Setting up database and adding other required configurations

All dependent service host urls and API endpoints should be added in application.properties. Along with it whatever properties can be overwritten during deployment should be part of this file(eg: DB url and passwords,Kafka server properties, control knobs for functionalities etc.). To remove boilerplate code for referring variables from application.properties, we create a configuration file and autowire this configuration file wherever we need to refer to these variables. Following properties should be added for configuring database and kafka server( Use the default values, in case you want to tune kafka server that can be overwritten during deployment).

Once all the external dependencies have been added to pom.xml and these maven changes have been reloaded, the following properties should be added to application.properties file to configure database and kafka for development -

#DATABASE CONFIGURATION
spring.datasource.driver-class-name=org.postgresql.Driver
spring.datasource.url=jdbc:postgresql://localhost:5432/postgres
spring.datasource.username=postgres
spring.datasource.password=postgres

Kafka Configuration properties -

# KAFKA SERVER CONFIGURATIONS
kafka.config.bootstrap_server_config=localhost:9092
spring.kafka.consumer.value-deserializer=org.egov.tracer.kafka.deserializer.HashMapDeserializer
spring.kafka.consumer.key-deserializer=org.apache.kafka.common.serialization.StringDeserializer
spring.kafka.consumer.group-id={PLACEHOLDER_PUT_KAFKA_CONSUMER_NAME}
spring.kafka.producer.key-serializer=org.apache.kafka.common.serialization.StringSerializer
spring.kafka.producer.value-serializer=org.springframework.kafka.support.serializer.JsonSerializer
spring.kafka.listener.missing-topics-fatal=false
spring.kafka.consumer.properties.spring.json.use.type.headers=false

# KAFKA CONSUMER CONFIGURATIONS
kafka.consumer.config.auto_commit=true
kafka.consumer.config.auto_commit_interval=100
kafka.consumer.config.session_timeout=15000
kafka.consumer.config.auto_offset_reset=earliest

# KAFKA PRODUCER CONFIGURATIONS
kafka.producer.config.retries_config=0
kafka.producer.config.batch_size_config=16384
kafka.producer.config.linger_ms_config=1
kafka.producer.config.buffer_memory_config=33554432

To add custom properties in application.properties file and then referencing them in your application -