: `2000`
+
+Timeout in milliseconds for smtp healthcheck. This is used as a timeout for connecting
+and receiving an answer. You may end up with twice the time spend.
+
 ### `UDP_ANSWERS`
 
 Default: `1`

healthcheck.py

@@ -25,6 +25,7 @@ def http_healthcheck():
     import pycurl
 
     check_url = os.environ.get("HTTP_HEALTHCHECK_URL", "http://localhost/")
+    check_timeout_ms = int(os.environ.get("HTTP_HEALTHCHECK_TIMEOUT_MS", 2000))
     target = os.environ.get("TARGET", "localhost")
     check_url_with_target = check_url.replace("$TARGET", target)
     port = re.search("https?://[^:]*(?::([^/]+))?", check_url_with_target)[1] or "80"
@@ -36,6 +37,8 @@ def http_healthcheck():
         # do not send the request to the target directly but use our own socat proxy process to check if it's still
         # working
         request.setopt(pycurl.RESOLVE, ["{}:{}:127.0.0.1".format(target, port)])
+        request.setopt(pycurl.CONNECTTIMEOUT_MS, check_timeout_ms)
+        request.setopt(pycurl.TIMEOUT_MS, check_timeout_ms)
         request.perform()
         request.close()
     except pycurl.error as e:
@@ -53,6 +56,7 @@ def smtp_healthcheck():
 
     check_url = os.environ.get("SMTP_HEALTHCHECK_URL", "smtp://localhost/")
     check_command = os.environ.get("SMTP_HEALTHCHECK_COMMAND", "HELP")
+    check_timeout_ms = int(os.environ.get("SMTP_HEALTHCHECK_TIMEOUT_MS", 2000))
     target = os.environ.get("TARGET", "localhost")
     check_url_with_target = check_url.replace("$TARGET", target)
     port = re.search("smtp://[^:]*(?::([^/]+))?", check_url_with_target)[1] or "25"
@@ -64,6 +68,8 @@ def smtp_healthcheck():
         # do not send the request to the target directly but use our own socat proxy process to check if it's still
         # working
         request.setopt(pycurl.RESOLVE, ["{}:{}:127.0.0.1".format(target, port)])
+        request.setopt(pycurl.CONNECTTIMEOUT_MS, check_timeout_ms)
+        request.setopt(pycurl.TIMEOUT_MS, check_timeout_ms)
         request.perform()
         request.close()
     except pycurl.error as e: