NewEntity does add the new entity to the integration

[jregovic]

Description

When calling integration.NewEntity in an integration, the entity is not added to the list of entities for the integration. This results in the integration data being missing

Expected Behavior

The entity should be added to the list of integrations and the data serialized.

Steps to Reproduce

• Install redis
• Download the redis example from https://github.com/newrelic/infra-integrations-sdk/blob/master/docs/tutorial-code/single-entity/redis.go
• Run the integration:

go run redis.go -metrics -hostname localhost 

{"protocol_version":"4","integration":{"name":"com.myorg.redis","version":"0.1.0"},"data":[]}

Your Environment

MacOS 10.15.7
infra-integrations-sdk v4.1.0

Additional context

The issue is fixed by creating the entity and adding :

i.Entities = append(i.Entities,entity)
go run redis.go -metrics -hostname localhost 

{"protocol_version":"4","integration":{"name":"com.myorg.redis","version":"0.1.0"},"data":[{"common":{},"entity":{"name":"redis_01","displayName":"RedisServer","type":"my-redis","metadata":{}},"metrics":[{"timestamp":1631239424,"name":"query.instantaneousOpsPerSecond","type":"gauge","attributes":{},"value":0}],"inventory":{},"events":[]}]}

[jregovic]

In v3.7.0, the somewhat equivalent method, Entity does add the new entity to the list of entities.

infra-integrations-sdk/integration/integration.go

Line 194 in 1f48f6c

i.Entities = append(i.Entities, e)

The AddEntity method exists, but it is not obvious that this would need to be called, especially when updating to the v4 protocol.