statemonitor contains three components: controller, config, handler
The config object contains statemonitor configuration, like handlers, filters.
A config object is used to creating new client.
The controller initializes using the config object by reading the .statemonitor.yaml or command line arguments.
If the parameters are not fully mentioned, the config falls back to read a set of standard environment variables.
Controller creates necessary SharedIndexInformers provided by kubernetes/client-go for listening and watching
resource changes. Controller updates this subscription information with Kubernetes API Server.
Whenever, the Kubernetes Controller Manager gets events related to the subscribed resources, it pushes the events to
SharedIndexInformer. This in-turn puts the events onto a rate-limiting queue for better handling of the events.
Controller picks the events from the queue and hands over the events to the appropriate handler after necessary filtering.
Handler manages how statemonitor handles events.
With each event get from k8s and matched filtering from configuration, it is passed to handler. Currently, statemonitor has 8 handlers:
Default: which just print the event in JSON formatFlock: which send notification to Flock channel based on information from configHipchat: which send notification to Hipchat room based on information from configMattermost: which send notification to Mattermost channel based on information from configMS Teams: which send notification to MS Team incoming webhook based on information from configSlack: which send notification to Slack channel based on information from configSmtp: which sends notifications to email recipients using a SMTP server obtained from configLark: which sends notifications to Lark incoming webhook based on information from config
More handlers will be added in future.
Each handler must implement the Handler interface