Rancher Server has recently added Docker Machine support, enabling us to easily deploy new Docker hosts on multiple cloud providers via Rancher’s UI/API and automatically have those hosts registered with Rancher. For now Rancher supports DigitalOcean and Amazon EC2 clouds, and more providers will be supported in the future. Another significant feature of Rancher is its networking implementation, because it enhances and facilitates the way you connect Docker containers and those services running on them. Rancher creates a private network across all Docker hosts that allows containers to communicate as if they were in the same subnet. In this post we will see how to use the new Docker Machine support and Rancher networking by deploying a Grafana installation on Amazon EC2. We are creating EC2 instances directly from Rancher UI and all our containers are being connected through the Rancher network. If you have never heard of Grafana, it is an open source rich metric web dashboard and graph editor for Graphite, influxDB and OpenTSBD metric storages. To set this up we are using these docker images:

  • tutum/influxdb for storing metrics and grafana dashboards
  • tutum/grafana for graphing influxDB metrics and serving dashboards
  • a custom linux image that will send linux O.S. metrics to influxDB using sysinfo_influxdb (CPU, memory, load, disks I/O, network traffic).

In a test environment you may want to deploy docker images in the same host, but we are using a total of 4 AWS instances listed below in order to mimic a large-scale production deployment and also to see how Rancher networking works.

  • 1 as a Rancher Server to provision and manage application stack AWS instances,
  • 1 running influxDB docker image (tutum/influxdb)
  • 1 running grafana docker image (tutum/grafana)
  • 1 running sysinfo docker image (nixel/sysinfo_influxdb)

Preparing AWS Environment

First you will need to create the following in AWS Console: a Key Pair for connecting to your servers, a Security Group to give you access to Rancher Console, and a Access Key for Rancher to provision EC2 instances. Creating a Key Pair Enter AWS EC2 Console, go to Key Pairs section, click Create Key Pair button and then enter a name for your Key Pair. Once created, your browser downloads a pem certificate. You will need it if you want to connect to your AWS instances. Creating a Security Group First of all go to VPC Console and enter Subnets section. You will get a list of available subnets in default VPC, choose one for deploying AWS instances and copy its ID and CIDR. Also copy VPC ID, you will need all this data later when creating Docker hosts with Machine integration. I am using subnet 172.31.32.0/20 for this tutorial. AWS-VPC-Subnets Then enter AWS EC2 Console, go to Security Groups section and click Create Security Group button. Enter the following data:

  • Security Group Name: Rancher and Grafana
  • Description: Open Rancher and Grafana ports
  • VPC: select the default one
  • Add a new inbound rule to allow 22 TCP port to be accessible only from your IP
  • Add a new inbound rule to allow 8080 TCP port to be accessible only from your IP
  • Add a new inbound rule to allow 9345-9346 TCP ports to be accessible from anywhere
  • Add a new inbound rule to allow all traffic from your VPC network. In this case source is 172.31.32.0/20, change it accordingly to your environment.

AWS-Security-Group-RancherServer Creating an Access Key Enter EC2 Console and click your user name in the top menu bar, click Security Credentials and then expand Access Keys option. Click Create New Access Key button and after it has been created you will click Show Access Key to get the ID and Secret Key. Save them because you are needing them later to create Docker hosts.

Rancher Server Setup

For launching Rancher Server you will need an AWS instance. I am using the t1.micro instance for writing this guide, but it is recommended to use a larger instance for real environments. Enter AWS EC2 Console and go to Instances section, click Launch Instance button, click Community AMIs and then search for RancherOS and select last version, for example rancheros-v0.2.1. Choose an instance type and click Next: Configure instance details button. In configuration screen be sure to select the same subnet you chose for Security Group. Expand Advanced Details section and enter this user data to initialize your instance and get Rancher Server installed and running.

#!/bin/bash
docker run -d -p 8080:8080 rancher/server:v0.14.1

AWS-RancherServer-userData You may keep default options for all steps excepting Security Group (choose Security Group named Rancher and Grafana). When launching AWS instance you are asked to choose a Key Pair, be sure to select the one that we created before. Go to Instances section and click your Rancher Server instance to know its private and public IPs. Wait a few minutes and then browse to http://RANCHER_SERVER_PUBLIC_IP:8080 to enter Rancher Web Console and click Add Host. You will be asked to confirm Rancher Server IP address, click Something else and enter RANCHER_SERVER_PRIVATE_IP:8080, finally click Save button. AWS-RancherServer-Host-setup

Docker hosts setup

Go to Rancher Console, click Add Host and select Amazon EC2. Here you will need to enter the new host name, the Access Key and the Secret Key. Also be sure to set the same Region, Zone, and VPC ID as those used by Rancher Server. Leave all other parameters with their default values. Repeat this process to create our three Docker hosts that will appear up and running after a while. AWS-DockerHosts Security Group for grafana Rancher Server has created a Security Group named docker-machine for your Docker hosts. Now in order to be able to connect to grafana you must go to VPC Console and add the following Inbound rules:

  • Add a new inbound rule to allow 80 TCP port to be accessible only from your IP
  • Add a new inbound rule to allow 8083-8084 TCP ports to be accessible only from your IP
  • Add a new inbound rule to allow 8086 TCP port to be accessible only from your IP
  • Add a new inbound rule to allow all traffic from your VPC network. In this case source is 172.31.32.0/20, change it accordingly to your environment.

AWS-DockerMachine-SecurityGroup

Installing application containers

This step consists of installing and configuring influxDB, grafana, and an ubuntu container running sysinfo_influxdb. This container will send O.S. metrics to influxDB which will be graphed in grafana. Installing influxDB container Go to Rancher Web Console and click + Add Container button at your first host, enter a container name like influxdb and tutum/influxdb in Select Image field. Add these three port mappings, all of them are TCP:

  • 8083 (on host) to 8083 (in container)
  • 8084 (on host) to 8084 (in container)
  • 8086 (on host) to 8086 (in container)

Expand Advanced Options section an add an environment variable named PRE_CREATE_DB which value is grafana, so influxDB will create an empty database for grafana metrics. Now go to Networking section and enter a hostname like influxdb for this container. Be sure that Network type is Managed Network on docker0 so this container can be reached by grafana and sysinfo_influxdb. You can leave other options with their default values. After a few minutes you will see your influxDB container launched and running in your host. Note that influxdb container has a private IP address, copy it to configure sysinfo_influxdb later. Copy also the public IP of host that is running this container, you will need it later to configure grafana. AWS-grafana1-host

Installing grafana container Go to Rancher Web Console and click + Add Container button at your second host, enter a container name like grafana and tutum/grafana in Select Image field. Add this TCP port mapping:

  • 80 (on host) to 80 (in container)

Expand Advanced Options section and enter the following environment variables needed by grafana:


Variable name Variable value Used for HTTP_USER admin User login for grafana basic HTTP authentication HTTP_PASS Some password User password for grafana basic HTTP authentication INFLUXDB_HOST 52.11.32.51 InfluxDB host’s public IP. Adapt this to your environment INFLUXDB_PORT 8086 InfluxDB port INFLUXDB_NAME grafana Name of previously created database INFLUXDB_USER root InfluxDB user credentials INFLUXDB_PASS root InfluxDB user credentials INFLUXDB_IS_GRAFANADB true Tell grafana to use InfluxDB for storing dashboards


AWS-Grafana-Env-Vars Grafana makes your browser to connect to influxDB directly. This is why we need to configure a public IP in INFLUXDB_HOST variable here. If not, your browser could not reach influxDB when reading metric values. Go to Networking section and enter a hostname like grafana for this container. Be sure that Network type is Managed Network on docker0 so this container can connect to influxdb. You can leave other options with their default values and after a few minutes you will see your grafana container launched and running in your host. AWS-grafana2-host Now go to Instances section in EC2 Console, click on the instance which is running grafana container and copy its public IP. Type the following url in your browser: http://GRAFANA_HOST_PUBLIC_IP, use HTTP_USER and HTTP_PASS credentials to log in. Grafana-Main-Page Installing sysinfo_influxdb container Go to Rancher Web Console and click + Add Container button at your third host, enter sysinfo in container name and nixel/sysinfo_influxdb in Select Image field. No port mapping is needed. Expand Advanced Options section and enter these environment variables which are needed by this container:


Variable name Variable value Used for INFLUXDB_HOST 10.42.169.239 InfluxDB container private IP. Adapt this to your environment INFLUXDB_PORT 8086 InfluxDB port INFLUXDB_NAME grafana Name of previously created database INFLUXDB_USER root InfluxDB user credentials INFLUXDB_PASS root InfluxDB user credentials SYSINFO_INTERVAL 5m Sysinfo frequency to update metric values. Default is 5m


Rancher-Sysinfo-Env-Vars Note that in this case INFLUXDB_HOST contains influxDB container private IP. This is because sysinfo_influxdb will directly connect to influxDB, using the VPN created by Rancher. Go to Networking section and be sure the container hostname is sysinfo because you will later import a sample grafana dashboard which needs this. Be sure that Network type is Managed Network on docker0 so this container can connect to influxdb. You can leave other options with their default values and after a few minutes you will see your sysinfo container launched and running in your host. AWS-grafana3-host

Graph metrics with grafana

At this point sysinfo container is collecting O.S. metrics and sending them to influxDB every 5 minutes using Rancher networking. In this final step we are graphing those metrics in grafana. First let’s import a sample grafana dashboard that is already configured. Execute the following command to download the dashboard definition:

curl -o https://raw.githubusercontent.com/nixelsolutions/sysinfo_influxdb/master/grafana_dashboard.json

Then open grafana web, browse to http://GRAFANA_HOST_PUBLIC_IP and click folder icon on top. Grafana-Import-dashboard Click import button and upload the file you have just downloaded. Click save button on top and now you will be able to see CPU, Load Average, RAM, Swap and Disks metrics that are being collected in your sysinfo container. Grafana-metrics

Conclusion

Rancher implements a networking solution that really simplifies the way you bring connectivity to those services running in your containers. Instead of managing port mappings it automatically puts all your containers into the same network without requiring any configuration from you. This is an important feature because, in fact, it brings containers closer to enterprise production platforms because it makes easier to deploy complex scenarios where some containers need to connect with others. With Rancher you can deploy any container on any host at any time without reconfiguring your environment, and there is no need to worry about defining, configuring or maintaining port mappings when interconnecting containers. To get more information on Rancher, feel free at any time to request a demonstration from one of our engineers, or sign up for an upcoming online meetup.

Manel Martinez is a Linux systems engineer with experience in the design and management of scalable, distributable and highly available open source web infrastructures based on products like KVM, Docker, Apache, Nginx, Tomcat, Jboss, RabbitMQ, HAProxy, MySQL and XtraDB. He lives in spain, and you can find him on Twitter @manel_martinezg.