Argo CD is a declarative, GitOps continuous delivery tool for Kubernetes. In this blog post we will see how to install, configure and manage ArgoCD on Amazon Elastic Container Service for Kubernetes (Amazon EKS).

Prerequisites

Installing and configuring AWS CLI
eksctl
Kubectl
ArgoCD CLI
Create a public hosted zone in Route 53. See tutorial
Request a public certificate with AWS Certificate Manager. See tutorial

EKS configuration

We start by creating the EKS cluster.



export AWS_PROFILE=<AWS_PROFILE>
export AWS_REGION=eu-west-1
export EKS_CLUSTER_NAME=devops
export EKS_VERSION=1.19

eksctl create cluster \
 --name $EKS_CLUSTER_NAME \
 --version $EKS_VERSION \
 --region $AWS_REGION \
 --managed

ArgoCD installation

Before installing ArgoCD in Kubernetes, we need to authenticate on Amazon EKS:



aws eks --region $AWS_REGION update-kubeconfig --name $EKS_CLUSTER_NAME

Install ArgoCD using the official yaml



$ kubectl create namespace argocd
$ kubectl config set-context --current --namespace=argocd 
$ kubectl apply -f https://raw.githubusercontent.com/argoproj/argo-cd/stable/manifests/install.yaml

ArgoCD configuration

Associate the public certificate that you created earlier to the ArgoCD server.



cat > argocd-server.patch.yaml << EOF
apiVersion: v1
kind: Service
metadata:
  annotations:
    service.beta.kubernetes.io/aws-load-balancer-ssl-cert: "<ACM_ARGOCD_ARN>"
spec:
  type: LoadBalancer
  loadBalancerSourceRanges:
  - "<LOCAL_IP_RANGES>"
EOF

ACM_ARGOCD_ARN=<ACM_ARGOCD_ARN>
sed -i "s,<ACM_ARGOCD_ARN>,${ACM_ARGOCD_ARN},g; s/<LOCAL_IP_RANGES>/$(curl -s http://checkip.amazonaws.com/)\/32/g; " argocd-server.patch.yaml
$ kubectl patch svc argocd-server -p "$(cat argocd-server.patch.yaml)"

Create a Record Set in your hosted zone that you created earlier. The CNAME record points to the ingress hostname of the ArgoCD server.



PUBLIC_DNS_NAME=<PUBLIC_DNS_NAME>
R53_HOSTED_ZONE_ID=<R53_HOSTED_ZONE_ID>
cat > argocd-recordset.json << EOF
{
            "Changes": [{
            "Action": "CREATE",
                        "ResourceRecordSet": {
                                    "Name": "argocd.${PUBLIC_DNS_NAME}.",
                                    "Type": "CNAME",
                                    "TTL": 300,
                                 "ResourceRecords": [{ "Value": "$(kubectl get services argocd-server --output jsonpath='{.status.loadBalancer.ingress[0].hostname}')"}]
}}]
}
EOF

aws route53 change-resource-record-sets --hosted-zone-id $R53_HOSTED_ZONE_ID --change-batch file://argocd-recordset.json

As the AWS Elastic Load Balancer is doing the SSL we need to start Argo CD in HTTP (insecure) mode by disabling the TLS. Edit the argocd-server deployment to add the --insecure flag to the argocd-server command:



cat > argocd-deployment-server.patch.yaml << EOF
spec:
  template:
    spec:
      containers:
        - command:
          - argocd-server
          - --staticassets
          - /shared/app
          - --insecure
          name: argocd-server
EOF

$ kubectl patch deployment argocd-server -p "$(cat argocd-deployment-server.patch.yaml)"

Amazon EKS creates a Classic Load Balancer.

An AWS Application Load Balancer can be used as Load Balancer for both UI and gRPC traffic. See ArgoCD Ingress Configuration.

ArgoCD Web UI configuration

The initial admin password is autogenerated to be the pod name of the Argo CD API server. Let's change it.

Edit the argocd-secret secret and update the admin.password field with a new bcrypt hash. You can use a site like https://www.browserling.com/tools/bcrypt to generate a new hash.



ARGOCD_ADDR="argocd.${PUBLIC_DNS_NAME}"

$ kubectl patch secret argocd-secret \
  -p '{"stringData": {
    "admin.password": "<BCRYPT_HASH>",
    "admin.passwordMtime": "'$(date +%FT%T%Z)'"
  }}'



argocd login $ARGOCD_ADDR

The admin user is a superuser and it has unrestricted access to the system. ArgoCD recommends to not use the admin user in daily work.

Let's add two new users demo and ci:

User demo will have read only access to the Web UI,
User ci will have write privileges and will be used to generate access tokens to execute argocd commands in CI / CD pipelines.

If you have a Git repository, you can specify it in the repositories attribute.



cat > argocd-configmap.yaml << EOF
apiVersion: v1
kind: ConfigMap
metadata:
  name: argocd-cm
  namespace: argocd
  labels:
    app.kubernetes.io/name: argocd-cm
    app.kubernetes.io/part-of: argocd
data:
  repositories: |
    - url: <GIT_REPOSITORY_URL>
      passwordSecret:
        name: demo
        key: password
      usernameSecret:
        name: demo
        key: username
  admin.enabled: "true"
  accounts.demo.enabled: "true"
  accounts.demo: login
  accounts.ci.enabled: "true"
  accounts.ci: apiKey
EOF

GIT_USERNAME=<GIT_USERNAME>
GIT_TOKEN=<GIT_TOKEN>

$ kubectl create secret generic demo \
--from-literal=username=$GIT_USERNAME \
--from-literal=password=$GIT_TOKEN

Let's create the users:



sed -i "s,<GIT_REPOSITORY_URL>,$GIT_REPOSITORY_URL,g" argocd-configmap.yaml

$ kubectl apply -f argocd-configmap.yaml

Add a password to the demo user:



argocd account update-password --account demo --current-password "${ADMIN_PASSWORD}" --new-password "<DEMO_PASSWORD>"

We can now assign the roles to the users:

demo user will have read only access,
ci user will manage projects, repositories, clusters and applications.



cat > argocd-rbac-configmap.yaml << EOF
apiVersion: v1
kind: ConfigMap
metadata:
  name: argocd-rbac-cm
  namespace: argocd
  labels:
    app.kubernetes.io/name: argocd-rbac-cm
    app.kubernetes.io/part-of: argocd
data:
  policy.default: role:readonly
  policy.csv: |
    p, role:ci, applications, sync, *, allow
    p, role:ci, applications, update, *, allow
    p, role:ci, applications, override, *, allow
    p, role:ci, applications, create, *, allow
    p, role:ci, applications, get, *, allow
    p, role:ci, applications, list, *, allow
    p, role:ci, clusters, create, *, allow
    p, role:ci, clusters, get, *, allow
    p, role:ci, clusters, list, *, allow
    p, role:ci, projects, create, *, allow
    p, role:ci, projects, get, *, allow
    p, role:ci, projects, list, *, allow
    p, role:ci, repositories, create, *, allow
    p, role:ci, repositories, get, *, allow
    p, role:ci, repositories, list, *, allow

    g, ci, role:ci
EOF

$ kubectl apply -f argocd-rbac-configmap.yaml

CI / CD integration

To create a token using the ci user you can run the command:



AROGOCD_TOKEN=$(argocd account generate-token --account ci)

The token can be stored in AWS Secret Manager and used in a CI / CD pipeline::



aws secretsmanager create-secret --name argocd-token \
    --description "ArgoCD Token" \
    --secret-string "${AROGOCD_TOKEN}"

The following Gitlab example demonstrates the use of this token to create a cluster, a project, and synchronize an application in ArgoCD.

If you want to understand how an IAM role can be attached to a Gitlab runner, please refer to my previous post on Securing access to AWS IAM Roles from Gitlab CI



stages:
  - init
  - deploy

variables: 
   KUBECTL_VERSION: 1.20.5
   ARGOCD_VERSION: 1.7.4
   ARGOCD_ADDR: argocd.example.com

# Get ArgoCD credentials from Secret Manager
before_script:
    - export AROGOCD_TOKEN="$(aws secretsmanager get-secret-value --secret-id argocd-token --version-stage AWSCURRENT --query SecretString --output text)"
    # install kubectl
    - curl -L "https://storage.googleapis.com/kubernetes-release/release/v${KUBECTL_VERSION}/bin/linux/amd64/kubectl" -o /usr/bin/kubectl 
    # install argocd
    - curl -sSL -o /usr/local/bin/argocd "https://github.com/argoproj/argo-cd/releases/download/v${ARGOCD_VERSION}/argocd-linux-amd64"

init demo project 🔬:
  stage: init
  when: manual
  image:
    name: amazon/aws-cli
  script:
    - argocd cluster add $BUSINESS_K8S_CONTEXT --name business-cluster-dev --kubeconfig $KUBE_CONFIG --auth-token=${AROGOCD_TOKEN} --server ${ARGOCD_ADDR} || echo 'cluster already added'
  tags:
    - k8s-dev-runner
  only:
    - master 

deploy demo project 🚀:
  stage: init
  when: manual
  image:
    name: amazon/aws-cli
  script:
    - sed -i "s,<KUBERNETES_CLUSTER_URL>,$BUSINESS_K8S_CLUSTER_URL,g;s,<GIT_REPOSITORY_URL>,$CI_PROJECT_URL.git,g" application.yaml
    # Connect to aws eks devops cluster
    - aws eks update-kubeconfig --region $AWS_REGION --name $EKS_CLUSTER_NAME
    # Create ArgoCD project
    - argocd proj create demo-dev -d $BUSINESS_K8S_CLUSTER_URL,app-dev -s $CI_PROJECT_URL.git --auth-token=${AROGOCD_TOKEN} --server ${ARGOCD_ADDR} || echo 'project already created' 
    # Create ArgoCD application
    - kubectl apply -n argocd -f application.yaml
  tags:
    - k8s-dev-runner
  only:
    - master

deploy demo app 🌐:
  stage: deploy
  image:
    name: amazon/aws-cli
  script:
    - cd envs/dev
    - argocd app sync demo-dev --auth-token=${AROGOCD_TOKEN} --server ${ARGOCD_ADDR}
  tags:
    - k8s-dev-runner
  only:
    - tags

And here the configuration of the ArgoCD application:



apiVersion: argoproj.io/v1alpha1
kind: Application
metadata:
  name: demo-dev
  namespace: argocd
spec:
  project: demo-dev
  source:
    repoURL: <GIT_REPOSITORY_URL>
    targetRevision: HEAD
    path: envs/dev
  destination:
    server: <KUBERNETES_CLUSTER_URL>
    namespace: app-dev

Before running such a pipeline, the Gitlab runner must have access to the argoproj.io API.

Create the RBAC:



cat - <<EOF | kubectl apply -f - --namespace "argocd"
apiVersion: rbac.authorization.k8s.io/v1
kind: Role
metadata:
  name: $GITLAB_RUNNER_IAM_ROLE_NAME
  namespace: argocd
rules:
  - apiGroups: ["argoproj.io"]
    resources: ["clusters", "projects", "applications", "repositories", "certificates", "accounts", "gpgkeys"]
    verbs: ["get", "create", "update", "delete", "sync", "override", "action"]

EOF    

cat - <<EOF | kubectl apply -f - --namespace "argocd"
apiVersion: rbac.authorization.k8s.io/v1
kind: RoleBinding
metadata:
  name: $GITLAB_RUNNER_IAM_ROLE_NAME
  namespace: argocd
subjects:
- kind: User
  name: $GITLAB_RUNNER_IAM_ROLE_NAME
  apiGroup: rbac.authorization.k8s.io
roleRef:
  kind: Role
  name: $GITLAB_RUNNER_IAM_ROLE_NAME
  apiGroup: rbac.authorization.k8s.io

EOF

GITLAB_RUNNER_IAM_ROLE_NAME is the name of the IAM role linked to the kubernetes service account attached to the runner.

Update the aws-auth configmap:



$ kubectl get configmap -n kube-system aws-auth -o yaml > aws-auth.yaml

Complete the config map with the following role:



  mapRoles: | 
    - rolearn: $GITLAB_RUNNER_IAM_ROLE_ARN
      username: $GITLAB_RUNNER_IAM_ROLE_NAME

Apply the change



$ kubectl apply -f aws-auth.yaml

That's it!

Conclusion

In this blog post we configured the ArgoCD server, ArgoCD Web UI and we ended up integrating ArgoCD into a CI / CD tool.

Hope you enjoyed reading this blog post.

If you have any questions or feedback, please feel free to leave a comment.

Thanks for reading!

Configuring ArgoCD on Amazon EKS