Go Edge, Microservice or Backend for Frontend with Gin

This Go Starter Kit Template can be the foundation for an Edge , Cloud-Native Microservice or a Backend for Frontend solution.

Features

The starter kit provides the following features:

• This Starter Kit has been optimised for deployment into OpenShift using the IBM Cloud Native Toolkit install this before following instructions
• Built with Go
• REST services using Gin
• Swagger documentation using Swagger UI
• Testing Framework with Go Test
• Experience Testing with Selenium UI Test
• Jenkins DevOps pipeline that support OpenShift or IKS deployment

In this sample web application, you will create a Go cloud application using Gin. This application contains an opinionated set of files for web serving:

• public/index.html
• public/404.html
• public/500.html

This application also enables a starting place for a Go microservice using Gin. A microservice is an individual component of an application that follows the microservice architecture - an architectural style that structures an application as a collection of loosely coupled services, which implement business capabilities. The microservice exposes a RESTful API matching a Swagger definition.

You can start to extend the Starter Kit by adding new API Endpoints in the routers directory.

Steps

You can build it locally by cloning this repo first using the template feature in git. After your app is live, you can access the /health endpoint to build out your cloud native application.

Also, this application comes with the following capabilities:

• Swagger UI running on: /explorer
• An OpenAPI 2.0 definition hosted on: /swagger/api
• A Healthcheck: /health

Building locally

To get started building this web application locally, you can either run the application natively or use the IBM Cloud Developer Tools for containerization and easy deployment to IBM Cloud.

All of your go dependencies are listed in go.mod.

Native application development

• Install Go

In order for Go applications to run anywhere including your $GOPATH/src

export GO111MODULE=on

Fetch and install dependencies listed in go.mod:

go build ./...

To run your application locally:

go run server.go

Your sources will be compiled to your $GOPATH/bin directory. Your application will be running at http://localhost:8080. You can also verify the state of your locally running application using the Selenium UI test script included in the scripts directory.

Local Development with Docker

To build the application into a local docker image you need to have the Docker Desktop installed

Run the following command to build it into a versioned package

./build

To run locally

./run

To boostrap into the running image run the following command

docker run -it --entrypoint /bin/sh -p 8080:8080 template-go-gin:1.0.1

Deploying to Red Hat OpenShift

Make sure you are logged into the IBM Cloud using the IBM Cloud CLI and have access to your OpenShift development cluster.

oc login
oc get pods
npm install -g @ibmgaragecloud/cloud-native-toolkit-cli
git clone <code pattern> | cd <code pattern>

Register the GIT Repo with Tekton or Jenkins CI engine

oc sync <project> --dev
oc pipeline
{select golang-pipeline pipeline}

View your Tekton pipelines in the Developer

oc dashboard

Click on Pipelines and then switch to Developer view and click on Pipelines to see the pipeline running

Deploy to IBM Edge Application Manager

The following steps assist you in the deployment of the edge app to the IBM Edge Application Manager.

Install HZN CLI MacOS

wget http://pkg.bluehorizon.network/macos/certs/horizon-cli.crt
sudo security add-trusted-cert -d -r trustRoot -k /Library/Keychains/System.keychain horizon-cli.crt
sudo installer -pkg horizon-cli-2.24.18.pkg -target / -allowUntrusted

Install HZN CLi Linux

arch=$(dpkg --print-architecture)
dist=bionic
version=2.26.12
wget http://pkg.bluehorizon.network/linux/ubuntu/pool/main/h/horizon/bluehorizon_${version}~ppa~ubuntu.${dist}_all.deb
wget http://pkg.bluehorizon.network/linux/ubuntu/pool/main/h/horizon/horizon-cli_${version}~ppa~ubuntu.${dist}_${arch}.deb
wget http://pkg.bluehorizon.network/linux/ubuntu/pool/main/h/horizon/horizon_${version}~ppa~ubuntu.${dist}_${arch}.deb
dpkg -i horizon-cli_${version}~ppa~ubuntu.${dist}_${arch}.deb
dpkg -i horizon_${version}~ppa~ubuntu.${dist}_${arch}.deb
dpkg -i bluehorizon_${version}~ppa~ubuntu.${dist}_all.deb

Build and Register the Edge App

Log into your Edge Management cluster and define these variables Configure the following properties before publishing the Service information to the Edge server

export APIKEY=<api-key>
export HZN_EXCHANGE_URL=https://$(oc get routes icp-console -o jsonpath='{.spec.host}' -n kube-system)/edge-exchange/v1
export EXCHANGE_ROOT_PASS=$(oc -n kube-system get secret ibm-edge-auth -o jsonpath="{.data.exchange-root-pass}" | base64 --decode)
HZN_EXCHANGE_USER_AUTH="root/root:$EXCHANGE_ROOT_PASS"
export HZN_ORG_ID=IBM

Trust your exchange server with your Development environment on MacOS

Extract the certificate from teh Edge Application Manager

oc --namespace kube-system get secret cluster-ca-cert -o jsonpath="{.data['tls\.crt']}" | base64 --decode > /tmp/icp-ca.crt

Register the certificate into MacOS Key Chain

sudo security add-trusted-cert -d -r trustRoot -k /Library/Keychains/System.keychain /tmp/icp-ca.crt

Register the certificate into Linux Chain

sudo cp /tmp/icp-ca.crt /usr/local/share/ca-certificates && sudo update-ca-certificates

Create your Signing Key pair the local registration will be trusted, you can use your org name and email address

hzn key create "IBM" "mjperrin@us.ibm.com"

Login to the IBM Image Registry using docker login

docker login -u iamapikey -p ${APIKEY} us.icr.io

To publish the service definition, and the deployment policy to the Edge Manager run the following command

docker login -u iamapikey -p $APIKEY us.icr.io

Publish the Edge Device Service

make publish-service

Configuring Edge CD with Tekton on Red Hat OpenShift

The first step is to extract the key meta data from the IBM Edge Application Manager Cluster and save this into a secret.

This secret then needs to be registered into your Red Hat OpenShift development project namespace on the cluster that you are using for development. This may be different to the cluster that the IBM Edge Application Manager has been installed into. This will enable a new Tekton task called edge-cd to be used in your pipeline to dynamically register the built image as a Service directly with IBM Edge Application Manager.

To extract this information first log into the IBM Edge Application Manager on the command line. Then run ./build-secret.sh to create the secret YAML definition edge-access-secret.yaml.

./build-secret.sh

Check the secret has been created in your file system and the data inside the secret is as expected. The secret is added to the .gitignore so will not be checked into your GIT repository.

Next step is to log into your development cluster on the command line and register the secret into the project/namespace you are building the Go Gin Edge application. Once logged in run this kubectl command to register the secret.

kubectl apply -f edge-access-secret.yaml

The Edge Tasks are now included in the IBM Garage Cloud Native Toolkit in the Garage Tekton Tasks repository these are automatically installed with the toolkit, you can upgrade them if newer releases are published.

Final part is create a repo from this template into your own repo in your own git organization. Then clone the code and register pipeline with OpenShift and Tekton.

Register the pipeline with Tekton

oc sync dev-edge --dev
oc pipeline
{select the `golang-pipeline-edge` pipeline}

Enjoy the end to end CI/CD with Tekton and IBM Edge Application Manager

Next steps

• Learn more about augmenting your Go applications on IBM Cloud with the Go Programming Guide.
• Explore other sample applications on IBM Cloud.

License

This sample application is licensed under the Apache License, Version 2. Separate third-party code objects invoked within this code pattern are licensed by their respective providers pursuant to their own separate licenses. Contributions are subject to the Developer Certificate of Origin, Version 1.1 and the Apache License, Version 2.

Apache License FAQ