Ontrack Infra DO K8S

Definition of a Kubernetes cluster in Digital Ocean with an Ingress controller.

Usage

Clone this repository and create a terraform.tfvars file at the root of the working copy with the following values:

# Digital Ocean token with read/write authorizations
# Create one by going to https://cloud.digitalocean.com/account/api/tokens
do_token        = "..."
# The Digital Ocean region where to install the cluster. For example:
do_region       = "fra1"
# The email used to register the ingress to the ACME Let's Encrypt server
do_acme_email   = "...@..."
# Unique name for the cluster
do_cluster_name = "..."

Run the plan:

terraform plan -input=false -out=plan

Apply the plan:

terraform apply plan

After a few minutes, your Digital Ocean cluster will be ready to accept workloads.

Resources

The following resources are created:

a VPC whose name is the same as the cluster - all resources of the cluster will be in this VPC
a K8S cluster, set in auto scaling mode for its default pool of nodes, from 1 node to do_cluster_default_count ( defaults to 3)
an Ingress controller, a Cert manager & a Cert issuer

Configuration of the Ingress controller

By default, the Ingress controller uses the https://kubernetes.github.io/ingress-nginx/ controller.

The Certificate issuer uses the ACME Let's Encrypt production server at https://acme-v02.api.letsencrypt.org/directory. To use the staging server, set:

do_acme_server = "https://acme-staging-v02.api.letsencrypt.org/directory"

Adding ingresses

An Ingress resource will typically look like:

apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: ingress-name
  namespace: target-namespace
  annotations:
    cert-manager.io/cluster-issuer: letsencrypt-prod
    kubernetes.io/ingress.class: nginx
spec:
  tls:
    - hosts:
        - host.domain.com
      secretName: host.domain.com.tls
  rules:
    - host: host.domain.com
      http:
        paths:
          - path: /
            pathType: Prefix
            backend:
              service:
                name: service-name
                port:
                  number: 8080

The two main attributes are the annotations on the Ingress resource:

cert-manager.io/cluster-issuer: letsencrypt-prod
kubernetes.io/ingress.class: nginx

Destruction

To remove the whole setup (the Ontrack K8S resources and its managed database), run:

terraform destroy

Note that the destruction of the VPC associated with the cluster might fail (because it times out before all its associated resources are actually removed). Launch tge destroy command to finally clean it.

Configuration variables

See variables.tf for the list of configuration variables, their types and their description.