Extra commands

[mathstuf]

Supporting extra commands would be nice. My containers would need at least:

• copy file (or directory)
  • Use case: copy a configuration file.
  • Use case: copy a binary and associated unit files (for unpackaged software).
• create user
  • Use case: mainly having to do with unpackaged software.
• create volume
  • Should support creating the directory with a custom ownership and mode.
• firstboot settings
  • Use case: setting the hostname, machine-id, etc.