From 0391995573fb79685d9fba0dfddb85c91a76e5ab Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Lucas=20K=C3=A4ldstr=C3=B6m?= Date: Tue, 27 Jun 2017 21:32:54 +0300 Subject: [PATCH] kubeadm v1.7 documentation updates (#4018) * v1.7 updates for kubeadm * Address review comments * Address Luke's comments --- docs/admin/kubeadm.md | 263 ++++++++++---- .../independent/create-cluster-kubeadm.md | 336 +++++------------- docs/setup/independent/install-kubeadm.md | 19 +- 3 files changed, 283 insertions(+), 335 deletions(-) diff --git a/docs/admin/kubeadm.md b/docs/admin/kubeadm.md index 74f697c384..381be28029 100644 --- a/docs/admin/kubeadm.md +++ b/docs/admin/kubeadm.md @@ -4,7 +4,7 @@ assignees: - luxas - errordeveloper - jbeda -title: kubeadm Setup Tool +title: kubeadm Setup Tool Reference Guide --- This document provides information on how to use kubeadm's advanced options. @@ -30,7 +30,7 @@ following steps: 1. Outputting a kubeconfig file for the kubelet to use to connect to the API server, as well as an additional kubeconfig file for administration. -1. kubeadm generates Kubernetes Static Pod manifests for the API server, +1. kubeadm generates Kubernetes static Pod manifests for the API server, controller manager and scheduler. It places them in `/etc/kubernetes/manifests`. The kubelet watches this directory for Pods to create on startup. These are the core components of Kubernetes. Once they are @@ -51,7 +51,7 @@ steps: 1. kubeadm creates a local key pair. It prepares a certificate signing request (CSR) and sends that off to the API server for signing. The bootstrap token - is used to authenticate. The API server is configured to sign this + is used to authenticate. The control plane will sign this CSR requested automatically. 1. kubeadm configures the local kubelet to connect to the API server @@ -318,8 +318,8 @@ schedulerExtraArgs: : : apiServerCertSANs: - - - - +- +- certificatesDir: ``` In addition, if authorizationMode is set to `ABAC`, you should write the config to `/etc/kubernetes/abac_policy.json`. @@ -333,16 +333,79 @@ kind: NodeConfiguration caCertPath: discoveryFile: discoveryToken: - -# Currently only the first server is used as a target for the cluster -# bootstrap flow. discoveryTokenAPIServers: - - - - - +- +- tlsBootstrapToken: ``` +## Securing your installation even more + +The defaults for kubeadm may not work for everyone. This section documents how to tighten up a kubeadm install +at the cost of some usability. + +### Turning off auto-approval of Node Client Certificates + +By default, there is an CSR auto-approver enabled that basically approves any client certificate request +for a kubelet when a Bootstrap Token was used when authenticating. If you don't want the cluster to +automatically approve kubelet client certs, you can turn it off by executing this command: + +```console +$ kubectl delete clusterrole kubeadm:node-autoapprove-bootstrap +``` + +After that, `kubeadm join` will block until the admin has manually approved the CSR in flight: + +```console +$ kubectl get csr +NAME AGE REQUESTOR CONDITION +node-csr-c69HXe7aYcqkS1bKmH4faEnHAWxn6i2bHZ2mD04jZyQ 18s system:bootstrap:878f07 Pending + +$ kubectl certificate approve node-csr-c69HXe7aYcqkS1bKmH4faEnHAWxn6i2bHZ2mD04jZyQ +certificatesigningrequest "node-csr-c69HXe7aYcqkS1bKmH4faEnHAWxn6i2bHZ2mD04jZyQ" approved + +$ kubectl get csr +NAME AGE REQUESTOR CONDITION +node-csr-c69HXe7aYcqkS1bKmH4faEnHAWxn6i2bHZ2mD04jZyQ 1m system:bootstrap:878f07 Approved,Issued +``` + +Only after `kubectl certificate approve` has been run, `kubeadm join` can proceed. + +### Turning off public access to the cluster-info ConfigMap + +In order to achieve the joining flow using the token as the only piece of validation information, a +public ConfigMap with some data needed for validation of the master's identity is exposed publicly by +default. While there is no private data in this ConfigMap, some users are sensitive and wish to turn +it off regardless. Doing so will disable the ability to use the `--discovery-token` flag of the +`kubeadm join` flow. Here are the steps to do so: + +Fetch the `cluster-info` file from the API Server: + +```console +$ kubectl -n kube-public get cm cluster-info -oyaml | grep "kubeconfig:" -A11 | grep "apiVersion" -A10 | sed "s/ //" | tee cluster-info.yaml +apiVersion: v1 +clusters: +- cluster: + certificate-authority-data: + server: https://: + name: "" +contexts: [] +current-context: "" +kind: Config +preferences: {} +users: [] +``` + +You can then use the `cluster-info.yaml` file as an argument to `kubeadm join --discovery-file`. + +Turning of public access to the `cluster-info` ConfigMap: + +```console +$ kubectl -n kube-public delete rolebinding kubeadm:bootstrap-signer-clusterinfo +``` + +These command should be run after `kubeadm init` but before `kubeadm join`. + ## Managing Tokens {#manage-tokens} You can use the `kubeadm` tool to manage tokens on a running cluster. It will @@ -380,13 +443,13 @@ parallelize the token distribution for easier automation. To implement this automation, you must know the IP address that the master will have after it is started. -1. Generate a token. This token must have the form `<6 character string>.<16 - character string>`. More formally, it must match the regex +1. Generate a token. This token must have the form `<6 character string>.<16 + character string>`. More formally, it must match the regex: `[a-z0-9]{6}\.[a-z0-9]{16}`. - Kubeadm can generate a token for you: + kubeadm can generate a token for you: - ``` bash + ```bash kubeadm token generate ``` @@ -397,55 +460,6 @@ started. Once the cluster is up, you can grab the admin credentials from the master node at `/etc/kubernetes/admin.conf` and use that to talk to the cluster. -## Environment variables - -There are some environment variables that modify the way that kubeadm works. -Most users will have no need to set these. These environment variables are a -short-term solution, eventually they will be integrated in the kubeadm -configuration file. - -| Variable | Default | Description | -| --- | --- | --- | -| `KUBE_KUBERNETES_DIR` | `/etc/kubernetes` | Where most configuration files are written to and read from | -| `KUBE_HYPERKUBE_IMAGE` | | If set, use a single hyperkube image with this name. If not set, individual images per server component will be used. | -| `KUBE_ETCD_IMAGE` | `gcr.io/google_containers/etcd-:3.0.17` | The etcd container image to use. | -| `KUBE_REPO_PREFIX` | `gcr.io/google_containers` | The image prefix for all images that are used. | - -If `KUBE_KUBERNETES_DIR` is specified, you may need to rewrite the arguments of the kubelet. -(e.g. --kubeconfig, --pod-manifest-path) - -If `KUBE_REPO_PREFIX` is specified, you may need to set the kubelet flag `--pod-infra-container-image` which specifies which pause image to use. -Defaults to `gcr.io/google_containers/pause-${ARCH}:3.0` where `${ARCH}` can be one of `amd64`, `arm`, `arm64`, `ppc64le` or `s390x`. - -```bash -cat > /etc/systemd/system/kubelet.service.d/20-pod-infra-image.conf < +``` + +Lastly, run `kubeadm init --config=kubeadm.conf` to bootstrap your cluster with +the cloud provider. + +This workflow is not yet fully supported, however we hope to make it extremely +easy to spin up clusters with cloud providers in the future. (See [this +proposal](https://github.com/kubernetes/community/pull/128) for more +information) The [Kubelet Dynamic +Settings](https://github.com/kubernetes/kubernetes/pull/29459) feature may also +help to fully automate this process in the future. + + +## Environment variables + +There are some environment variables that modify the way that kubeadm works. +Most users will have no need to set these. These environment variables are a +short-term solution, eventually they will be integrated in the kubeadm +configuration file. + +**Note:** These environment variables are deprecated and will stop functioning in v1.8! + +| Variable | Default | Description | +| --- | --- | --- | +| `KUBE_KUBERNETES_DIR` | `/etc/kubernetes` | Where most configuration files are written to and read from | +| `KUBE_HYPERKUBE_IMAGE` | | If set, use a single hyperkube image with this name. If not set, individual images per server component will be used. | +| `KUBE_ETCD_IMAGE` | `gcr.io/google_containers/etcd-:3.0.17` | The etcd container image to use. | +| `KUBE_REPO_PREFIX` | `gcr.io/google_containers` | The image prefix for all images that are used. | + +If `KUBE_KUBERNETES_DIR` is specified, you may need to rewrite the arguments of the kubelet. +(e.g. --kubeconfig, --pod-manifest-path) + +If `KUBE_REPO_PREFIX` is specified, you may need to set the kubelet flag +`--pod-infra-container-image` which specifies which pause image to use. + +Defaults to `gcr.io/google_containers/pause-${ARCH}:3.0` where `${ARCH}` +can be one of `amd64`, `arm`, `arm64`, `ppc64le` or `s390x`. + +```bash +cat > /etc/systemd/system/kubelet.service.d/20-pod-infra-image.conf < [apiconfig] Created RBAC rules -[addons] Created essential addon: kube-proxy -[addons] Created essential addon: kube-dns +[addons] Applied essential addon: kube-proxy +[addons] Applied essential addon: kube-dns Your Kubernetes master has initialized successfully! To start using your cluster, you need to run (as a regular user): - sudo cp /etc/kubernetes/admin.conf $HOME/ - sudo chown $(id -u):$(id -g) $HOME/admin.conf - export KUBECONFIG=$HOME/admin.conf + mkdir -p $HOME/.kube + sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config + sudo chown $(id -u):$(id -g) $HOME/.kube/config You should now deploy a pod network to the cluster. Run "kubectl apply -f [podnetwork].yaml" with one of the options listed at: @@ -178,28 +183,10 @@ token can add authenticated nodes to your cluster. These tokens can be listed, created and deleted with the `kubeadm token` command. See the [reference guide](/docs/admin/kubeadm/#manage-tokens). -#### Master Images - -All of these components run in pods started by kubelet and the following images -are required and will be automatically pulled by kubelet if they are absent -while `kubeadm init` is initializing your master: - -| Image Name | Version | -|---|---| -| gcr.io/google_containers/kube-apiserver-amd64 | v1.6.0 -| gcr.io/google_containers/kube-controller-manager-amd64 | v1.6.0 -| gcr.io/google_containers/kube-scheduler-amd64 | v1.6.0 -| gcr.io/google_containers/kube-proxy-amd64 | v1.6.0 -| gcr.io/google_containers/etcd-amd64 | 3.0.17 -| gcr.io/google_containers/pause-amd64 | 3.0 -| gcr.io/google_containers/k8s-dns-sidecar-amd64 | 1.14.1 -| gcr.io/google_containers/k8s-dns-kube-dns-amd64 | 1.14.1 -| gcr.io/google_containers/k8s-dns-dnsmasq-nanny-amd64 | 1.14.1 - #### Master Isolation By default, your cluster will not schedule pods on the master for security -reasons. If you want to be able to schedule pods on the master, e.g. a +reasons. If you want to be able to schedule pods on the master, e.g. for a single-machine Kubernetes cluster for development, run: ``` bash @@ -242,22 +229,20 @@ You can install a pod network add-on with the following command: kubectl apply -f ``` -Please refer to the specific add-on installation guide for exact details. You -should only install one pod network per cluster. +Please refer to the specific add-on installation guide for exact details. + +**NOTE:** You can install **only one** pod network per cluster. If you are on another architecture than amd64, you should use the flannel or Weave Net overlay networks as described in [the multi-platform section](#multi-platform) -NOTE: You can install **only one** pod network per cluster. - Once a pod network has been installed, you can confirm that it is working by -checking that the kube-dns pod is Running in the output of `kubectl get pods ---all-namespaces`. And once the kube-dns pod is up and running, you can continue by joining your -nodes. +checking that the kube-dns pod is Running in the output of `kubectl get pods --all-namespaces`. +And once the kube-dns pod is up and running, you can continue by joining your nodes. If your network is not working or kube-dns is not in the Running state, check -out the [troubleshooting section](#pod-network-trouble) below. +out the [troubleshooting section](#troubleshooting) below. ### (4/4) Joining your nodes @@ -280,7 +265,7 @@ The output should look something like: [discovery] Created cluster-info discovery client, requesting info from "https://10.138.0.4:6443" [discovery] Cluster info signature and contents are valid, will use API Server "https://10.138.0.4:6443" [discovery] Successfully established connection with API Server "10.138.0.4:6443" -[bootstrap] Detected server version: v1.6.0-beta.3 +[bootstrap] Detected server version: v1.7.0 [bootstrap] The server supports the Certificates API (certificates.k8s.io/v1beta1) [csr] Created API client to obtain unique certificate for this node, generating keys and certificate signing request [csr] Received signed certificate from the API server, generating KubeConfig... @@ -300,20 +285,20 @@ nodes` when run on the master. ### (Optional) Controlling your cluster from machines other than the master In order to get a kubectl on some other computer (e.g. laptop) to talk to your -cluster, you need to copy the kubeconfig file from your master to your -workstation like this: +cluster, you need to copy the administrator kubeconfig file from your master +to your workstation like this: ``` bash scp root@:/etc/kubernetes/admin.conf . kubectl --kubeconfig ./admin.conf get nodes ``` -**Note:** If you are using GCE, instances, by default, disable ssh access for -root. First log in to the machine, copy the file someplace that can be accessed -and then use [`gcloud compute -copy-files`](https://cloud.google.com/sdk/gcloud/reference/compute/copy-files) +**Note:** If you are using GCE, instances disable ssh access for root by default. +If that's the case you can log in to the machine, copy the file someplace that +can be accessed and then use +[`gcloud compute copy-files`](https://cloud.google.com/sdk/gcloud/reference/compute/copy-files) -### (Optional) Connecting to the API Server +### (Optional) Proxying API Server to localhost If you want to connect to the API Server from outside the cluster you can use `kubectl proxy`: @@ -347,7 +332,7 @@ running: kubectl -n sock-shop get svc front-end ``` -Output: +Sample output: ``` NAME CLUSTER-IP EXTERNAL-IP PORT(S) AGE @@ -409,68 +394,33 @@ control of your Kubernetes cluster. ## Feedback -* Slack Channel: +* kubeadm support Slack Channel: + [#kubeadm](https://kubernetes.slack.com/messages/kubeadm/) +* General SIG Cluster Lifecycle Development Slack Channel: [#sig-cluster-lifecycle](https://kubernetes.slack.com/messages/sig-cluster-lifecycle/) * Mailing List: [kubernetes-sig-cluster-lifecycle](https://groups.google.com/forum/#!forum/kubernetes-sig-cluster-lifecycle) * [GitHub Issues in the kubeadm repository](https://github.com/kubernetes/kubeadm/issues) + +## Version skew policy + +The kubeadm CLI tool of version vX.Y may deploy clusters with a control plane of version vX.Y or vX.(Y-1). +kubeadm CLI vX.Y can also upgrade an existing kubeadm-created cluster of version vX.(Y-1). + +Due to that we can't see into the future, kubeadm CLI vX.Y may or may not be able to deploy vX.(Y+1) clusters. + +Example: kubeadm v1.7 can deploy both v1.6 and v1.7 clusters and upgrade v1.6 kubeadm-created clusters to +v1.7. + ## kubeadm is multi-platform {#multi-platform} -kubeadm deb/rpm packages and binaries are built for amd64, arm64, armhfp, -ppc64el, and s390x following the [multi-platform +kubeadm deb/rpm packages and binaries are built for amd64, arm (32-bit), arm64, ppc64le, and s390x +following the [multi-platform proposal](https://github.com/kubernetes/kubernetes/blob/master/docs/proposals/multi-platform.md). -Currently, only the pod networks flannel and Weave Net work on multiple architectures. -For Weave Net just use its [standard install](https://www.weave.works/docs/net/latest/kube-addon/). - -Flannel requires special installation instructions: - -``` bash -export ARCH=amd64 -curl -sSL "https://github.com/coreos/flannel/blob/master/Documentation/kube-flannel.yml?raw=true" | sed "s/amd64/${ARCH}/g" | kubectl create -f - -``` - -Replace `ARCH=amd64` with `ARCH=arm` or `ARCH=arm64` depending on the platform -you're running on. Note that the Raspberry Pi 3 is in ARM 32-bit mode, so for -RPi 3 you should set `ARCH` to `arm`, not `arm64`. - -## Cloudprovider integrations (experimental) - -Enabling specific cloud providers is a common request. This currently requires -manual configuration and is therefore not yet fully supported. If you wish to do -so, edit the kubeadm dropin for the kubelet service -(`/etc/systemd/system/kubelet.service.d/10-kubeadm.conf`) on all nodes, -including the master. If your cloud provider requires any extra packages -installed on host, for example for volume mounting/unmounting, install those -packages. - -Specify the `--cloud-provider` flag to kubelet and set it to the cloud of your -choice. If your cloudprovider requires a configuration file, create the file -`/etc/kubernetes/cloud-config` on every node. The exact format and content of -that file depends on the requirements imposed by your cloud provider. If you use -the `/etc/kubernetes/cloud-config` file, you must append it to the kubelet -arguments as follows: `--cloud-config=/etc/kubernetes/cloud-config` - -Next, specify the cloud provider in the kubeadm config file. Create a file called -`kubeadm.conf` with the following contents: - -``` yaml -kind: MasterConfiguration -apiVersion: kubeadm.k8s.io/v1alpha1 -cloudProvider: -``` - -Lastly, run `kubeadm init --config=kubeadm.conf` to bootstrap your cluster with -the cloud provider. - -This workflow is not yet fully supported, however we hope to make it extremely -easy to spin up clusters with cloud providers in the future. (See [this -proposal](https://github.com/kubernetes/community/pull/128) for more -information) The [Kubelet Dynamic -Settings](https://github.com/kubernetes/kubernetes/pull/29459) feature may also -help to fully automate this process in the future. +Currently, only the pod networks [flannel](https://github.com/coreos/flannel) and [Weave Net](https://www.weave.works/docs/net/latest/kube-addon/) work on multiple architectures. ## Limitations @@ -487,31 +437,36 @@ addressed in due course. etcd](https://coreos.com/etcd/docs/latest/admin_guide.html). The etcd data directory configured by kubeadm is at `/var/lib/etcd` on the master. -1. The `HostPort` and `HostIP` functionality does not work with kubeadm due to - that CNI networking is used, see issue - [#31307](https://github.com/kubernetes/kubernetes/issues/31307). - Workaround: use the [NodePort feature of - services](/docs/concepts/services-networking/service/#type-nodeport) instead, or use - HostNetwork. -1. Some users on RHEL/CentOS 7 have reported issues with traffic being routed - incorrectly due to iptables being bypassed. You should ensure - `net.bridge.bridge-nf-call-iptables` is set to 1 in your sysctl config, eg. +## Troubleshooting {#troubleshooting} - ``` bash - cat /etc/sysctl.d/k8s.conf - ``` +You may have trouble in the configuration if you see Pod statuses like `RunContainerError`, +`CrashLoopBackOff` or `Error`. - Should have: +1. **There are Pods in the `RunContainerError`, `CrashLoopBackOff` or `Error` state** + Right after `kubeadm init` there should not be any such Pods. If there are Pods in + such a state _right after_ `kubeadm init`, please open an issue in the kubeadm repo. + `kube-dns` should be in the `Pending` state until you have deployed the network solution. + However, if you see Pods in the `RunContainerError`, `CrashLoopBackOff` or `Error` state + after deploying the network solution and nothing happens to `kube-dns`, it's very + likely that the Pod Network solution that you installed is somehow broken. You + might have to grant it more RBAC privileges or use a newer version. Please file + an issue in the Pod Network providers' issue tracker and get the issue triaged there. - ``` - net.bridge.bridge-nf-call-ip6tables = 1 - net.bridge.bridge-nf-call-iptables = 1 - ``` +1. **The `kube-dns` Pod is stuck in the `Pending` state forever** + This is expected and part of the design. kubeadm is network provider-agnostic, so the admin + should [install the pod network solution](/docs/concepts/cluster-administration/addons/) + of choice. You have to install a Pod Network + before `kube-dns` may deployed fully. Hence the `Pending` state before the network is set up. -1. Users can list, create and delete tokens using the `kubeadm token` command. - See the [reference guide](/docs/admin/kubeadm/#manage-tokens) for details. +1. **I tried to set `HostPort` on one workload, but it didn't have any effect** + The `HostPort` and `HostIP` functionality is available depending on your Pod Network + provider. Please contact the author of the Pod Network solution to find out whether + `HostPort` and `HostIP` functionality are available. + + If not, you may still use the [NodePort feature of + services](/docs/concepts/services-networking/service/#type-nodeport) or use `HostNetwork=true`. 1. If you are using VirtualBox (directly or via Vagrant), you will need to ensure that `hostname -i` returns a routable IP address (i.e. one on the @@ -520,138 +475,15 @@ addressed in due course. usually NATed. Workaround: Modify `/etc/hosts`, take a look at this [`Vagrantfile`][ubuntu-vagrantfile] for how this can be achieved. -[ubuntu-vagrantfile]: https://github.com/errordeveloper/k8s-playground/blob/22dd39dfc06111235620e6c4404a96ae146f26fd/Vagrantfile#L11), +[ubuntu-vagrantfile]: https://github.com/errordeveloper/k8s-playground/blob/22dd39dfc06111235620e6c4404a96ae146f26fd/Vagrantfile#L11) -## Troubleshooting {#troubleshooting} - -### Pod Network Troubleshooting {#pod-network-trouble} - -You may have trouble in the configuration if you see the following statuses. -This example is for canal but there may be similar errors for other pod network -systems. - -``` -NAMESPACE NAME READY STATUS RESTARTS AGE -kube-system canal-node-f0lqp 2/3 RunContainerError 2 48s -kube-system canal-node-77d0h 2/3 CrashLoopBackOff 3 3m -kube-system kube-dns-2924299975-7q1vq 0/4 ContainerCreating 0 15m -``` - -The three statuses RunContainerError and CrashLoopBackOff and ContainerCreating -are very common. - -To help diagnose what happened, you can use the following command to check what -is in the logs: - -``` bash -kubectl describe -n kube-system po {YOUR_POD_NAME} -``` - -Do not use kubectl logs as they only work with Pods that have started. If you run: - -``` bash -kubectl logs -n kube-system canal-node-f0lqp -``` - -You will got the following error: - -``` -Error from server (BadRequest): the server rejected our request for an unknown reason (get pods canal-node-f0lqp) -``` - -The `kubectl describe` comand gives you more details about what went wrong. - -``` bash -kubectl describe -n kube-system po kube-dns-2924299975-1l2t7 -``` - -The events should show something like this: - -``` - 2m 2m 1 {kubelet nac} spec.containers{flannel} Warning Failed Failed to start container with docker id 927e7ccdc32b with error: Error response from daemon: {"message":"chown /etc/resolv.conf: operation not permitted"} -``` - -Or this: - -``` - 6m 1m 191 {kubelet nac} Warning FailedSync Error syncing pod, skipping: failed to "SetupNetwork" for "kube-dns-2924299975-1l2t7_kube-system" with SetupNetworkError: "Failed to setup network for pod \"kube-dns-2924299975-1l2t7_kube-system(dee8ef21-fbcb-11e6-ba19-38d547e0006a)\" using network plugins \"cni\": open /run/flannel/subnet.env: no such file or directory; Skipping pod" -``` - -A web search on the error message may help narrow down the issue. Or -communicate the errors you are seeing to the community/company that provides the -pod network implementation you are using. - -### Installing kubeadm 1.5 {#old-kubeadm} - -This section covers the previous version, kubeadm 1.5. It is still available but is a little tricky to get to. Also note that the command line options and other configuration parameters have changed. - -As root, run the following. This is very similar to the regular instructions except for pinning the versions. Note that, due to some unfortunate version strings, kubeadm isn't indexed in the repos and the packages must be downloaded and installed directly. - -#### Ubuntu +As with all Kubernetes troubleshooting, normal commands you can take advantage of to help diagnose +what happened are `kubectl describe pod` or `kubectl logs`. Example usage: ```bash -apt-get update && apt-get install -y apt-transport-https -curl -s https://packages.cloud.google.com/apt/doc/apt-key.gpg | apt-key add - -cat </etc/apt/sources.list.d/kubernetes.list -deb http://apt.kubernetes.io/ kubernetes-xenial main -EOF -apt-get update +kubectl -n ${NAMESPACE} describe pod ${POD_NAME} -# 1.5.6 does exist in the repo but it has a hard depenedency on a newer kubernetes-cni. Use 1.5.3 instead. -sudo apt-get -y install kubectl=1.5.3-00 kubelet=1.5.3-00 kubernetes-cni=0.3.0.1-07a8a2-00 - -# Versioning strangeness for how we packaged kubeadm pre-1.6 means that the version number -# says 1.6.0-alpha even though it is the 1.5 version of kubeadm. Because of how this sorts, -# we cannot keep this deb in the repo. Download it manually and install it. -curl -Lo /tmp/old-kubeadm.deb https://apt.k8s.io/pool/kubeadm_1.6.0-alpha.0.2074-a092d8e0f95f52-00_amd64_0206dba536f698b5777c7d210444a8ace18f48e045ab78687327631c6c694f42.deb -sudo dpkg -i /tmp/old-kubeadm.deb -sudo apt-get install -f - -# Hold these packages back so that we don't accidentally upgrade them. -sudo apt-mark hold kubeadm kubectl kubelet kubernetes-cni -``` - -#### CentOS - -```bash -cat < /etc/yum.repos.d/kubernetes.repo -[kubernetes] -name=Kubernetes -baseurl=http://yum.kubernetes.io/repos/kubernetes-el7-x86_64 -enabled=1 -gpgcheck=1 -repo_gpgcheck=1 -gpgkey=https://packages.cloud.google.com/yum/doc/yum-key.gpg - https://packages.cloud.google.com/yum/doc/rpm-package-key.gpg -EOF - -setenforce 0 - -# 1.5.4 is the latest previous version in the repo. Because of messed up -# versioning in the 1.5 release, kubeadm is no longer indexed in the repos -# so we have to refer to the RPM directly. -sudo yum -y install \ - yum-versionlock \ - docker \ - kubectl-1.5.4-0 \ - kubelet-1.5.4-0 \ - kubernetes-cni-0.3.0.1-0.07a8a2 \ - http://yum.kubernetes.io/pool/082436e6e6cad1852864438b8f98ee6fa3b86b597554720b631876db39b8ef04-kubeadm-1.6.0-0.alpha.0.2074.a092d8e0f95f52.x86_64.rpm - -# Lock the version of these packages so that we don't upgrade them accidentally. -sudo yum versionlock add kubectl kubelet kubernetes-cni kubeadm - -# Enable and start up docker and the kubelet -systemctl enable docker && systemctl start docker -systemctl enable kubelet && systemctl start kubelet -``` - -#### Running `kubeadm init` - -Finally, when running `kubeadm init` you must specify the `--use-kubernetes-version` flag: - -```bash -kubeadm init --use-kubernetes-version=v1.5.6 +kubectl -n ${NAMESPACE} logs ${POD_NAME} -c ${CONTAINER_NAME} ``` {% endcapture %} diff --git a/docs/setup/independent/install-kubeadm.md b/docs/setup/independent/install-kubeadm.md index 612b52b3c1..3718afc41c 100644 --- a/docs/setup/independent/install-kubeadm.md +++ b/docs/setup/independent/install-kubeadm.md @@ -31,15 +31,15 @@ For installation instructions, see On each of your machines, [install kubectl](/docs/tasks/tools/install-kubectl/). -You only need kubectl on the master, but it can be useful to have on the other -nodes as well. +You only need kubectl on the master and/or your workstation, but it can be +useful to have on the other nodes as well. ## Installing kubelet and kubeadm You will install these packages on all of your machines: -* `kubelet`: the most core component of Kubernetes. It runs on all of the - machines in your cluster and does things like starting pods and containers. +* `kubelet`: the component that runs on all of the machines in your cluster + and does things like starting pods and containers. * `kubeadm`: the command to bootstrap the cluster. @@ -62,9 +62,7 @@ For each machine: deb http://apt.kubernetes.io/ kubernetes-xenial main EOF apt-get update - # Install docker if you don't have it already. - apt-get install -y docker-engine - apt-get install -y kubelet kubeadm kubernetes-cni + apt-get install -y kubelet kubeadm ``` * If the machine is running CentOS, run: @@ -81,8 +79,7 @@ For each machine: https://packages.cloud.google.com/yum/doc/rpm-package-key.gpg EOF setenforce 0 - yum install -y docker kubelet kubeadm kubernetes-cni - systemctl enable docker && systemctl start docker + yum install -y kubelet kubeadm systemctl enable kubelet && systemctl start kubelet ``` @@ -93,10 +90,6 @@ For each machine: containers to access the host filesystem, which is required by pod networks for example. You have to do this until SELinux support is improved in the kubelet. -While this guide is correct for kubeadm 1.6, the previous version is still -available but can be a bit tricky to install. [See below](#old-kubeadm) for -details. - {% endcapture %} {% capture whatsnext %}