CI/CD with Go, Docker, Kubernetes, Codefresh, and Google Compute Engine

1.) Create an app

Let's create a Hello World! app in Go to keep things simple :D

// main.go
package main

import (
  "fmt"
  "net/http"
  "runtime"
)

func helloHandler(rw http.ResponseWriter, r *http.Request) {
  fmt.Fprintf(rw, `
      <h1>Hello World!</h1>
      <p>Greetings from %s with an %s CPU.
      <p>Check out the <a href="https://github.com/ogryzek/hello_go">source code</a>.
      `, runtime.GOOS, runtime.GOARCH)
}

func main(){
  http.HandleFunc("/", helloHandler)
  http.ListenAndServe(":3000", nil)
}

2.) Create a Docker image

Create the Dockerfile

FROM golang

ADD . /go/src/github.com/ogryzek/hello_go
RUN go install github.com/ogryzek/hello_go
ENTRYPOINT /go/bin/hello_go

EXPOSE 3000

Build the image

docker build -t hello_go .

Run a container with the image we just built

docker run -p 3000:3000 hello_go

3.) Add Source Control

If you haven't already, initialize a git repo, and push your source to somewhere like GitHub

git init
git add -A
git commit -m 'I <3 my mom!'
git remote add origin git@github.com:<github-username>/<reponame>.git
git push origin master

4.) Get started with Codefresh

You can sign up for an account with your Github, Bitbucket, or Gitlab account (you will need to sign in with the account from the repo host you want to use).

Next up:

• Create a Basic Pipeline
• Push to Docker registry

5.) Add Integration Tests

We want to run some integration tests, so first let's Create a Composition.

docker-compose.yml

version: '3'
services:
  hello_go:
    build: .
    ports:
    - "3000:3000"

Codefresh compositions don't support port mapping. Also, it will try to guess from your service name what the registry image is called.

In this case, we should modify the codefresh composition compose file to

version: '3'
services:
  hello_go:
    ports:
      - '3000'
    image: 'ogryzek:hellogo:master'

(Note: Glossing over this, because we haven't tagged out build images, and it's looking for "latest" may need to use a codefresh.yml to resolve).

6.) Get Ready to Deploy

Let's get ready to deploy to Kubernetes

Sign into console.cloud.google.com and create a new project.

Enable Container Engine API

Enable Compute Engine API

To create a Kubernetes cluster, visit this short guide.

# Set default compute zone
gcloud config set compute/zone us-west1-a

# create cluster
gcloud container clusters create hello-go-cluster # this takes a long time (5 minutes+ ?)

# Run container
kubectl run hello-go --image=ogryzek/hellogo:master --port=3000


# Expose the container
kubectl expose deployment hello-go --type="LoadBalancer" 

# Get public IP
kubectl get service hello-go # takes about 1 minute to change from pending to having an IP

# the external IP will resolve about 5 minutes after creating it

Note: To clean up the cluster (you will be billed)

kubectl delete service hello-go
gcloud container clusters delete hello-go-cluster

Next, deploy to GKE