Clojube

Kubernetes YAML config generator.

Rationale

To minimise friction for onboarding any application that runs with docker 19 onto kubernetes.

All apps will use a network port, some storage and an image, however, applications usually have a different setup for different environments. Clojube will handle generation of YAML of multiple environments for you.

Additionally, clojure also provides the feature where you can replace any part of the environment config with the name of another enviroment (as long as it's not in a list) and it will automatically be filled in for you. See the examples folder.

Installation

Linux and macOS

Install bb

bash <(curl -s https://raw.githubusercontent.com/borkdude/babashka/master/install)

copy the script somewhere

install -m +rx -o $USER clojube.clj /usr/local/bin/clojube.clj

Windows

Install bb

Grab it from github https://github.com/borkdude/babashka/releases/download/v0.2.1/babashka-0.2.1-windows-amd64.zip

copy the script somewhere

this should be on your path

Usage

clojube.clj config.edn

Clojube will created YAML files that can be applied by kubectl apply -f in the correct order.

You need to provide config.edn, which is some edn file. An edn file is basically similar to JSON, but is far easier to read.

The edn file must include a name, output folder and environments. Example valid EDN:

{:name          "core"
 :output-folder "output"
 :develop       {:image      "nginx:1.19"
                 :ports      [8001, {:from 8080
                                     :to   30080}]
                 :volumes    [{:path      "/var/www/html"
                               :host-path "/html"
                               :mode      :rw
                               :id        "webroot"}]
                 :deployment {:type   :anywhere
                              :number 1}}

Top level required keys

:name : the name of the app

:output-folder : this is the output folder relative to the config.edn location

Environment required keys

:image : docker image, must be available with the gitlab-registry-key secret

:ports : a list of ports. If it's just a number, it will be a port internal to the pod, but if it's a map, then it will create a service with the container port and the host port

:volumes : a list of volumes, in the docker sense.

• :path : local to the container
• :host-path : local to the node (computer)
• :mode : :rw (read-write) and :ro (read-only) is allowed.
• :id : optional id

:deployment : explains how this should be deployed across the cluster

• :type : :anywhere and :per-machine allowed
• :number: replicas created, only when :anywhere is selected