Devoxx 2016 - Going Global with Nomad & Google Cloud Platform

Demo setup for a federated Nomad cluster in Google Cloud Platform in EU, US and AS (Asia) regions.

Slides: http://www.slideshare.net/asgfdashg/devoxx-2016-talk-going-global-with-nomad-and-google-cloud-platform

Prerequisites

gcloud

The latest gcloud Comand Line Interface should be installed and the folowing environment variables should be set:

GCLOUD_PROJECT=global-datacenter
GCLOUD_REGION=europe-west1

Authorization to manage the 'global-datacenter' (or your) project. See https://cloud.google.com/sdk/gcloud/reference/auth/ for details.

Create a Nomad Cluster in EU region

Create 3 Nomad server nodes in separate zones.

use

cd scripts/
./install-servers.sh

Or perform the steps manually:

cd scripts/
gcloud compute instances create nomad-eu-1 --zone europe-west1-b \
  --machine-type g1-small \
  --image-project coreos-cloud \
  --image-family coreos-stable \
  --metadata-from-file startup-script=server-script&
gcloud compute instances create nomad-eu-2 --zone europe-west1-c \
  --machine-type g1-small \
  --image-project coreos-cloud \
  --image-family coreos-stable \
  --metadata-from-file startup-script=server-script&
gcloud compute instances create nomad-eu-3 --zone europe-west1-d \
  --machine-type g1-small \
  --image-project coreos-cloud \
  --image-family coreos-stable \
  --metadata-from-file startup-script=server-script&

Wait for completion

watch -d gcloud compute instances list nomad-eu-{1,2,3}

Bootstrap the cluster

Login to a Nomad server and forward some ports:

./ssh-nomad-eu

See server status:

nomad server-members

Join servers together:

nomad server-join nomad-eu-{1,2,3}

See server status:

nomad server-members

See client node status:

nomad node-status
nomad node-status -self

Schedule our first job

Schedule nomad-ui as a system job on all Nomad servers:

cd /tmp/devoxx-2016/jobs
nomad plan nomad-ui.nomad
nomad run nomad-ui.nomad

See the results:

nomad status
nomad status nomad-ui
nomad status -verbose nomad-ui
nomad alloc-status _xxx_

Browse to http://localhost:3000/

Create a Farm of worker nodes

use

cd scripts/
./install-clients.sh

The clients will automatically join the Nomad cluster

check with

nomad node-status

Run Helloworld

nomad run helloworld.nomad

Lookup host and port

nomad status helloworld
nomad alloc-status _xxx_

Call helloworld

curl -s http://_ip_:_port_/hello
curl -s http://_ip_:_port_/env | jq .

Add Service discovery

nomad run consul.nomad

See cluster:

consul members

Check the UI at http://localhost:8500/ui

Add HTTP routing

nomad run fabio.nomad

Check the UI at http://localhost:9998/

Test routing:

curl -s -H 'Host: helloworld.gce.nauts.io' http://localhost:9999/hello

Make helloworld available via Google Load balancer

Prerequisites:

1. http-fabio health check
2. firewall rule to let LB access fabio
3. allocated static (global-dc)
4. helloword.gce.nauts.io DNS entry points to static IP.

In GCP console:

1. go to Networking / Load Balancer
2. click 'create load balancer'
3. HTTP(S) load balancing / Start configuration
4. Enter name devoxx
5. Backend Configuration / Create a Backend service
6. Enter name farm-backend
7. New Backend farm-eu
8. port number: 9999
9. Health check http-fabio
10. Leave Host and Path rules as is.
11. Frontend configuration / select a static IP global-dc for HTTP port 80
12. Create

Select 'monitoring' on created LB and wait until backends are healthy. Check helloworld:

curl -s http://helloworld.gce.nauts.io/hello

Load balance across regions

Create cluster in us-central1 region with zones a, b and c:

cd scripts/
./install-region us-central1 a b c

Add backend to load balancer.

Perform requests to helloworld from US and Asia to see them served by the US cluster. Latency will be lower.