Replace kube-dns with CoreDNS

* Add system:coredns ClusterRole and binding
* Annotate CoreDNS for Prometheus metrics scraping
* Remove kube-dns deployment, service, & service account
* poseidon/terraform-render-bootstrap#71
* https://kubernetes.io/blog/2018/06/27/kubernetes-1.11-release-announcement/

CHANGES.md

@@ -6,6 +6,8 @@ Notable changes between versions.
 
 * Kubernetes [v1.11.0](https://github.com/kubernetes/kubernetes/blob/master/CHANGELOG-1.11.md#v1110)
 * Force apiserver to stop listening on `127.0.0.1:8080`
+* Replace `kube-dns` with [CoreDNS](https://coredns.io/) ([#261](https://github.com/poseidon/typhoon/pull/261))
+  * Edit the `coredns` ConfigMap to [customize](https://coredns.io/plugins/)
 
 #### AWS
 

README.md

@@ -101,10 +101,10 @@ NAMESPACE     NAME                                      READY  STATUS    RESTART
 kube-system   calico-node-1cs8z                         2/2    Running   0         6m
 kube-system   calico-node-d1l5b                         2/2    Running   0         6m
 kube-system   calico-node-sp9ps                         2/2    Running   0         6m
+kube-system   coredns-1187388186-zj5dl                  1/1    Running   0         6m
 kube-system   kube-apiserver-zppls                      1/1    Running   0         6m
 kube-system   kube-controller-manager-3271970485-gh9kt  1/1    Running   0         6m
 kube-system   kube-controller-manager-3271970485-h90v8  1/1    Running   1         6m
-kube-system   kube-dns-1187388186-zj5dl                 3/3    Running   0         6m
 kube-system   kube-proxy-117v6                          1/1    Running   0         6m
 kube-system   kube-proxy-9886n                          1/1    Running   0         6m
 kube-system   kube-proxy-njn47                          1/1    Running   0         6m

aws/container-linux/kubernetes/bootkube.tf

@@ -1,6 +1,6 @@
 # Self-hosted Kubernetes assets (kubeconfig, manifests)
 module "bootkube" {
-  source = "git::https://github.com/poseidon/terraform-render-bootkube.git?ref=eb2dfa64de3f6c31bf5d2a8ca8912223ac1aef05"
+  source = "git::https://github.com/poseidon/terraform-render-bootkube.git?ref=81ba300e712e116c9ea9470ccdce7859fecc76b6"
 
   cluster_name          = "${var.cluster_name}"
   api_servers           = ["${format("%s.%s", var.cluster_name, var.dns_zone)}"]

aws/container-linux/kubernetes/variables.tf

@@ -116,15 +116,15 @@ variable "pod_cidr" {
 variable "service_cidr" {
   description = <<EOD
 CIDR IPv4 range to assign Kubernetes services.
-The 1st IP will be reserved for kube_apiserver, the 10th IP will be reserved for kube-dns.
+The 1st IP will be reserved for kube_apiserver, the 10th IP will be reserved for coredns.
 EOD
 
   type    = "string"
   default = "10.3.0.0/16"
 }
 
 variable "cluster_domain_suffix" {
-  description = "Queries for domains with the suffix will be answered by kube-dns. Default is cluster.local (e.g. foo.default.svc.cluster.local) "
+  description = "Queries for domains with the suffix will be answered by coredns. Default is cluster.local (e.g. foo.default.svc.cluster.local) "
   type        = "string"
   default     = "cluster.local"
 }

aws/container-linux/kubernetes/workers/variables.tf

@@ -79,15 +79,15 @@ variable "ssh_authorized_key" {
 variable "service_cidr" {
   description = <<EOD
 CIDR IPv4 range to assign Kubernetes services.
-The 1st IP will be reserved for kube_apiserver, the 10th IP will be reserved for kube-dns.
+The 1st IP will be reserved for kube_apiserver, the 10th IP will be reserved for coredns.
 EOD
 
   type    = "string"
   default = "10.3.0.0/16"
 }
 
 variable "cluster_domain_suffix" {
-  description = "Queries for domains with the suffix will be answered by kube-dns. Default is cluster.local (e.g. foo.default.svc.cluster.local) "
+  description = "Queries for domains with the suffix will be answered by coredns. Default is cluster.local (e.g. foo.default.svc.cluster.local) "
   type        = "string"
   default     = "cluster.local"
 }

aws/fedora-atomic/kubernetes/bootkube.tf

@@ -1,6 +1,6 @@
 # Self-hosted Kubernetes assets (kubeconfig, manifests)
 module "bootkube" {
-  source = "git::https://github.com/poseidon/terraform-render-bootkube.git?ref=eb2dfa64de3f6c31bf5d2a8ca8912223ac1aef05"
+  source = "git::https://github.com/poseidon/terraform-render-bootkube.git?ref=81ba300e712e116c9ea9470ccdce7859fecc76b6"
 
   cluster_name          = "${var.cluster_name}"
   api_servers           = ["${format("%s.%s", var.cluster_name, var.dns_zone)}"]

aws/fedora-atomic/kubernetes/variables.tf

@@ -98,15 +98,15 @@ variable "pod_cidr" {
 variable "service_cidr" {
   description = <<EOD
 CIDR IPv4 range to assign Kubernetes services.
-The 1st IP will be reserved for kube_apiserver, the 10th IP will be reserved for kube-dns.
+The 1st IP will be reserved for kube_apiserver, the 10th IP will be reserved for coredns.
 EOD
 
   type    = "string"
   default = "10.3.0.0/16"
 }
 
 variable "cluster_domain_suffix" {
-  description = "Queries for domains with the suffix will be answered by kube-dns. Default is cluster.local (e.g. foo.default.svc.cluster.local) "
+  description = "Queries for domains with the suffix will be answered by coredns. Default is cluster.local (e.g. foo.default.svc.cluster.local) "
   type        = "string"
   default     = "cluster.local"
 }

aws/fedora-atomic/kubernetes/workers/variables.tf

@@ -67,15 +67,15 @@ variable "ssh_authorized_key" {
 variable "service_cidr" {
   description = <<EOD
 CIDR IPv4 range to assign Kubernetes services.
-The 1st IP will be reserved for kube_apiserver, the 10th IP will be reserved for kube-dns.
+The 1st IP will be reserved for kube_apiserver, the 10th IP will be reserved for coredns.
 EOD
 
   type    = "string"
   default = "10.3.0.0/16"
 }
 
 variable "cluster_domain_suffix" {
-  description = "Queries for domains with the suffix will be answered by kube-dns. Default is cluster.local (e.g. foo.default.svc.cluster.local) "
+  description = "Queries for domains with the suffix will be answered by coredns. Default is cluster.local (e.g. foo.default.svc.cluster.local) "
   type        = "string"
   default     = "cluster.local"
 }

bare-metal/container-linux/kubernetes/bootkube.tf

@@ -1,6 +1,6 @@
 # Self-hosted Kubernetes assets (kubeconfig, manifests)
 module "bootkube" {
-  source = "git::https://github.com/poseidon/terraform-render-bootkube.git?ref=eb2dfa64de3f6c31bf5d2a8ca8912223ac1aef05"
+  source = "git::https://github.com/poseidon/terraform-render-bootkube.git?ref=81ba300e712e116c9ea9470ccdce7859fecc76b6"
 
   cluster_name                    = "${var.cluster_name}"
   api_servers                     = ["${var.k8s_domain_name}"]

bare-metal/container-linux/kubernetes/variables.tf

@@ -91,7 +91,7 @@ variable "pod_cidr" {
 variable "service_cidr" {
   description = <<EOD
 CIDR IPv4 range to assign Kubernetes services.
-The 1st IP will be reserved for kube_apiserver, the 10th IP will be reserved for kube-dns.
+The 1st IP will be reserved for kube_apiserver, the 10th IP will be reserved for coredns.
 EOD
 
   type    = "string"
@@ -101,7 +101,7 @@ EOD
 # optional
 
 variable "cluster_domain_suffix" {
-  description = "Queries for domains with the suffix will be answered by kube-dns. Default is cluster.local (e.g. foo.default.svc.cluster.local) "
+  description = "Queries for domains with the suffix will be answered by coredns. Default is cluster.local (e.g. foo.default.svc.cluster.local) "
   type        = "string"
   default     = "cluster.local"
 }

bare-metal/fedora-atomic/kubernetes/bootkube.tf

@@ -1,6 +1,6 @@
 # Self-hosted Kubernetes assets (kubeconfig, manifests)
 module "bootkube" {
-  source = "git::https://github.com/poseidon/terraform-render-bootkube.git?ref=eb2dfa64de3f6c31bf5d2a8ca8912223ac1aef05"
+  source = "git::https://github.com/poseidon/terraform-render-bootkube.git?ref=81ba300e712e116c9ea9470ccdce7859fecc76b6"
 
   cluster_name          = "${var.cluster_name}"
   api_servers           = ["${var.k8s_domain_name}"]

bare-metal/fedora-atomic/kubernetes/variables.tf

@@ -86,15 +86,15 @@ variable "pod_cidr" {
 variable "service_cidr" {
   description = <<EOD
 CIDR IPv4 range to assign Kubernetes services.
-The 1st IP will be reserved for kube_apiserver, the 10th IP will be reserved for kube-dns.
+The 1st IP will be reserved for kube_apiserver, the 10th IP will be reserved for coredns.
 EOD
 
   type    = "string"
   default = "10.3.0.0/16"
 }
 
 variable "cluster_domain_suffix" {
-  description = "Queries for domains with the suffix will be answered by kube-dns. Default is cluster.local (e.g. foo.default.svc.cluster.local) "
+  description = "Queries for domains with the suffix will be answered by coredns. Default is cluster.local (e.g. foo.default.svc.cluster.local) "
   type        = "string"
   default     = "cluster.local"
 }

digital-ocean/container-linux/kubernetes/bootkube.tf

@@ -1,6 +1,6 @@
 # Self-hosted Kubernetes assets (kubeconfig, manifests)
 module "bootkube" {
-  source = "git::https://github.com/poseidon/terraform-render-bootkube.git?ref=eb2dfa64de3f6c31bf5d2a8ca8912223ac1aef05"
+  source = "git::https://github.com/poseidon/terraform-render-bootkube.git?ref=81ba300e712e116c9ea9470ccdce7859fecc76b6"
 
   cluster_name          = "${var.cluster_name}"
   api_servers           = ["${format("%s.%s", var.cluster_name, var.dns_zone)}"]

digital-ocean/container-linux/kubernetes/variables.tf

@@ -80,15 +80,15 @@ variable "pod_cidr" {
 variable "service_cidr" {
   description = <<EOD
 CIDR IPv4 range to assign Kubernetes services.
-The 1st IP will be reserved for kube_apiserver, the 10th IP will be reserved for kube-dns.
+The 1st IP will be reserved for kube_apiserver, the 10th IP will be reserved for coredns.
 EOD
 
   type    = "string"
   default = "10.3.0.0/16"
 }
 
 variable "cluster_domain_suffix" {
-  description = "Queries for domains with the suffix will be answered by kube-dns. Default is cluster.local (e.g. foo.default.svc.cluster.local) "
+  description = "Queries for domains with the suffix will be answered by coredns. Default is cluster.local (e.g. foo.default.svc.cluster.local) "
   type        = "string"
   default     = "cluster.local"
 }

digital-ocean/fedora-atomic/kubernetes/bootkube.tf

@@ -1,6 +1,6 @@
 # Self-hosted Kubernetes assets (kubeconfig, manifests)
 module "bootkube" {
-  source = "git::https://github.com/poseidon/terraform-render-bootkube.git?ref=eb2dfa64de3f6c31bf5d2a8ca8912223ac1aef05"
+  source = "git::https://github.com/poseidon/terraform-render-bootkube.git?ref=81ba300e712e116c9ea9470ccdce7859fecc76b6"
 
   cluster_name          = "${var.cluster_name}"
   api_servers           = ["${format("%s.%s", var.cluster_name, var.dns_zone)}"]

digital-ocean/fedora-atomic/kubernetes/variables.tf

@@ -73,15 +73,15 @@ variable "pod_cidr" {
 variable "service_cidr" {
   description = <<EOD
 CIDR IPv4 range to assign Kubernetes services.
-The 1st IP will be reserved for kube_apiserver, the 10th IP will be reserved for kube-dns.
+The 1st IP will be reserved for kube_apiserver, the 10th IP will be reserved for coredns.
 EOD
 
   type    = "string"
   default = "10.3.0.0/16"
 }
 
 variable "cluster_domain_suffix" {
-  description = "Queries for domains with the suffix will be answered by kube-dns. Default is cluster.local (e.g. foo.default.svc.cluster.local) "
+  description = "Queries for domains with the suffix will be answered by coredns. Default is cluster.local (e.g. foo.default.svc.cluster.local) "
   type        = "string"
   default     = "cluster.local"
 }

docs/architecture/concepts.md

@@ -12,7 +12,7 @@ Cluster nodes provision themselves from a declarative configuration upfront. Nod
 
 #### Controllers
 
-Controller nodes are scheduled to run the Kubernetes `apiserver`, `scheduler`, `controller-manager`, `kube-dns`, and `kube-proxy`. A fully qualified domain name (e.g. cluster_name.domain.com) resolving to a network load balancer or round-robin DNS (depends on platform) is used to refer to the control plane.
+Controller nodes are scheduled to run the Kubernetes `apiserver`, `scheduler`, `controller-manager`, `coredns`, and `kube-proxy`. A fully qualified domain name (e.g. cluster_name.domain.com) resolving to a network load balancer or round-robin DNS (depends on platform) is used to refer to the control plane.
 
 #### Workers
 

docs/atomic/aws.md

@@ -7,7 +7,7 @@ In this tutorial, we'll create a Kubernetes v1.11.0 cluster on AWS with Fedora A
 
 We'll declare a Kubernetes cluster using the Typhoon Terraform module. Then apply the changes to create a VPC, gateway, subnets, security groups, controller instances, worker auto-scaling group, network load balancer, and TLS assets. Instances are provisioned on first boot with cloud-init.
 
-Controllers are provisioned to run an `etcd` peer and a `kubelet` service. Workers run just a `kubelet` service. A one-time [bootkube](https://github.com/kubernetes-incubator/bootkube) bootstrap schedules the `apiserver`, `scheduler`, `controller-manager`, and `kube-dns` on controllers and schedules `kube-proxy` and `calico` (or `flannel`) on every node. A generated `kubeconfig` provides `kubectl` access to the cluster.
+Controllers are provisioned to run an `etcd` peer and a `kubelet` service. Workers run just a `kubelet` service. A one-time [bootkube](https://github.com/kubernetes-incubator/bootkube) bootstrap schedules the `apiserver`, `scheduler`, `controller-manager`, and `coredns` on controllers and schedules `kube-proxy` and `calico` (or `flannel`) on every node. A generated `kubeconfig` provides `kubectl` access to the cluster.
 
 ## Requirements
 
@@ -169,10 +169,10 @@ NAMESPACE     NAME                                      READY  STATUS    RESTART
 kube-system   calico-node-1m5bf                         2/2    Running   0         34m              
 kube-system   calico-node-7jmr1                         2/2    Running   0         34m              
 kube-system   calico-node-bknc8                         2/2    Running   0         34m              
+kube-system   coredns-1187388186-wx1lg                  1/1    Running   0         34m              
 kube-system   kube-apiserver-4mjbk                      1/1    Running   0         34m              
 kube-system   kube-controller-manager-3597210155-j2jbt  1/1    Running   1         34m              
 kube-system   kube-controller-manager-3597210155-j7g7x  1/1    Running   0         34m              
-kube-system   kube-dns-1187388186-wx1lg                 3/3    Running   0         34m              
 kube-system   kube-proxy-14wxv                          1/1    Running   0         34m              
 kube-system   kube-proxy-9vxh2                          1/1    Running   0         34m              
 kube-system   kube-proxy-sbbsh                          1/1    Running   0         34m              
@@ -233,7 +233,7 @@ Reference the DNS zone id with `"${aws_route53_zone.zone-for-clusters.zone_id}"`
 | host_cidr | CIDR IPv4 range to assign to EC2 instances | "10.0.0.0/16" | "10.1.0.0/16" |
 | pod_cidr | CIDR IPv4 range to assign to Kubernetes pods | "10.2.0.0/16" | "10.22.0.0/16" |
 | service_cidr | CIDR IPv4 range to assign to Kubernetes services | "10.3.0.0/16" | "10.3.0.0/24" |
-| cluster_domain_suffix | FQDN suffix for Kubernetes services answered by kube-dns. | "cluster.local" | "k8s.example.com" |
+| cluster_domain_suffix | FQDN suffix for Kubernetes services answered by coredns. | "cluster.local" | "k8s.example.com" |
 
 Check the list of valid [instance types](https://aws.amazon.com/ec2/instance-types/).
 

docs/atomic/bare-metal.md

@@ -7,7 +7,7 @@ In this tutorial, we'll network boot and provision a Kubernetes v1.11.0 cluster
 
 First, we'll deploy a [Matchbox](https://github.com/coreos/matchbox) service and setup a network boot environment. Then, we'll declare a Kubernetes cluster using the Typhoon Terraform module and power on machines. On PXE boot, machines will install Fedora Atomic via kickstart, reboot into the disk install, and provision themselves as Kubernetes controllers or workers via cloud-init.
 
-Controllers are provisioned to run `etcd` and `kubelet` [system containers](http://www.projectatomic.io/blog/2016/09/intro-to-system-containers/). Workers run just a `kubelet` system container. A one-time [bootkube](https://github.com/kubernetes-incubator/bootkube) bootstrap schedules the `apiserver`, `scheduler`, `controller-manager`, and `kube-dns` on controllers and schedules `kube-proxy` and `calico` (or `flannel`) on every node. A generated `kubeconfig` provides `kubectl` access to the cluster.
+Controllers are provisioned to run `etcd` and `kubelet` [system containers](http://www.projectatomic.io/blog/2016/09/intro-to-system-containers/). Workers run just a `kubelet` system container. A one-time [bootkube](https://github.com/kubernetes-incubator/bootkube) bootstrap schedules the `apiserver`, `scheduler`, `controller-manager`, and `coredns` on controllers and schedules `kube-proxy` and `calico` (or `flannel`) on every node. A generated `kubeconfig` provides `kubectl` access to the cluster.
 
 ## Requirements
 
@@ -373,10 +373,10 @@ NAMESPACE     NAME                                       READY     STATUS    RES
 kube-system   calico-node-6qp7f                          2/2       Running   1          11m
 kube-system   calico-node-gnjrm                          2/2       Running   0          11m
 kube-system   calico-node-llbgt                          2/2       Running   0          11m
+kube-system   coredns-1187388186-mx9rt                   1/1       Running   0          11m
 kube-system   kube-apiserver-7336w                       1/1       Running   0          11m
 kube-system   kube-controller-manager-3271970485-b9chx   1/1       Running   0          11m
 kube-system   kube-controller-manager-3271970485-v30js   1/1       Running   1          11m
-kube-system   kube-dns-1187388186-mx9rt                  3/3       Running   0          11m
 kube-system   kube-proxy-50sd4                           1/1       Running   0          11m
 kube-system   kube-proxy-bczhp                           1/1       Running   0          11m
 kube-system   kube-proxy-mp2fw                           1/1       Running   0          11m
@@ -419,6 +419,6 @@ Check the [variables.tf](https://github.com/poseidon/typhoon/blob/master/bare-me
 | network_mtu | CNI interface MTU (calico-only) | 1480 | - | 
 | pod_cidr | CIDR IPv4 range to assign to Kubernetes pods | "10.2.0.0/16" | "10.22.0.0/16" |
 | service_cidr | CIDR IPv4 range to assign to Kubernetes services | "10.3.0.0/16" | "10.3.0.0/24" |
-| cluster_domain_suffix | FQDN suffix for Kubernetes services answered by kube-dns. | "cluster.local" | "k8s.example.com" |
+| cluster_domain_suffix | FQDN suffix for Kubernetes services answered by coredns. | "cluster.local" | "k8s.example.com" |
 | kernel_args | Additional kernel args to provide at PXE boot | [] | "kvm-intel.nested=1" |