linux deployment - set agent socket path

[qrkourier]

The Linux deployments place the agent's socket file in the default path which requires the admin to mount the filesystem namespace.

systemctl show -p MainPID --value ziti-controller.service \
| xargs -rIPID sudo nsenter --target PID --mount -- \
ziti agent stats

It will be a better experience if the agent's socket is reachable directly by the admin, e.g., after this issue is resolved:

sudo ziti agent stats --client-agent-addr /var/lib/ziti-controller/gops-agent.sock

Or, after this issue is resolved, simply:

sudo ziti agent stats

[qrkourier]

After some discussion in the linked issue #2499, the Linux deployments will use a socket filename that more closely resembles the default socket filename, e.g., gops-agent.1110840.sock:

• /var/lib/ziti-controller/gops-agent.sock
• /var/lib/ziti-router/gops-agent.sock

It's crucial the filename is predictable, or appears in a predictable location, so that orchestration/wrappers can self-configure

[qrkourier]

blocked by #2502

[dovholuknf]

this seems liek the sort of thing we can do later, no?