A very simple app that listens on port 8080. Any request query path is logged and sent as a response to the client with a "Pong" prefix.
Run without using docker or openshift:
go get github.com/prometheus/client_golang
go run src/main/ping.go
Any endpoint other than /metrics will return a pong:
$ curl http://localhost:8080/it-works
Pong: "/it-works"
The /metrics endpoint will return Prometheus style metrics.
minikube start
NAMESPACE=jewzaam
# build the image
docker build . -t $(minikube ip):5000/$NAMESPACE/go-ping-pong:latest
# push it
docker push $(minikube ip):5000/$NAMESPACE/go-ping-pong:latest
oc create -f oc/deployment/01-deployment.yml
oc create -f oc/deployment/02-service.yml
oc port-forward $(oc get pods -l=app=go-ping-pong -o name) 8080:8080 &
curl localhost:8080/hello
Required for all other sections, you need minishift running, the docker-env setup, and need to be logged in. First, Install Minishift Then...
minishift start
# setup docker env to use the minishift docker
eval $(minishift docker-env)
# setup to use minishift's oc binary
eval $(minishift oc-env)
# log into the registry as user 'developer'
oc login -u developer
docker login -u $(oc whoami) -p $(oc whoami -t) $(minishift openshift registry)
NAMESPACE=jewzaam
# build the image
docker build . -t $NAMESPACE/go-ping-pong:latest
# tag it
docker tag $NAMESPACE/go-ping-pong:latest $(minishift openshift registry)/$NAMESPACE/go-ping-pong:latest
# push it
docker push $(minishift openshift registry)/$NAMESPACE/go-ping-pong:latest
If you are working locally and want to push changes without having to push to master on github use the "Deploy: Manual" option. For triggered rebuilds use "Deploy: BuildConfig". Verify steps are the same for both.
Only needs to be done for initial deployment. Subsequent pushes will automatically be deployed.
Deploy the new app, scale to 2 replicas, and expose on port 8080:
NAMESPACE=jewzaam
# create the app from the pushed image stream
oc new-app $NAMESPACE/go-ping-pong
# scale to 2 pods, so subsequent updates are rolling
oc scale --replicas=2 dc go-ping-pong
# expose the service on port 8080 (creates a route)
oc expose service go-ping-pong --port=8080
Create the build config:
oc create -f oc/build/buildconfig.yml
Deploy from remote image on quay.io. Creates a deployment, service, and route.
oc apply -f oc/deployment/
View project by using this URL:
minishift console --machine-readable | grep CONSOLE_URL | awk -F= '{print $2 "/console/project/jewzaam/overview"}'
It's assumed you have Prometheus installed. You can review OpenShift and Prometheus for some help getting started.
Once this project is installed you can add 'go-ping-pong' to the prometheus config. Note this connects to the service (internal), not the route (external), and therefore uses the internal port (8080) and service name (go-ping-pong.jewzaam.svc).
View config map: oc describe configMap $(oc get configMap | grep -v NAME | awk '{print $1}')
Edit config map: oc edit configMap $(oc get configMap | grep -v NAME | awk '{print $1}')
A sample config is provided in prometheus.yml.
Additional network configuration may be necessary if you are monitoring an app outside of the prometheus project and are not using the ovs-subnet plugin. See the Managing Networking documentation on how to join project networks.