check-container-sizes.zsh

#!/usr/bin/env zsh
# Copyright (C) 2025 Jim Chen <[email protected]>, licensed under GPL-3.0-or-later
#
# Container Image Size Checker Script
# Purpose: Quickly check the size of container images using skopeo and jq.
# Features:
#   - Parses multiple repository:tag arguments
#   - Uses skopeo inspect and jq to extract image and layer sizes
#   - Formats and displays size in B, KB, MB, or GB
#   - Sums total size for all images
#   - Handles errors and invalid arguments gracefully
#   - Outputs results in a readable table format
# Requirements:
#   - skopeo
#   - jq

# Enable zsh options for better array support
setopt LOCAL_OPTIONS
setopt EXTENDED_GLOB

# Check for required tools
if ! command -v skopeo >/dev/null 2>&1; then
    print "ERROR: skopeo is required but not installed" >&2
    exit 1
fi

if ! command -v jq >/dev/null 2>&1; then
    print "ERROR: jq is required but not installed" >&2
    exit 1
fi

# Function to format file size
format_size() {
    local size=$1
    
    if (( size < 1024 )); then
        printf "%d B" $size
    elif (( size < 1048576 )); then
        printf "%.2f KB" $((size / 1024.0))
    elif (( size < 1073741824 )); then
        printf "%.2f MB" $((size / 1048576.0))
    else
        printf "%.2f GB" $((size / 1073741824.0))
    fi
}

# Check arguments
if [[ $# -eq 0 ]]; then
    print "Usage: $0 <repository:tag> [repository:tag] ..."
    print "Example: $0 ghcr.io/jim60105/yt-dlp:latest docker.io/library/ubuntu:22.04"
    exit 1
fi

print "🔍 Checking container image sizes"
print "============================================================"

typeset -i TOTAL_SIZE=0
typeset -i result_count=0

for ITEM in "$@"; do
    # Parse repository:tag using zsh parameter expansion
    if [[ ! "$ITEM" =~ ":" ]]; then
        print "  ❌ Invalid argument format: $ITEM (use repository:tag format)"
        continue
    fi
    
    local REPO="${ITEM%:*}"
    local TAG="${ITEM##*:}"
    
    if [[ -z "$REPO" || -z "$TAG" || "$REPO" == "$TAG" ]]; then
        print "  ❌ Invalid argument format: $ITEM (use repository:tag format)"
        continue
    fi
    
    local IMAGE_URL="docker://$REPO:$TAG"
    print "📋 Checking image: $REPO:$TAG"

    # Use skopeo inspect and parse size
    local SIZE_INFO=""
    SIZE_INFO=$(skopeo inspect "$IMAGE_URL" 2>/dev/null | jq -r '
        [
            (.config.size // 0),
            (.LayersData // .layers // [] | map(.Size // .size // 0) | add // 0)
        ] | add
    ' 2>/dev/null)

    if [[ "$SIZE_INFO" != "null" ]] && [[ "$SIZE_INFO" -gt 0 ]]; then
        local SIZE_STR=$(format_size $SIZE_INFO)
        
        printf "  %-40s | %10s | %15s bytes\n" "$REPO:$TAG" "$SIZE_STR" "$(printf "%'d" "$SIZE_INFO")"
        (( TOTAL_SIZE += SIZE_INFO ))
        (( result_count++ ))
    else
        print "  ❌ Unable to get image size ($REPO:$TAG)"
    fi
done

if (( result_count > 0 )); then
    print "------------------------------------------------------------"
    
    local TOTAL_SIZE_STR=$(format_size $TOTAL_SIZE)
    printf "📦 %-40s | %10s | %15s bytes\n" "Total:" "$TOTAL_SIZE_STR" "$(printf "%'d" "$TOTAL_SIZE")"
fi

print ""
print "✅ Check complete!"