drone/internal/api/handler/logs/tail.go
2023-09-08 14:51:29 +01:00

127 lines
2.9 KiB
Go

// Copyright 2022 Harness Inc. All rights reserved.
// Use of this source code is governed by the Polyform Free Trial License
// that can be found in the LICENSE.md file for this repository.
package logs
import (
"context"
"encoding/json"
"io"
"net/http"
"time"
"github.com/harness/gitness/internal/api/controller/logs"
"github.com/harness/gitness/internal/api/render"
"github.com/harness/gitness/internal/api/request"
"github.com/rs/zerolog/log"
)
var (
pingInterval = 30 * time.Second
tailMaxTime = 1 * time.Hour
)
func HandleTail(logCtrl *logs.Controller) http.HandlerFunc {
return func(w http.ResponseWriter, r *http.Request) {
ctx := r.Context()
session, _ := request.AuthSessionFrom(ctx)
pipelineUID, err := request.GetPipelineUIDFromPath(r)
if err != nil {
render.TranslatedUserError(w, err)
return
}
executionNum, err := request.GetExecutionNumberFromPath(r)
if err != nil {
render.TranslatedUserError(w, err)
return
}
stageNum, err := request.GetStageNumberFromPath(r)
if err != nil {
render.TranslatedUserError(w, err)
return
}
stepNum, err := request.GetStepNumberFromPath(r)
if err != nil {
render.TranslatedUserError(w, err)
return
}
repoRef, err := request.GetRepoRefFromPath(r)
if err != nil {
render.TranslatedUserError(w, err)
return
}
f, ok := w.(http.Flusher)
if !ok {
log.Error().Msg("http writer type assertion failed")
render.InternalError(w)
return
}
h := w.Header()
h.Set("Content-Type", "text/event-stream")
h.Set("Cache-Control", "no-cache")
h.Set("Connection", "keep-alive")
h.Set("X-Accel-Buffering", "no")
h.Set("Access-Control-Allow-Origin", "*")
io.WriteString(w, ": ping\n\n")
f.Flush()
linec, errc, err := logCtrl.Tail(
ctx, session, repoRef, pipelineUID,
executionNum, int(stageNum), int(stepNum))
if err != nil {
render.TranslatedUserError(w, err)
return
}
// could not get error channel
if errc == nil {
io.WriteString(w, "event: error\ndata: eof\n\n")
return
}
ctx, cancel := context.WithTimeout(r.Context(), tailMaxTime)
defer cancel()
enc := json.NewEncoder(w)
pingTimer := time.NewTimer(pingInterval)
defer pingTimer.Stop()
L:
for {
// ensure timer is stopped before resetting (see documentation)
if !pingTimer.Stop() {
// in this specific case the timer's channel could be both, empty or full
select {
case <-pingTimer.C:
default:
}
}
pingTimer.Reset(pingInterval)
select {
case <-ctx.Done():
break L
case err := <-errc:
log.Err(err).Msg("received error in the tail channel")
break L
case <-pingTimer.C:
// if time b/w messages takes longer, send a ping
io.WriteString(w, ": ping\n\n")
f.Flush()
case line := <-linec:
io.WriteString(w, "data: ")
enc.Encode(line)
io.WriteString(w, "\n\n")
f.Flush()
}
}
io.WriteString(w, "event: error\ndata: eof\n\n")
f.Flush()
}
}