https://github.com/ahmetb/kubectl-foreach
Run kubectl commands in all/some contexts in parallel (similar to GNU xargs+parallel)
https://github.com/ahmetb/kubectl-foreach
kubectl kubectl-plugins
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Run kubectl commands in all/some contexts in parallel (similar to GNU xargs+parallel)
- Host: GitHub
- URL: https://github.com/ahmetb/kubectl-foreach
- Owner: ahmetb
- License: apache-2.0
- Created: 2022-05-21T02:29:17.000Z (almost 3 years ago)
- Default Branch: master
- Last Pushed: 2025-03-12T00:30:12.000Z (about 2 months ago)
- Last Synced: 2025-04-01T08:44:04.822Z (29 days ago)
- Topics: kubectl, kubectl-plugins
- Language: Go
- Homepage:
- Size: 81.1 KB
- Stars: 470
- Watchers: 6
- Forks: 23
- Open Issues: 4
-
Metadata Files:
- Readme: README.md
- License: LICENSE
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README
# kubectl foreach
Run a `kubectl` command in one or more contexts (clusters) in parallel (similar
to GNU parallel/xargs). Useful for querying multiple clusters at once or making
changes against the cluster fleet.
## Usage
```text
Usage:
kubectl foreach [OPTIONS] [PATTERN]... -- [KUBECTL_ARGS...]
Patterns can be used to match context names from kubeconfig:
(empty): matches all contexts
NAME: matches context with exact name
/PATTERN/: matches context with regular expression
^NAME: remove context with exact name from the matched results
^/PATTERN/: remove contexts matching the regular expression from the results
Options:
-c=NUM Limit parallel executions (default: 0, unlimited)
-I=VAL Replace VAL occurring in KUBECTL_ARGS with context name
-q Disable and accept confirmation prompts ($KUBECTL_FOREACH_DISABLE_PROMPTS)
-h/--help Print help
```
## Demo
Query a pod by label in `minikube` and `*-prod*` contexts:
```text
$ kubectl foreach /-prod/ minikube -- get pods -n kube-system --selector compute.twitter.com/app=coredns --no-headers
eu-prod | coredns-59bd9867bb-6rbx7 2/2 Running 0 78d
eu-prod | coredns-59bd9867bb-9xczh 2/2 Running 0 78d
eu-prod | coredns-59bd9867bb-fvn6t 2/2 Running 0 78d
minikube | No resources found in kube-system namespace.
useast-prod | coredns-6fd4bd9db4-7w9wv 2/2 Running 0 78d
useast-prod | coredns-6fd4bd9db4-9pk8n 2/2 Running 0 78d
useast-prod | coredns-6fd4bd9db4-xphr4 2/2 Running 0 78d
uswest-prod | coredns-6f987df9bc-6fgc2 2/2 Running 0 78d
uswest-prod | coredns-6f987df9bc-9gxvt 2/2 Running 0 78d
uswest-prod | coredns-6f987df9bc-d88jk 2/2 Running 0 78d
```
## Examples
**Match to contexts by name:** Run a command ("kubectl version") on contexts `c1`, `c2`
and `c3`:
```sh
kubectl foreach c1 c2 c3 -- version
```
**Match to contexts by pattern:** Run a command on contexts starting with `gke`
(regular expression syntax):
```sh
kubectl foreach /^gke/ -- get pods
```
**Match all contexts:** empty context matches all contexts.
```sh
kubectl foreach -- version
```
**Excluding contexts:** Use the matching syntaxes with a `^` prefix to use them
for exclusion. If no matching contexts are specified.
e.g. match all contexts **except** `c1` and except those ending
with `prod` (single quotes for escaping `$` in the shell):
```shell
kubectl foreach ^c1 ^/prod'$'/ -- version
```
**Using with kubectl plugins:** Customize how context name is passed to the command
(useful for kubectl plugins as `--context` must be specified after plugin name).
In this example, `_` is replaced with the context name when calling "kubectl
my_plugin".
```shell
kubectl foreach -I _ -- my_plugin -ctx=_
```
**Limit parallelization:** Only run 3 commands at a time:
```
kubectl foreach -c 3 /^gke-/
```
## Install
Use [Krew](https://krew.sigs.k8s.io/) kubectl plugin manager:
```shell
kubectl krew install foreach
```
You can also build from source but you won't receive new version updates:
```
go install github.com/ahmetb/kubectl-foreach@latest
```
## Remarks/FAQ
**Do not use this tool programmatically:**
This tool is not intended for deploying workloads to clusters, or using
programmatically. Therefore, it does not provide a structured output format or
ordered printing that is meant to be parsed by or piped to other programs (maybe
except for `grep`).
**error: pipe: too many open files:**
macOS default open files limit seems to be 256. kubectl command opens files
and sockets that easily exhausts this number while running the command against
50+ clusters. Run `ulimit -n 2048` to bump this limit to a higher number and
you should not be seeing the error anymore.