Add missing /-/healthy endpoint

[danielmotaleite]

Thanos, Prometheus and Golang version used

thanos_build_info{branch="master",goversion="go1.10.5",revision="9cec8371f78cd96dba7405885773eb7afc8556dc",version="0.1.0"} 1
improbable/thanos:master-2018-11-12-9cec837

What happened
on thanos-sidecar i have done this:

curl localhost:10902/-/healthy

What you expected to happen
Thanos-sidecar health status .. instead i got 404. Notice that /metrics do return successful

So while thanos-query return the /-/healthy endpoint, at least thanos-sidecar and thanos-store do not. They should exist for consistency and to help building proper healthchecks

i still haven't deployed thanos-rules and thanos-compact, so i can't tell if they are also missing the endpoint

[bwplotka]

This known. The advice is to use /metrics as healthy endpoint for now which nicely shows when service is ready.

This might be not elegant as metrics endpoint is for different purposes, so PRs welcome (:

[FUSAKLA]

Hooray so this should be finally resolved, thanks @kakkoyun for helping with this and everyone reviewing 🎉

Related PRs:

• #1540 Thanos Downsample added /-/ready and /-/healthy endpoints.
• #1538 Thanos Rule added /-/ready and /-/healthy endpoints.
• #1537 Thanos Receive added /-/ready and /-/healthy endpoints.
• #1460 Thanos Store Added /-/ready and /-/healthy endpoints.
• #1534 Thanos Query Added /-/ready and /-/healthy endpoints.
• #1395 Thanos Sidecar added /-/ready and /-/healthy endpoints to Thanos sidecar.
• #1297 Thanos Compact added /-/ready and /-/healthy endpoints to Thanos compact.