cloud-provider-aws

The AWS cloud provider provides the interface between a Kubernetes cluster and AWS service APIs. This project allows a Kubernetes cluster to provision, monitor and remove AWS resources necessary for operation of the cluster.

Flags

The flag --cloud-provider=external needs to be passed to kubelet, kube-apiserver, and kube-controller-manager. You should not pass the --cloud-provider flag to aws-cloud-controller-manager.

IAM Policy

For the aws-cloud-controller-manager to be able to communicate to AWS APIs, you will need to create a few IAM policies for your EC2 instances. The master policy is a bit open and can be scaled back depending on the use case. Adjust these based on your needs.

Master Policy

  {
  "Version": "2012-10-17",
  "Statement": [
    {
      "Effect": "Allow",
      "Action": [
        "autoscaling:DescribeAutoScalingGroups",
        "autoscaling:DescribeLaunchConfigurations",
        "autoscaling:DescribeTags",
        "ec2:DescribeInstances",
        "ec2:DescribeRegions",
        "ec2:DescribeRouteTables",
        "ec2:DescribeSecurityGroups",
        "ec2:DescribeSubnets",
        "ec2:DescribeVolumes",
        "ec2:CreateSecurityGroup",
        "ec2:CreateTags",
        "ec2:CreateVolume",
        "ec2:ModifyInstanceAttribute",
        "ec2:ModifyVolume",
        "ec2:AttachVolume",
        "ec2:AuthorizeSecurityGroupIngress",
        "ec2:CreateRoute",
        "ec2:DeleteRoute",
        "ec2:DeleteSecurityGroup",
        "ec2:DeleteVolume",
        "ec2:DetachVolume",
        "ec2:RevokeSecurityGroupIngress",
        "ec2:DescribeVpcs",
        "elasticloadbalancing:AddTags",
        "elasticloadbalancing:AttachLoadBalancerToSubnets",
        "elasticloadbalancing:ApplySecurityGroupsToLoadBalancer",
        "elasticloadbalancing:CreateLoadBalancer",
        "elasticloadbalancing:CreateLoadBalancerPolicy",
        "elasticloadbalancing:CreateLoadBalancerListeners",
        "elasticloadbalancing:ConfigureHealthCheck",
        "elasticloadbalancing:DeleteLoadBalancer",
        "elasticloadbalancing:DeleteLoadBalancerListeners",
        "elasticloadbalancing:DescribeLoadBalancers",
        "elasticloadbalancing:DescribeLoadBalancerAttributes",
        "elasticloadbalancing:DetachLoadBalancerFromSubnets",
        "elasticloadbalancing:DeregisterInstancesFromLoadBalancer",
        "elasticloadbalancing:ModifyLoadBalancerAttributes",
        "elasticloadbalancing:RegisterInstancesWithLoadBalancer",
        "elasticloadbalancing:SetLoadBalancerPoliciesForBackendServer",
        "elasticloadbalancing:AddTags",
        "elasticloadbalancing:CreateListener",
        "elasticloadbalancing:CreateTargetGroup",
        "elasticloadbalancing:DeleteListener",
        "elasticloadbalancing:DeleteTargetGroup",
        "elasticloadbalancing:DescribeListeners",
        "elasticloadbalancing:DescribeLoadBalancerPolicies",
        "elasticloadbalancing:DescribeTargetGroups",
        "elasticloadbalancing:DescribeTargetHealth",
        "elasticloadbalancing:ModifyListener",
        "elasticloadbalancing:ModifyTargetGroup",
        "elasticloadbalancing:RegisterTargets",
        "elasticloadbalancing:DeregisterTargets",
        "elasticloadbalancing:SetLoadBalancerPoliciesOfListener",
        "iam:CreateServiceLinkedRole",
        "kms:DescribeKey"
      ],
      "Resource": [
        "*"
      ]
    }
  ]
}

Node Policy

  {
      "Version": "2012-10-17",
      "Statement": [
          {
              "Effect": "Allow",
              "Action": [
                  "ec2:DescribeInstances",
                  "ec2:DescribeRegions",
                  "ecr:GetAuthorizationToken",
                  "ecr:BatchCheckLayerAvailability",
                  "ecr:GetDownloadUrlForLayer",
                  "ecr:GetRepositoryPolicy",
                  "ecr:DescribeRepositories",
                  "ecr:ListImages",
                  "ecr:BatchGetImage"
              ],
              "Resource": "*"
          } 
      ]
  }

Proper Node Names

The cloud provider currently uses the instance private DNS name as the node name, but this is subject to change in the future.

Development

A local single node cluster can be brought up on AWS by running the local up script while on an AWS EC2 instance. Before running this, ensure that the instance you are running on has the KubernetesCluster tag. The tag can be any value.

./hack/local-up-cluster.sh

By default this script will use the cloud provider binary from this repository. You will need to have the k8s main repo cloned before running this script.

Note