Inside minikube source code

NOTE: The source code discussed in this article is based on master branch

We are going to create a separate brand new GOPATH directory for minikube to demonstrate how to do the whole process fresh from scratch. On my local machine I’ve create a directory called minikubegopath with the following structure

.
├── bin
├── pkg
└── src
    └── k8s.io

Make sure are you inside the src/k8s.io directory when cloning minikube

git clone https://github.com/kubernetes/minikube

Open the minikube inside the IDE and set the GOPATH to the new GOPATH directory that have minikube, setup it as shown in the screenshot below

MinikubeSourceCodeSettingGoPath

Select the the main.go file that reside in cmd/minikube directory and hit the run button. You will get an error output as shown below, this is because there are some files that need to be generated and this can be done using the make command

MinikubeSourceCodeHitRun

go: downloading github.com/mattn/go-isatty v0.0.8
go: downloading github.com/pkg/profile v0.0.0-20161223203901-3a8809bd8a80
go: downloading github.com/golang/glog v0.0.0-20160126235308-23def4e6c14b

.....
.....
.....


# k8s.io/minikube/pkg/minikube/translate
../../pkg/minikube/translate/translate.go:77:12: undefined: Asset

Compilation finished with exit code 2

Use the following make command to generate the files needed

make pkg/minikube/assets/assets.go pkg/minikube/translate/translations.go

You will see the following output

which go-bindata || GO111MODULE=off GOBIN=XXXXXXXX/minikubegopath/bin go get github.com/jteeuwen/go-bindata/...
....... go-bindata -nomemcopy -o pkg/minikube/assets/assets.go -pkg assets deploy/addons/...
gofmt -s -w pkg/minikube/assets/assets.go
......
GOOS="linux" GOARCH="amd64" go build -tags "container_image_ostree_stub containers_image_openpgp" -ldflags="-X k8s.io/minikube/pkg/version.version=v1.4.0-beta.2 -X k8s.io/minikube/pkg/version.isoVersion=v1.4.0-beta.2 -X k8s.io/minikube/pkg/version.isoPath=minikube/iso -X k8s.io/minikube/pkg/version.gitCommitID="d1e468085d9af12e5d130a6cb3b2186a5db87a0e-dirty"" -a -o out/minikube-linux-amd64 k8s.io/minikube/cmd/minikube

Following are the generated files

pkg/minikube/assets/assets.go --> generate source code to allow loading of addons .yaml files
pkg/minikube/translate/translations.go --> generate source code for translations data file

Makefile

Following table explains some of the available tasks:


pkg/minikube/assets/assets.go ==> generate source code needed to build minikube. Source code generated are used for loading of .yaml file
pkg/minikube/translate/translations.go ==> generate source code for translations data file
minikube-linux-amd64 ==> generate minikube for Linux 64-bit. Windows task minikube-windows-amd64.exe and MacOS minikube-darwin-amd64
out/e2e-linux-amd64 ==> compile end-to-end testing and minikube binary for testing purposes
minikube_iso ==> used internally to generate the .iso file. Better use the out/minikube.iso
iso-menuconfig ==> change buildroot configuration for minikube iso
linux-menuconfig ==> change kernel configuration for minikube iso
all ==> compile and generate minikube for the 3 platforms - Linux, Windows and MacOS
cross ==> build minikube for the 3 platforms - Linux, Windows and MacOS

Source structure

.
├── cmd
│   ├── drivers
│   │   ├── hyperkit
│   │   └── kvm
│   ├── extract
│   ├── gvisor
│   ├── minikube
│   │   └── cmd
│   │       └── config
│   └── storage-provisioner
├── deploy
│   ├── addons
│   │   ├── dashboard
│   │   ├── efk
│   │   ├── freshpod
│   │   ├── gpu
│   │   ├── gvisor
│   │   ├── heapster
│   │   ├── ingress
│   │   ├── logviewer
│   │   ├── metrics-server
│   │   ├── registry
│   │   ├── registry-creds
│   │   ├── storageclass
│   │   ├── storage-provisioner
│   │   └── storage-provisioner-gluster
│   ├── gvisor
│   ├── iso
│   │   └── minikube-iso
│   │       ├── board
│   │       │   └── coreos
│   │       │       └── minikube
│   │       │           └── rootfs-overlay
│   │       │               ├── etc
│   │       │               │   ├── cni
│   │       │               │   │   └── net.d
│   │       │               │   ├── docker
│   │       │               │   ├── ssh
│   │       │               │   ├── systemd
│   │       │               │   │   ├── network
│   │       │               │   │   └── system
│   │       │               │   │       ├── getty.target.wants
│   │       │               │   │       └── systemd-timesyncd.service.d
│   │       │               │   └── udev
│   │       │               │       └── rules.d
│   │       │               ├── usr
│   │       │               │   └── bin
│   │       │               └── var
│   │       │                   ├── lib
│   │       │                   │   └── boot2docker
│   │       │                   ├── log
│   │       │                   └── run
│   │       │                       └── crio
│   │       ├── configs
│   │       └── package
│   │           ├── automount
│   │           ├── cni-bin
│   │           ├── cni-plugins-bin
│   │           ├── conmon-master
│   │           ├── containerd-bin
│   │           ├── crictl-bin
│   │           ├── crio-bin
│   │           ├── docker-bin
│   │           ├── gluster
│   │           ├── hyperv-daemons
│   │           ├── podman
│   │           ├── runc-master
│   │           └── vbox-guest
│   ├── minikube
│   └── storage-provisioner
├── docs
│   └── contributors
├── hack
│   ├── boilerplate
│   ├── help_text
│   ├── jenkins
│   │   └── installers
│   ├── kubernetes_version
│   ├── prow
│   └── release_notes
├── images
│   └── logo
├── installers
│   ├── darwin
│   │   └── brew-cask
│   ├── linux
│   │   ├── archlinux
│   │   ├── archlinux-driver
│   │   ├── deb
│   │   │   ├── kvm2_deb_template
│   │   │   │   └── DEBIAN
│   │   │   └── minikube_deb_template
│   │   │       └── DEBIAN
│   │   ├── kvm
│   │   └── rpm
│   │       ├── kvm2_rpm_template
│   │       └── minikube_rpm_template
│   └── windows
├── pkg
│   ├── drivers
│   │   ├── hyperkit
│   │   ├── kvm
│   │   └── none
│   ├── gvisor
│   ├── initflag
│   ├── kapi
│   ├── minikube
│   │   ├── assets
│   │   ├── bootstrapper
│   │   │   └── kubeadm
│   │   │       └── testdata
│   │   │           ├── v1.11
│   │   │           ├── v1.12
│   │   │           ├── v1.13
│   │   │           ├── v1.14
│   │   │           ├── v1.15
│   │   │           └── v1.16
│   │   ├── cluster
│   │   ├── command
│   │   ├── config
│   │   │   └── testdata
│   │   ├── constants
│   │   ├── cruntime
│   │   ├── drivers
│   │   │   ├── hyperkit
│   │   │   ├── hyperv
│   │   │   ├── kvm2
│   │   │   ├── none
│   │   │   ├── parallels
│   │   │   ├── virtualbox
│   │   │   ├── vmware
│   │   │   └── vmwarefusion
│   │   ├── exit
│   │   ├── extract
│   │   │   └── testdata
│   │   ├── kubeconfig
│   │   │   └── testdata
│   │   │       └── kubeconfig
│   │   ├── logs
│   │   ├── machine
│   │   ├── notify
│   │   ├── out
│   │   ├── problem
│   │   ├── proxy
│   │   ├── registry
│   │   ├── service
│   │   ├── sshutil
│   │   ├── storageclass
│   │   ├── tests
│   │   ├── translate
│   │   └── tunnel
│   ├── provision
│   ├── storage
│   ├── util
│   │   ├── lock
│   │   └── retry
│   └── version
├── site
│   ├── assets
│   │   ├── icons
│   │   └── scss
│   ├── content
│   │   └── en
│   │       ├── blog
│   │       │   ├── news
│   │       │   └── releases
│   │       ├── community
│   │       └── docs
│   │           ├── Concepts
│   │           ├── Contributing
│   │           ├── Examples
│   │           ├── Overview
│   │           ├── Reference
│   │           │   ├── Commands
│   │           │   ├── Configuration
│   │           │   ├── Drivers
│   │           │   │   └── includes
│   │           │   └── Networking
│   │           ├── Start
│   │           │   └── includes
│   │           ├── Tasks
│   │           │   └── Registry
│   │           └── Tutorials
│   ├── layouts
│   │   ├── partials
│   │   │   └── hooks
│   │   └── shortcodes
│   ├── static
│   │   ├── css
│   │   └── js
│   └── themes
│       └── docsy
├── test
│   └── integration
│       └── testdata
│           ├── kvm2-driver-older-version
│           └── kvm2-driver-without-version
├── third_party
│   └── go9p
│       └── ufs
└── translations

Following table are description of the different directories of minikube’s source code. Note: This is by no means a complete list of the source directory structure as master branch do change from time to time

Directory Name	Description
drivers	docker-machine plugin code (libvirt and hyperkit)
cmd/gvisor	Code to start gvisor and do all the necessary steps to restart the dependencies (containerd, etc)
minikube	minikube cli handling code
storage-provisioner	Main function to trigger the storage provisioner module
deploy	Contains files that are needed to build minikube inside docker
deploy/addons	Lots of minikube addons (*.yaml) inside this directory such as: gvisor → used to securely run pods with untrusted workloads, freshpods → restart container,etc
deploy/gvisor	contain Dockerfile to run gvisor-addon
deploy/iso	Contains documentation, packages and configuration for building minikube iso. Some of the packages that are included – automount,containerd and many more. It also contains configuration file for building buildroot. Pretty much anything related to building iso in inside this directory
deploy/minikube	Contains few json files related to release
deploy/storage-provisioner	Contain dockerfile to run storage-provisioner
hack/jenkins	Jenkins configuration file
hack/kubernetes_version	Tool to generate Minikube version number
hack/release_notes	Code to create release notes
installers/darwin	script to create Darwin installer
installers/linux	Linux – deb, archlinux, rpm, etc
installers/windows	Windows installers
pkg/drivers	Driver related code – kvm, hyperkit
site	Docsy template for generating documents as website
test	Integration test for Minikube
go9p	Go implementation of 9P2000 protocol (9P (or the Plan 9 Filesystem Protocol or Styx) is a network protocol developed for the Plan 9 from Bell Labs distributed operating system as the means of connecting the components of a Plan 9 system. Files are key objects in Plan 9. They represent windows, network connections, processes, and almost anything else available in the operating system. )
translations	Language translation at the moment CN and FR