m7dock/go-app repository overview

⁠Web App in Go

This is a sample web application developed in Go lang that can be run on various cloud /native platforms:

• Native
• Docker
• OpenShift
• Cloud Foundary

Features - Bootstrap4 / Go Template but bare bones and none necessary.

⁠0. Clone Project

git clone https://github.com/ajarv/go-app.git ~/workspace/go-app

⁠1. Run on Local Host

cd ~/workspace/go-app
#Install Go dependencies
go get github.com/thedevsaddam/gojsonq  github.com/go-redis/redis gopkg.in/yaml.v2 github.com/gorilla/mux github.com/yalp/jsonpath
go run main.go

Access the app using curl

curl localhost:8080

⁠2. Create docker Image

Two phaze docker build

docker build -t go-app .

⁠3. Open shift

Assuming you have openshift installed somewhere And you are logged into openshift with oc.

oc login ...
oc new-project gotum-city --display-name "Gotum City"

⁠3.1 Deploy on OpenShift plain directly

oc new-app https://github.com/ajarv/go-app.git

⁠3.2 Deploy on openshift using template

A compiled image of this repo has been put on docker.io/m7dock/go-app Below openshift template uses that

oc process -f  kube-cfg/openshift-app-template.yaml -p APP_NAME=gcpd -p C1_NAME=batman -p C2_NAME=bruce  -pLBVIP=10.231.63.150  | oc create -f -

⁠4 Cloud Foundary

⁠Cloudfoundry access

If you don't have access to cloudfoundry you can follow the tutorial here⁠ to provision it on a local linux box. OR you may get a trial account at https://pivotal.io/platform⁠

⁠Preparing workspace

Preparing Space

cf login -u admin -p $CF_ADMIN_PASSWORD
cf create-org order-manager
cf target -o "order-manager"
cf create-space uat
cf target -o "order-manager" -s "uat"

Configure Domain names for exposing the applicaitons from virtual box based CF installation

cf create-domain order-manager cf.< Virtual box host IP >.nip.io
cf create-domain order-manager cf.< Your domain name suffix e.g    example.com  this needs  you to have a wildcard lb setup for this hostname.>

Configure Dev User

cf create-user marco polo
cf set-space-role marco "order-manager" uat  SpaceDeveloper

⁠App Management

Login with a developer who has developer role

git clone https://github.com/ajarv/go-app.git ~/workspace/go-app
cd ~/workspace/go-app

cf login -u marco -p polo
# See running apps
cf apps

⁠4.1 Base deployment

cf push orders-app -n orders

Showing health and status for app orders-app in org ajar_v / space uat as [email protected]...
OK

requested state: started
instances: 1/1
usage: 32M x 1 instances
urls: orders.cfapps.io
last uploaded: Thu Jan 10 21:52:20 UTC 2019
stack: cflinuxfs2

Access the app at any of the urls e.g. http://orders.cfapps.io/⁠

⁠For VM based CF installation Add domain name to the app

cf map-route orders-app cf..nip.io -n orders

⁠Scale the app

cf scale orders-app -i 2
cf app orders-app

⁠4.2 Add Color to the App and change Version

Update an environment variable and redeploy the app

cf set-env orders-app APP_COLOR green
cf set-env orders-app APP_VERSION v9.2.33
cf restage orders-app

Access the app at any of the urls e.g. http://orders.cfapps.io/⁠

Problem with blue deployment updates the existing app instances and while updating he existing instances are evicted.

Lets try a blue-green deployment

⁠4.3 Green deployment

Lets deploy a new version of the app which will become a new app instance group.i.e. it wont overwrite the existing app instances

cf push orders-app-v1 -n orders-v1

Update environment variables for new app to demo that its a new version

cf set-env orders-app-v1  APP_COLOR blue
cf set-env orders-app-v1  APP_VERSION v9.2.34
cf restage orders-app-v1

See if you can access the app at http://orders-v1.cfapps.io/⁠

⁠4.4 Mapping Routes

cf map-route orders-app-v1 cfapps.io -n orders

Enabled automatic build integration with m7dock/go-app