How to post topics using Hermes Kafka messaging and Kafka Stream Connect

[Shubham44]

Producer Setup

Now let's talk about how to setup hermes messaging service which will connect to your own servicenow instance to act as a Kafka bus, well the steps are pretty straight-forward defined in the url below
https://docs.servicenow.com/bundle/utah-servicenow-platform/page/administer/hermes-messaging-service... 

Once you follow these setups, the folder for hermes will look like this it will have the keystore file and the private key.

Once you are done with this . Create a test flow using kafka stream connect to trigger messages from Servicenow  acting as a producer to the consumer instance

All you need to add is the custom action with the kafka producer step and the trigger can be of your own choice . For e.g. in the video above i am using trigger of incident creation. 

After the action is created , please add that to the flow.

Consumer setup

1. Download and install Apache Kafka
2. Once the download is done , open the config/consumer.properties file and make the below changes

   group.id=test-consumer-group
   
   # What to do when there is no initial offset in Kafka or if the current
   # offset does not exist any more on the server: latest, earliest, none
   #auto.offset.reset=
   security.protocol=SSL
   
   ssl.truststore.password=####
   
   ssl.truststore.location=/Users/shubham.mittal/Documents/hermeskafka/hermesQuickStart/hermestruststore.p12
   
   
   ssl.truststore.type=PKCS12
   
   ssl.keystore.password=#####
   
   ssl.keystore.location=/Users/shubham.mittal/Documents/hermeskafka/hermesQuickStart/hermesdemoKafkaKeystore.p12
   
   ssl.keystore.type=PKCS12
   ssl.key.password=####

Add the truststore and the key password that you have defined while setting the hermes messaging service.

Now let's also do the same configuration in the config/producer.properties to act your local kafka as a producer as well.

the cli commands to start the local kafka as a consumer is 

./bin/kafka-console-consumer.sh --consumer.config ./config/consumer.properties --topic snc.<instance_name>.<namespace>.sn_<app_id>.<topic_name> --group snc.<instance_name>.<consumer_group_id> --from-beginning --bootstrap-server <instance_name>.service-now.com:4100,<instance_name>.service-now.com:4101,<instance_name>.service-now.com:4102,<instance_name>.service-now.com:4103

and to act as a producer is

./bin/kafka-console-producer.sh --topic snc.<instance_name>.<namespace>.sn_<app_id>.<topic_name> --producer.config ./config/producer.properties --bootstrap-server <instance_name>.service-now.com:4000,<instance_name>.service-now.com:4001,<instance_name>.service-now.com:4002,<instance_name>.service-now.com:4003

the sample flow to consume messages is

#hermesmessaging #kafkastreamconnect