apt-ostree/.notes/out-of-scope/apt-ostree.md

apt-ostree Out of Scope Features

Overview

This document outlines features and functionality that are considered out of scope for apt-ostree. These features are either not aligned with apt-ostree's core philosophy, would add unnecessary complexity, or are better handled by other tools.

Core Philosophy Constraints

"From Scratch" Philosophy

apt-ostree follows a strict "from scratch" philosophy where every change regenerates the target filesystem completely. This constrains certain features:

Out of Scope:

• Incremental package updates: Cannot modify existing packages in-place
• Live package modifications: Cannot change packages while system is running
• Partial rollbacks: Cannot rollback individual packages, only entire deployments
• Package version pinning: Cannot pin specific package versions within a deployment

Rationale: These features would violate the immutable, atomic nature of apt-ostree deployments.

Atomic Operations

apt-ostree requires all operations to be atomic with proper rollback support:

Out of Scope:

• Non-atomic package operations: Cannot install packages without creating new deployment
• Partial transaction support: Cannot commit partial changes
• Live system modifications: Cannot modify running system directly
• Package dependency resolution conflicts: Cannot resolve conflicts by modifying existing packages

Rationale: These would break the atomicity guarantees that make apt-ostree reliable.

Package Management Limitations

Traditional APT Features

apt-ostree intentionally omits certain traditional APT features:

Out of Scope:

• Package version management: Cannot downgrade individual packages
• Package configuration management: Cannot modify package configurations in-place
• Package script customization: Cannot customize package installation scripts
• Package repository management: Cannot add/remove repositories dynamically
• Package signing verification: Cannot verify individual package signatures

Rationale: These features are better handled by traditional APT or would add unnecessary complexity.

Advanced APT Features

Certain advanced APT features are not supported:

Out of Scope:

• Package groups: Cannot install/remove package groups
• Package collections: Cannot manage package collections
• Package patterns: Cannot use package patterns for installation
• Package recommendations: Cannot handle package recommendations
• Package suggestions: Cannot handle package suggestions

Rationale: These features add complexity without providing significant value in the apt-ostree model.

System Management Limitations

Traditional System Administration

apt-ostree intentionally limits traditional system administration capabilities:

Out of Scope:

• User management: Cannot create/modify users directly
• Group management: Cannot create/modify groups directly
• Service management: Cannot enable/disable services directly
• Configuration management: Cannot modify system configurations in-place
• Network configuration: Cannot configure networking directly

Rationale: These are better handled by systemd, user management tools, or configuration management systems.

Live System Modifications

apt-ostree does not support live system modifications:

Out of Scope:

• Live kernel updates: Cannot update kernel without reboot
• Live library updates: Cannot update libraries while applications are running
• Live service updates: Cannot update services without restart
• Live configuration changes: Cannot change configurations without deployment

Rationale: These would violate the immutable filesystem model and atomicity guarantees.

Development and Testing Limitations

Development Workflow Features

Certain development workflow features are not supported:

Out of Scope:

• Development package installation: Cannot install development packages directly
• Debug package installation: Cannot install debug packages directly
• Source package management: Cannot manage source packages
• Package building: Cannot build packages from source
• Package patching: Cannot apply patches to packages

Rationale: These features are better handled by development tools, build systems, or traditional APT.

Testing and Validation

Certain testing features are not supported:

Out of Scope:

• Package testing: Cannot test individual packages
• Integration testing: Cannot test package integrations
• Performance testing: Cannot benchmark package performance
• Security testing: Cannot audit package security
• Compatibility testing: Cannot test package compatibility

Rationale: These are better handled by dedicated testing frameworks and tools.

Container and Virtualization Limitations

Container Integration

apt-ostree has limited container integration capabilities:

Out of Scope:

• Container runtime management: Cannot manage container runtimes
• Container orchestration: Cannot orchestrate containers
• Container networking: Cannot configure container networking
• Container storage: Cannot manage container storage
• Container security: Cannot manage container security policies

Rationale: These are better handled by dedicated container management tools.

Virtualization Support

apt-ostree has limited virtualization support:

Out of Scope:

• Virtual machine management: Cannot manage virtual machines
• Virtual machine templates: Cannot create VM templates
• Virtual machine snapshots: Cannot manage VM snapshots
• Virtual machine networking: Cannot configure VM networking
• Virtual machine storage: Cannot manage VM storage

Rationale: These are better handled by dedicated virtualization management tools.

Network and Security Limitations

Network Management

apt-ostree has limited network management capabilities:

Out of Scope:

• Network configuration: Cannot configure networking
• Network services: Cannot manage network services
• Network security: Cannot configure network security
• Network monitoring: Cannot monitor network traffic
• Network troubleshooting: Cannot troubleshoot network issues

Rationale: These are better handled by dedicated network management tools.

Security Management

apt-ostree has limited security management capabilities:

Out of Scope:

• Access control: Cannot manage access control policies
• Authentication: Cannot manage authentication systems
• Authorization: Cannot manage authorization policies
• Audit logging: Cannot manage audit logs
• Security scanning: Cannot scan for security vulnerabilities

Rationale: These are better handled by dedicated security management tools.

Monitoring and Logging Limitations

System Monitoring

apt-ostree has limited system monitoring capabilities:

Out of Scope:

• Performance monitoring: Cannot monitor system performance
• Resource monitoring: Cannot monitor system resources
• Application monitoring: Cannot monitor applications
• Service monitoring: Cannot monitor services
• Health checking: Cannot perform health checks

Rationale: These are better handled by dedicated monitoring tools.

Logging Management

apt-ostree has limited logging management capabilities:

Out of Scope:

• Log collection: Cannot collect logs
• Log analysis: Cannot analyze logs
• Log rotation: Cannot rotate logs
• Log archiving: Cannot archive logs
• Log searching: Cannot search logs

Rationale: These are better handled by dedicated logging management tools.

Backup and Recovery Limitations

Backup Management

apt-ostree has limited backup capabilities:

Out of Scope:

• File backup: Cannot backup individual files
• Directory backup: Cannot backup directories
• Database backup: Cannot backup databases
• Application backup: Cannot backup applications
• Configuration backup: Cannot backup configurations

Rationale: These are better handled by dedicated backup tools.

Recovery Management

apt-ostree has limited recovery capabilities:

Out of Scope:

• File recovery: Cannot recover individual files
• Directory recovery: Cannot recover directories
• Database recovery: Cannot recover databases
• Application recovery: Cannot recover applications
• Configuration recovery: Cannot recover configurations

Rationale: These are better handled by dedicated recovery tools.

Ubuntu/Debian Specific Limitations

Ubuntu-Specific Features

apt-ostree intentionally omits certain Ubuntu-specific features:

Out of Scope:

• Ubuntu-specific package management: Cannot use Ubuntu-specific package features
• Ubuntu-specific configurations: Cannot use Ubuntu-specific configurations
• Ubuntu-specific services: Cannot manage Ubuntu-specific services
• Ubuntu-specific tools: Cannot use Ubuntu-specific tools
• Ubuntu-specific workflows: Cannot use Ubuntu-specific workflows

Rationale: These features are better handled by Ubuntu-specific tools or would add unnecessary complexity.

Debian-Specific Features

apt-ostree intentionally omits certain Debian-specific features:

Out of Scope:

• Debian-specific package management: Cannot use Debian-specific package features
• Debian-specific configurations: Cannot use Debian-specific configurations
• Debian-specific services: Cannot manage Debian-specific services
• Debian-specific tools: Cannot use Debian-specific tools
• Debian-specific workflows: Cannot use Debian-specific workflows

Rationale: These features are better handled by Debian-specific tools or would add unnecessary complexity.

Future Considerations

Potential Future Scope

Some features currently out of scope may be considered in the future:

Future Considerations:

• Enhanced container support: May add more container integration features
• Advanced monitoring: May add basic monitoring capabilities
• Security enhancements: May add basic security features
• Network integration: May add basic network features
• Backup integration: May add basic backup features

Criteria for Inclusion:

• Must align with core philosophy
• Must maintain atomicity guarantees
• Must not add unnecessary complexity
• Must provide significant value
• Must not duplicate existing tools

Integration with Other Tools

apt-ostree focuses on integration rather than duplication:

Integration Approach:

• Use existing tools: Leverage existing tools for out-of-scope features
• Provide interfaces: Provide interfaces to external tools
• Support workflows: Support workflows that use external tools
• Maintain focus: Maintain focus on core functionality
• Enable ecosystem: Enable ecosystem of complementary tools

Benefits:

• Reduced complexity
• Better tool specialization
• Improved maintainability
• Enhanced ecosystem
• Focused development

Comparison with rpm-ostree

Similarities

apt-ostree and rpm-ostree share similar out-of-scope features:

Common Out of Scope:

• Incremental package updates: Both follow "from scratch" philosophy
• Live system modifications: Both require atomic operations
• Traditional system administration: Both focus on package management
• Container orchestration: Both have limited container support
• Network management: Both have limited network capabilities

Rationale: Both tools follow similar core philosophies and design principles.

Differences

apt-ostree has some Ubuntu/Debian-specific out-of-scope features:

apt-ostree Specific:

• Ubuntu-specific features: apt-ostree omits Ubuntu-specific features
• Debian-specific features: apt-ostree omits Debian-specific features
• APT-specific features: apt-ostree omits certain APT features
• DEB-specific features: apt-ostree omits certain DEB features

rpm-ostree Specific:

• RPM-specific features: rpm-ostree omits certain RPM features
• DNF-specific features: rpm-ostree omits certain DNF features
• Fedora-specific features: rpm-ostree omits Fedora-specific features
• RHEL-specific features: rpm-ostree omits RHEL-specific features

Rationale: Each tool focuses on its specific package management ecosystem.