Files
dozzle-monitor-container/web/events.go
2021-10-15 11:52:41 -07:00

112 lines
2.6 KiB
Go

package web
import (
"encoding/json"
"fmt"
"net/http"
"github.com/amir20/dozzle/docker"
log "github.com/sirupsen/logrus"
)
func (h *handler) streamEvents(w http.ResponseWriter, r *http.Request) {
f, ok := w.(http.Flusher)
if !ok {
http.Error(w, "Streaming unsupported!", http.StatusInternalServerError)
return
}
w.Header().Set("Content-Type", "text/event-stream")
w.Header().Set("Cache-Control", "no-transform")
w.Header().Add("Cache-Control", "no-cache")
w.Header().Set("Connection", "keep-alive")
w.Header().Set("X-Accel-Buffering", "no")
ctx := r.Context()
events, err := h.client.Events(ctx)
stats := make(chan docker.ContainerStat)
if containers, err := h.client.ListContainers(); err == nil {
for _, c := range containers {
if c.State == "running" {
if err := h.client.ContainerStats(ctx, c.ID, stats); err != nil {
log.Errorf("error while streaming container stats: %v", err)
}
}
}
}
if err := sendContainersJSON(h.client, w); err != nil {
log.Errorf("error while encoding containers to stream: %v", err)
}
f.Flush()
for {
select {
case stat := <-stats:
bytes, _ := json.Marshal(stat)
if _, err := fmt.Fprintf(w, "event: container-stat\ndata: %s\n\n", string(bytes)); err != nil {
log.Errorf("error writing stat to event stream: %v", err)
return
}
f.Flush()
case event, ok := <-events:
if !ok {
return
}
switch event.Name {
case "start", "die":
log.Debugf("triggering docker event: %v", event.Name)
if event.Name == "start" {
log.Debugf("found new container with id: %v", event.ActorID)
if err := h.client.ContainerStats(ctx, event.ActorID, stats); err != nil {
log.Errorf("error when streaming new container stats: %v", err)
}
if err := sendContainersJSON(h.client, w); err != nil {
log.Errorf("error encoding containers to stream: %v", err)
return
}
}
bytes, _ := json.Marshal(event)
if _, err := fmt.Fprintf(w, "event: container-%s\ndata: %s\n\n", event.Name, string(bytes)); err != nil {
log.Errorf("error writing event to event stream: %v", err)
return
}
f.Flush()
default:
// do nothing
}
case <-ctx.Done():
return
case <-err:
return
}
}
}
func sendContainersJSON(client docker.Client, w http.ResponseWriter) error {
containers, err := client.ListContainers()
if err != nil {
return err
}
if _, err := fmt.Fprint(w, "event: containers-changed\ndata: "); err != nil {
return err
}
if err := json.NewEncoder(w).Encode(containers); err != nil {
return err
}
if _, err := fmt.Fprint(w, "\n\n"); err != nil {
return err
}
return nil
}