kubectl-envx

A kubectl plugin or standalone bash script to extract and inject Kubernetes environment variables to local commands.

• kubectl-envx
  • Features
  • Requirements
  • Installation
  • Usage
    • Supported arguments
    • Examples
    • Development setup

Features

kubectl envx extracts environment variables from Kubernetes resources including those defined in envFrom references (ConfigMaps and Secrets). It can display these variables or use them to run local commands.

• Lists all environment variables from a Kubernetes resource
• Resolves envFrom references (ConfigMaps and Secrets), a typical limitation of kubectl set env --resolve --list.
• Supports variable overrides
• Can execute commands with the extracted variables (e.g. execute the same job locally)
• Works with any Kubernetes resource type (Pods, Deployments, StatefulSets, CronJobs, etc.)

Requirements

bash, sed, kubectl and jq must be installed.

The following versions of these dependencies are currently tested and supported:

Dep	Supported Versions
kubectl	1.28, 1.29, 1.30, 1.31, 1.32
jq	1.6, 1.7.1
bash	5.2
(GNU) sed	4.9

Installation

Easiest way to install is via the kubectl plugin manager krew:

kubectl krew install envx

For standalone installation, see the latest GitHub Release.

Usage

You can use this script via kubectl envx (as kubectl plugin) or simply as standalone script kubectl-envx.

kubectl envx <kind/name> [-n|--namespace <namespace>] [-c|--container <container>] [ENV_KEY=ENV_VALUE...] [-- command [args...]]

Supported arguments

• kind/name: Kubernetes resource kind and name (required)
• -n, --namespace: Kubernetes namespace
• -c, --container: Container name
• ENV_KEY=ENV_VALUE: Environment variable overrides
• -- command [args...]: Command to run with the environment variables

Examples

# Print all environment variables of a resource, e.g.
kubectl envx deployment/myapp
kubectl envx pod/myapp
kubectl envx job/myapp
kubectl envx cronjob/myapp
kubectl envx daemonset/myapp

# Print variables from specific namespace and container
kubectl envx deployment/myapp -n prod -c nginx

# Override variables
kubectl envx deployment/myapp DEBUG=true API_URL=http://localhost:8080

# Run command with variables
kubectl envx deployment/myapp -- env

# Use with docker (e.g. to run a local container with the extracted ENV variables)
# Note: This example uses process substitution, which is a bash feature.
# If you are using a different shell, you can save the output of `kubectl envx` to a file and use `--env-file` instead.
docker run --env-file <(kubectl envx deployment/postgres) -it alpine env

Development setup

# Ensure you have docker and kind installed on your **local** host.
# This project requires kind (Kubernetes in Docker) to do the testing.

# Launch a new kind cluster on your *LOCAL* host:
brew install kind
make kind-cluster-init

# the dev container is autoconfigured to use the above kind cluster
./docker-helper --up

development@da38d91ede55:/app$ k get nodes
NAME                         STATUS   ROLES           AGE     VERSION
kubectl-envx-control-plane   Ready    control-plane   5m33s   v1.31.4

# Runs lint and tests
development@20c533ecf4c7:/app$ make

# Runs tests for all supported dependencies (kubectl 1.xx)
development@20c533ecf4c7:/app$ make test-matrix

# Run a command with the extracted environment variables from deployment/sample (see test/manifests/sample.deployment.yml)
development@da38d91ede55:/app$ kubectl envx deployment/sample -n default -- sh -c 'echo "# $SAMPLE_SINGLE"'
# Simple String