jq

# Identity (pretty-print JSON)
cat file.json | jq '.'

# Access a field
jq '.name'

# Nested field
jq '.metadata.name'

# Array index
jq '.[0]'

# Array slice
jq '.[2:5]'

# All array elements
jq '.[]'

# Multiple fields (object construction)
jq '{name: .name, age: .age}'

# Map over array
jq '[.[] | .name]'

# Filter array (select)
jq '[.[] | select(.status == "Running")]'

# Select with regex
jq '[.[] | select(.name | test("^web-"))]'

# Flatten nested array
jq '[.[] | .tags[]]'

# Sort by field
jq 'sort_by(.age)'

# Unique values
jq '[.[].status] | unique'

# Length of array
jq '.items | length'

# Group by field
jq 'group_by(.namespace)'

# String interpolation
jq '"Hello, \(.name)!"'

# Convert to string
jq '.port | tostring'

# Convert to number
jq '.replicas | tonumber'

# Keys of an object
jq 'keys'

# Values of an object (as array)
jq '[.[]]'

# Check if field exists
jq 'has("metadata")'

# Null-safe access
jq '.labels? // {}'

# Default value
jq '.timeout // 30'

# List all pod names
kubectl get pods -o json \
  | jq -r '.items[].metadata.name'

# Get pod names and their node
kubectl get pods -o json \
  | jq -r '.items[] | "\(.metadata.name) -> \(.spec.nodeName)"'

# Get all non-running pods
kubectl get pods -A -o json \
  | jq -r '.items[] | select(.status.phase != "Running") | "\(.metadata.namespace)/\(.metadata.name)"'

# Get container image versions
kubectl get pods -o json \
  | jq -r '.items[].spec.containers[] | "\(.name): \(.image)"'

# Find pods with high restart count
kubectl get pods -A -o json \
  | jq -r '.items[] | select(.status.containerStatuses[]?.restartCount > 5) | .metadata.name'

# Sum values
jq '[.[].count] | add'

# Min / max
jq '[.[].cpu] | min'
jq '[.[].cpu] | max'

# Count items matching condition
jq '[.[] | select(.ready == true)] | length'

# Reduce with accumulator
jq 'reduce .[] as $item (0; . + $item.value)'

# Build lookup map from array
jq 'INDEX(.[]; .id)'

# Raw string output (no quotes)
jq -r '.name'

# Compact output (no whitespace)
jq -c '.'

# Null input (generate data)
jq -n '{version: "1.0", env: "prod"}'

# Read from file
jq '.' config.json

# Multiple input files
jq -s '.[0] * .[1]' base.json override.json

# Tab-separated output
jq -r '[.name, .namespace, .status] | @tsv'

# CSV output
jq -r '[.name, .age] | @csv'