Kafka observ lib (#1291)

* Update grafonnet dependency in commonlib

* Add support for building tables in commonlib.

* Revert newline

* Update tests

* Fix tests

* Add tests

* Add kafka-observ-lib

* Drop lag and topics dashboards

* Add kafka topics overview dashboard in kafka-mixin (use kafka-observ-lib)

* Update readme

* Update legendFormat

* Add alert

* Fix stub

* Add consumerGroupLagTime signal

* Add KafkaLagIsTooHigh alert

* Fix typo in alert

* Add dynamic severity

kafka-mixin/README.md

@@ -4,12 +4,11 @@ The Kafka Mixin is a set of configurable, reusable, and extensible dashboards ba
 
 This mixin includes the following dashboards:
 Kafka Overview - Gives an overview of your Kafka cluster resource usage, throughput, and general healthiness 
-kafka-topics - Gives informations about the throughput of specific (filterable) topics
+Kafka topics overview - Gives informations about the throughput of specific (filterable) topics and consumer groups (rate, lag)
 Zookeeper Overview - Gives an overview of your Zookeeper nodes resource usage and general healthiness 
 Ksqldb Overview - Gives an overview of your ksqldb cluster as queries resource usage, throughput, and general healthiness 
 Connect Overview - Gives an overview of your Kafka Connect cluster and tasks resource usage, throughput, and general healthiness
 Schema Registry Overview - Gives an overview of your Kafka Schema Registry cluster resource usage, throughput, and general healthiness
-Kafka Lag Overview - Gives Lag metrics by time and offset count on topics and partitions of the cluster
 
 To use them, you need to have `mixtool` and `jsonnetfmt` installed. If you have a working Go development environment, it's easiest to run the following:
 

kafka-mixin/config.libsonnet

@@ -7,5 +7,6 @@
     ksqldbFilteringSelector: 'job=~"integrations/kafka-ksqldb|integrations/kafka"',
     groupLabels: ['job', 'kafka_cluster'],
     instanceLabels: ['instance'],
+    dashboardTags: ['kafka-integration'],
   },
 }

kafka-mixin/dashboards/dashboards.libsonnet

@@ -3,9 +3,7 @@
   grafanaDashboards+:: {
     'connect-overview.json': (import 'connect-overview.json'),
     'kafka-ksqldb-overview.json': (import 'kafka-ksqldb-overview.json'),
-    'kafka-lag-overview.json': (import 'kafka-lag-overview.json'),
     'kafka-overview.json': (import 'kafka-overview.json'),
-    'kafka-topics.json': (import 'kafka-topics.json'),
     'schema-registry-overview.json': (import 'schema-registry-overview.json'),
     'zookeeper-overview.json': (import 'zookeeper-overview.json'),
   },