📶 Elastic Stack Docker + Sample Go App

Elastic Stack which includes Elasticsearch, Kibana, Filebeat and Metricbeat. It comes with a very simple Go application that publishes a tiny HTTP API. Go app connects to a MySQL database. Also there's an Nginx that acts as the load balancer of the Go App to allow scale up/down the app containers.

How to run it?

For spinning up the stack:

docker-compose up -d

After all services are running, you can use following Go application endpoints to generate random data (:8080 is the exposed port of th Nginx connected to Go application instances):

• curl http://localhost:8080/
• curl http://localhost:8080/create -d {}

To scale up/down Go application:

docker-compose up -d --scale app=3

To change where to tog change LOG_TO env var in .env:

• elasticsearch to send logs directly to ES
• stdout to send logs to standard output

ES Clustering

docker-compose-es-cluster.yml file will allow us to spin up an ES cluster con 3 nodes.

docker-compose -f docker-compose-es-cluster.yml up -d --remove-orphans

Once done, we can check the status of the cluster:

curl http://localhost:9200/_cluster/health?pretty

Now we create a new index with replication set to 2 and we add a new document:

curl -H "Content-Type: application/json" -XPUT http://localhost:9200/test -d '{"settings" : {"index" : {"number_of_shards" : 3, "number_of_replicas" : 2 }}}'
curl -H "Content-Type: application/json" -XPUT http://localhost:9200/test/docs/1 -d '{"name": "ruben"}'

For getting index and document distribution through the Cluster:

curl http://127.0.0.1:9200/_cat/indices?v

There's an extra service with an UI for admin the cluster:

http://localhost:9100