From fddf50ce71b92482fb853c6938dc8ebfebded689 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?J=C3=B6rn=20Friedrich=20Dreyer?= <jfd@butonic.de>
Date: Thu, 24 Oct 2024 15:13:45 +0200
Subject: [PATCH] make sse keepalive interval configurable
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Signed-off-by: Jörn Friedrich Dreyer <jfd@butonic.de>
---
 changelog/unreleased/sse-keepalive.md |  5 +++++
 services/sse/pkg/config/config.go     |  4 +++-
 services/sse/pkg/service/service.go   | 13 +++++++++++++
 3 files changed, 21 insertions(+), 1 deletion(-)
 create mode 100644 changelog/unreleased/sse-keepalive.md

diff --git a/changelog/unreleased/sse-keepalive.md b/changelog/unreleased/sse-keepalive.md
new file mode 100644
index 0000000000..8b61ffba7d
--- /dev/null
+++ b/changelog/unreleased/sse-keepalive.md
@@ -0,0 +1,5 @@
+Bugfix: make SSE keepalive interval configurable
+
+To prevent intermediate proxies from closing the SSE connection admins can now configure a `SSE_KEEPALIVE_INTERVAL`.
+
+https://github.com/owncloud/ocis/pull/10411
diff --git a/services/sse/pkg/config/config.go b/services/sse/pkg/config/config.go
index fef62abc11..81a56d1e1c 100644
--- a/services/sse/pkg/config/config.go
+++ b/services/sse/pkg/config/config.go
@@ -2,6 +2,7 @@ package config
 
 import (
 	"context"
+	"time"
 
 	"github.com/owncloud/ocis/v2/ocis-pkg/shared"
 )
@@ -14,7 +15,8 @@ type Config struct {
 	Debug   Debug    `mask:"struct" yaml:"debug"`
 	Tracing *Tracing `yaml:"tracing"`
 
-	Service Service `yaml:"-"`
+	Service           Service       `yaml:"-"`
+	KeepAliveInterval time.Duration `yaml:"keepalive_interval" env:"SSE_KEEPALIVE_INTERVAL" desc:"To prevent intermediate proxies from closing the SSE connection send periodic SSE comments." introductionVersion:"6.7"`
 
 	Events       Events
 	HTTP         HTTP          `yaml:"http"`
diff --git a/services/sse/pkg/service/service.go b/services/sse/pkg/service/service.go
index aac0cdd426..df94316acb 100644
--- a/services/sse/pkg/service/service.go
+++ b/services/sse/pkg/service/service.go
@@ -2,6 +2,7 @@ package service
 
 import (
 	"net/http"
+	"time"
 
 	"github.com/go-chi/chi/v5"
 	"github.com/r3labs/sse/v2"
@@ -81,6 +82,18 @@ func (s SSE) HandleSSE(w http.ResponseWriter, r *http.Request) {
 	stream := s.sse.CreateStream(uid)
 	stream.AutoReplay = false
 
+	if s.c.KeepAliveInterval != 0 {
+		ticker := time.NewTicker(s.c.KeepAliveInterval)
+		defer ticker.Stop()
+		go func() {
+			for range ticker.C {
+				s.sse.Publish(uid, &sse.Event{
+					Comment: []byte("keepalive"),
+				})
+			}
+		}()
+	}
+
 	// add stream to URL
 	q := r.URL.Query()
 	q.Set("stream", uid)