Northwatch

Appearance

Monitor multiple clusters ​

A single Northwatch process can monitor several independent OVN deployments at once. You describe them in a JSON config file and pass it with --config-file.

Write a config file ​

json
{
  "clusters": [
    {
      "name": "production",
      "label": "Production",
      "ovn_nb_addr": "tcp:10.0.0.1:6641,tcp:10.0.0.2:6641,tcp:10.0.0.3:6641",
      "ovn_sb_addr": "tcp:10.0.0.1:6642,tcp:10.0.0.2:6642,tcp:10.0.0.3:6642",
      "enrichment": {
        "type": "openstack",
        "os_auth_url": "https://keystone.example.com:5000/v3",
        "os_username": "northwatch",
        "os_password": "secret",
        "os_project_name": "admin",
        "os_domain_name": "Default",
        "os_region_name": "RegionOne"
      }
    },
    {
      "name": "staging",
      "label": "Staging",
      "ovn_nb_addr": "tcp:ovn-nb.staging.example.com:6641",
      "ovn_sb_addr": "tcp:ovn-sb.staging.example.com:6642"
    }
  ]
}

Each cluster needs a unique name and both addresses; label defaults to the name, and enrichment is optional and per-cluster. For the full field list see Configuration file.

Start with the config file ​

bash
./bin/northwatch --config-file /etc/northwatch/clusters.json

When the file defines more than one cluster, Northwatch prints Multi-cluster mode enabled with N clusters and advertises the multi-cluster capability.

Precedence

--snapshot takes precedence over everything. Otherwise, when --config-file is set, the flat --ovn-nb-addr / --ovn-sb-addr flags are ignored.

Reach each cluster ​

The first cluster in the file is the default and is served at the top-level routes (/api/v1/...). Every cluster — including the default — is also reachable under a per-cluster prefix:

bash
curl -s http://localhost:8080/api/v1/clusters                      # list clusters
curl -s http://localhost:8080/api/v1/clusters/staging/topology     # staging's topology
curl -s http://localhost:8080/api/v1/clusters/production/search?q=10.0.0.42

Try it with the lab ​

Bring up the bundled second lab cluster and point a config file at both:

bash
make lab-multi-up        # second cluster on NB :6643 / SB :6644
make lab-seed NB=tcp:127.0.0.1:6643

Then list two clusters in your config file (tcp:127.0.0.1:6641/6642 and tcp:127.0.0.1:6643/6644) and start Northwatch with --config-file.

Next steps ​