Files
netwatch/backend/internal/handlers/report.go
T
sneak a2dd439812
check / check (push) Successful in 1m28s
Delete the oldest report files to stay under the size cap (closes #54)
When a report would take the report files past DATA_DIR_MAX_BYTES,
reportbuf now deletes the oldest report files until it fits, and does
the same at start when files left by an earlier run are already past
it. A file joins the files that may be deleted only once it is
completely written, so a file still being written is never deleted. A
report is refused with 507 only when the reports waiting to be written
fill the cap on their own, and then no file is deleted. The reports of
a failed write stop counting, and the part of its file written is
removed. A file whose deletion fails keeps counting; one already
deleted by hand counts as freed.

Model: opus-5-5
2026-10-03 14:12:07 +00:00

122 lines
3.0 KiB
Go

package handlers
import (
"encoding/json"
"errors"
"net/http"
"sneak.berlin/go/netwatch/internal/logger"
"sneak.berlin/go/netwatch/internal/reportbuf"
)
type reportSample struct {
T int64 `json:"t"`
Latency *int `json:"latency"`
Error *string `json:"error"`
}
type reportHost struct {
History []reportSample `json:"history"`
Name string `json:"name"`
Status string `json:"status"`
URL string `json:"url"`
}
type report struct {
ClientID string `json:"clientId"`
Geo json.RawMessage `json:"geo"`
Hosts []reportHost `json:"hosts"`
Timestamp string `json:"timestamp"`
}
// HandleReport returns a handler that accepts telemetry
// reports from NetWatch clients.
func (s *Handlers) HandleReport() http.HandlerFunc {
type response struct {
Status string `json:"status"`
}
return func(w http.ResponseWriter, r *http.Request) {
var rpt report
err := s.decodeJSON(w, r, &rpt)
if err != nil {
s.respondJSON(w, r,
&response{Status: "error"},
s.decodeErrorStatus(err),
)
return
}
s.logReportReceived(rpt)
err = s.buf.Append(rpt)
if err != nil {
s.respondJSON(w, r,
&response{Status: "error"},
s.appendErrorStatus(err),
)
return
}
s.respondJSON(w, r, &response{Status: "ok"}, http.StatusOK)
}
}
// decodeErrorStatus logs a report decode failure and returns the
// status to send: 413 when the body exceeded the size limit,
// otherwise 400 for malformed JSON.
func (s *Handlers) decodeErrorStatus(err error) int {
var tooLarge *http.MaxBytesError
if errors.As(err, &tooLarge) {
s.log.Warn("report body too large", "limit_bytes", tooLarge.Limit)
return http.StatusRequestEntityTooLarge
}
// The decoder's error text can quote request bytes (a whole
// oversized number, for example), so it is bounded too.
s.log.Error("failed to decode report",
"error", logger.BoundedForLog(err.Error()),
)
return http.StatusBadRequest
}
// appendErrorStatus logs a failure to store a report and returns
// the status to send: 507 when the reports waiting to be written fill
// the size cap, otherwise 500.
func (s *Handlers) appendErrorStatus(err error) int {
if errors.Is(err, reportbuf.ErrFull) {
s.log.Warn("report refused: " +
"reports waiting to be written fill the size cap")
return http.StatusInsufficientStorage
}
s.log.Error("failed to buffer report", "error", err)
return http.StatusInternalServerError
}
// logReportReceived logs an accepted report. Untrusted fields are
// bounded (client_id, timestamp) or reduced to a length
// (geo_bytes) so the raw attacker-controlled body never reaches
// the log.
func (s *Handlers) logReportReceived(rpt report) {
totalSamples := 0
for _, h := range rpt.Hosts {
totalSamples += len(h.History)
}
s.log.Info("report received",
"client_id", logger.BoundedForLog(rpt.ClientID),
"timestamp", logger.BoundedForLog(rpt.Timestamp),
"host_count", len(rpt.Hosts),
"total_samples", totalSamples,
"geo_bytes", len(rpt.Geo),
)
}