Quartx Dev Blog

A new and upcoming Data Analytics startups techinal journey.

Setting up an Elasticsearch, Fluentd and Kibana (EFK) Stack

When it comes to managing our currently small infrastructure, it became clear very early on that logging is vital. Taking the proper care in logging everything in the code base etc. was carried out. However we had one small problem, it was a very difficult job to go visit any or all of these logs, whether it be system logs, docker logs or logs directly from our main application.

Here’s where the journey to look into implementing a centralised logging system began. There was a few important key features we needed:

  1. The ability to store and collect logs of any kind by pulling from any location at any time.

  2. Using open source technology to achieve all this.

  3. Being able to filter, aggregate, compare and analyze the logs.

After doing a bit of research, I found a nice group of components which make up a stack called EFK named after the following components respectivally,

Elasticsearch: An open source distributed, RESTful search and analyics engine.

Fluentd: An open source data collector with tones of plugins.

Kibana: A web UI for Elasticsearch.

These are the steps to manually set up the EFK stack:

We will be setting up each component in its own Docker container. Docker enables us to deploy each component faster and gives us more control over the behaviour of the components individually.

  • Increase the mmap limits by running the following command as root:

This is required to stop and prevent Elasticsearch from crashing.

sudo sysctl -w vm.max_map_count=262144
  • Set up a docker network:

We must set up a docker network to allow the containers communicate with each other, this is achieved by executing the following docker command.

sudo docker network create efk
  • Deploy Elasticsearch using the following docker command:
sudo docker run --network=efk --name elasticsearch -d -p 9200:9200 -p 9300:9300 -e "discovery.type=single-node" -e "cluster.name=docker-cluster" -e "bootstrap.memory_lock=true" -e "ES_JAVA_OPTS=-Xms512m -Xmx512m" --ulimit memlock=-1:-1 -v elasticdata:/usr/share/elasticsearch/data docker.elastic.co/elasticsearch/elasticsearch-oss:6.2.2

You can verify if this container is running using the following command.

sudo docker ps

This should output a response similar to this.

╰─❯ sudo docker ps 
CONTAINER ID        IMAGE                                                     COMMAND                  CREATED             STATUS              PORTS                                            NAMES
dd2add2fb581        docker.elastic.co/elasticsearch/elasticsearch-oss:6.2.2   "/usr/local/bin/dock…"   28 minutes ago      Up 28 minutes>9200/tcp,>9300/tcp   elasticsearch

  • Deploying Kibana using the following command
sudo docker run --network=efk --name kibana -d -p 5601:5601 docker.elastic.co/kibana/kibana-oss:6.2.2

Verify using the same command again to check if the container has started.

╰─❯ sudo docker ps
CONTAINER ID        IMAGE                                                     COMMAND                  CREATED              STATUS              PORTS                                            NAMES
7bcb4595347b        docker.elastic.co/kibana/kibana-oss:6.2.2                 "/bin/bash /usr/loca…"   About a minute ago   Up About a minute>5601/tcp                           kibana
dd2add2fb581        docker.elastic.co/elasticsearch/elasticsearch-oss:6.2.2   "/usr/local/bin/dock…"   36 minutes ago       Up 36 minutes>9200/tcp,>9300/tcp   elasticsearch

  • Configuring Fluentd to collect logs

Create a directory structure for Fluentd configuration.

mkdir -p fluentd/plugins

Now lets create a Fluentd config file.

nano fluentd/fluent.conf

For example, I will use the configuration to pull logs from docker containers, paste this example into your fluentd/fluent.conf.

  @type forward
  port 24224
<match *.**>
  @type copy
    @type elasticsearch
    host elasticsearch
    port 9200
    logstash_format true
    logstash_prefix fluentd
    logstash_dateformat %Y%m%d
    include_tag_key true
    type_name access_log
    tag_key @log_name
    flush_interval 1s
    @type stdout
  • Setting up a Dockerfile for fluentd

Create another file in the fluentd directory called Dockerfile.

nano fluentd/Dockerfile

Adding in the following config to build a docker image.

FROM fluent/fluentd:v0.12-onbuild

RUN apk add --update --virtual .build-deps \
        sudo build-base ruby-dev \
 && sudo gem install \
        fluent-plugin-elasticsearch \
 && sudo gem sources --clear-all \
 && apk del .build-deps \
 && rm -rf /var/cache/apk/* \

Now the directory should look like the following.

╰─❯ ls fluentd
Dockerfile  fluent.conf  plugins
  • Building docker image for fluentd

Using the following command you can build the previously made Dockerfile, it should create an Image ID as shown, keep note of this Image ID as we will use it for the next command.

sudo docker build fluentd/


Successfully built <Image ID>
  • Deploying fluentd

Take note of the Image ID from the last step, and run the following command with the Image ID included to deploy the fluentd container.

sudo docker run -d --network efk --name fluentd -p 24224:24224/tcp -p 42185:42185/udp <Image ID>
  • Checking if it works

First go and see if kibana is up by going to the port you have set it, in our case it is set as following.

Now send a message to fluentd using docker as follows.

docker run --log-driver=fluentd --log-opt tag="docker.{.ID}}" ubuntu echo 'Hello Fluentd!'

This should now be visible in the Kibana Dashboard.

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