WARNING: This documentation is not complete.

Configs

This directory contains all of the configs needed to run M3 in a variety of modes (local, clustered, etc.)

How-To

Below are instructions for how to generate a yaml file for the clustered M3DB jsonnet file. Other jsonnet files follow a similar pattern.

1. Navigate to ./m3db/clustered-etcd directory
2. Add any changes to either the db or coordinator sections of the config that you want to change from the base file (m3dbnode.libsonnet) in m3dbnode_cmd.libsonnet using local variables. For example, to change the listen address of the coordinator as well as input the hosts and IP addresses of the etcd nodes:

local lib = import 'm3dbnode.libsonnet';

local cluster = {
  HOST1_ETCD_ID: "host_name1",
  HOST1_ETCD_IP_ADDRESS: "host_ip1",
  HOST2_ETCD_ID: "host_name2",
  HOST2_ETCD_IP_ADDRESS: "host_ip2",
  HOST3_ETCD_ID: "host_name3",
  HOST3_ETCD_IP_ADDRESS: "host_ip3",
};

local coordinator = {
        "listenAddress": {
            "type": "config",
            "value": "localhost:7208"
    },
};

std.manifestYamlDoc(lib(cluster, coordinator))

3. Run the following jsonnet command. This will generate a file called generated.yaml within the directory.

	make config-gen

Configuration Schemas

At this time, each service's configuration is defined as a Go struct in a corresponding config package. For instance, m3aggregator's config is in src/cmd/services/m3aggregator/config/config.go.

Validation is done using https://godoc.org/gopkg.in/go-playground/validator.v2, look for validate tags in the structs.

Advanced: Environment Variable Interpolation

M3 uses go.uber.org/config to load its configuration. This means that we support environment variable interpolation of configs. For example:

Given the following config:

foo: ${MY_ENV_VAR}

and an environment of MY_ENV_VAR=bar, the interpolated YAML will be:

foo: bar

This can be useful for further tweaking your configuration without generating different files for every config permutation.