Changes for multi schematic Services

Follow the generic updates before starting with the following changes

General update for services to be Central-Instance compatible

Application.properties variables to be added

state.level.tenantid.length=2
State-level tenant value will be picked from the full tenant-id separated by the '.' dot. once the tenant-id is separated by dot the resulting array of size given above will be considered state level.
is.environment.central.instance=true
Declares whether the environment in which the service is deployed belong to a central-instance kind of setup.

The both above said variable has to be overridden in the values YAML file of the respective service to pick up the values from the environment.

  {{- if index .Values "global" "is-environment-central-instance" }}        
  - name: IS_ENVIRONMENT_CENTRAL_INSTANCE
    valueFrom:
      configMapKeyRef:
        name: egov-config
        key: is-environment-central-instance
  {{- end }}
  {{- if index .Values "global" "is-environment-central-instance" }}        
  - name: STATE_LEVEL_TENANTID_LENGTH
    valueFrom:
      configMapKeyRef:
        name: egov-config
        key: state-level-tenantid-length
  {{- end }}

The host of the state-specific services referred by this service should be changed to the internal gateway host for tenant-based(namespace) redirection.
```
  - name: EGOV_MDMS_HOST
    valueFrom:
      configMapKeyRef:
        name: egov-service-host
        key: internal-gateway
```
Sample values YAML file to refer to the above-said changes
https://github.com/egovernments/DIGIT-DevOps/blob/central-instance/deploy-as-code/helm/charts/municipal-services/property-services/values.yaml

If this service allows the search of data without tenant-id then the following validation should be added to all the search APIs belonging to the service. searches without state-level tenant-id (as described by this variable - state.level.tenantid.length) will render the application useless, so the following is mandatory

	if(configs.getIsEnvironmentCentralInstance() && criteria.getTenantId() == null)
		throw new CustomException("EG_PT_INVALID_SEARCH"," TenantId is mandatory for search ");
	else if(configs.getIsEnvironmentCentralInstance() && criteria.getTenantId().split("\\.").length < configs.getStateLevelTenantIdLength())
		throw new CustomException("EG_PT_INVALID_SEARCH"," TenantId should be mandatorily " + configs.getStateLevelTenantIdLength() + " levels for search");

Replace all the table names in the queries present with the {schema} placeholder

private static String PROEPRTY_AUDIT_QUERY = "select property from {schema}.eg_pt_property_audit where propertyid=?";

Add the following Schema replacer utility method and use the same to replace all queries with the respective schema.

	/**
	 * Method to fetch the state name from the tenantId
	 * 
	 * @param query
	 * @param tenantId
	 * @return
	 */
	public String replaceSchemaPlaceholder(String query, String tenantId) {

		String finalQuery = null;
		if (tenantId.contains(".")) {
			String schemaName = tenantId.split("\\.")[1];
			finalQuery = query.replace(PTConstants.SCHEMA_REPLACE_STRING, schemaName);
		} else {
			finalQuery = query.replace(PTConstants.SCHEMA_REPLACE_STRING.concat("."), "");
		}
		return finalQuery;
	}
	
   /*
	* Sample method example to replace query with schema
	*/	
	public List<String> getPropertyIds(Set<String> ownerIds, String tenantId) {

		List<Object> preparedStmtList = new ArrayList<>();
		String query = queryBuilder.getPropertyIdsQuery(ownerIds, tenantId, preparedStmtList);
		query = util.replaceSchemaPlaceholder(query, tenantId);
		return jdbcTemplate.queryForList(query, preparedStmtList.toArray(), String.class);
	}

Change the persister config to alter the Kafka topic names for the configs belonging to your respective multi-schema service. The kafka topic name should be appended with the schema name of the respective state schema.