apt-ostree/docs/.old/apt-ostree-daemon-plan/architecture/advanced-commands.md

Advanced Commands Architecture

Overview

This document describes the advanced commands architecture for apt-ostree, covering complex operations such as tree composition, database management, package overrides, and system composition. These commands provide advanced functionality for system administrators and developers.

Advanced Command Categories

Tree Composition Commands

apt-ostree compose

Creates and manages OSTree compositions for deployment.

Purpose:

• Build custom OSTree trees
• Create deployment images
• Manage tree variants
• Generate reproducible builds

Implementation Details:

• Tree definition parsing
• Package dependency resolution
• OSTree commit creation
• Image generation and validation

Example:

# Compose a new tree
apt-ostree compose tree --repo=/srv/repo --treefile=treefile.json

# Compose with specific packages
apt-ostree compose tree --repo=/srv/repo --include=nginx,postgresql

# Compose for specific architecture
apt-ostree compose tree --repo=/srv/repo --arch=amd64

Options:

• --repo: OSTree repository path
• --treefile: Tree definition file
• --include: Packages to include
• --exclude: Packages to exclude
• --arch: Target architecture
• --output: Output directory

apt-ostree compose commit

Creates commits for composed trees.

Purpose:

• Generate OSTree commits
• Update tree references
• Create deployment points
• Manage tree versions

Example:

# Create commit from tree
apt-ostree compose commit --repo=/srv/repo --tree=my-tree

# Create commit with metadata
apt-ostree compose commit --repo=/srv/repo --tree=my-tree --subject="Update packages"

Database Management Commands

apt-ostree db

Manages the APT package database within OSTree.

Purpose:

• Database operations
• Package metadata management
• Dependency resolution
• Cache management

Subcommands:

apt-ostree db diff

Shows differences between database states.

Example:

# Show differences between deployments
apt-ostree db diff --from=deployment1 --to=deployment2

# Show package differences
apt-ostree db diff --packages --from=deployment1 --to=deployment2

apt-ostree db list

Lists database contents.

Example:

# List all packages
apt-ostree db list

# List installed packages
apt-ostree db list --installed

# List available packages
apt-ostree db list --available

apt-ostree db verify

Verifies database integrity.

Example:

# Verify database integrity
apt-ostree db verify

# Verify specific packages
apt-ostree db verify --packages=nginx,postgresql

Package Override Commands

apt-ostree override

Manages package overrides for deployments.

Purpose:

• Override package versions
• Replace system packages
• Customize package behavior
• Manage package conflicts

Subcommands:

apt-ostree override replace

Replaces a package with a different version or source.

Example:

# Replace system package
apt-ostree override replace nginx --with=nginx-custom

# Replace with specific version
apt-ostree override replace nginx --with=nginx=1.18.0-1

# Replace from different repository
apt-ostree override replace nginx --with=nginx --repo=custom-repo

Options:

• --with: Replacement package specification
• --repo: Source repository
• --version: Specific version
• --force: Force replacement

apt-ostree override remove

Removes package overrides.

Example:

# Remove specific override
apt-ostree override remove nginx

# Remove all overrides
apt-ostree override remove --all

apt-ostree override reset

Resets package overrides to default.

Example:

# Reset specific override
apt-ostree override reset nginx

# Reset all overrides
apt-ostree override reset --all

apt-ostree override list

Lists current package overrides.

Example:

# List all overrides
apt-ostree override list

# List overrides for specific package
apt-ostree override list nginx

System Composition Commands

apt-ostree compose image

Creates system images from composed trees.

Purpose:

• Generate bootable images
• Create deployment artifacts
• Manage image variants
• Support multiple formats

Example:

# Create raw disk image
apt-ostree compose image --format=raw --output=system.img

# Create ISO image
apt-ostree compose image --format=iso --output=system.iso

# Create cloud image
apt-ostree compose image --format=qcow2 --output=system.qcow2

Options:

• --format: Output format (raw, iso, qcow2, vmdk)
• --output: Output file path
• --size: Image size specification
• --compression: Compression algorithm

apt-ostree compose treefile

Manages tree definition files.

Purpose:

• Create tree specifications
• Manage tree configurations
• Version control tree definitions
• Template management

Example:

# Create new treefile
apt-ostree compose treefile --create=my-tree.json

# Validate treefile
apt-ostree compose treefile --validate=my-tree.json

# Show treefile schema
apt-ostree compose treefile --schema

Advanced Features

Tree Composition Engine

Tree Definition Format

Tree definitions use JSON format:

{
  "arch": "x86_64",
  "repos": ["base", "updates"],
  "packages": {
    "include": ["nginx", "postgresql"],
    "exclude": ["unwanted-package"]
  },
  "customizations": {
    "files": ["/etc/nginx/nginx.conf"],
    "services": ["nginx", "postgresql"]
  },
  "output": {
    "format": "raw",
    "size": "10G"
  }
}

Composition Process

1. Tree Definition Parsing

   • Parse tree definition file
   • Validate configuration
   • Resolve dependencies

2. Package Resolution

   • Resolve package dependencies
   • Handle conflicts
   • Determine versions

3. Tree Generation

   • Create OSTree commits
   • Apply customizations
   • Generate metadata

4. Output Generation

   • Create requested format
   • Validate output
   • Generate checksums

Package Override System

Override Types

1. Version Overrides

   • Replace package versions
   • Pin specific versions
   • Handle version conflicts

2. Source Overrides

   • Change package sources
   • Use custom repositories
   • Handle source conflicts

3. Behavior Overrides

   • Modify package behavior
   • Customize configurations
   • Handle conflicts

Override Management

Storage:

• Overrides stored in OSTree metadata
• Per-deployment override tracking
• Override history and rollback

Resolution:

• Override priority system
• Conflict resolution rules
• Dependency handling

Persistence:

• Overrides persist across reboots
• Override inheritance rules
• Override cleanup and maintenance

Database Management System

Database Architecture

Components:

• Package metadata storage
• Dependency resolution engine
• Cache management system
• Integrity verification

Storage:

• SQLite database backend
• JSON metadata storage
• Binary package data
• Index and search optimization

Database Operations

Query Operations:

• Package search and filtering
• Dependency resolution
• Version comparison
• Metadata retrieval

Modification Operations:

• Package installation tracking
• Dependency updates
• Cache invalidation
• Integrity maintenance

Integration Points

OSTree Integration

Advanced commands integrate deeply with OSTree:

• Repository management - OSTree repository operations
• Commit creation - OSTree commit generation
• Deployment management - Deployment operations
• Metadata handling - OSTree metadata management

APT Integration

Leverages APT's capabilities:

• Package resolution - APT dependency resolver
• Repository management - APT source management
• Package metadata - APT package information
• Cache management - APT cache operations

System Integration

System-level integration:

• Image generation - System image creation
• Boot management - Bootloader integration
• Service management - Systemd integration
• File operations - File system operations

Security Considerations

Package Override Security

Validation:

• Package signature verification
• Source authenticity checking
• Override permission control
• Conflict resolution validation

Access Control:

• Override creation permissions
• Override modification rights
• Override removal privileges
• Override viewing access

Composition Security

Input Validation:

• Tree definition validation
• Package source verification
• Configuration sanitization
• Output validation

Execution Security:

• Isolated execution environment
• Resource limitation
• Output verification
• Audit logging

Performance Optimization

Composition Optimization

Parallel Processing:

• Concurrent package resolution
• Parallel dependency checking
• Concurrent file operations
• Parallel output generation

Caching Strategy:

• Package metadata caching
• Dependency resolution caching
• Output format caching
• Tree definition caching

Database Optimization

Query Optimization:

• Index optimization
• Query caching
• Result caching
• Connection pooling

Storage Optimization:

• Data compression
• Efficient storage formats
• Cleanup and maintenance
• Archival strategies

Error Handling

Composition Errors

Common Issues:

• Package dependency conflicts
• Repository access problems
• Disk space issues
• Configuration errors

Recovery Strategies:

• Automatic conflict resolution
• Partial composition recovery
• Error reporting and guidance
• Rollback mechanisms

Override Errors

Common Issues:

• Package conflicts
• Dependency problems
• Source availability
• Permission issues

Recovery Strategies:

• Conflict resolution
• Override removal
• Source fallback
• Permission escalation

Future Enhancements

Planned Features

1. Advanced Composition

   • Multi-architecture support
   • Custom composition plugins
   • Advanced customization options
   • Template system

2. Enhanced Overrides

   • Override inheritance
   • Override templates
   • Override validation rules
   • Override rollback

3. Database Enhancements

   • Advanced query language
   • Performance monitoring
   • Automated maintenance
   • Backup and recovery

4. Integration Improvements

   • CI/CD integration
   • Cloud platform support
   • Container integration
   • Monitoring integration

Implementation Notes

Current Status

• Basic advanced commands implemented
• Tree composition framework
• Package override system
• Database management

Next Steps

1. Advanced Features

   • Enhanced composition engine
   • Advanced override system
   • Database optimization
   • Integration improvements

2. Performance Optimization

   • Parallel processing
   • Caching strategies
   • Query optimization
   • Storage optimization

3. Testing and Validation

   • Comprehensive testing
   • Performance testing
   • Security testing
   • Integration testing