Add a random offset to the update script when running non-interactively. (#9245)

* Revert "Revert "Introduce a random sleep in the Netdata updater (#9079)" (#9161)"

This reverts commit e92d2ce7a1.

* Add option to updater to disable randomized delay.

Primarily intended for CI, also useful for automated deployment tools
like Ansible.

* Use correct paths in CI.

* Mke variable name match option name.

packaging/installer/netdata-updater.sh

@@ -213,6 +213,23 @@ tmpdir=
 
 trap cleanup EXIT
 
+while [ -n "${1}" ]; do
+  if [ "${1}" = "--not-running-from-cron" ]; then
+    NETDATA_NOT_RUNNING_FROM_CRON=1
+    shift 1
+  else
+    break
+  fi
+done
+
+# Random sleep to aileviate stampede effect of Agents upgrading
+# and disconnecting/reconnecting at the same time (or near to).
+# But only we're not a controlling terminal (tty)
+# Randomly sleep between 1s and 60m
+if [ ! -t 1 ] && [ -z "${NETDATA_NOT_RUNNING_FROM_CRON}" ]; then
+  sleep $(((RANDOM % 3600) + 1))s
+fi
+
 # Usually stored in /etc/netdata/.environment
 : "${ENVIRONMENT_FILE:=THIS_SHOULD_BE_REPLACED_BY_INSTALLER_SCRIPT}"
 

tests/lifecycle.bats

@@ -50,7 +50,7 @@ setup() {
 
 @test "update netdata" {
 	export ENVIRONMENT_FILE="${ENV}"
-	/etc/cron.daily/netdata-updater
+	${INSTALLATION}/netdata/usr/libexec/netdata/netdata-updater.sh --not-running-from-cron
 	! grep "new_installation" "${ENV}"
 }
 

tests/updater_checks.bats

@@ -54,9 +54,8 @@ setup() {
 @test "update netdata using the new updater" {
 	export ENVIRONMENT_FILE="${ENV}"
 	# Run the updater, with the override so that it uses the local repo we have at hand
-	# Try to run the installed, if any, otherwise just run the one from the repo
 	export NETDATA_LOCAL_TARBAL_OVERRIDE="${PWD}"
-	/etc/cron.daily/netdata-updater || ./packaging/installer/netdata-updater.sh
+	${INSTALLATION}/netdata/usr/libexec/netdata/netdata-updater.sh --not-running-from-cron
 	! grep "new_installation" "${ENV}"
 }