boulder/test/consul/README.md

Consul in Boulder

We use Consul in development mode (flag: -dev), which configures Consul as an in-memory server and client with persistence disabled for ease of use.

Configuring the Service Registry

• Open ./test/consul/config.hcl

• Add a services stanza for each IP address and (optional) port combination you wish to have returned as an DNS record. The following stanza will return two records when resolving foo-purger. (docs).

  services {
    id      = "foo-purger-a"
    name    = "foo-purger"
    address = "10.77.77.77"
    port    = 1338
  }
  
  services {
    id      = "foo-purger-b"
    name    = "foo-purger"
    address = "10.88.88.88"
    port    = 1338
  }
  

• To target individual foo-purger's, add these additional service sections which allow resolving foo-purger-1 and foo-purger-2 respectively.

  services {
    id      = "foo-purger-1"
    name    = "foo-purger-1"
    address = "10.77.77.77"
    port    = 1338
  }
  
  services {
    id      = "foo-purger-2"
    name    = "foo-purger-2"
    address = "10.88.88.88"
    port    = 1338
  }
  

• For RFC 2782 (SRV RR) lookups to work ensure you that you add a tag for the supported protocol (usually "tcp" and or "udp") to the tags field. Consul implemented the the Proto field as a tag filter for SRV RR lookups. For more information see the docs.

  services {
    id      = "foo-purger-a"
    name    = "foo-purger"
    address = "10.77.77.77"
    port    = 1338
    tags    = ["udp", "tcp"]
  }
  ...
  

• Services are not live-reloaded. You will need to cycle the container for every Service Registry change.

Accessing the web UI

Linux

Consul should be accessible at http://10.55.55.10:8500.

Mac

Docker desktop on macOS doesn't expose the bridge network adapter so you'll need to add the following port lines (temporarily) to docker-compose.yml:

  bconsul:
    ports:
      - 8500:8500 # forwards 127.0.0.1:8500 -> 10.55.55.10:8500

For testing DNS resolution locally using dig you'll need to add the following:

  bconsul:
    ports:
      - 53:53/udp # forwards 127.0.0.1:53 -> 10.55.55.10:53

The next time you bring the container up you should be able to access the web UI at http://127.0.0.1:8500.