Add logs helper

logs.sh

@@ -0,0 +1,91 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+log() {
+  printf '[logs] %s\n' "$*"
+}
+
+usage() {
+  cat <<'EOF'
+Usage: ./logs.sh <id-or-name-prefix> [--follow]
+
+Prints the Firecracker log for a VM. Use --follow to tail -f.
+EOF
+}
+
+get_prop() {
+  local info="$1"
+  local key="$2"
+  awk -F= -v k="$key" '$1==k {print $2}' "$info"
+}
+
+find_vm_info() {
+  local query="$1"
+  local info match_count=0 match=""
+
+  for info in state/vms/*/info; do
+    [[ -f "$info" ]] || continue
+    local id name
+    id="$(get_prop "$info" "id")"
+    name="$(get_prop "$info" "name")"
+    if [[ "$id" == "$query"* || "$name" == "$query"* ]]; then
+      match="$info"
+      match_count=$((match_count + 1))
+    fi
+  done
+
+  if (( match_count == 0 )); then
+    log "no VM found for prefix: $query"
+    exit 1
+  fi
+  if (( match_count > 1 )); then
+    log "multiple VMs found for prefix: $query"
+    exit 1
+  fi
+
+  printf '%s' "$match"
+}
+
+QUERY="${1:-}"
+FOLLOW=0
+while [[ $# -gt 0 ]]; do
+  case "$1" in
+    --follow|-f)
+      FOLLOW=1
+      shift
+      ;;
+    -h|--help)
+      usage
+      exit 0
+      ;;
+    *)
+      if [[ -z "$QUERY" ]]; then
+        QUERY="$1"
+        shift
+      else
+        log "unknown option: $1"
+        usage
+        exit 1
+      fi
+      ;;
+  esac
+done
+
+if [[ -z "$QUERY" ]]; then
+  usage
+  exit 1
+fi
+
+INFO_FILE="$(find_vm_info "$QUERY")"
+LOG_FILE="$(get_prop "$INFO_FILE" "log")"
+
+if [[ -z "$LOG_FILE" || ! -f "$LOG_FILE" ]]; then
+  log "log file not found: $LOG_FILE"
+  exit 1
+fi
+
+if (( FOLLOW == 1 )); then
+  tail -f "$LOG_FILE"
+else
+  cat "$LOG_FILE"
+fi