# Adding a new EKS Cluster

## EKS requirements

Before creating your first cluster on Amazon EKS with GitLab's integration, make sure the following
requirements are met:

- An [Amazon Web Services](https://aws.amazon.com/) account is set up and you are able to log in.
- You have permissions to manage IAM resources.
- If you want to use an [existing EKS cluster](add_new_eks_cluster.md#existing-eks-cluster):
  - An Amazon EKS cluster with worker nodes properly configured.
  - `kubectl` [installed and configured](https://docs.aws.amazon.com/eks/latest/userguide/getting-started.html#get-started-kubectl)
    for access to the EKS cluster.

### Additional requirements for self-managed instances **(CORE ONLY)**

If you are using a self-managed GitLab instance, GitLab must first be configured with a set of
Amazon credentials. These credentials will be used to assume an Amazon IAM role provided by the user
creating the cluster. Create an IAM user and ensure it has permissions to assume the role(s) that
your users will use to create EKS clusters.

For example, the following policy document allows assuming a role whose name starts with
`gitlab-eks-` in account `123456789012`:

```json
{
  "Version": "2012-10-17",
  "Statement": {
    "Effect": "Allow",
    "Action": "sts:AssumeRole",
    "Resource": "arn:aws:iam::123456789012:role/gitlab-eks-*"
  }
}
```

Generate an access key for the IAM user, and configure GitLab with the credentials:

1. Navigate to **Admin Area > Settings > Integrations** and expand the **Amazon EKS** section.
1. Check **Enable Amazon EKS integration**.
1. Enter the account ID and access key credentials into the respective
   `Account ID`, `Access key ID` and `Secret access key` fields.
1. Click **Save changes**.

## New EKS cluster

> [Introduced](https://gitlab.com/gitlab-org/gitlab/issues/22392) in GitLab 12.5.

To create and add a new Kubernetes cluster to your project, group, or instance:

1. Navigate to your:
   - Project's **Operations > Kubernetes** page, for a project-level cluster.
   - Group's **Kubernetes** page, for a group-level cluster.
   - **Admin Area > Kubernetes** page, for an instance-level cluster.
1. Click **Add Kubernetes cluster**.
1. Under the **Create new cluster** tab, click **Amazon EKS**. You will be provided with an
   `Account ID` and `External ID` to use in the next step.
1. In the [IAM Management Console](https://console.aws.amazon.com/iam/home), create an IAM role:
   1. From the left panel, select **Roles**.
   1. Click **Create role**.
   1. Under `Select type of trusted entity`, select **Another AWS account**.
   1. Enter the Account ID from GitLab into the `Account ID` field.
   1. Check **Require external ID**.
   1. Enter the External ID from GitLab into the `External ID` field.
   1. Click **Next: Permissions**.
   1. Click **Create Policy**, which will open a new window.
   1. Select the **JSON** tab, and paste in the following snippet in place of the existing content:

      ```json
      {
          "Version": "2012-10-17",
          "Statement": [
              {
                  "Effect": "Allow",
                  "Action": [
                      "autoscaling:CreateAutoScalingGroup",
                      "autoscaling:DescribeAutoScalingGroups",
                      "autoscaling:DescribeScalingActivities",
                      "autoscaling:UpdateAutoScalingGroup",
                      "autoscaling:CreateLaunchConfiguration",
                      "autoscaling:DescribeLaunchConfigurations",
                      "cloudformation:CreateStack",
                      "cloudformation:DescribeStacks",
                      "ec2:AuthorizeSecurityGroupEgress",
                      "ec2:AuthorizeSecurityGroupIngress",
                      "ec2:RevokeSecurityGroupEgress",
                      "ec2:RevokeSecurityGroupIngress",
                      "ec2:CreateSecurityGroup",
                      "ec2:createTags",
                      "ec2:DescribeImages",
                      "ec2:DescribeKeyPairs",
                      "ec2:DescribeRegions",
                      "ec2:DescribeSecurityGroups",
                      "ec2:DescribeSubnets",
                      "ec2:DescribeVpcs",
                      "eks:CreateCluster",
                      "eks:DescribeCluster",
                      "iam:AddRoleToInstanceProfile",
                      "iam:AttachRolePolicy",
                      "iam:CreateRole",
                      "iam:CreateInstanceProfile",
                      "iam:CreateServiceLinkedRole",
                      "iam:GetRole",
                      "iam:ListRoles",
                      "iam:PassRole",
                      "ssm:GetParameters"
                  ],
                  "Resource": "*"
              }
          ]
      }
      ```

      NOTE: **Note:**
      These permissions give GitLab the ability to create resources, but not delete them.
      This means that if an error is encountered during the creation process, changes will
      not be rolled back and you must remove resources manually. You can do this by deleting
      the relevant [CloudFormation stack](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/cfn-console-delete-stack.html)

   1. Click **Review policy**.
   1. Enter a suitable name for this policy, and click **Create Policy**. You can now close this window.
   1. Switch back to the "Create role" window, and select the policy you just created.
   1. Click **Next: Tags**, and optionally enter any tags you wish to associate with this role.
   1. Click **Next: Review**.
   1. Enter a role name and optional description into the fields provided.
   1. Click **Create role**, the new role name will appear at the top. Click on its name and copy the `Role ARN` from the newly created role.
1. In GitLab, enter the copied role ARN into the `Role ARN` field.
1. Click **Authenticate with AWS**.
1. Choose your cluster's settings:
   - **Kubernetes cluster name** - The name you wish to give the cluster.
   - **Environment scope** - The [associated environment](index.md#setting-the-environment-scope-premium) to this cluster.
   - **Kubernetes version** - The Kubernetes version to use. Currently the only version supported is 1.14.
   - **Role name** - Select the [IAM role](https://docs.aws.amazon.com/eks/latest/userguide/service_IAM_role.html)
     to allow Amazon EKS and the Kubernetes control plane to manage AWS resources on your behalf. This IAM role is separate
     to the IAM role created above, you will need to create it if it does not yet exist.
   - **Region** - The [region](https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/using-regions-availability-zones.html)
     in which the cluster will be created.
   - **Key pair name** - Select the [key pair](https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/ec2-key-pairs.html)
     that you can use to connect to your worker nodes if required.
   - **VPC** - Select a [VPC](https://docs.aws.amazon.com/vpc/latest/userguide/what-is-amazon-vpc.html)
     to use for your EKS Cluster resources.
   - **Subnets** - Choose the [subnets](https://docs.aws.amazon.com/vpc/latest/userguide/VPC_Subnets.html)
     in your VPC where your worker nodes will run.
   - **Security group** - Choose the [security group](https://docs.aws.amazon.com/vpc/latest/userguide/VPC_SecurityGroups.html)
     to apply to the EKS-managed Elastic Network Interfaces that are created in your worker node subnets.
   - **Instance type** - The [instance type](https://aws.amazon.com/ec2/instance-types/) of your worker nodes.
   - **Node count** - The number of worker nodes.
   - **GitLab-managed cluster** - Leave this checked if you want GitLab to manage namespaces and service accounts for this cluster.
     See the [Managed clusters section](index.md#gitlab-managed-clusters) for more information.
1. Finally, click the **Create Kubernetes cluster** button.

After about 10 minutes, your cluster will be ready to go. You can now proceed
to install some [pre-defined applications](index.md#installing-applications).

NOTE: **Note:**
You will need to add your AWS external ID to the
[IAM Role in the AWS CLI](https://docs.aws.amazon.com/cli/latest/userguide/cli-configure-role.html#cli-configure-role-xaccount)
to manage your cluster using `kubectl`.

## Existing EKS cluster

To add an existing EKS cluster to your project, group, or instance:

1. Perform the following steps on the EKS cluster:
   1. Retrieve the certificate. A valid Kubernetes certificate is needed to authenticate to the
      EKS cluster. We will use the certificate created by default.
      Open a shell and use `kubectl` to retrieve it:

      1. List the secrets with `kubectl get secrets`, and one should named similar to
         `default-token-xxxxx`. Copy that token name for use below.
      1. Get the certificate with:

         ```shell
         kubectl get secret <secret name> -o jsonpath="{['data']['ca\.crt']}" | base64 --decode
         ```

   1. Create admin token. A `cluster-admin` token is required to install and manage Helm Tiller.
      GitLab establishes mutual SSL authentication with Helm Tiller and creates limited service
      accounts for each application. To create the token we will create an admin service account as
      follows:

      1. Create a file called `eks-admin-service-account.yaml` with contents:

         ```yaml
         apiVersion: v1
         kind: ServiceAccount
         metadata:
           name: eks-admin
           namespace: kube-system
         ```

      1. Apply the service account to your cluster:

         ```shell
         $ kubectl apply -f eks-admin-service-account.yaml
         serviceaccount "eks-admin" created
         ```

      1. Create a file called `eks-admin-cluster-role-binding.yaml` with contents:

         ```yaml
         apiVersion: rbac.authorization.k8s.io/v1beta1
         kind: ClusterRoleBinding
         metadata:
           name: eks-admin
         roleRef:
           apiGroup: rbac.authorization.k8s.io
           kind: ClusterRole
           name: cluster-admin
         subjects:
         - kind: ServiceAccount
           name: eks-admin
           namespace: kube-system
         ```

      1. Apply the cluster role binding to your cluster:

         ```shell
         $ kubectl apply -f eks-admin-cluster-role-binding.yaml
         clusterrolebinding "eks-admin" created
         ```

      1. Retrieve the token for the `eks-admin` service account:

         ```shell
         kubectl -n kube-system describe secret $(kubectl -n kube-system get secret | grep eks-admin | awk '{print $1}')
         ```

         Copy the `<authentication_token>` value from the output:

         ```yaml
         Name:         eks-admin-token-b5zv4
         Namespace:    kube-system
         Labels:       <none>
         Annotations:  kubernetes.io/service-account.name=eks-admin
                    kubernetes.io/service-account.uid=bcfe66ac-39be-11e8-97e8-026dce96b6e8

         Type:  kubernetes.io/service-account-token

         Data
         ====
         ca.crt:     1025 bytes
         namespace:  11 bytes
         token:      <authentication_token>
         ```

   1. Locate the the API server endpoint so GitLab can connect to the cluster. This is displayed on
      the AWS EKS console, when viewing the EKS cluster details.
1. Navigate to your:
   - Project's **Operations > Kubernetes** page, for a project-level cluster.
   - Group's **Kubernetes** page, for a group-level cluster.
   - **Admin Area > Kubernetes** page, for an instance-level cluster.
1. Click **Add Kubernetes cluster**.
1. Click the **Add existing cluster** tab and fill in the details:
   - **Kubernetes cluster name**: A name for the cluster to identify it within GitLab.
   - **Environment scope**: Leave this as `*` for now, since we are only connecting a single cluster.
   - **API URL**: The API server endpoint retrieved earlier.
   - **CA Certificate**: The certificate data from the earlier step, as-is.
   - **Service Token**: The admin token value.
   - For project-level clusters, **Project namespace prefix**: This can be left blank to accept the
     default namespace, based on the project name.
1. Click on **Add Kubernetes cluster**. The cluster is now connected to GitLab.

At this point, [Kubernetes deployment variables](index.md#deployment-variables) will
automatically be available during CI/CD jobs, making it easy to interact with the cluster.

If you would like to utilize your own CI/CD scripts to deploy to the cluster, you can stop here.

### Create a default Storage Class

Amazon EKS doesn't have a default Storage Class out of the box, which means
requests for persistent volumes will not be automatically fulfilled. As part
of Auto DevOps, the deployed PostgreSQL instance requests persistent storage,
and without a default storage class it will fail to start.

If a default Storage Class doesn't already exist and is desired, follow Amazon's
[guide on storage classes](https://docs.aws.amazon.com/eks/latest/userguide/storage-classes.html)
to create one.

Alternatively, disable PostgreSQL by setting the project variable
[`POSTGRES_ENABLED`](../../../topics/autodevops/#environment-variables) to `false`.

### Deploy the app to EKS

With RBAC disabled and services deployed,
[Auto DevOps](../../../topics/autodevops/index.md) can now be leveraged
to build, test, and deploy the app.

[Enable Auto DevOps](../../../topics/autodevops/index.md#at-the-project-level)
if not already enabled. If a wildcard DNS entry was created resolving to the
Load Balancer, enter it in the `domain` field under the Auto DevOps settings.
Otherwise, the deployed app will not be externally available outside of the cluster.

![Deploy Pipeline](img/pipeline.png)

A new pipeline will automatically be created, which will begin to build, test,
and deploy the app.

After the pipeline has finished, your app will be running in EKS and available
to users. Click on **CI/CD > Environments**.

![Deployed Environment](img/environment.png)

You will see a list of the environments and their deploy status, as well as
options to browse to the app, view monitoring metrics, and even access a shell
on the running pod.
