Add schema registry to Kafka tools

Author: onobc

tools/kafka/docker-compose/README.adoc

@@ -20,21 +20,45 @@ TIP: To start the containers in the foreground simply add `-d` to the start comm
 === Control Center UI
 Runs a https://docs.confluent.io/platform/current/control-center/index.html[Confluent Control Center] that exposes a UI at http://locahost:9021.
 
-NOTE: It is expected that the brokers are already running
+NOTE: The scripts must be chained together as the UI depends on the brokers
 
-To start the Control Center run the following command:
+To start the brokers and the Control Center UI run the following command:
 [source,shell]
 ----
-docker-compose -f ./control-center-ui.yml up
+docker-compose -f ./kafka-cluster.yml -f ./control-center-ui.yml up
 ----
-To stop the Control Center run the following command:
+To stop the brokers and the Control Center UI run the following command:
 [source,shell]
 ----
-docker-compose -f ./control-center-ui.yml down
+docker-compose -f ./kafka-cluster.yml -f ./control-center-ui.yml down
 ----
 
-TIP: The scripts can be chained together to start both cluster and UI in a single command
+=== Schema Registry
+Runs a https://docs.confluent.io/platform/current/schema-registry/index.html[Confluent Schema Registry] available at http://locahost:8081.
+
+NOTE: The scripts must be chained together as the schema registry depends on the brokers
+
+To start the brokers and the schema registry run the following command:
 [source,shell]
 ----
-docker-compose -f kafka-cluster.yml -f ./control-center-ui.yml up`
+docker-compose -f ./kafka-cluster.yml -f ./schema-registry.yml up
+----
+To stop the brokers and the schema registry run the following command:
+[source,shell]
 ----
+docker-compose -f ./kafka-cluster.yml -f ./schema-registry.yml down
+----
+
+=== All The Things
+The scripts can be chained together to start the cluster, UI and schema registry with the following commmand:
+[source,shell]
+----
+docker-compose -f kafka-cluster.yml -f ./control-center-ui.yml -f ./schema-registry.yml up
+----
+Likewise, to stop all the things:
+[source,shell]
+----
+docker-compose -f kafka-cluster.yml -f ./control-center-ui.yml -f ./schema-registry.yml down
+----
+
+TIP: The only "UI" representation of the schema registry is by navigating to a `Topic` and then clicking the `Schema` tab for the topic

tools/kafka/docker-compose/control-center-ui.yml

@@ -21,7 +21,7 @@ services:
       #CONTROL_CENTER_CONNECT_CONNECT-DEFAULT_CLUSTER: 'connect:8083'
       #CONTROL_CENTER_KSQL_KSQLDB1_URL: "http://ksqldb-server:8088"
       #CONTROL_CENTER_KSQL_KSQLDB1_ADVERTISED_URL: "http://localhost:8088"
-      #CONTROL_CENTER_SCHEMA_REGISTRY_URL: "http://schema-registry:8081"
+      CONTROL_CENTER_SCHEMA_REGISTRY_URL: "http://schema-registry:8081"
       CONTROL_CENTER_REPLICATION_FACTOR: 1
       CONTROL_CENTER_INTERNAL_TOPICS_PARTITIONS: 1
       CONTROL_CENTER_MONITORING_INTERCEPTOR_TOPIC_PARTITIONS: 1

tools/kafka/docker-compose/schema-registry.yml

@@ -0,0 +1,22 @@
+version: '2'
+
+# Runs a Confluent Schema Registry instance on 'http://localhost:8081'.
+#
+# Pre-requisites: The brokers are already running.
+
+services:
+  schema-registry:
+    image: confluentinc/cp-schema-registry:7.0.1
+    hostname: schema-registry
+    container_name: schema-registry
+    depends_on:
+      - broker1
+      - broker2
+      - broker3
+    ports:
+      - "8081:8081"
+    environment:
+      SCHEMA_REGISTRY_HOST_NAME: schema-registry
+      SCHEMA_REGISTRY_KAFKASTORE_BOOTSTRAP_SERVERS: 'broker1:29091,broker2:29092,broker3:29093'
+      SCHEMA_REGISTRY_LISTENERS: http://0.0.0.0:8081
+      SCHEMA_REGISTRY_LOG4J_ROOT_LOGLEVEL: WARN