Overview

OpenShift can be configured to access an AWS EC2 infrastructure, including using AWS volumes as persistent storage for application data. After AWS is configured properly, some additional configurations will need to be completed on the OpenShift hosts.

Configuring AWS Variables

To set the required AWS variables, create a /etc/aws/aws.conf file with the following contents on all of your OpenShift hosts, both masters and nodes:

[Global]
Zone = us-east-1c (1)
1 This is the Availability Zone of your AWS Instance and where your EBS Volume resides; this information is obtained from the AWS Managment Console.

Configuring Masters

Edit or create the master configuration file on all masters (/etc/origin/master/master-config.yaml by default) and update the contents of the apiServerArguments and controllerArguments sections:

kubernetesMasterConfig:
  ...
  apiServerArguments:
    cloud-provider:
      - "aws"
    cloud-config:
      - "/etc/aws/aws.conf"
  controllerArguments:
    cloud-provider:
      - "aws"
    cloud-config:
      - "/etc/aws/aws.conf"

Configuring Nodes

Edit or create the node configuration file on all nodes (/etc/origin/node/node-config.yaml by default) and update the contents of the kubeletArguments section:

kubeletArguments:
  cloud-provider:
    - "aws"
  cloud-config:
    - "/etc/aws/aws.conf"

Setting Key Value Access Pairs

Make sure the following environment variables are set in the /etc/sysconfig/atomic-openshift-master file on masters and the /etc/sysconfig/atomic-openshift-node file on nodes:

AWS_ACCESS_KEY_ID=<key_ID>
AWS_SECRET_ACCESS_KEY=<secret_key>

Access keys are obtained when setting up your AWS IAM user.

Applying Configuration Changes

Start or restart OpenShift services on all master and node hosts to apply your configuration changes:

# systemctl restart atomic-openshift-master
# systemctl restart atomic-openshift-node

Switching from not using a cloud provider to using a cloud provider produces an error message. Adding the cloud provider tries to delete the node because the node switches from using the hostname as the externalID (which would have been the case when no cloud provider was being used) to using the AWS instance-id (which is what the AWS cloud provider specifies). To resolve this issue:

  1. Log in to the CLI as a cluster administrator.

  2. Delete the nodes:

    $ oc delete node <node_name>
  3. On each node host, restart the atomic-openshift-node service.

  4. Add back any labels on each node that you previously had.