Consul Jsonnet

A set of extensible configs for running Consul on Kubernetes.

To use this libary, install Tanka and Jsonnet Bundler.

In your config repo, if you don't have a Tanka application, make a new one (will copy credentials from current context):

$ mkdir <application name>
$ cd <application name>
$ tk init

Then you can install the library with:

jb install github.com/grafana/jsonnet-libs/consul

• Assuming you want to run in the default namespace ('environment' in Tanka parlance), add the following to the file environments/default/main.jsonnet:

local consul = import "consul/consul.libsonnet";

consul + {
  _config+:: {
    consul_replicas: 1,
  }
}

• Apply your config:

$ tk apply default

Customising and Extending.

The choice of Tanka for configuring these jobs was intentional; it allows users to easily override setting in these configurations to suit their needs, without having to fork or modify this library. For instance, to override the resource requests and limits for the Consul container, you would:

local consul = import "consul/consul.libsonnet";

consul {
  consul_container+::
     $.util.resourcesRequests("1", "2Gi") +
     $.util.resourcesLimits("2", "4Gi"),
}

We sometimes specify config options in a _config dict; there are two situations under which we do this:

• When you must provide a value for the parameter (such as namesapce).
• When the parameter get referenced in multiple places, and overriding it using the technique above would be cumbersome and error prone (such as with cluster_dns_suffix).

We use these two guidelines for when to put parameters in _config as otherwise the config field would just become the same as the jobs it declares - and lets not forget, this whole thing is config - so its completely acceptable to override pretty much any of it.