Fix GCS S3 upload client timeouts

.github/workflows/fluentbit.yaml

@@ -6,10 +6,12 @@ on:
     paths:
     - .github/workflows/fluentbit.yaml
     - images/fluentbit/Dockerfile
+    - images/fluentbit/*.patch
   pull_request:
     paths:
     - .github/workflows/fluentbit.yaml
     - images/fluentbit/Dockerfile
+    - images/fluentbit/*.patch
 
 permissions:
   contents: read
@@ -48,3 +50,23 @@ jobs:
         labels: ${{ steps.meta.outputs.labels }}
         cache-from: type=gha
         cache-to: type=gha,mode=max
+
+    - uses: docker/metadata-action@v5
+      id: meta-debug
+      with:
+        images: ghcr.io/yolean/fluentbit
+        tags: |
+          type=raw,value=debug-${{ github.sha }}
+
+    - uses: docker/build-push-action@v6
+      with:
+        context: images/fluentbit
+        platforms: linux/amd64,linux/arm64
+        push: ${{ github.event_name == 'push' }}
+        tags: ${{ steps.meta-debug.outputs.tags }}
+        labels: ${{ steps.meta-debug.outputs.labels }}
+        build-args: |
+          FLB_TRACE=On
+          FLB_HTTP_CLIENT_DEBUG=On
+        cache-from: type=gha
+        cache-to: type=gha,mode=max

images/fluentbit/.dockerignore

@@ -1 +1,2 @@
 *
+!*.patch

images/fluentbit/Dockerfile

@@ -1,6 +1,8 @@
 FROM debian:trixie@sha256:2c91e484d93f0830a7e05a2b9d92a7b102be7cab562198b984a84fdbc7806d91 AS build
 
 ARG FLB_VERSION=v4.2.2
+ARG FLB_TRACE=Off
+ARG FLB_HTTP_CLIENT_DEBUG=Off
 
 RUN set -ex; \
   export DEBIAN_FRONTEND=noninteractive; \
@@ -39,10 +41,15 @@ RUN set -ex; \
 
 RUN git clone --depth 1 --branch $FLB_VERSION https://github.com/fluent/fluent-bit.git /src/fluent-bit
 
+COPY *.patch /src/
+RUN cd /src/fluent-bit && git apply /src/*.patch
+
 WORKDIR /src/fluent-bit/build
 
 RUN cmake \
     -DFLB_RELEASE=On \
+    -DFLB_TRACE=${FLB_TRACE} \
+    -DFLB_HTTP_CLIENT_DEBUG=${FLB_HTTP_CLIENT_DEBUG} \
     -DFLB_JEMALLOC=On \
     -DFLB_TLS=On \
     -DFLB_SHARED_LIB=Off \
@@ -80,7 +87,7 @@ RUN set -ex; \
   done; \
   ls "$LIBDIR"
 
-FROM gcr.io/distroless/cc-debian13:nonroot@sha256:5c94e1d2e831f0fadfe4048427f6ff3a91481606da2841c5b26674220ac84d2d
+FROM gcr.io/distroless/cc-debian13:nonroot@sha256:84fcd3c223b144b0cb6edc5ecc75641819842a9679a3a58fd6294bec47532bf7
 
 COPY --from=build /fluent-bit/bin/fluent-bit /usr/local/bin/
 COPY --from=build /fluent-bit/etc/ /fluent-bit/etc/

images/fluentbit/fix-gcs-header-lookup.patch

@@ -0,0 +1,22 @@
+diff --git a/src/flb_http_client.c b/src/flb_http_client.c
+--- a/src/flb_http_client.c
++++ b/src/flb_http_client.c
+@@ -477,8 +477,16 @@ static int header_lookup(struct flb_http_client *c,
+         return FLB_HTTP_MORE;
+     }
+
+-    /* Lookup the beginning of the header */
+-    p = strcasestr(c->resp.data, header);
++    /* Lookup the beginning of the header, ensuring it starts a line.
++     * GCS returns x-goog-stored-content-length before Content-Length;
++     * strcasestr matches "Content-Length" inside the longer header name. */
++    p = c->resp.data;
++    while ((p = strcasestr(p, header)) != NULL) {
++        if (p == c->resp.data || *(p - 1) == '\n') {
++            break;
++        }
++        p++;
++    }
+     end = strstr(c->resp.data, "\r\n\r\n");
+     if (!p) {
+         if (end) {