Comprehensive documentation overhaul for Charon features: Rewrite features.md as marketing overview (87% reduction) Create comprehensive dns-challenge.md for new DNS feature Expand 18 feature stub pages into complete documentation: SSL certificates, CrowdSec, WAF, ACLs, rate limiting Security headers, proxy headers, web UI, Docker integration Caddyfile import, logs, WebSocket, backup/restore Live reload, localization, API, UI themes, supply chain security Update README.md with DNS Challenge in Top Features Total: ~2,000+ lines of new user-facing documentation Refs: #21, #461
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title, description
| title | description |
|---|---|
| Zero-Downtime Updates | Make changes without interrupting your users |
Zero-Downtime Updates
Make changes without interrupting your users. Update domains, modify security rules, or add new services instantly. Your sites stay up while you work—no container restarts needed.
Overview
Charon leverages Caddy's live reload capability to apply configuration changes without dropping connections. When you save changes in the UI, Caddy gracefully transitions to the new configuration while maintaining all active connections.
This means your users experience zero interruption—even during significant configuration changes.
Why Use This
- No Downtime: Active connections remain unaffected
- Instant Changes: New configuration takes effect immediately
- Safe Iteration: Make frequent adjustments without risk
- Production Friendly: Update live systems confidently
How It Works
When you save configuration changes:
- Charon generates updated Caddy configuration
- Caddy validates the new configuration
- If valid, Caddy atomically swaps to the new config
- Existing connections continue on old config until complete
- New connections use the updated configuration
The entire process typically completes in milliseconds.
What Can Be Changed Live
These changes apply instantly without any restart:
| Change Type | Live Reload |
|---|---|
| Add/remove proxy hosts | ✅ Yes |
| Modify upstream servers | ✅ Yes |
| Update SSL certificates | ✅ Yes |
| Change access lists | ✅ Yes |
| Modify headers | ✅ Yes |
| Update redirects | ✅ Yes |
| Add/remove domains | ✅ Yes |
CrowdSec Integration Note
Important
: CrowdSec integration requires a one-time container restart when first enabled or when changing the CrowdSec API endpoint.
After the initial setup, CrowdSec decisions update automatically without restart. Only the connection to the CrowdSec API requires the restart.
To minimize disruption:
- Configure CrowdSec during a maintenance window
- After restart, all future updates are live
Validation and Rollback
Charon validates all configuration changes before applying:
- Syntax Validation: Catches configuration errors
- Connection Testing: Verifies upstream availability
- Automatic Rollback: Invalid configs are rejected
If validation fails, your current configuration remains active and an error message explains the issue.
Monitoring Changes
View configuration change history:
- Check the Real-Time Logs for reload events
- Review Settings → Backup for configuration snapshots