hello go docker

Docker images build with various docker build command flags.

docker images

preconditions

• golang
• modern make go get github.com/tj/mmake/cmd/mmake
• gopherjs go get -u github.com/gopherjs/gopherjs
• gopher-count go get github.com/steveoc64/gopher-count

build

$ make build

run

$ make run
go build -o mybinary -v ./...
./mybinary
2018/06/23 09:07:25 Server at http://localhost:1234.

6 main ways to build a docker image

$ make build.docker
$ make build.docker-cache
$ make build.dockerbuilder
$ make build.dockerbuilder-cache
$ make build.dockeralpine
$ make build.docker-min

note about ca-certificates

# $ make build.docker-min
# requires ca-certificates.crt file in project directory
# For many Linux distributions, 
# you can copy the file from /etc/ssl/certs/ca-certificates.crt :
cp /etc/ssl/certs/ca-certificates.crt .

build.log shows

• docker image build times
• docker image sizes

docker experimental functions

In order to run the squash build commands above, you need to run the docker deamon with experimental functions:

$ cat <<EOT >> /etc/docker/daemon.json
{ 
    "experimental": true 
} 
EOT
$ sudo service docker restart

#check result
$ docker version -f '{{.Server.Experimental}}'
true

Docker on Mac OS offers to set the experimental functions via UI as well. That would be Preferences->Daemon->Advanced.

docker run

docker run -p 1234:1234 -name hellogodocker lotharschulz/hellogo:[tag]
# e.g. docker run -p 1234:1234 --name hellogodocker lotharschulz/hellogo:build.docker--0.2.102

kubernetes deployment

create k8s resources

kubectl create -f k8s/dpl_svc.yaml --record=true

check k8s resources

kubectl get po -w                   # watch progress
kubectl get po,rs,deploy,svc        # check k8s resources

access the service

minikube service hellogo-svc
# opens the service in default browser

minikube service hellogo-svc --url
# sample output: http://192.168.99.100:30037 
curl http://192.168.99.100:30037

clean up

kubectl delete deploy,svc,po,rs -l app=hellogo

blog post

let’s go build a minimal docker image