kc - make kubectl less annoying

A small wrapper for kubectl that make some some functionality a bit friendlier.

Automatically set namespace, cluster configuration, and environment variables for a directory tree
Add a number of convenient new verbs, such as:
- select: search for names by labels
- browse: open a browser to a NodePort

Install

git clone https://github.com/timothyb89/kc.git
sudo pip install -r kc/requirements.txt
ln -s `pwd`/kc/kc.py ~/bin/kc

You can update by running git pull in the checked out kc directory.

Usage

Directory configuration

Add a .kc.yml in your project directory containing something like the following:

namespace: my-namespace
env:
  NO_PROXY: kube1,kube2,kube3,kube4
  KUBECONFIG: /home/my_user/admin.conf

Everything shown above is optional. If KUBECONFIG is set under env, it will override the default file (usually ~/.kube/config). If namespace is set, it automatically appends -n <namespace>.

Then, instead of running kubectl, run kc. The actual parameters you enter are passed to kubectl, but will be adjusted based on values in .kc.yml.

Examples:

kubectl get pods -n my-namespace becomes kc get pods
kubectl --kubeconfig /path/to/some/config.conf ... becomes kc ...

By default the environment for all kubectl commands is inherited. If desired, this can be disabled by setting inherit: false in .kc.yml.

Environment configuration

Most options can also be configured using environment variables. If a .kc.yml exists, settings configured in environment variables will override any in the config file.

KC_NAMESPACE: if set, automatically appends -n $KC_NAMESPACE to all generated kubectl commands

Some common environment variables can also be overridden. If set, these will override any values configured in .kc.yml, or if inherit: false is set, will be passed to the kubectl child process:

KC_KUBECONFIG
KC_HTTP_PROXY
KC_HTTPS_PROXY
KC_NO_PROXY

Helper commands

In addition to wrapping all standard kubectl commands, kc also provides a few extra subcommands that make common operations a bit easier:

kc select (aka kc sel, kc s): returns a space-separated list of full resource names given a set of labels. For example:
```
$ kc select app=grafana
grafana-1548781338-gjlps
```
This can be used to easily run commands on resources whose names may change, for example:
```
$ kc logs -f $(kc select app=grafana)
$ kc exec -it $(kc select app=grafana) bash
```
Note that by default the resource is pod but that can be overridden with -r <type>. See also: kc select --help.

If the selector matches multiple results, by default they will be returned as a space-separated list. If a single result is desired, the index can be specified in any position:
```
$ kc logs -f $(kc select app=grafana 0)
```
Additionally, kubectl also supports set-based selectors. These are supported, but must be quoted:
```
$ kc select 'environment notin (production, qa)'
```
Pod names can also be specified exactly. If one argument is provided and it literally matches a pod, the input will be returned as-is. This isn't particularly useful for kc select, but can be convenient for other commands inheriting its functionality, like kc bash.
kc nodeport (aka kc np): returns a plain integer port for a service NodePort, useful for finding where a randomly-allocated port can be accessed. Example:
```
$ kc nodeport grafana
31577
```
If multiple ports are exposed, the first is returned. This can be overridden by specifying an integer index (e.g. kc nodeport grafana 1) or a port name (e.g. kc nodeport grafana http).
kc browse (aka kc br, kc b): opens a browser to view a named service. Accepts the same options as kc nodeport w.r.t. selecting a particular nodeport. Example:
```
$ kc browse grafana
Created new window in existing browser session.
```
The hostname opened is derived from the current kubectl cluster and context, as per kubectl config current-context and kubectl config view. This can be overridden by setting the KUBECONFIG variable in .kc.yml as described above.

By default, the protocol opened is http. To override, pass -p <scheme>:
```
$ kc browse -p https grafana
```
The namespace can also be overridden with -n:
```
$ kc browse -n kube-system monitoring-grafana
```
kc sh / kc bash: Open an interactive terminal in the pod given by the selector. Selector semantics are the same as kc select.

If there are multiple containers in the selected pods, one should be selected with -c <name>, e.g.:
```
$ kc bash app=grafana -c grafana
```

A full list of supported sub-commands is available when running kc help (it will be printed at the bottom of the existing kubectl help message).

timothyb89 / kc