consul: add support for service weight

[mvegter]

Manual verification

No `weights`

$ curl -s http://127.0.0.1:8500/v1/agent/services  | jq '.[] | select(.Service=="global-redis-check") | .Weights'
{
  "Passing": 1,
  "Warning": 1
}

$ dig @127.0.0.1 -p 8600 global-redis-check.service.consul SRV +short
1 1 27982 7f000001.addr.dc1.consul.

---

weights {}

$ ./bin/nomad job plan ./job.hcl
+/- Job: "redis"
+/- Task Group: "cache" (1 in-place update)
  +/- Task: "redis" (forces in-place update)
    +/- Service {
        Address:           ""
        ...
      + Weights {
        + Passing: "1"
        + Warning: "1"
        }
        }

$ curl -s http://127.0.0.1:8500/v1/agent/services  | jq '.[] | select(.Service=="global-redis-check") | .Weights'
{
  "Passing": 1,
  "Warning": 1
}	

---

weights {
  passing = 5
}

$ ./bin/nomad job plan ./job.hcl
+/- Job: "redis"
+/- Task Group: "cache" (1 in-place update)
  +/- Task: "redis" (forces in-place update)
    +/- Service {
          Address:           ""
          ...
      +/- Weights {
        +/- Passing: "1" => "5"
            Warning: "1"
          }
        }

$ curl -s http://127.0.0.1:8500/v1/agent/services  | jq '.[] | select(.Service=="global-redis-check") | .Weights'
{
  "Passing": 5,
  "Warning": 1
}

$ dig @127.0.0.1 -p 8600 global-redis-check.service.consul SRV +short
1 5 30957 7f000001.addr.dc1.consul.

[tgross]

Hi @mvegter! Just wanted to let you know we do see this PR and appreciate that you're trying to get tests green. We're a little swamped with some post-1.9.0 mop-up but we'll review this as soon as feasible. Thanks!

[mvegter]

hey @tgross , thanks for the heads up. After some more testing I noticed a small issue where the agentServiceUpdateRequired returned false when going from having the weights stanza to unsetting it. It should now be fixed and added some more tests to cover this as well, I see the last failing pipelines turning green as we speak. Looking forward to your feedback !

[Juanadelacuesta]

Hello @mvegter thank you for putting more work into your PR, @philrenaud can give you a hand on the Vercel problems.

[tgross]

Hi @mvegter! This is looking really good. I've left some comments but once those are resolved I think we'll be ready to merge.

[tgross]

LGTM! Once CI has finished we'll get this merged and it'll ship in the next release of Nomad. Thanks @mvegter!

[mvegter]

Thanks @tgross , looking forward to the next release of 1.9.x !