torjus/nixos-exporter
Archived
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

feat: add NATS cache sharing and smart cache refresh

Browse Source 
Add two complementary features to reduce remote revision cache staleness:

1. Smart local cache: When current system revision matches cached remote
   revision, force an immediate cache refresh to check for newer revisions.

2. NATS integration: Share cache updates across hosts via NATS pub/sub.
   Hosts publish revision updates when they fetch new data, and subscribe
   to receive updates from other hosts. Features include:
   - Auto-reconnect with infinite retries
   - Graceful fallback when NATS unavailable
   - Filtering by flake URL and hostname

New CLI flags:
  --flake.nats.enable
  --flake.nats.url
  --flake.nats.subject
  --flake.nats.credentials-file

New NixOS module options under services.prometheus.exporters.nixos.flake.nats

Bumps version to 0.3.0.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
This commit is contained in:
Torjus Håkestad
2026-02-08 23:05:52 +01:00
parent cf0ce85899
commit 5cc0e7eadd
7 changed files with 315 additions and 18 deletions
Download Patch File Download Diff File Expand all files Collapse all files

16
config/config.go
View File

@@ -11,6 +11,12 @@ type Config struct {
FlakeCollector bool
FlakeURL string
FlakeCheckInterval time.Duration
// NATS configuration
FlakeNATSEnable bool
FlakeNATSURL string
FlakeNATSSubject string
FlakeNATSCredentialsFile string
}
func Parse() (*Config, error) {
@@ -21,11 +27,21 @@ func Parse() (*Config, error) {
flag.StringVar(&cfg.FlakeURL, "flake.url", "", "Flake URL for revision comparison (required if flake collector enabled)")
flag.DurationVar(&cfg.FlakeCheckInterval, "flake.check-interval", time.Hour, "Interval between remote flake checks")
// NATS flags
flag.BoolVar(&cfg.FlakeNATSEnable, "flake.nats.enable", false, "Enable NATS cache sharing")
flag.StringVar(&cfg.FlakeNATSURL, "flake.nats.url", "nats://localhost:4222", "NATS server URL")
flag.StringVar(&cfg.FlakeNATSSubject, "flake.nats.subject", "nixos-exporter.remote-rev", "NATS subject for revision updates")
flag.StringVar(&cfg.FlakeNATSCredentialsFile, "flake.nats.credentials-file", "", "NATS credentials file (optional)")
flag.Parse()
if cfg.FlakeCollector && cfg.FlakeURL == "" {
return nil, fmt.Errorf("--flake.url is required when --collector.flake is enabled")
}
if cfg.FlakeNATSEnable && !cfg.FlakeCollector {
return nil, fmt.Errorf("--flake.nats.enable requires --collector.flake to be enabled")
}
return cfg, nil
}