Preparing AWS networking

To set up an externally facing load balancer with GKE on AWS, you need to tag your VPC and public subnet with your cluster ID. If you have already tagged your VPC and subnet, skip to Enabling Ingress.

Before you begin

Before you start using GKE on AWS, make sure you have performed the following tasks:

• Complete the Prerequisites.

• Install a management service.
• Create a user cluster.

GKE on AWS requires tags on subnets that contain load balancer endpoints. GKE on AWS automatically tags all subnets specified in the spec.Networking.ServiceLoadBalancerSubnetIDs field of the AWSCluster resource.

If you would like to add additional subnets to your user cluster, or if you need to re-apply tags to existing subnets, perform the following steps.

1. From your anthos-aws directory, use anthos-gke to switch context to your management service.

   cd anthos-aws
   anthos-gke aws management get-credentials

   Note: anthos-gke uses the credentials you specified when you ran aws configure.

2. Get the ID of your cluster's AWS VPC with kubectl and store it as a variable.

    export VPC_ID=$(\
    env HTTPS_PROXY=http://localhost:8118 \
    kubectl get awscluster cluster-0 -o jsonpath='{.spec.networking.vpcID}')
   

3. Check the variables content with echo. The output resembles vpc-12345678abcdef0.

   echo $VPC_ID
   

4. Save your cluster ID into an environment variable.

   export CLUSTER_ID=$(\
   env HTTPS_PROXY=http://localhost:8118 \
   kubectl get awscluster cluster-0 -o jsonpath='{.status.clusterID}')
   

   You can check the variable with echo:

   echo $CLUSTER_ID
   

   The response includes your cluster ID.

   gke-12345678
   

5. If you installed GKE on AWS into a dedicated VPC, you can use the aws command-line tool to retrieve the subnet ID.

   Select from the following options:

   • Public, if you want to expose Services on your public subnet.
   • Private, if you want to expose Services on your private subnet.

   • Multiple subnets, if you want to expose Services on multiple subnets.

   Public

    export SUBNET_ID=$(aws ec2 describe-subnets \
    --filters "Name=vpc-id,Values=$VPC_ID" "Name=tag:Name,Values=*public*" \
    --query "Subnets[*].SubnetId" \
    --output text)
   

   The output is an object that contains your subnet ID. It resembles subnet-1234abcdefg. You can check the variable with echo:

   echo $SUBNET_ID
   

   The response includes your subnet ID.

   subnet-012345678abcdef
   

   Private

    export SUBNET_ID=$(aws ec2 describe-subnets \
    --filters "Name=vpc-id,Values=$VPC_ID" "Name=tag:Name,Values=*private*" \
    --query "Subnets[*].SubnetId" \
    --output text)
   

   The output is an object that contains your subnet ID. It resembles subnet-1234abcdefg. You can check the variable with echo:

   echo $SUBNET_ID
   

   The response includes your subnet ID.

   subnet-012345678abcdef
   

   Multiple subnets

   If you are using multiple subnets for your AWSNodePools (for example, if you use multiple availability zones), you need to tag your subnet IDs individually.

   Note: The following commands assume your subnets have public or private in their name. If your subnets do not include this text, change the parameters of the --filters flag. See Using filtering for more information.

   Retrieve your list of subnet IDs with aws ec2 describe-subnets.

   To get a list of all public subnets, run the following command:

   aws ec2 describe-subnets \
    --filters "Name=vpc-id,Values=$VPC_ID" "Name=tag:Name,Values=*public*" \
    --query "Subnets[*].SubnetId" \
    --output text
   

   To get a list of all private subnets, run the following command:

   aws ec2 describe-subnets \
    --filters "Name=vpc-id,Values=$VPC_ID" "Name=tag:Name,Values=*private*" \
    --query "Subnets[*].SubnetId" \
    --output text
   

   The response includes your subnet IDs.

   subnet-012345678abcdef
   subnet-abcdef123456789
   subnet-123456789abcdef
   

6. Tag your subnet with your cluster ID. If you have multiple subnets, select Multiple subnets.

   Single subnet

   aws ec2 create-tags \
   --resources $SUBNET_ID \
   --tags Key=kubernetes.io/cluster/$CLUSTER_ID,Value=shared
   

   Multiple subnets

   For each of your subnets, run the following command:

   aws ec2 create-tags \
   --resources subnet-ids \
   --tags Key=kubernetes.io/cluster/$CLUSTER_ID,Value=shared
   

   Replace subnet-ids with the list of subnet IDs, separated by spaces. For example, subnet-012345678abcdef subnet-abcdef123456789 subnet-123456789abcdef.