init.tf

resource "null_resource" "first_control_plane" {
  connection {
    user           = "root"
    private_key    = var.ssh_private_key
    agent_identity = local.ssh_agent_identity
    host           = module.control_planes[keys(module.control_planes)[0]].ipv4_address
    port           = var.ssh_port
  }

  # Generating k3s master config file
  provisioner "file" {
    content = yamlencode(
      merge(
        {
          node-name                   = module.control_planes[keys(module.control_planes)[0]].name
          token                       = random_password.k3s_token.result
          cluster-init                = true
          disable-cloud-controller    = true
          disable                     = local.disable_extras
          kubelet-arg                 = local.kubelet_arg
          kube-controller-manager-arg = local.kube_controller_manager_arg
          flannel-iface               = local.flannel_iface
          node-ip                     = module.control_planes[keys(module.control_planes)[0]].private_ipv4_address
          advertise-address           = module.control_planes[keys(module.control_planes)[0]].private_ipv4_address
          node-taint                  = local.control_plane_nodes[keys(module.control_planes)[0]].taints
          node-label                  = local.control_plane_nodes[keys(module.control_planes)[0]].labels
        },
        lookup(local.cni_k3s_settings, var.cni_plugin, {}),
        var.use_control_plane_lb ? {
          tls-san = concat([hcloud_load_balancer.control_plane.*.ipv4[0], hcloud_load_balancer_network.control_plane.*.ip[0]], var.additional_tls_sans)
          } : {
          tls-san = concat([module.control_planes[keys(module.control_planes)[0]].ipv4_address], var.additional_tls_sans)
        },
        local.etcd_s3_snapshots,
        var.control_planes_custom_config
      )
    )

    destination = "/tmp/config.yaml"
  }

  # Install k3s server
  provisioner "remote-exec" {
    inline = local.install_k3s_server
  }

  # Upon reboot start k3s and wait for it to be ready to receive commands
  provisioner "remote-exec" {
    inline = [
      "/etc/cloud/rename_interface.sh",
      "systemctl start k3s",
      # prepare the post_install directory
      "mkdir -p /var/post_install",
      # wait for k3s to become ready
      <<-EOT
      timeout 120 bash <<EOF
        until systemctl status k3s > /dev/null; do
          systemctl start k3s
          echo "Waiting for the k3s server to start..."
          sleep 2
        done
        until [ -e /etc/rancher/k3s/k3s.yaml ]; do
          echo "Waiting for kubectl config..."
          sleep 2
        done
        until [[ "\$(kubectl get --raw='/readyz' 2> /dev/null)" == "ok" ]]; do
          echo "Waiting for the cluster to become ready..."
          sleep 2
        done
      EOF
      EOT
    ]
  }

  depends_on = [
    hcloud_network_subnet.control_plane
  ]
}

# Needed for rancher setup
resource "random_password" "rancher_bootstrap" {
  count   = length(var.rancher_bootstrap_password) == 0 ? 1 : 0
  length  = 48
  special = false
}

# This is where all the setup of Kubernetes components happen
resource "null_resource" "kustomization" {
  triggers = {
    # Redeploy helm charts when the underlying values change
    helm_values_yaml = join("---\n", [
      local.traefik_values,
      local.nginx_values,
      local.calico_values,
      local.cilium_values,
      local.longhorn_values,
      local.cert_manager_values,
      local.rancher_values
    ])
    # Redeploy when versions of addons need to be updated
    versions = join("\n", [
      coalesce(var.cluster_autoscaler_version, "N/A"),
      coalesce(var.hetzner_ccm_version, "N/A"),
      coalesce(var.hetzner_csi_version, "N/A"),
      coalesce(var.kured_version, "N/A"),
      coalesce(var.calico_version, "N/A"),
    ])
    options = join("\n", [
      for option, value in var.kured_options : "${option}=${value}"
    ])
  }

  connection {
    user           = "root"
    private_key    = var.ssh_private_key
    agent_identity = local.ssh_agent_identity
    host           = module.control_planes[keys(module.control_planes)[0]].ipv4_address
    port           = var.ssh_port
  }

  # Upload kustomization.yaml, containing Hetzner CSI & CSM, as well as kured.
  provisioner "file" {
    content = yamlencode({
      apiVersion = "kustomize.config.k8s.io/v1beta1"
      kind       = "Kustomization"

      resources = concat(
        [
          "https://github.com/hetznercloud/hcloud-cloud-controller-manager/releases/download/${local.ccm_version}/ccm-networks.yaml",
          "https://github.com/weaveworks/kured/releases/download/${local.kured_version}/kured-${local.kured_version}-dockerhub.yaml",
          "https://raw.githubusercontent.com/rancher/system-upgrade-controller/master/manifests/system-upgrade-controller.yaml",
        ],
        var.disable_hetzner_csi ? [] : [
          "hcloud-csi.yml"
        ],
        lookup(local.ingress_controller_install_resources, local.ingress_controller, []),
        lookup(local.cni_install_resources, var.cni_plugin, []),
        var.enable_longhorn ? ["longhorn.yaml"] : [],
        var.enable_cert_manager || var.enable_rancher ? ["cert_manager.yaml"] : [],
        var.enable_rancher ? ["rancher.yaml"] : [],
        var.rancher_registration_manifest_url != "" ? [var.rancher_registration_manifest_url] : []
      ),
      patchesStrategicMerge = concat(
        [
          file("${path.module}/kustomize/system-upgrade-controller.yaml"),
          "kured.yaml",
          "ccm.yaml",
        ],
        lookup(local.cni_install_resource_patches, var.cni_plugin, [])
      )
    })
    destination = "/var/post_install/kustomization.yaml"
  }

  # Upload traefik ingress controller config
  provisioner "file" {
    content = templatefile(
      "${path.module}/templates/traefik_ingress.yaml.tpl",
      {
        values = indent(4, trimspace(local.traefik_values))
    })
    destination = "/var/post_install/traefik_ingress.yaml"
  }

  # Upload nginx ingress controller config
  provisioner "file" {
    content = templatefile(
      "${path.module}/templates/nginx_ingress.yaml.tpl",
      {
        values = indent(4, trimspace(local.nginx_values))
    })
    destination = "/var/post_install/nginx_ingress.yaml"
  }

  # Upload the CCM patch config
  provisioner "file" {
    content = templatefile(
      "${path.module}/templates/ccm.yaml.tpl",
      {
        cluster_cidr_ipv4   = var.cluster_ipv4_cidr
        default_lb_location = var.load_balancer_location
        using_klipper_lb    = local.using_klipper_lb
    })
    destination = "/var/post_install/ccm.yaml"
  }

  # Upload the calico patch config, for the kustomization of the calico manifest
  # This method is a stub which could be replaced by a more practical helm implementation
  provisioner "file" {
    content = templatefile(
      "${path.module}/templates/calico.yaml.tpl",
      {
        values = trimspace(local.calico_values)
    })
    destination = "/var/post_install/calico.yaml"
  }

  # Upload the cilium install file
  provisioner "file" {
    content = templatefile(
      "${path.module}/templates/cilium.yaml.tpl",
      {
        values = indent(4, trimspace(local.cilium_values))
    })
    destination = "/var/post_install/cilium.yaml"
  }

  # Upload the system upgrade controller plans config
  provisioner "file" {
    content = templatefile(
      "${path.module}/templates/plans.yaml.tpl",
      {
        channel = var.initial_k3s_channel
    })
    destination = "/var/post_install/plans.yaml"
  }

  # Upload the Longhorn config
  provisioner "file" {
    content = templatefile(
      "${path.module}/templates/longhorn.yaml.tpl",
      {
        longhorn_namespace  = var.longhorn_namespace
        longhorn_repository = var.longhorn_repository
        values              = indent(4, trimspace(local.longhorn_values))
    })
    destination = "/var/post_install/longhorn.yaml"
  }

  # Upload the cert-manager config
  provisioner "file" {
    content = templatefile(
      "${path.module}/templates/cert_manager.yaml.tpl",
      {
        values = indent(4, trimspace(local.cert_manager_values))
    })
    destination = "/var/post_install/cert_manager.yaml"
  }

  # Upload the Rancher config
  provisioner "file" {
    content = templatefile(
      "${path.module}/templates/rancher.yaml.tpl",
      {
        rancher_install_channel = var.rancher_install_channel
        values                  = indent(4, trimspace(local.rancher_values))
    })
    destination = "/var/post_install/rancher.yaml"
  }

  provisioner "file" {
    content = templatefile(
      "${path.module}/templates/kured.yaml.tpl",
      {
        options = local.kured_options
      }
    )
    destination = "/var/post_install/kured.yaml"
  }

  # Deploy secrets, logging is automatically disabled due to sensitive variables
  provisioner "remote-exec" {
    inline = [
      "set -ex",
      "kubectl -n kube-system create secret generic hcloud --from-literal=token=${var.hcloud_token} --from-literal=network=${hcloud_network.k3s.name} --dry-run=client -o yaml | kubectl apply -f -",
      "kubectl -n kube-system create secret generic hcloud-csi --from-literal=token=${var.hcloud_token} --dry-run=client -o yaml | kubectl apply -f -",
      "curl https://raw.githubusercontent.com/hetznercloud/csi-driver/${local.csi_version}/deploy/kubernetes/hcloud-csi.yml | sed -e 's|k8s.gcr.io|registry.k8s.io|g' > /var/post_install/hcloud-csi.yml"
    ]
  }

  # Deploy our post-installation kustomization
  provisioner "remote-exec" {
    inline = concat([
      "set -ex",

      # This ugly hack is here, because terraform serializes the
      # embedded yaml files with "- |2", when there is more than
      # one yamldocument in the embedded file. Kustomize does not understand
      # that syntax and tries to parse the blocks content as a file, resulting
      # in weird errors. so gnu sed with funny escaping is used to
      # replace lines like "- |3" by "- |" (yaml block syntax).
      # due to indendation this should not changes the embedded
      # manifests themselves
      "sed -i 's/^- |[0-9]\\+$/- |/g' /var/post_install/kustomization.yaml",

      # Wait for k3s to become ready (we check one more time) because in some edge cases,
      # the cluster had become unvailable for a few seconds, at this very instant.
      <<-EOT
      timeout 360 bash <<EOF
        until [[ "\$(kubectl get --raw='/readyz' 2> /dev/null)" == "ok" ]]; do
          echo "Waiting for the cluster to become ready..."
          sleep 2
        done
      EOF
      EOT
      ]
      ,

      [
        # Ready, set, go for the kustomization
        "kubectl apply -k /var/post_install",
        "echo 'Waiting for the system-upgrade-controller deployment to become available...'",
        "kubectl -n system-upgrade wait --for=condition=available --timeout=360s deployment/system-upgrade-controller",
        "sleep 7", # important as the system upgrade controller CRDs sometimes don't get ready right away, especially with Cilium.
        "kubectl -n system-upgrade apply -f /var/post_install/plans.yaml"
      ],
      local.has_external_load_balancer ? [] : [
        <<-EOT
      timeout 360 bash <<EOF
      until [ -n "\$(kubectl get -n ${lookup(local.ingress_controller_namespace_names, local.ingress_controller)} service/${lookup(local.ingress_controller_service_names, local.ingress_controller)} --output=jsonpath='{.status.loadBalancer.ingress[0].${var.lb_hostname != "" ? "hostname" : "ip"}}' 2> /dev/null)" ]; do
          echo "Waiting for load-balancer to get an IP..."
          sleep 2
      done
      EOF
      EOT
    ])
  }

  depends_on = [
    null_resource.first_control_plane,
    random_password.rancher_bootstrap,
    hcloud_volume.longhorn_volume
  ]
}