flatten iso for symlinks

flatten-iso-proxmox.sh

#!/bin/bash

# ================= CONFIGURATION =================
SOURCE_DIR="/mnt/pool_name/dataset_name/iso"
PROXMOX_DIR="${SOURCE_DIR}/template/iso"

# true  = Always use "Folder-Filename.iso"
# false = Only use prefix if filenames collide
APPEND_DIRNAME_ALWAYS=false
# =================================================

mkdir -p "$PROXMOX_DIR"

# Temporary file to track which links are valid during this run
VALID_LINKS_LOG=$(mktemp)

echo "Starting Sync..."
echo "Source: $SOURCE_DIR"
echo "Target: $PROXMOX_DIR"
echo "Mode:   APPEND_DIRNAME_ALWAYS=$APPEND_DIRNAME_ALWAYS"

# 1. PRE-CALCULATE DUPLICATES (If needed)
if [ "$APPEND_DIRNAME_ALWAYS" = false ]; then
    echo "Scanning for duplicates..."
    # Get list of filenames that appear more than once
    DUPLICATES=$(find "$SOURCE_DIR" -type f -name "*.iso" -not -path "${PROXMOX_DIR}/*" -exec basename {} \; | sort | uniq -d)
fi

# 2. SYNC LOOP (Create & Update)
# We process every source ISO and ensure its link exists and points to the right place.
find "$SOURCE_DIR" -type f -name "*.iso" -not -path "${PROXMOX_DIR}/*" | while read filepath; do

    filename=$(basename "$filepath")
    parentdir=$(basename "$(dirname "$filepath")")

    # --- DETERMINE LINK NAME ---
    use_prefix=false
    
    if [ "$APPEND_DIRNAME_ALWAYS" = true ]; then
        use_prefix=true
    elif echo "$DUPLICATES" | grep -Fxq "$filename"; then
        use_prefix=true
    fi

    if [ "$use_prefix" = true ]; then
        linkname="${parentdir}-${filename}"
    else
        linkname="${filename}"
    fi
    
    # Track that this link name is valid
    echo "$linkname" >> "$VALID_LINKS_LOG"

    # --- CALCULATE RELATIVE PATH ---
    # Python is safest for reliable relative path math on TrueNAS
    target_rel_path=$(python3 -c "import os.path; print(os.path.relpath('$filepath', '$PROXMOX_DIR'))")
    full_link_path="${PROXMOX_DIR}/${linkname}"

    # --- CHECK STATE & UPDATE ---
    # Check if link exists and where it points
    if [ -L "$full_link_path" ]; then
        current_target=$(readlink "$full_link_path")
        if [ "$current_target" == "$target_rel_path" ]; then
            # Link exists and is correct. Do nothing.
            continue
        fi
        echo "Updating changed link: $linkname"
    else
        echo "Creating new link: $linkname"
    fi

    # Create/Overwrite the link (-f forces overwrite)
    ln -sf "$target_rel_path" "$full_link_path"

done

# 3. CLEANUP ORPHANS
# Delete any symlink in PROXMOX_DIR that was not added to our "VALID_LINKS_LOG"
echo "Cleaning up orphans..."

# We loop through existing links in the target dir
find "$PROXMOX_DIR" -maxdepth 1 -type l -name "*.iso" | while read link_obj; do
    link_basename=$(basename "$link_obj")
    
    # Grep the temp file to see if this link was processed in Step 2
    # grep -F (fixed string) -x (exact match) -q (quiet)
    if ! grep -Fxq "$link_basename" "$VALID_LINKS_LOG"; then
        echo "Removing orphan/stale link: $link_basename"
        rm "$link_obj"
    fi
done

# Cleanup temp file
rm "$VALID_LINKS_LOG"

echo "Sync Complete."