Minimal troubleshooting image for Kubernetes clusters and local Docker.

Docker

docker pull ghcr.io/sheludchenko/debugbox:latest
docker run --rm -it ghcr.io/sheludchenko/debugbox:latest

Build locally:

docker build -t ghcr.io/sheludchenko/debugbox:latest .

Kubernetes

kubectl run debugbox --rm -it --image=ghcr.io/sheludchenko/debugbox:latest --restart=Never -- /bin/bash

Schedule on a specific node, including tainted ones:

kubectl run debugbox --rm -it --image=ghcr.io/sheludchenko/debugbox:latest --restart=Never \
  --overrides='{"spec":{"nodeSelector":{"kubernetes.io/hostname":"NODE"},"tolerations":[{"operator":"Exists"}]}}' \
  -- /bin/bash

Tools

Tool	Purpose
curl, wget	HTTP
dig, nslookup	DNS
ip, ss	Interfaces and sockets
ping	ICMP
nc	TCP/UDP
tcping	TCP port connectivity
traceroute	Path tracing
tcpdump	Packet capture
openssl	TLS and certificates
jq, yq	JSON and YAML
psql	PostgreSQL
mysql	MySQL
sqlcmd	SQL Server

Interactive bash includes cls as an alias for clear.

Usage

# HTTP
curl -I https://example.com
wget -qO- https://example.com

# DNS
dig example.com
nslookup example.com

# Interfaces and sockets
ip addr
ip route
ss -lntup

# ICMP
ping -c 4 example.com

# TCP/UDP
nc -vz example.com 443
echo ping | nc example.com 80

# TCP port connectivity
tcping example.com 443

# Path tracing
traceroute example.com

# Packet capture
tcpdump -i any -nn port 443

# TLS and certificates
openssl s_client -connect example.com:443 -servername example.com </dev/null
echo | openssl s_client -connect example.com:443 2>/dev/null | openssl x509 -noout -dates -subject

# JSON and YAML
echo '{"ok":true}' | jq .
echo 'ok: true' | yq .

# PostgreSQL
psql -h HOST -p 5432 -U USER -d DATABASE

# MySQL
mysql -h HOST -P 3306 -u USER -p DATABASE

# SQL Server
sqlcmd -S HOST,1433 -U USER -P PASSWORD -d DATABASE -Q "SELECT 1"