Mostly copied from here (gist).
- Added a timer to keepalive the connection. If you put
sseseverbehindnginxwithout sending heartbeat, it will close the connection after a period. To keep the connection alive, added a timer to periodically sent heartbeat. - Port number as argument.
- Removed
w.Header().Set("Access-Control-Allow-Origin", "*"). Idea is to put it behind a proxy like nginx.
go build -o sseserver main.go
# on first terminal
% go run main.go 8080
# on second terminal
% curl -v localhost:8080/messages -d '{"title": "1", "text": "2"}'
# on third terminal
% curl -Nv localhost:8080/stream
* Trying 127.0.0.1:8080...
* Connected to localhost (127.0.0.1) port 8080
> GET /stream HTTP/1.1
> Host: localhost
> User-Agent: curl/8.4.0
> Accept: */*
>
< HTTP/1.1 200 OK
< Cache-Control: no-cache
< Connection: keep-alive
< Content-Type: text/event-stream
< X-Accel-Buffering: no
< Date: Wed, 12 Jun 2024 21:07:22 GMT
< Transfer-Encoding: chunked
<
data: {"title":"1","text":"2"}
data: {"text":"2024-06-13 06:56:34.791516 +1000 AEST m=+23640.003301834","title":"keepalive"}
data: {"text":"2024-06-13 06:57:34.790542 +1000 AEST m=+23700.003241793","title":"keepalive"}