Deploy Alpine debug/utility pod

Alpine is the best choice for this job ,but need some more setting

# debug.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
  creationTimestamp: null
  labels:
    app: debug
  name: debug
spec:
  replicas: 1
  selector:
    matchLabels:
      app: debug
  strategy: {}
  template:
    metadata:
      creationTimestamp: null
      labels:
        app: debug
    spec:
      containers:

# sample usefull package: 
# apk add curl jq wget openssl bash openssh-client hey bind-tools lynx

      - args:
        - |-
          apk add curl jq openssl bash bind-tools
          sleep infinity
        command:
        - /bin/sh
        - -c
        image: alpine:3.18
        name: alpine
        resources:
          limits:
            memory: 128Mi
            cpu: 100m
status: {}

This will used 29 MB disk space and add 45 packages into each container.

Example:

$ kubectl apply -f debug.yaml 
deployment.apps/debug created
$ kubectl exec -it deployments/debug -- bash
debug-555ddf66c7-d956b:/#
debug-555ddf66c7-d956b:/# curl -V
curl 8.1.2 (x86_64-alpine-linux-musl) libcurl/8.1.2 OpenSSL/3.1.1 zlib/1.2.13 brotli/1.0.9 libidn2/2.3.4 nghttp2/1.53.0
Release-Date: 2023-05-30
debug-555ddf66c7-d956b:/# openssl version
OpenSSL 3.1.1 30 May 2023 (Library: OpenSSL 3.1.1 30 May 2023)

Hope that help.

edit1:

version 1.1 use postStart instead

    spec:
      containers:
      - args:
        - sleep infinity
        command:
        - /bin/sh
        - -c
        image: ubuntu:22.04
        imagePullPolicy: IfNotPresent
        lifecycle:
          postStart:
            exec:
              command:
              - sh
              - -c
              - apt update -y ; DEBIAN_FRONTEND=noninteractive apt -y --no-install-recommends
                install vim-tiny curl openssl dnsutils ldap-utils 389-ds-base
        name: ubuntu