SC-4946: Send container id, name and image as tags for application metrics

[sivasamyk]

• Update AA to send container name, id, image, hostname, host.hostname and kubernetes pod, namespace, and cluster tags if present as physical tags with all metrics
• The above tags can be passed as env vars to AA container image from STA or during manual startup. AA expects either all container tags or all kubernetes tags to be present. else will throw an error and won't proceed
• when these params are set AA assumes it is running in a container or k8s env
• The old logic of .docker file will continue to work with nodejs based disco.
• Adjusted container.hostname to be read from any app config param which ends with _HOST_PORT

Tested with normal process based install (should not send any of the above tags ) and from STA auto disco. Tested k8s by manually passing the env vars but not in actual k8s setup

Sample output:

The physical hostname is optimus-prime and AA is monitoring ES docker container

tag.alias,token=df372e3b-7e40-4d05-8ca3-b6a8f8905485,container.id=b58e4f3c7ebfa51b585f64b1fcf331e809fb43cdade113a53bd559fd22159684,container.host.hostname=optimus-prime,container.image=docker.elastic.co/elasticsearch/elasticsearch:6.2.4,os.host=optimus-prime,container.name=brave_brahmagupta,jvm=brave_brahmagupta,tag.alias.type=config,container.hostname=172.17.0.2 appType="elasticsearch" 1559814609209000000

jvm,token=df372e3b-7e40-4d05-8ca3-b6a8f8905485,jvm=brave_brahmagupta,es.node.id=JUdHzleNRsWUxVfII2fNqw,container.hostname=172.17.0.2,container.name=brave_brahmagupta,container.host.hostname=optimus-prime,os.host=optimus-prime,container.image=docker.elastic.co/elasticsearch/elasticsearch:6.2.4,es.node=JUdHzle,container.id=b58e4f3c7ebfa51b585f64b1fcf331e809fb43cdade113a53bd559fd22159684 threads.peak=32i,threads=32i,files.open=460i,files.max=1048576i 1559814612238000000

heartbeat,token=df372e3b-7e40-4d05-8ca3-b6a8f8905485,container.id=b58e4f3c7ebfa51b585f64b1fcf331e809fb43cdade113a53bd559fd22159684,container.host.hostname=optimus-prime,container.image=docker.elastic.co/elasticsearch/elasticsearch:6.2.4,os.host=optimus-prime,jvm=brave_brahmagupta,container.name=brave_brahmagupta,container.hostname=172.17.0.2 alive=1i 1559814612238000000