98 lines
2.2 KiB
Go
98 lines
2.2 KiB
Go
// Package checker periodically HTTP-checks services and updates status.json.
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package checker
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import (
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"log"
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"net/http"
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"path/filepath"
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"time"
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"ridgwaysystems.org/website/internal/status"
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"ridgwaysystems.org/website/internal/uptime"
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)
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// Start launches the background checker. It checks services every interval
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// and updates status.json in dataDir. Services without a CheckURL are skipped.
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func Start(dataDir string, interval time.Duration) {
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go run(dataDir, interval)
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}
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func run(dataDir string, interval time.Duration) {
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client := &http.Client{
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Timeout: 10 * time.Second,
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CheckRedirect: func(req *http.Request, via []*http.Request) error {
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if len(via) >= 3 {
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return http.ErrUseLastResponse
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}
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return nil
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},
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}
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statusPath := filepath.Join(dataDir, "status.json")
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uptimePath := filepath.Join(dataDir, "uptime.json")
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for {
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check(client, statusPath, uptimePath)
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time.Sleep(interval)
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}
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}
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func check(client *http.Client, statusPath, uptimePath string) {
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page, err := status.Load(statusPath)
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if err != nil {
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log.Printf("checker: load %s: %v", statusPath, err)
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return
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}
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changed := false
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for i, svc := range page.Services {
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if svc.CheckURL == "" {
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continue
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}
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prev := svc.Status
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newStatus := probe(client, svc.CheckURL)
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if newStatus != prev {
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log.Printf("checker: %s %s → %s", svc.Name, prev, newStatus)
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page.Services[i].Status = newStatus
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changed = true
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}
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}
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if changed {
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if err := status.Save(statusPath, page); err != nil {
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log.Printf("checker: save %s: %v", statusPath, err)
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}
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} else {
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page.LastChecked = time.Now().UTC()
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if err := status.Save(statusPath, page); err != nil {
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log.Printf("checker: save %s: %v", statusPath, err)
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}
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}
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// Record hourly uptime snapshot.
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statuses := make(map[string]string, len(page.Services))
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for _, svc := range page.Services {
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statuses[svc.Name] = svc.Status
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}
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if err := uptime.Record(uptimePath, statuses); err != nil {
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log.Printf("checker: uptime record: %v", err)
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}
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}
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func probe(client *http.Client, url string) string {
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resp, err := client.Get(url)
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if err != nil {
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return "down"
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}
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defer resp.Body.Close()
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switch {
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case resp.StatusCode < 400:
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return "up"
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case resp.StatusCode >= 500:
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return "down"
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default:
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return "degraded"
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}
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}
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