From 8bbe87f42d7736b3f11db0fcfb4557b214e0356d Mon Sep 17 00:00:00 2001 From: Christian Svensson Date: Tue, 23 Jun 2020 19:06:01 +0200 Subject: [PATCH] Set Content-Length for Metrics requests (#7730) HTTP requires the response to contain a Content-Length header unless chunked encoding is being used. Prometheus metrics endpoint did not set this, causing software such as prometheus-proxy to not be able to scrape synapse for metrics. Signed-off-by: Christian Svensson --- changelog.d/7730.bugfix | 1 + synapse/metrics/_exposition.py | 5 ++++- 2 files changed, 5 insertions(+), 1 deletion(-) create mode 100644 changelog.d/7730.bugfix diff --git a/changelog.d/7730.bugfix b/changelog.d/7730.bugfix new file mode 100644 index 000000000..9da254b56 --- /dev/null +++ b/changelog.d/7730.bugfix @@ -0,0 +1 @@ +Fix missing `Content-Length` on HTTP responses from the metrics handler. diff --git a/synapse/metrics/_exposition.py b/synapse/metrics/_exposition.py index ab7f948ed..4304c60d5 100644 --- a/synapse/metrics/_exposition.py +++ b/synapse/metrics/_exposition.py @@ -208,6 +208,7 @@ class MetricsHandler(BaseHTTPRequestHandler): raise self.send_response(200) self.send_header("Content-Type", CONTENT_TYPE_LATEST) + self.send_header("Content-Length", str(len(output))) self.end_headers() self.wfile.write(output) @@ -261,4 +262,6 @@ class MetricsResource(Resource): def render_GET(self, request): request.setHeader(b"Content-Type", CONTENT_TYPE_LATEST.encode("ascii")) - return generate_latest(self.registry) + response = generate_latest(self.registry) + request.setHeader(b"Content-Length", str(len(response))) + return response