From 34bbec31f553cccff0aa7bd28991e5db13ce96c1 Mon Sep 17 00:00:00 2001 From: gbzhu Date: Wed, 28 Dec 2016 18:22:20 +0800 Subject: [PATCH] fix typo --- docs/user-guide/kubeconfig-file.md | 314 ----------------------------- 1 file changed, 314 deletions(-) diff --git a/docs/user-guide/kubeconfig-file.md b/docs/user-guide/kubeconfig-file.md index 581bc9ccfb..e69de29bb2 100644 --- a/docs/user-guide/kubeconfig-file.md +++ b/docs/user-guide/kubeconfig-file.md @@ -1,314 +0,0 @@ ---- -assignees: -- mikedanese -- thockin -title: Authenticating Across Clusters with kubeconfig ---- - -Authentication in Kubernetes can differ for different individuals. - -- A running kubelet might have one way of authenticating (i.e. certificates). -- Users might have a different way of authenticating (i.e. tokens). -- Administrators might have a list of certificates which they provide individual users. -- There may be multiple clusters, and we may want to define them all in one place - giving users the ability to use their own certificates and reusing the same global configuration. - -So in order to easily switch between multiple clusters, for multiple users, a kubeconfig file was defined. - -This file contains a series of authentication mechanisms and cluster connection information associated with nicknames. It also introduces the concept of a tuple of authentication information (user) and cluster connection information called a context that is also associated with a nickname. - -Multiple kubeconfig files are allowed, if specified explicitly. At runtime they are loaded and merged along with override options specified from the command line (see [rules](#loading-and-merging) below). - -## Related discussion - -http://issue.k8s.io/1755 - -## Components of a kubeconfig file - -### Example kubeconfig file - -```yaml -current-context: federal-context -apiVersion: v1 -clusters: -- cluster: - api-version: v1 - server: http://cow.org:8080 - name: cow-cluster -- cluster: - certificate-authority: path/to/my/cafile - server: https://horse.org:4443 - name: horse-cluster -- cluster: - insecure-skip-tls-verify: true - server: https://pig.org:443 - name: pig-cluster -contexts: -- context: - cluster: horse-cluster - namespace: chisel-ns - user: green-user - name: federal-context -- context: - cluster: pig-cluster - namespace: saw-ns - user: black-user - name: queen-anne-context -kind: Config -preferences: - colors: true -users: -- name: blue-user - user: - token: blue-token -- name: green-user - user: - client-certificate: path/to/my/client/cert - client-key: path/to/my/client/key -``` - -### Breakdown/explanation of components - -#### cluster - -```yaml -clusters: -- cluster: - certificate-authority: path/to/my/cafile - server: https://horse.org:4443 - name: horse-cluster -- cluster: - insecure-skip-tls-verify: true - server: https://pig.org:443 - name: pig-cluster -``` - -A `cluster` contains endpoint data for a Kubernetes cluster. This includes the fully -qualified url for the Kubernetes apiserver, as well as the cluster's certificate -authority or `insecure-skip-tls-verify: true`, if the cluster's serving -certificate is not signed by a system trusted certificate authority. -A `cluster` has a name (nickname) which acts as a dictionary key for the cluster -within this kubeconfig file. You can add or modify `cluster` entries using -[`kubectl config set-cluster`](/docs/user-guide/kubectl/kubectl_config_set-cluster/). - -#### user - -```yaml -users: -- name: blue-user - user: - token: blue-token -- name: green-user - user: - client-certificate: path/to/my/client/cert - client-key: path/to/my/client/key -``` - -A `user` defines client credentials for authenticating to a Kubernetes cluster. A -`user` has a name (nickname) which acts as its key within the list of user entries -after kubeconfig is loaded/merged. Available credentials are `client-certificate`, -`client-key`, `token`, and `username/password`. `username/password` and `token` -are mutually exclusive, but client certs and keys can be combined with them. -You can add or modify `user` entries using -[`kubectl config set-credentials`](/docs/user-guide/kubectl/kubectl_config_set-credentials). - -#### context - -```yaml -contexts: -- context: - cluster: horse-cluster - namespace: chisel-ns - user: green-user - name: federal-context -``` - -A `context` defines a named [`cluster`](#cluster),[`user`](#user),[`namespace`](/docs/user-guide/namespaces) tuple -which is used to send requests to the specified cluster using the provided authentication info and -namespace. Each of the three is optional; it is valid to specify a context with only one of `cluster`, -`user`,`namespace`, or to specify none. Unspecified values, or named values that don't have corresponding -entries in the loaded kubeconfig (e.g. if the context specified a `pink-user` for the above kubeconfig file) -will be replaced with the default. See [Loading and merging rules](#loading-and-merging) below for override/merge behavior. -You can add or modify `context` entries with [`kubectl config set-context`](/docs/user-guide/kubectl/kubectl_config_set-context). - -#### current-context - -```yaml -current-context: federal-context -``` - -`current-context` is the nickname or 'key' for the cluster,user,namespace tuple that kubectl -will use by default when loading config from this file. You can override any of the values in kubectl -from the commandline, by passing `--context=CONTEXT`, `--cluster=CLUSTER`, `--user=USER`, and/or `--namespace=NAMESPACE` respectively. -You can change the `current-context` with [`kubectl config use-context`](/docs/user-guide/kubectl/kubectl_config_use-context). - -#### miscellaneous - -```yaml -apiVersion: v1 -kind: Config -preferences: - colors: true -``` - -`apiVersion` and `kind` identify the version and schema for the client parser and should not -be edited manually. - -`preferences` specify optional (and currently unused) kubectl preferences. - -## Viewing kubeconfig files - -`kubectl config view` will display the current kubeconfig settings. By default -it will show you all loaded kubeconfig settings; you can filter the view to just -the settings relevant to the `current-context` by passing `--minify`. See -[`kubectl config view`](/docs/user-guide/kubectl/kubectl_config_view) for other options. - -## Building your own kubeconfig file - -NOTE, that if you are deploying k8s via kube-up.sh, you do not need to create your own kubeconfig files, the script will do it for you. - -In any case, you can easily use this file as a template to create your own kubeconfig files. - -So, lets do a quick walk through the basics of the above file so you can easily modify it as needed... - -The above file would likely correspond to an api-server which was launched using the `--token-auth-file=tokens.csv` option, where the tokens.csv file looked something like this: - -```conf -blue-user,blue-user,1 -mister-red,mister-red,2 -``` - -Also, since we have other users who validate using **other** mechanisms, the api-server would have probably been launched with other authentication options (there are many such options, make sure you understand which ones YOU care about before crafting a kubeconfig file, as nobody needs to implement all the different permutations of possible authentication schemes). - -- Since the user for the current context is "green-user", any client of the api-server using this kubeconfig file would naturally be able to log in successfully, because we are providing the green-user's client credentials. -- Similarly, we can operate as the "blue-user" if we choose to change the value of current-context. - -In the above scenario, green-user would have to log in by providing certificates, whereas blue-user would just provide the token. All this information would be handled for us by the - -## Loading and merging rules - -The rules for loading and merging the kubeconfig files are straightforward, but there are a lot of them. The final config is built in this order: - - 1. Get the kubeconfig from disk. This is done with the following hierarchy and merge rules: - - - If the `CommandLineLocation` (the value of the `kubeconfig` command line option) is set, use this file only. No merging. Only one instance of this flag is allowed. - - - Else, if `EnvVarLocation` (the value of `$KUBECONFIG`) is available, use it as a list of files that should be merged. - Merge files together based on the following rules. - Empty filenames are ignored. Files with non-deserializable content produced errors. - The first file to set a particular value or map key wins and the value or map key is never changed. - This means that the first file to set `CurrentContext` will have its context preserved. It also means that if two files specify a "red-user", only values from the first file's red-user are used. Even non-conflicting entries from the second file's "red-user" are discarded. - - - Otherwise, use HomeDirectoryLocation (`~/.kube/config`) with no merging. - 1. Determine the context to use based on the first hit in this chain - 1. command line argument - the value of the `context` command line option - 1. `current-context` from the merged kubeconfig file - 1. Empty is allowed at this stage - 1. Determine the cluster info and user to use. At this point, we may or may not have a context. They are built based on the first hit in this chain. (run it twice, once for user, once for cluster) - 1. command line argument - `user` for user name and `cluster` for cluster name - 1. If context is present, then use the context's value - 1. Empty is allowed - 1. Determine the actual cluster info to use. At this point, we may or may not have a cluster info. Build each piece of the cluster info based on the chain (first hit wins): - 1. command line arguments - `server`, `api-version`, `certificate-authority`, and `insecure-skip-tls-verify` - 1. If cluster info is present and a value for the attribute is present, use it. - 1. If you don't have a server location, error. - 1. Determine the actual user info to use. User is built using the same rules as cluster info, EXCEPT that you can only have one authentication technique per user. - 1. Load precedence is 1) command line flag, 2) user fields from kubeconfig - 1. The command line flags are: `client-certificate`, `client-key`, `username`, `password`, and `token`. - 1. If there are two conflicting techniques, fail. - 1. For any information still missing, use default values and potentially prompt for authentication information - 1. All file references inside of a kubeconfig file are resolved relative to the location of the kubeconfig file itself. When file references are presented on the command line - they are resolved relative to the current working directory. When paths are saved in the ~/.kube/config, relative paths are stored relatively while absolute paths are stored absolutely. - -Any path in a kubeconfig file is resolved relative to the location of the kubeconfig file itself. - - -## Manipulation of kubeconfig via `kubectl config ` - -In order to more easily manipulate kubeconfig files, there are a series of subcommands to `kubectl config` to help. -See [kubectl/kubectl_config.md](/docs/user-guide/kubectl/kubectl_config) for help. - -### Example - -```shell -$ kubectl config set-credentials myself --username=admin --password=secret -$ kubectl config set-cluster local-server --server=http://localhost:8080 -$ kubectl config set-context default-context --cluster=local-server --user=myself -$ kubectl config use-context default-context -$ kubectl config set contexts.default-context.namespace the-right-prefix -$ kubectl config view -``` - -produces this output - -```yaml -apiVersion: v1 -clusters: -- cluster: - server: http://localhost:8080 - name: local-server -contexts: -- context: - cluster: local-server - namespace: the-right-prefix - user: myself - name: default-context -current-context: default-context -kind: Config -preferences: {} -users: -- name: myself - user: - password: secret - username: admin -``` - -and a kubeconfig file that looks like this - -```yaml -apiVersion: v1 -clusters: -- cluster: - server: http://localhost:8080 - name: local-server -contexts: -- context: - cluster: local-server - namespace: the-right-prefix - user: myself - name: default-context -current-context: default-context -kind: Config -preferences: {} -users: -- name: myself - user: - password: secret - username: admin -``` - -#### Commands for the example file - -```shell -$ kubectl config set preferences.colors true -$ kubectl config set-cluster cow-cluster --server=http://cow.org:8080 --api-version=v1 -$ kubectl config set-cluster horse-cluster --server=https://horse.org:4443 --certificate-authority=path/to/my/cafile -$ kubectl config set-cluster pig-cluster --server=https://pig.org:443 --insecure-skip-tls-verify=true -$ kubectl config set-credentials blue-user --token=blue-token -$ kubectl config set-credentials green-user --client-certificate=path/to/my/client/cert --client-key=path/to/my/client/key -$ kubectl config set-context queen-anne-context --cluster=pig-cluster --user=black-user --namespace=saw-ns -$ kubectl config set-context federal-context --cluster=horse-cluster --user=green-user --namespace=chisel-ns -$ kubectl config use-context federal-context -``` - -### Final notes for tying it all together - -So, tying this all together, a quick start to creating your own kubeconfig file: - -- Take a good look and understand how your api-server is being launched: You need to know YOUR security requirements and policies before you can design a kubeconfig file for convenient authentication. - -- Replace the snippet above with information for your cluster's api-server endpoint. - -- Make sure your api-server is launched in such a way that at least one user (i.e. green-user) credentials are provided to it. You will of course have to look at api-server documentation in order to determine the current state-of-the-art in terms of providing authentication details.