National Parks - Java Tomcat Application

This is an example Java Tomcat application packaged by Habitat. This example app has existed for some time, and another example can be found here. The differences with this example versus previous examples are the following:

• core/mongodb - Previous examples had you build a version of mongodb that was already populated with data before the application
• mongo.toml - This repo includes a user.toml file for overriding the default configuration of mongodb
• core/haproxy = This repo uses the core/haproxy package as a loadbalancer in front of National Parks
• Scaling - In both the terrform/azure and terraform/aws plans there is a count variable which allows you to scale out the web instances to demonstrate the concept of choreography vs orchestration in Habitat.

Usage

In order run this repo, you must first install Habitat. You can find setup docs on the Habitat Website.

Build/Test National-Parks App Locally:

1. Clone this repo
2. cd national-parks-demo
3. Export environment variables to forward ports on the export HAB_DOCKER_OPTS='-p 8000:8000 -p 8080:8080 -p 8085:8085 -p 9631:9631'
4. hab studio enter
5. build
6. source results/last_build.env
7. Load core/mongodb package from the public depot:
   hab svc load core/mongodb
8. Override the default configuration of mongodb:
   hab config apply mongodb.default $(date +%s) mongo.toml
9. Load the most recent build of national-parks:
   hab svc load $pkg_ident --bind database:mongodb.default
10. Load core/haproxy from the public depot:
    hab svc load core/haproxy --bind backend:national-parks.default
11. Override the default configuration of HAProxy:
    hab config apply haproxy.default $(date +%s) haproxy.toml
12. Run sup-log to see the output of the supervisor

You should now be able to hit the front end of the national-parks site as follows:

• Directly - http://localhost:8080/national-parks
• HAProxy - http://localhost:8085/national-parks

You can also view the admin console for HAProxy to see how the webserver was added dynamically to the load balancer:

http://localhost:8000/haproxy-stats

username: admin
password: password

Build a new version of the application

There is also an index.html file in the root of the repo that updates the map of the National-Parks app to use red pins and colored map. This can be used to demonstrate the package promotion capabilities of Habitat.

1. create a new feature branch - git checkout -b update_homepage
2. Bump the pkg_version in habitat/plan.sh
3. Overwrite src/main/webapp/index.html with the contents of the red-index.html in the root directory _NOTE: the index.html has a version number hard coded on line 38. Update that to your version number if you want it to match.
4. hab studio enter
5. build

Terraform

Included in the repo is terraform code for launching the application in AWS and Google Kubernetes Engine. Provision either AWS, GKE, or both, and then you can watch Habitat update across cloud deployments.

Terraform.

Proivision National-Parks in AWS

You will need to have an AWS account already created

Step

1. cd terraform/aws
2. cp tfvars.example terraform.tfvars
3. edit terraform.tfvars with your own values
4. terraform apply

Once the provisioning finishes you will see the output with the various public IP addresses

Apply complete! Resources: 0 added, 0 changed, 0 destroyed.

Outputs:

haproxy_public_ip = 34.216.185.16
mongodb_public_ip = 54.185.74.152
national_parks_public_ip = 34.220.209.230
permanent_peer_public_ip = 34.221.251.189

http://<haproxy_public_ip>:8085/national-parks
or
http://<haproxy_public_ip>:8000/haproxy-stats

Proivision National-Parks in Azure

You will need to have an Azure account already created

Step

1. cd terraform/azure
2. terraform init
3. az login
4. cp tfvars.example terraform.tfvars
5. edit terraform.tfvars with your own values
6. terraform apply

Once provisioning finishes you will see the output withthe various public IP addresses:

Apply complete! Resources: 19 added, 0 changed, 0 destroyed.

Outputs:

haproxy-public-ip = 40.76.29.195
instance_ips = [
    40.76.29.123
]
mongodb-public-ip = 40.76.17.2
permanent-peer-public-ip = 40.76.31.133

Scaling out Azure and AWS Deployments

Both the AWS and Azure deployments support scaling of the web front end instances to demonstrate the concept of 'choreography' vs 'orchestration' with Habitat. The choreography comes from the idea that when the front end instances scale out, the supervisor for the HAProxy instance automatically takes care of the adding the new members to the pool and begins balancing traffic correctly across all instances.

Scaling out

1. In your terraform.tfvars add a line for count = 3
2. run terraform apply
3. Once provisioning finishes, go to the http://<haproxy-public-ip>:8000/haproxy-stats to see the new instances in the pool

Deploy National-Parks in Google Kubernetes Engine

You will need to have an Google Cloud account already created, and install the Google Cloud SDK

Before you begin

• git clone https://github.com/habitat-sh/habitat-operator
• git clone https://github.com/habitat-sh/habitat-updater
• create a terraform.tfvars

Provision Kubernetes

1. cd terraform/gke

2. terraform apply

3. When provisioning completes you will see two commands you need to run:

   • 1_creds_command = gcloud container clusters get-credentials...
   • 2_admin_permissions = kubectl create clusterrolebinding cluster-admin-binding...

Deploy Habitat Operator and Habitat Updater

First we need to deploy the Habitat Operator

1. git clone https://github.com/habitat-sh/habitat-operator
2. cd habitat-operator
3. kubectl apply -f examples/rbac/rbac.yml
4. kubectl apply -f examples/rbac/habitat-operator.yml

Now we can deploy the Habitat Updater

1. git clone https://github.com/habitat-sh/habitat-updater
2. cd habitat-updater
3. kubectl apply -f kubernetes/rbac/rbac.yml
4. kubectl apply -f kubernetes/rbac/updater.yml

Deploy National-Parks into Kubernetes

Now that we have k8s stood up and the Habitat Operator and Updater deployed we are are ready to deploy our app.

1. cd national-parks-demo/terraform/gke/habitat-operator
2. Deploy the GKE load balancer: kubectl create -f gke-service.yml
3. Next, edit the habitat.yml template with the proper origin names on lines 19 and 36
4. Deploy the application: kubectl create -f habitat.yml

Once deployment finishes you can run kubectl get all and see the running pods:

$ kubectl get all
NAME                                   READY   STATUS    RESTARTS   AGE
pod/habitat-operator-c7c559d7b-z5z7m   1/1     Running   0          3d1h
pod/habitat-updater-578c99fbcd-kbs2d   1/1     Running   0          3d1h
pod/national-parks-app-0               1/1     Running   0          2d14h
pod/national-parks-db-0                1/1     Running   0          3d1h

NAME                        TYPE           CLUSTER-IP      EXTERNAL-IP     PORT(S)          AGE
service/kubernetes          ClusterIP      10.47.240.1     <none>          443/TCP          3d2h
service/national-parks      NodePort       10.47.241.104   <none>          8080:30001/TCP   3d1h
service/national-parks-lb   LoadBalancer   10.47.254.247   35.227.157.16   80:31247/TCP     3d1h

NAME                                     DESIRED   CURRENT   UP-TO-DATE   AVAILABLE   AGE
deployment.extensions/habitat-operator   1         1         1            1           3d1h
deployment.extensions/habitat-updater    1         1         1            1           3d1h

NAME                                               DESIRED   CURRENT   READY   AGE
replicaset.extensions/habitat-operator-c7c559d7b   1         1         1       3d1h
replicaset.extensions/habitat-updater-578c99fbcd   1         1         1       3d1h

NAME                               DESIRED   CURRENT   UP-TO-DATE   AVAILABLE   AGE
deployment.apps/habitat-operator   1         1         1            1           3d1h
deployment.apps/habitat-updater    1         1         1            1           3d1h

NAME                                         DESIRED   CURRENT   READY   AGE
replicaset.apps/habitat-operator-c7c559d7b   1         1         1       3d1h
replicaset.apps/habitat-updater-578c99fbcd   1         1         1       3d1h

NAME                                  DESIRED   CURRENT   AGE
statefulset.apps/national-parks-app   1         1         3d1h
statefulset.apps/national-parks-db    1         1         3d1h

Find the EXTERNAL-IP for service/national-parks-lb:

http://<EXTERNAL-IP>/national-parks