Add `--manager`, `--service`, and `--namespace` flags

[clcollins]

Add management/service/hive & namespace login flags

• Adds --manager and --service flags to allow logging into MC/Hive and SC clusters for a provided --cluster-id.
• Adds --namespace flag to override the default NS on whatever cluster is being logged into
• Removes login logic from ~/.bashrc.d/* files inside the container, moving the responsibility of login to ocm-container's binary
• Adds related and other helpful ENV vars inside the container

Example ENVs logging into a classic cluster (or it's hive):

CLUSTER_NAME=
HIVE_NAME=
HIVE_NS=
CLUSTER_UID=
CLUSTER_ID=
CLUSTER_UUID=

And example for HPC:

CLUSTER_NAME=
CLUSTER_UID=
SC_ID=
HCP_NS=
CLUSTER_ID=
HC_NS=
MC_ID=
KUBELET_NS=
CLUSTER_UUID=

And extra vars that might be helpful, for any cluster:

CLUSTER_STS=
CLUSTER_PRIVATE_LINK=
CLUSTER_CCS=
CLUSTER_CLOUD_PROVIDER=

Fixes #271 Fixes #270

WIP - TODO:

• Add a log message immediately before spawning login execs so users will have positive feedback on why they're waiting. This used to be incidental as a result of the different bash scripts, making it feel like login wasn't just hanging, but even though it's the same length if ocm-container executes the login, because there's no feedback it feels like ocm-container has hung.
• Figure out how to perform the login to ocm and backplane in order, but async from the container attachment, to speed up the login.
• Do the plumbing to pick the right cluster if --manager, --service or --namespace are provided.

Signed-off-by: Chris Collins collins.christopher@gmail.com

[openshift-ci[bot]]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: clcollins

The full list of commands accepted by this bot can be found here.

The pull request process is described here

Needs approval from an approver in each of these files: - ~~[OWNERS](https://github.com/openshift/ocm-container/blob/master/OWNERS)~~ [clcollins] Approvers can indicate their approval by writing `/approve` in a comment Approvers can cancel approval by writing `/approve cancel` in a comment

[rendhalver]

I have been thinking about this one. I think replicating the flags ocm backplane login uses is a good idea so we can just pass them to backplane. Adding extra flags seems like something we should do in backplane so we aren't doing things differently and we can share idea across the teams. Other thoughts: does backplane have anything we can use to work out which flags are mutually exclusive so we don't need to keep our own copy of those?

The new --ohss and existing --pd flags would also be good to replicate. https://source.redhat.com/groups/public/sre/wiki/setup_backplane_cli#isPasted4

Kirk's changes in #295 will also help with the OCM logins.

[openshift-merge-robot]

PR needs rebase.

Instructions for interacting with me using PR comments are available [here](https://git.k8s.io/community/contributors/guide/pull-requests.md). If you have questions or suggestions related to my behavior, please file an issue against the [kubernetes-sigs/prow](https://github.com/kubernetes-sigs/prow/issues/new?title=Prow%20issue:) repository.