Add Phase 2 migration script for git sync verification

- Compares state event refs to actual git data on disk
- Uses git show-ref to handle both loose and packed refs
- Outputs TSV format compatible with Phase 3 categorization
- Optional --categorize flag for inline categorization
- Includes progress indicators and ETA (~20 min runtime on VPS)
- Improved error handling and validation over original script

1 files changed, 557 insertions, 0 deletions

diff --git a/docs/how-to/migration-scripts/10-check-git-sync.sh b/docs/how-to/migration-scripts/10-check-git-sync.sh
new file mode 100755
index 0000000..493d50a
--- /dev/null
+++ b/docs/how-to/migration-scripts/10-check-git-sync.sh
@@ -0,0 +1,557 @@
+#!/usr/bin/env bash
+#
+# 10-check-git-sync.sh - Compare state events to actual git data on disk
+#
+# PHASE 2 of the ngit-relay to ngit-grasp migration analysis pipeline.
+# Compares kind 30618 state events against actual git refs on disk.
+#
+# USAGE:
+#   ./10-check-git-sync.sh <state-events.json> <git-base-dir> <output-dir> [--categorize]
+#
+# EXAMPLES:
+#   # Check prod relay against prod git data
+#   ./10-check-git-sync.sh output/prod/raw/state-events.json /var/lib/ngit-relay/git output/prod
+#
+#   # Check archive relay against archive git data
+#   ./10-check-git-sync.sh output/archive/raw/state-events.json /var/lib/ngit-relay-archive/git output/archive
+#
+#   # Check and categorize in one step (convenience mode)
+#   ./10-check-git-sync.sh output/prod/raw/state-events.json /var/lib/ngit-relay/git output/prod --categorize
+#
+# INPUT:
+#   state-events.json  - JSONL file from Phase 1 (01-fetch-events.sh)
+#                        One kind 30618 event per line
+#   git-base-dir       - Base directory containing git repos
+#                        Structure: <git-base>/<npub>/<repo>.git/
+#
+# OUTPUT:
+#   <output-dir>/git-sync-status.tsv - Tab-separated values:
+#     repo<TAB>npub<TAB>state_refs<TAB>git_refs<TAB>matches<TAB>reason
+#
+#   With --categorize flag, also outputs:
+#     <output-dir>/category1-complete-match.txt
+#     <output-dir>/category2-empty-blank.txt
+#     <output-dir>/category3-partial-match.txt
+#     <output-dir>/category4-no-match.txt
+#
+# CATEGORIES:
+#   1. Complete Match - All refs in state event match git data perfectly
+#   2. Empty/Blank - No git data available (directory missing or empty)
+#   3. Partial Match - Some refs match, some don't
+#   4. No Match - Git data exists but commit hashes don't match
+#
+# PREREQUISITES:
+#   - nak (for npub encoding) - https://github.com/fiatjaf/nak
+#   - jq (for JSON parsing)
+#   - Read access to git directories (may need sudo)
+#
+# RUNTIME: ~20 minutes on VPS (git operations are slow)
+#
+# NOTES:
+#   - Must run on VPS with access to git directories
+#   - Progress indicator updates every 10 events
+#   - Handles packed refs (git show-ref) and loose refs
+#
+# SEE ALSO:
+#   docs/how-to/migrate-ngit-relay-to-ngit-grasp.md - Full migration guide
+#   01-fetch-events.sh - Phase 1 script that produces input for this script
+#   20-categorize.sh - Phase 3a script that consumes output from this script
+#
+
+set -euo pipefail
+
+# Colors for output (disabled if not a terminal)
+if [[ -t 1 ]]; then
+    RED='\033[0;31m'
+    GREEN='\033[0;32m'
+    YELLOW='\033[0;33m'
+    BLUE='\033[0;34m'
+    NC='\033[0m'
+else
+    RED=''
+    GREEN=''
+    YELLOW=''
+    BLUE=''
+    NC=''
+fi
+
+log_info() {
+    echo -e "${BLUE}[INFO]${NC} $*" >&2
+}
+
+log_success() {
+    echo -e "${GREEN}[OK]${NC} $*" >&2
+}
+
+log_warn() {
+    echo -e "${YELLOW}[WARN]${NC} $*" >&2
+}
+
+log_error() {
+    echo -e "${RED}[ERROR]${NC} $*" >&2
+}
+
+log_progress() {
+    # Overwrite current line for progress updates
+    echo -ne "\r${BLUE}[PROGRESS]${NC} $*" >&2
+}
+
+usage() {
+    echo "Usage: $0 <state-events.json> <git-base-dir> <output-dir> [--categorize]"
+    echo ""
+    echo "Arguments:"
+    echo "  state-events.json  JSONL file from Phase 1 (kind 30618 events)"
+    echo "  git-base-dir       Base directory for git repos (e.g., /var/lib/ngit-relay/git)"
+    echo "  output-dir         Directory to store output files"
+    echo "  --categorize       Optional: also output category files (like Phase 3)"
+    echo ""
+    echo "Examples:"
+    echo "  $0 output/prod/raw/state-events.json /var/lib/ngit-relay/git output/prod"
+    echo "  $0 output/archive/raw/state-events.json /var/lib/ngit-relay-archive/git output/archive"
+    echo ""
+    echo "Output:"
+    echo "  git-sync-status.tsv - TSV with: repo, npub, state_refs, git_refs, matches, reason"
+    exit 1
+}
+
+# Check prerequisites
+check_prerequisites() {
+    local missing=0
+    
+    if ! command -v nak &> /dev/null; then
+        log_error "nak not found. Install from: https://github.com/fiatjaf/nak"
+        log_error "Or run: nix-shell -p nak jq --run \"$0 $*\""
+        missing=1
+    fi
+    
+    if ! command -v jq &> /dev/null; then
+        log_error "jq not found. Install with your package manager."
+        missing=1
+    fi
+    
+    if [[ $missing -eq 1 ]]; then
+        exit 1
+    fi
+}
+
+# Convert hex pubkey to npub
+# Args: $1=hex_pubkey
+# Returns: npub string or empty on error
+hex_to_npub() {
+    local hex="$1"
+    nak encode npub "$hex" 2>/dev/null || echo ""
+}
+
+# Count refs in state event (only refs/heads/)
+# Args: $1=event_json
+# Returns: count
+count_state_refs() {
+    local event="$1"
+    echo "$event" | jq '[.tags[] | select(.[0] | startswith("refs/heads/"))] | length' 2>/dev/null || echo "0"
+}
+
+# Get git refs from disk
+# Args: $1=git_dir
+# Returns: count of refs/heads/ refs
+count_git_refs() {
+    local git_dir="$1"
+    
+    if [[ ! -d "$git_dir" ]]; then
+        echo "0"
+        return
+    fi
+    
+    # Use git show-ref to handle both packed and loose refs
+    # Fall back to counting loose refs if git show-ref fails
+    if git --git-dir="$git_dir" show-ref --heads 2>/dev/null | wc -l | tr -d ' '; then
+        return
+    fi
+    
+    # Fallback: count loose refs
+    if [[ -d "$git_dir/refs/heads" ]]; then
+        find "$git_dir/refs/heads" -type f 2>/dev/null | wc -l | tr -d ' '
+    else
+        echo "0"
+    fi
+}
+
+# Get ref hash from git directory
+# Args: $1=git_dir, $2=ref_path (e.g., refs/heads/main)
+# Returns: commit hash or empty
+get_git_ref_hash() {
+    local git_dir="$1"
+    local ref_path="$2"
+    
+    # Try git show-ref first (handles packed refs)
+    local hash
+    hash=$(git --git-dir="$git_dir" show-ref --hash "$ref_path" 2>/dev/null | head -1 || echo "")
+    
+    if [[ -n "$hash" ]]; then
+        echo "$hash"
+        return
+    fi
+    
+    # Fallback: read loose ref file
+    local ref_file="$git_dir/$ref_path"
+    if [[ -f "$ref_file" ]]; then
+        cat "$ref_file" 2>/dev/null | tr -d '\n' || echo ""
+    else
+        echo ""
+    fi
+}
+
+# Compare state event refs to git refs
+# Args: $1=event_json, $2=git_dir
+# Returns: count of matching refs
+count_matching_refs() {
+    local event="$1"
+    local git_dir="$2"
+    local matching=0
+    
+    # Extract refs/heads/ tags and compare
+    while IFS= read -r ref_tag; do
+        [[ -z "$ref_tag" ]] && continue
+        
+        local ref_path expected_hash
+        ref_path=$(echo "$ref_tag" | jq -r '.[0]' 2>/dev/null || echo "")
+        expected_hash=$(echo "$ref_tag" | jq -r '.[1]' 2>/dev/null || echo "")
+        
+        # Skip if not a heads ref or hash is missing
+        [[ ! "$ref_path" =~ ^refs/heads/ ]] && continue
+        [[ -z "$expected_hash" || "$expected_hash" == "null" ]] && continue
+        
+        # Get actual hash from git
+        local actual_hash
+        actual_hash=$(get_git_ref_hash "$git_dir" "$ref_path")
+        
+        if [[ "$expected_hash" == "$actual_hash" ]]; then
+            matching=$((matching + 1))
+        fi
+    done < <(echo "$event" | jq -c '.tags[] | select(.[0] | startswith("refs/heads/"))' 2>/dev/null)
+    
+    echo "$matching"
+}
+
+# Categorize a single entry
+# Args: $1=state_refs, $2=git_refs, $3=matches, $4=reason
+# Returns: category number (1-4)
+categorize_entry() {
+    local state_refs="$1"
+    local git_refs="$2"
+    local matches="$3"
+    local reason="$4"
+    
+    # Category 2: Empty/Blank
+    if [[ -n "$reason" ]] || [[ "$git_refs" -eq 0 ]]; then
+        echo "2"
+        return
+    fi
+    
+    # Category 1: Complete Match
+    if [[ "$state_refs" -gt 0 ]] && [[ "$state_refs" -eq "$git_refs" ]] && [[ "$matches" -eq "$state_refs" ]]; then
+        echo "1"
+        return
+    fi
+    
+    # Category 4: No Match
+    if [[ "$git_refs" -gt 0 ]] && [[ "$matches" -eq 0 ]]; then
+        echo "4"
+        return
+    fi
+    
+    # Category 3: Partial Match (default for anything else with matches > 0)
+    if [[ "$matches" -gt 0 ]]; then
+        echo "3"
+        return
+    fi
+    
+    # Fallback to category 2
+    echo "2"
+}
+
+# Format entry for category file
+# Args: $1=repo, $2=npub, $3=state_refs, $4=git_refs, $5=matches, $6=reason
+format_category_line() {
+    local repo="$1"
+    local npub="$2"
+    local state_refs="$3"
+    local git_refs="$4"
+    local matches="$5"
+    local reason="$6"
+    
+    if [[ -n "$reason" ]]; then
+        echo "$repo | $npub | state_refs=$state_refs | git_refs=$git_refs | matches=$matches | reason=$reason"
+    else
+        echo "$repo | $npub | state_refs=$state_refs | git_refs=$git_refs | matches=$matches"
+    fi
+}
+
+# Process a single state event
+# Args: $1=event_json, $2=git_base
+# Outputs: TSV line to stdout
+process_event() {
+    local event="$1"
+    local git_base="$2"
+    
+    # Extract repository identifier (d tag)
+    local identifier
+    identifier=$(echo "$event" | jq -r '.tags[] | select(.[0] == "d") | .[1]' 2>/dev/null | head -1 || echo "")
+    
+    if [[ -z "$identifier" ]]; then
+        return 1
+    fi
+    
+    # Extract maintainer pubkey (hex)
+    local hex_pubkey
+    hex_pubkey=$(echo "$event" | jq -r '.pubkey' 2>/dev/null || echo "")
+    
+    if [[ -z "$hex_pubkey" ]]; then
+        return 1
+    fi
+    
+    # Convert to npub
+    local npub
+    npub=$(hex_to_npub "$hex_pubkey")
+    
+    if [[ -z "$npub" ]]; then
+        return 1
+    fi
+    
+    # Count state refs
+    local state_refs
+    state_refs=$(count_state_refs "$event")
+    
+    # Find git directory
+    local git_dir="$git_base/${npub}/${identifier}.git"
+    
+    # Check git directory status
+    local git_refs=0
+    local matches=0
+    local reason=""
+    
+    if [[ ! -d "$git_dir" ]]; then
+        reason="no_git_dir"
+    elif [[ ! -d "$git_dir/refs/heads" ]] && [[ ! -f "$git_dir/packed-refs" ]]; then
+        reason="empty_refs"
+    else
+        git_refs=$(count_git_refs "$git_dir")
+        
+        if [[ "$git_refs" -eq 0 ]]; then
+            reason="empty_refs"
+        elif [[ "$state_refs" -eq 0 ]]; then
+            reason="no_state_refs"
+        else
+            matches=$(count_matching_refs "$event" "$git_dir")
+        fi
+    fi
+    
+    # Output TSV line: repo, npub, state_refs, git_refs, matches, reason
+    printf '%s\t%s\t%s\t%s\t%s\t%s\n' "$identifier" "$npub" "$state_refs" "$git_refs" "$matches" "$reason"
+}
+
+# Main
+main() {
+    local do_categorize=0
+    local args=()
+    
+    # Parse arguments
+    for arg in "$@"; do
+        if [[ "$arg" == "--categorize" ]]; then
+            do_categorize=1
+        else
+            args+=("$arg")
+        fi
+    done
+    
+    if [[ ${#args[@]} -ne 3 ]]; then
+        usage
+    fi
+    
+    local state_events_file="${args[0]}"
+    local git_base="${args[1]}"
+    local output_dir="${args[2]}"
+    
+    # Validate inputs
+    if [[ ! -f "$state_events_file" ]]; then
+        log_error "State events file not found: $state_events_file"
+        exit 1
+    fi
+    
+    if [[ ! -d "$git_base" ]]; then
+        log_error "Git base directory not found: $git_base"
+        log_error "This script must run on the VPS with access to git directories."
+        exit 1
+    fi
+    
+    # Check read permissions
+    if ! ls "$git_base" >/dev/null 2>&1; then
+        log_error "Cannot read git base directory (permission denied): $git_base"
+        log_error "Try running with sudo or grant read permissions."
+        exit 1
+    fi
+    
+    check_prerequisites
+    
+    log_info "=== Git State Synchronization Check ==="
+    log_info "State events: $state_events_file"
+    log_info "Git base: $git_base"
+    log_info "Output: $output_dir"
+    if [[ $do_categorize -eq 1 ]]; then
+        log_info "Mode: TSV + categorization"
+    else
+        log_info "Mode: TSV only (use 20-categorize.sh for categories)"
+    fi
+    log_info "Started: $(date)"
+    echo ""
+    
+    # Create output directory
+    mkdir -p "$output_dir"
+    
+    # Output files
+    local tsv_file="$output_dir/git-sync-status.tsv"
+    
+    # Initialize TSV with header
+    echo -e "repo\tnpub\tstate_refs\tgit_refs\tmatches\treason" > "$tsv_file"
+    
+    # Initialize category files if categorizing
+    local cat1="" cat2="" cat3="" cat4=""
+    if [[ $do_categorize -eq 1 ]]; then
+        cat1="$output_dir/category1-complete-match.txt"
+        cat2="$output_dir/category2-empty-blank.txt"
+        cat3="$output_dir/category3-partial-match.txt"
+        cat4="$output_dir/category4-no-match.txt"
+        > "$cat1"
+        > "$cat2"
+        > "$cat3"
+        > "$cat4"
+    fi
+    
+    # Count total events
+    local total_events
+    total_events=$(wc -l < "$state_events_file" | tr -d ' ')
+    log_info "Processing $total_events state events..."
+    echo ""
+    
+    # Process each event
+    local count=0
+    local processed=0
+    local skipped=0
+    local count_cat1=0 count_cat2=0 count_cat3=0 count_cat4=0
+    local start_time
+    start_time=$(date +%s)
+    
+    while IFS= read -r event; do
+        count=$((count + 1))
+        
+        # Skip empty lines
+        [[ -z "$event" ]] && continue
+        
+        # Process event
+        local result
+        if result=$(process_event "$event" "$git_base"); then
+            processed=$((processed + 1))
+            
+            # Write to TSV (skip header line)
+            echo "$result" >> "$tsv_file"
+            
+            # Categorize if requested
+            if [[ $do_categorize -eq 1 ]]; then
+                # Parse result
+                IFS=$'\t' read -r repo npub state_refs git_refs matches reason <<< "$result"
+                
+                local category
+                category=$(categorize_entry "$state_refs" "$git_refs" "$matches" "$reason")
+                
+                local cat_line
+                cat_line=$(format_category_line "$repo" "$npub" "$state_refs" "$git_refs" "$matches" "$reason")
+                
+                case "$category" in
+                    1) echo "$cat_line" >> "$cat1"; count_cat1=$((count_cat1 + 1)) ;;
+                    2) echo "$cat_line" >> "$cat2"; count_cat2=$((count_cat2 + 1)) ;;
+                    3) echo "$cat_line" >> "$cat3"; count_cat3=$((count_cat3 + 1)) ;;
+                    4) echo "$cat_line" >> "$cat4"; count_cat4=$((count_cat4 + 1)) ;;
+                esac
+            fi
+        else
+            skipped=$((skipped + 1))
+        fi
+        
+        # Progress indicator every 10 events
+        if [[ $((count % 10)) -eq 0 ]]; then
+            local elapsed=$(($(date +%s) - start_time))
+            local rate=0
+            if [[ $elapsed -gt 0 ]]; then
+                rate=$((count / elapsed))
+            fi
+            local eta="?"
+            if [[ $rate -gt 0 ]]; then
+                eta=$(( (total_events - count) / rate ))
+            fi
+            log_progress "Processed $count/$total_events events (~${rate}/s, ETA: ${eta}s)..."
+        fi
+    done < "$state_events_file"
+    
+    # Clear progress line
+    echo "" >&2
+    
+    local end_time
+    end_time=$(date +%s)
+    local duration=$((end_time - start_time))
+    
+    # Summary
+    echo ""
+    log_info "=== Analysis Complete ==="
+    log_info "Finished: $(date)"
+    log_info "Duration: ${duration}s"
+    log_info "Processed: $processed events"
+    if [[ $skipped -gt 0 ]]; then
+        log_warn "Skipped: $skipped events (missing identifier or pubkey)"
+    fi
+    echo ""
+    
+    if [[ $do_categorize -eq 1 ]]; then
+        # Calculate percentages
+        local total=$((count_cat1 + count_cat2 + count_cat3 + count_cat4))
+        local pct1=0 pct2=0 pct3=0 pct4=0
+        if [[ $total -gt 0 ]]; then
+            pct1=$(awk "BEGIN {printf \"%.1f\", ($count_cat1/$total)*100}")
+            pct2=$(awk "BEGIN {printf \"%.1f\", ($count_cat2/$total)*100}")
+            pct3=$(awk "BEGIN {printf \"%.1f\", ($count_cat3/$total)*100}")
+            pct4=$(awk "BEGIN {printf \"%.1f\", ($count_cat4/$total)*100}")
+        fi
+        
+        log_info "=== Category Summary ==="
+        log_success "Category 1 (Complete Match): $count_cat1 ($pct1%)"
+        log_warn "Category 2 (Empty/Blank): $count_cat2 ($pct2%)"
+        log_warn "Category 3 (Partial Match): $count_cat3 ($pct3%)"
+        log_error "Category 4 (No Match): $count_cat4 ($pct4%)"
+        echo ""
+        
+        # Validation warning
+        if [[ $count_cat2 -eq $total ]] && [[ $total -gt 0 ]]; then
+            log_error "WARNING: 100% of repos categorized as Empty/Blank"
+            log_error "This usually indicates a permission or path issue."
+            echo ""
+            log_info "Troubleshooting:"
+            echo "  1. Verify git data exists: sudo ls -la $git_base | head -10"
+            echo "  2. Check sample repo: sudo find $git_base -name '*.git' -type d | head -1"
+            echo "  3. Re-run with sudo if not already using it"
+            echo ""
+        fi
+    fi
+    
+    log_info "Output files:"
+    echo "  $tsv_file"
+    if [[ $do_categorize -eq 1 ]]; then
+        echo "  $cat1"
+        echo "  $cat2"
+        echo "  $cat3"
+        echo "  $cat4"
+    else
+        echo ""
+        log_info "Next step: Run 20-categorize.sh to categorize results"
+        echo "  ./20-categorize.sh $tsv_file $output_dir"
+    fi
+}
+
+main "$@"