kubecfg

A tool for managing Kubernetes resources as code.

kubecfg allows you to express the patterns across your infrastructure and reuse these powerful "templates" across many services, and then manage those templates as files in version control. The more complex your infrastructure is, the more you will gain from using kubecfg.

Status: Basic functionality works, and the tool is usable. The focus now is on clearer error reporting and advanced features.

Yes, Google employees will recognise this as being very similar to a similarly-named internal tool ;)

Install

Pre-compiled executables exist for some platforms on the Github releases page.

To build from source:

% PATH=$PATH:$GOPATH/bin
% go get github.com/ksonnet/kubecfg

Requires golang >=1.7 and a functional cgo environment (C++ with libstdc++). Note that recent OSX environments require golang >=1.8.1 to avoid an immediate Killed: 9.

Quickstart

# Include <kubecfg.git>/lib in kubecfg/jsonnet library search path.
# Can also use explicit `-J` args everywhere.
% export KUBECFG_JPATH=/path/to/kubecfg/lib

# Show generated YAML
% kubecfg show -o yaml -f examples/guestbook.jsonnet

# Create resources
% kubecfg update -f examples/guestbook.jsonnet

# Modify configuration (downgrade gb-frontend image)
% sed -i.bak '\,gcr.io/google-samples/gb-frontend,s/:v4/:v3/' examples/guestbook.jsonnet
# See differences vs server
% kubecfg diff -f examples/guestbook.jsonnet

# Update to new config
% kubecfg update -f examples/guestbook.jsonnet

# Clean up after demo
% kubecfg delete -f examples/guestbook.jsonnet

Features

• Supports JSON, YAML or jsonnet files (by file suffix).
• Best-effort sorts objects before updating, so that dependencies are pushed to the server before objects that refer to them.
• Additional jsonnet builtin functions. See lib/kubecfg.libsonnet.

Infrastructure-as-code Philosophy

The idea is to describe as much as possible about your configuration as files in version control (eg: git).

Changes to the configuration follow a regular review, approve, merge, etc code change workflow (github pull-requests, phabricator diffs, etc). At any point, the config in version control captures the entire desired-state, so the system can be easily recreated in a QA cluster or to recover from disaster.

Jsonnet

Kubecfg relies heavily on jsonnet to describe Kubernetes resources, and is really just a thin Kubernetes-specific wrapper around jsonnet evaluation. You should read the jsonnet tutorial, and skim the functions available in the jsonnet std library.