Chapter 16. Configuring for Amazon Web Services (AWS)

OpenShift Container Platform can be configured to access an AWS EC2 infrastructure, including using AWS volumes as persistent storage for application data. After you configure AWS, some additional configurations must be completed on the OpenShift Container Platform hosts.

Configuring AWS for OpenShift Container Platform requires the following permissions:

When installing OpenShift Container Platform on AWS, ensure that you set up the appropriate security groups.

These are some ports that you must have in your security groups, without which the installation fails. You may need more depending on the cluster configuration you want to install. For more information and to adjust your security groups accordingly, see Required Ports for more information.

If configuring external load-balancers (ELBs) for load balancing the masters and/or routers, you also need to configure Ingress and Egress security groups for the ELBs appropriately.

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

[Global]
Zone = us-east-1c 1

You can set the AWS configuration on OpenShift Container Platform in two ways:

# Cloud Provider Configuration
#
# Note: You may make use of environment variables rather than store
# sensitive configuration within the ansible inventory.
# For example:
#openshift_cloudprovider_aws_access_key="{{ lookup('env','AWS_ACCESS_KEY_ID') }}"
#openshift_cloudprovider_aws_secret_key="{{ lookup('env','AWS_SECRET_ACCESS_KEY') }}"
#
#openshift_clusterid=unique_identifier_per_availablility_zone
#
# AWS (Using API Credentials)
#openshift_cloudprovider_kind=aws
#openshift_cloudprovider_aws_access_key=aws_access_key_id
#openshift_cloudprovider_aws_secret_key=aws_secret_access_key
#
# AWS (Using IAM Profiles)
#openshift_cloudprovider_kind=aws
# Note: IAM roles must exist before launching the instances.

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

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

AWS_ACCESS_KEY_ID=<key_ID>
AWS_SECRET_ACCESS_KEY=<secret_key>

Start or restart OpenShift Container Platform services on all master and node hosts to apply your configuration changes, see Restarting OpenShift Container Platform services:

# systemctl restart atomic-openshift-master-api atomic-openshift-master-controllers
# 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 cloud provider’s instance-id (which is what the cloud provider specifies). To resolve this issue:

Starting with OpenShift Container Platform version 3.7 of the atomic-openshift-installer, if you configured AWS provider credentials, you must also ensure that all hosts are labeled.

To correctly identify which resources are associated with a cluster, tag resources with the key kubernetes.io/cluster/<clusterid>, where:

Set the corresponding value to owned if the node belongs exclusively to the cluster or to shared if it is a resource shared with other systems.

Tagging all resources with the kubernetes.io/cluster/<clusterid>,Value=(owned|shared) tag avoids potential issues with multiple zones or multiple clusters.

See Pods and Services to learn more about labeling and tagging in OpenShift Container Platform.