Add support for Helm3 (helm2 still supported)

[rmccorm4]

• Move securityContext from container scope to pod scope to support Helm3 in addition to Helm2.
• Update gcp/README.md and aws/README.md with instructions on Helm3 and Helm2 installation.

Before

Helm3

Helm3 fails with this error described here: zammad/zammad-helm#40

Fix is to move securityContext up one level from container scope to pod scope.

$ helm3 install local-helm3 . 
Error: unable to build kubernetes objects from release manifest: error validating "": error validating data: ValidationError(Deployment.spec.template.spec.containers[0].securityContext): unknown field "fsGroup" in io.k8s.api.core.v1.SecurityContext

Helm2

$ helm2 install --name local-helm2 .
NAME:   local-helm2
LAST DEPLOYED: Fri Jun 25 15:40:34 2021
NAMESPACE: default
STATUS: DEPLOYED

After

Helm3:

$ helm3 install local-helm3 .
--
NAME: local-helm3
LAST DEPLOYED: Fri Jun 25 15:12:41 2021
NAMESPACE: default
STATUS: deployed
REVISION: 1
TEST SUITE: None

Can query server status:

$ curl "${TRITON_IP}:${TRITON_HTTP_PORT_HELM3}/v2"
{"name":"triton","version":"2.10.0","extensions":["classification","sequence","model_repository","model_repository(unload_dependents)","schedule_policy","model_configuration","system_shared_memory","cuda_shared_memory","binary_tensor_data","statistics"]}

Helm2:

$ helm2 install --name local-helm2 .
--
NAME: local-helm2
LAST DEPLOYED: Fri Jun 25 15:13:06 2021
NAMESPACE: default
STATUS: DEPLOYED

Can query server status:

$ curl "${TRITON_IP}:${TRITON_HTTP_PORT_HELM2}/v2"
{"name":"triton","version":"2.10.0","extensions":["classification","sequence","model_repository","model_repository(unload_dependents)","schedule_policy","model_configuration","system_shared_memory","cuda_shared_memory","binary_tensor_data","statistics"]}

[rmccorm4]

@deadeyegoodwin for feedback on README installation changes

[orkenstein]

Was it updated here? https://catalog.ngc.nvidia.com/orgs/nvidia/helm-charts/tritoninferenceserver/files

I still get this error:

helm install https://helm.ngc.nvidia.com/nvidia/charts/tritoninferenceserver-1.0.0.tgz --generate-name

Error: INSTALLATION FAILED: unable to build kubernetes objects from release manifest: error validating "": error validating data: ValidationError(Deployment.spec.template.spec.containers[0].securityContext): unknown field "fsGroup" in io.k8s.api.core.v1.SecurityContext