Add latest changes from gitlab-org/gitlab@master

1 files changed, 30 insertions, 0 deletions

diff --git a/lib/version_check.rb b/lib/version_check.rb
index 2d132001f54..35014f3ddf0 100644
--- a/lib/version_check.rb
+++ b/lib/version_check.rb
@@ -5,6 +5,36 @@ require "base64"
 class VersionCheck
   include ReactiveCaching
 
+  ## Version Check Reactive Caching
+  ## This cache stores the external API response from https://version.gitlab.com
+  ##
+  ## Example API Response
+  ## {
+  ##   "latest_version": "15.2.2",
+  ##   "severity": "success"
+  ## }
+  ##
+  ## This response from this endpoint only changes in 2 scenarios:
+  ## 1. Customer upgrades their GitLab Instance
+  ## 2. GitLab releases a new version
+  ##
+  ## We use GitLab::VERSION as the identifier for the cached information.
+  ## This means if the user upgrades their version we will create a new cache record.
+  ## The old one will be invalidated and cleaned up at the end of the self.reactive_cache_lifetime.
+  ##
+  ## - self.reactive_cache_refresh_interval = 12.hours
+  ## We want to prevent as many external API calls as possible to save on resources.
+  ## Since an EXISTING cache record will only become "invalid" if GitLab releases a new version we
+  ## determined that 12 hour intervals is enough of a window to capture an available upgrade.
+  ##
+  ## - self.reactive_cache_lifetime = 7.days
+  ## We don't want the data to be missing every time a user revisits a page using this info.
+  ## Thus 7 days seems like a fair amount of time before we erase the cache.
+  ## This also will handle cleaning up old cache records as they will no longer be accessed after an upgrade.
+  ##
+
+  self.reactive_cache_refresh_interval = 12.hours
+  self.reactive_cache_lifetime = 7.days
   self.reactive_cache_work_type = :external_dependency
   self.reactive_cache_worker_finder = ->(_id, *args) { from_cache }