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authorAlyssa Ross <hi@alyssa.is>2022-05-31 09:59:33 +0000
committerAlyssa Ross <hi@alyssa.is>2022-05-31 09:59:57 +0000
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Last good Nixpkgs for Weston+nouveau? archive
I came this commit hash to terwiz[m] on IRC, who is trying to figure out
what the last version of Spectrum that worked on their NUC with Nvidia
graphics is.
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+# Kubernetes {#sec-kubernetes}
+
+The NixOS Kubernetes module is a collective term for a handful of
+individual submodules implementing the Kubernetes cluster components.
+
+There are generally two ways of enabling Kubernetes on NixOS. One way is
+to enable and configure cluster components appropriately by hand:
+
+```nix
+services.kubernetes = {
+  apiserver.enable = true;
+  controllerManager.enable = true;
+  scheduler.enable = true;
+  addonManager.enable = true;
+  proxy.enable = true;
+  flannel.enable = true;
+};
+```
+
+Another way is to assign cluster roles (\"master\" and/or \"node\") to
+the host. This enables apiserver, controllerManager, scheduler,
+addonManager, kube-proxy and etcd:
+
+```nix
+services.kubernetes.roles = [ "master" ];
+```
+
+While this will enable the kubelet and kube-proxy only:
+
+```nix
+services.kubernetes.roles = [ "node" ];
+```
+
+Assigning both the master and node roles is usable if you want a single
+node Kubernetes cluster for dev or testing purposes:
+
+```nix
+services.kubernetes.roles = [ "master" "node" ];
+```
+
+Note: Assigning either role will also default both
+[](#opt-services.kubernetes.flannel.enable)
+and [](#opt-services.kubernetes.easyCerts)
+to true. This sets up flannel as CNI and activates automatic PKI bootstrapping.
+
+As of kubernetes 1.10.X it has been deprecated to open non-tls-enabled
+ports on kubernetes components. Thus, from NixOS 19.03 all plain HTTP
+ports have been disabled by default. While opening insecure ports is
+still possible, it is recommended not to bind these to other interfaces
+than loopback. To re-enable the insecure port on the apiserver, see options:
+[](#opt-services.kubernetes.apiserver.insecurePort) and
+[](#opt-services.kubernetes.apiserver.insecureBindAddress)
+
+::: {.note}
+As of NixOS 19.03, it is mandatory to configure:
+[](#opt-services.kubernetes.masterAddress).
+The masterAddress must be resolveable and routeable by all cluster nodes.
+In single node clusters, this can be set to `localhost`.
+:::
+
+Role-based access control (RBAC) authorization mode is enabled by
+default. This means that anonymous requests to the apiserver secure port
+will expectedly cause a permission denied error. All cluster components
+must therefore be configured with x509 certificates for two-way tls
+communication. The x509 certificate subject section determines the roles
+and permissions granted by the apiserver to perform clusterwide or
+namespaced operations. See also: [ Using RBAC
+Authorization](https://kubernetes.io/docs/reference/access-authn-authz/rbac/).
+
+The NixOS kubernetes module provides an option for automatic certificate
+bootstrapping and configuration,
+[](#opt-services.kubernetes.easyCerts).
+The PKI bootstrapping process involves setting up a certificate authority (CA)
+daemon (cfssl) on the kubernetes master node. cfssl generates a CA-cert
+for the cluster, and uses the CA-cert for signing subordinate certs issued
+to each of the cluster components. Subsequently, the certmgr daemon monitors
+active certificates and renews them when needed. For single node Kubernetes
+clusters, setting [](#opt-services.kubernetes.easyCerts)
+= true is sufficient and no further action is required. For joining extra node
+machines to an existing cluster on the other hand, establishing initial
+trust is mandatory.
+
+To add new nodes to the cluster: On any (non-master) cluster node where
+[](#opt-services.kubernetes.easyCerts)
+is enabled, the helper script `nixos-kubernetes-node-join` is available on PATH.
+Given a token on stdin, it will copy the token to the kubernetes secrets directory
+and restart the certmgr service. As requested certificates are issued, the
+script will restart kubernetes cluster components as needed for them to
+pick up new keypairs.
+
+::: {.note}
+Multi-master (HA) clusters are not supported by the easyCerts module.
+:::
+
+In order to interact with an RBAC-enabled cluster as an administrator,
+one needs to have cluster-admin privileges. By default, when easyCerts
+is enabled, a cluster-admin kubeconfig file is generated and linked into
+`/etc/kubernetes/cluster-admin.kubeconfig` as determined by
+[](#opt-services.kubernetes.pki.etcClusterAdminKubeconfig).
+`export KUBECONFIG=/etc/kubernetes/cluster-admin.kubeconfig` will make
+kubectl use this kubeconfig to access and authenticate the cluster. The
+cluster-admin kubeconfig references an auto-generated keypair owned by
+root. Thus, only root on the kubernetes master may obtain cluster-admin
+rights by means of this file.