In this chapter, we will cover the following recipes:

• Exploring an image's contents
• Adding a new software layer
• Selecting a specific package version and provider
• Adding supported packages
• Adding new packages
• Adding data, scripts, or configuration files
• Managing users and groups
• Using the sysvinit initialization system
• Using the systemd initialization system
• Installing package installation scripts
• Reducing the Linux kernel image size
• Reducing the root filesystem image size
• Memory-based root filesystems
• Securing the root filesystem
• Releasing software
• Analyzing your system for compliance
• Working with open source and proprietary code