fix: add migration script for flat-path firecracker binaries to amd64/ (#14)

* fix: add migration script for flat-path firecracker binaries to amd64/

Before ARM64 support was added, firecracker binaries were uploaded to GCS
at the flat path firecrackers/{version}/firecracker. The orchestrator's
arch-aware path resolution expects firecrackers/{version}/amd64/firecracker,
so old builds are not found via the arch-based lookup.

Add migrate-gcs-arch.sh to dry-run/copy (and optionally delete) existing
flat-path GCS objects into the amd64/ subdirectory.

* move migrate-gcs-arch.sh to scripts/

* simplify migration script: remove --delete-old

* fix: don't hardcode firecrackers/ prefix, accept full GCS path

* skip versions that already have amd64/firecracker

Author: ValentaTomas

scripts/migrate-gcs-arch.sh

@@ -0,0 +1,82 @@
+#!/bin/bash
+# Copies flat-path firecracker binaries into amd64/ subdirectories in GCS.
+#
+# Before ARM64 support was added, builds were uploaded as:
+#   {version_name}/firecracker
+#
+# The arch-aware layout expects:
+#   {version_name}/amd64/firecracker
+#
+# This script finds flat-path binaries and copies them into the amd64/ subdir
+# so the orchestrator's arch-based path resolution can find them.
+#
+# Usage:
+#   ./scripts/migrate-gcs-arch.sh <bucket-or-path>          # dry-run: show what would be copied
+#   ./scripts/migrate-gcs-arch.sh <bucket-or-path> --apply   # copy flat -> amd64/
+#
+# Examples:
+#   ./scripts/migrate-gcs-arch.sh gs://e2b-staging-fc-versions
+#   ./scripts/migrate-gcs-arch.sh gs://e2b-prod-public-builds/firecrackers --apply
+
+set -euo pipefail
+
+GCS_PATH="${1:?Usage: $0 <bucket-or-path> [--apply]}"
+shift
+
+APPLY=false
+for arg in "$@"; do
+  case "$arg" in
+    --apply) APPLY=true ;;
+    *) echo "Unknown flag: $arg"; exit 1 ;;
+  esac
+done
+
+# Normalize: strip trailing slash
+GCS_PATH="${GCS_PATH%/}"
+
+echo "Scanning ${GCS_PATH} for flat-path firecracker binaries..."
+echo ""
+
+# Match only flat-path binaries: {version}/firecracker
+# The single * does NOT match path separators, so this excludes
+# {version}/{arch}/firecracker.
+objects=$(gsutil ls "${GCS_PATH}/*/firecracker" 2>/dev/null || true)
+
+if [[ -z "$objects" ]]; then
+  echo "No flat-path firecracker binaries found in ${GCS_PATH}"
+  exit 0
+fi
+
+copied=0
+skipped=0
+while IFS= read -r src; do
+  [[ -z "$src" ]] && continue
+
+  # Insert /amd64 before the filename:
+  #   .../v1.10.1/firecracker -> .../v1.10.1/amd64/firecracker
+  dst="${src%/firecracker}/amd64/firecracker"
+
+  # Skip if destination already exists
+  if gsutil -q stat "$dst" 2>/dev/null; then
+    echo "  SKIP  $dst (already exists)"
+    ((skipped++)) || true
+    continue
+  fi
+
+  if [[ "$APPLY" == true ]]; then
+    echo "  COPY  $src"
+    echo "    ->  $dst"
+    gsutil cp "$src" "$dst"
+  else
+    echo "  [dry-run] $src"
+    echo "         -> $dst"
+  fi
+  ((copied++)) || true
+done <<< "$objects"
+
+echo ""
+echo "Total: $copied to copy, $skipped skipped (already exist)"
+if [[ "$APPLY" != true && "$copied" -gt 0 ]]; then
+  echo ""
+  echo "This was a dry run. Add --apply to actually copy."
+fi