Overview

Tanka is a composable configuration utility for Kubernetes. It leverages the Jsonnet language to realize flexible, reusable and concise configuration.

• 🔁 ksonnet drop-in replacement: Tanka aims to provide the same workflow as ksonnet: show, diff and apply are just where you expect them.
• 🔩 integrates with the ecosystem: Tanka doesn't re-invent the wheel. It rather makes heavy use of what is already there: jsonnet-bundler for package management and kubectl for communicating with Kubernetes clusters.
• 🔨 powerful: Being a jsonnet-compatibility layer for Kubernetes, it removes the limitations of static (or template-based) configuration languages.
• 🚀 used in production: We use Tanka internally at Grafana Labs for all of our Kubernetes configuration needs.
• ❤️ fully open-source: This is an open-source project. It is free as in beer and as in speech and this will never change.

Getting started

Head over to the Releases section and download the most latest release of Tanka for your OS and arch.

Then check everything is working correctly with

$ tk --version
tk version v0.3.0

It is also recommended to install Jsonnet bundler:

$ go get -u github.com/jsonnet-bundler/jsonnet-bundler/cmd/jb

Creating a new project

To start from scratch with the recommended directory structure, do the following:

# create a directory and enter it
$ mkdir poetry && cd poetry

# initialize the Tanka application
$ tk init

Deploying an application

As an example, Promtail is being deployed using Tanka now.

After you initialized the directory structure, install the required libraries using jb:

# Ksonnet kubernetes libraries
$ jb install github.com/ksonnet/ksonnet-lib/ksonnet.beta.4/k.libsonnet
$ jb install github.com/ksonnet/ksonnet-lib/ksonnet.beta.4/k8s.libsonnet

# Promtail library
$ jb install github.com/grafana/loki/production/ksonnet/promtail

Then, replace the contents of environments/default/main.jsonnet with the following:

local promtail = import 'promtail/promtail.libsonnet';

promtail + {
  _config+:: {
    namespace: 'loki',

    promtail_config+: {
      clients: [
        {
          scheme:: 'https',
          hostname:: 'logs-us-west1.grafana.net',
          username:: 'user-id',
          password:: 'password',
          external_labels: {},
        }
      ],
      container_root_path: '/var/lib/docker',
    },
  },
}

As a last step, fill add the correct spec.apiServer and spec.namespace to environments/default/spec.json:

{
  "apiVersion": "tanka.dev/v1alpha1",
  "kind": "Environment",
  "spec": {
    "apiServer": "https://localhost:6443",
    "namespace": "default"
  }
}

Now use tk show environments/default to see the yaml, and tk apply environments/default to apply it to the cluster.

Congratulations! You have successfully set up your first application using Tanka 🎉

Additional resources

• https://jsonnet.org/, the official Jsonnet documentation provides lots of examples on how to use the language.
• https://github.com/grafana/jsonnet-libs: Grafana Labs' Jsonnet libraries are a rich set of configuration examples compatible with Tanka.

License

Licensed Apache 2.0, see LICENSE.