feat: add vanilla Prometheus + prw2gcm e2e tests

.github/workflows/presubmit.yml

@@ -77,3 +77,8 @@ jobs:
         GCM_SECRET: ${{ secrets.GCM_SECRET }}
         GMP_PROMETHEUS_IMAGE: "gmp-prometheus:amd64"
       run: make -C ./google/internal/promqle2etest test
+    - name: Run prw2gcm GCM tests
+      env:
+        GCM_SECRET: ${{ secrets.GCM_SECRET }}
+        GMP_PROMETHEUS_IMAGE: "gmp-prometheus:amd64"
+      run: make -C ./google/cmd/prw2gcm test

Dockerfile.google

@@ -81,6 +81,11 @@ RUN CGO_ENABLED=0 go build \
     -ldflags="-X github.com/prometheus/common/version.Version=$(cat VERSION) \
     -X github.com/prometheus/common/version.BuildDate=$(date --iso-8601=seconds)" \
     ./cmd/promtool
+RUN CGO_ENABLED=0 go build \
+    -mod=vendor \
+    -ldflags="-X github.com/prometheus/common/version.Version=$(cat VERSION) \
+    -X github.com/prometheus/common/version.BuildDate=$(date --iso-8601=seconds)" \
+    ./google/cmd/prw2gcm
 
 # Configure distroless base image like the upstream Prometheus image.
 # Since the directory and symlink setup needs shell access, we need yet another
@@ -97,6 +102,7 @@ FROM ${IMAGE_BASE} AS app
 
 COPY --from=buildbase /workspace/prometheus /bin/prometheus
 COPY --from=buildbase /workspace/promtool /bin/promtool
+COPY --from=buildbase /workspace/prw2gcm /bin/prw2gcm
 COPY --from=appbase --chown=nobody:nobody /etc/prometheus /etc/prometheus
 COPY --from=appbase --chown=nobody:nobody /prometheus /prometheus
 COPY --from=appbase /usr/share/prometheus /usr/share/prometheus

go.mod

@@ -5,6 +5,7 @@ go 1.24.0
 toolchain go1.24.4
 
 require (
+	cloud.google.com/go/auth v0.16.0
 	cloud.google.com/go/compute/metadata v0.6.0
 	cloud.google.com/go/monitoring v1.24.2
 	github.com/Azure/azure-sdk-for-go/sdk/azcore v1.18.0
@@ -33,6 +34,7 @@ require (
 	github.com/go-openapi/strfmt v0.23.0
 	github.com/go-zookeeper/zk v1.0.3
 	github.com/gogo/protobuf v1.3.2
+	github.com/golang/protobuf v1.5.4
 	github.com/golang/snappy v0.0.4
 	github.com/google/go-cmp v0.7.0
 	github.com/google/pprof v0.0.0-20241029153458-d1b30febd7db
@@ -58,10 +60,12 @@ require (
 	github.com/oklog/run v1.1.0
 	github.com/oklog/ulid v1.3.1
 	github.com/ovh/go-ovh v1.5.1
+	github.com/planetscale/vtprotobuf v0.6.1-0.20240319094008-0393e58bdf10
 	github.com/prometheus/alertmanager v0.27.0
-	github.com/prometheus/client_golang v1.21.1
-	github.com/prometheus/client_model v0.6.1
-	github.com/prometheus/common v0.63.0
+	github.com/prometheus/client_golang v1.23.0
+	github.com/prometheus/client_golang/exp v0.0.0-20250820144310-1f3a9042681e
+	github.com/prometheus/client_model v0.6.2
+	github.com/prometheus/common v0.65.0
 	github.com/prometheus/common/assets v0.2.0
 	github.com/prometheus/common/sigv4 v0.1.0
 	github.com/prometheus/compliance/promqle2e v0.0.0-20250417063348-1215c9d17a1a
@@ -104,7 +108,6 @@ require (
 )
 
 require (
-	cloud.google.com/go/auth v0.16.0 // indirect
 	cloud.google.com/go/auth/oauth2adapt v0.2.8 // indirect
 	github.com/Azure/azure-sdk-for-go/sdk/internal v1.11.1 // indirect
 	github.com/AzureAD/microsoft-authentication-library-for-go v1.4.2 // indirect
@@ -143,7 +146,6 @@ require (
 	github.com/godbus/dbus/v5 v5.0.4 // indirect
 	github.com/golang-jwt/jwt/v5 v5.2.2 // indirect
 	github.com/golang/glog v1.2.4 // indirect
-	github.com/golang/protobuf v1.5.4 // indirect
 	github.com/google/gnostic-models v0.6.9 // indirect
 	github.com/google/go-querystring v1.1.0 // indirect
 	github.com/google/gofuzz v1.2.0 // indirect
@@ -183,9 +185,8 @@ require (
 	github.com/pbnjay/memory v0.0.0-20210728143218-7b4eea64cf58 // indirect
 	github.com/pkg/browser v0.0.0-20240102092130-5ac0b6a4141c // indirect
 	github.com/pkg/errors v0.9.1 // indirect
-	github.com/planetscale/vtprotobuf v0.6.1-0.20240319094008-0393e58bdf10 // indirect
 	github.com/pmezard/go-difflib v1.0.1-0.20181226105442-5d4384ee4fb2 // indirect
-	github.com/prometheus/procfs v0.15.1 // indirect
+	github.com/prometheus/procfs v0.16.1 // indirect
 	github.com/sirupsen/logrus v1.9.3 // indirect
 	github.com/spf13/pflag v1.0.5 // indirect
 	github.com/stretchr/objx v0.5.2 // indirect

go.sum

@@ -555,15 +555,18 @@ github.com/prometheus/client_golang v1.3.0/go.mod h1:hJaj2vgQTGQmVCsAACORcieXFeD
 github.com/prometheus/client_golang v1.4.0/go.mod h1:e9GMxYsXl05ICDXkRhurwBS4Q3OK1iX/F2sw+iXX5zU=
 github.com/prometheus/client_golang v1.11.0/go.mod h1:Z6t4BnS23TR94PD6BsDNk8yVqroYurpAkEiz0P2BEV0=
 github.com/prometheus/client_golang v1.20.4/go.mod h1:PIEt8X02hGcP8JWbeHyeZ53Y/jReSnHgO035n//V5WE=
-github.com/prometheus/client_golang v1.21.1 h1:DOvXXTqVzvkIewV/CDPFdejpMCGeMcbGCQ8YOmu+Ibk=
-github.com/prometheus/client_golang v1.21.1/go.mod h1:U9NM32ykUErtVBxdvD3zfi+EuFkkaBvMb09mIfe0Zgg=
+github.com/prometheus/client_golang v1.23.0 h1:ust4zpdl9r4trLY/gSjlm07PuiBq2ynaXXlptpfy8Uc=
+github.com/prometheus/client_golang v1.23.0/go.mod h1:i/o0R9ByOnHX0McrTMTyhYvKE4haaf2mW08I+jGAjEE=
+github.com/prometheus/client_golang/exp v0.0.0-20250820144310-1f3a9042681e h1:RIcfJKXvsP1EFz4EOA/Xq2Z8Bi+b0SSyA8gsHkOYoDA=
+github.com/prometheus/client_golang/exp v0.0.0-20250820144310-1f3a9042681e/go.mod h1:FGJuwvfcPY0V5enm+w8zF1RNS062yugQtPPQp1c4Io4=
 github.com/prometheus/client_model v0.0.0-20190115171406-56726106282f/go.mod h1:MbSGuTsp3dbXC40dX6PRTWyKYBIrTGTE9sqQNg2J8bo=
 github.com/prometheus/client_model v0.0.0-20190129233127-fd36f4220a90/go.mod h1:xMI15A0UPsDsEKsMN9yxemIoYk6Tm2C1GtYGdfGttqA=
 github.com/prometheus/client_model v0.0.0-20190812154241-14fe0d1b01d4/go.mod h1:xMI15A0UPsDsEKsMN9yxemIoYk6Tm2C1GtYGdfGttqA=
 github.com/prometheus/client_model v0.1.0/go.mod h1:xMI15A0UPsDsEKsMN9yxemIoYk6Tm2C1GtYGdfGttqA=
 github.com/prometheus/client_model v0.2.0/go.mod h1:xMI15A0UPsDsEKsMN9yxemIoYk6Tm2C1GtYGdfGttqA=
-github.com/prometheus/client_model v0.6.1 h1:ZKSh/rekM+n3CeS952MLRAdFwIKqeY8b62p8ais2e9E=
 github.com/prometheus/client_model v0.6.1/go.mod h1:OrxVMOVHjw3lKMa8+x6HeMGkHMQyHDk9E3jmP2AmGiY=
+github.com/prometheus/client_model v0.6.2 h1:oBsgwpGs7iVziMvrGhE53c/GrLUsZdHnqNwqPLxwZyk=
+github.com/prometheus/client_model v0.6.2/go.mod h1:y3m2F6Gdpfy6Ut/GBsUqTWZqCUvMVzSfMLjcu6wAwpE=
 github.com/prometheus/common v0.61.0 h1:3gv/GThfX0cV2lpO7gkTUwZru38mxevy90Bj8YFSRQQ=
 github.com/prometheus/common v0.61.0/go.mod h1:zr29OCN/2BsJRaFwG8QOBr41D6kkchKbpeNH7pAjb/s=
 github.com/prometheus/common/assets v0.2.0 h1:0P5OrzoHrYBOSM1OigWL3mY8ZvV2N4zIE/5AahrSrfM=
@@ -578,8 +581,9 @@ github.com/prometheus/procfs v0.0.0-20190117184657-bf6a532e95b1/go.mod h1:c3At6R
 github.com/prometheus/procfs v0.0.2/go.mod h1:TjEm7ze935MbeOT/UhFTIMYKhuLP4wbCsTZCD3I8kEA=
 github.com/prometheus/procfs v0.0.8/go.mod h1:7Qr8sr6344vo1JqZ6HhLceV9o3AJ1Ff+GxbHq6oeK9A=
 github.com/prometheus/procfs v0.6.0/go.mod h1:cz+aTbrPOrUb4q7XlbU9ygM+/jj0fzG6c1xBZuNvfVA=
-github.com/prometheus/procfs v0.15.1 h1:YagwOFzUgYfKKHX6Dr+sHT7km/hxC76UB0learggepc=
 github.com/prometheus/procfs v0.15.1/go.mod h1:fB45yRUv8NstnjriLhBQLuOUt+WW4BsoGhij/e3PBqk=
+github.com/prometheus/procfs v0.16.1 h1:hZ15bTNuirocR6u0JZ6BAHHmwS1p8B4P6MRqxtzMyRg=
+github.com/prometheus/procfs v0.16.1/go.mod h1:teAbpZRB1iIAJYREa1LsoWUXykVXA1KlTmWl8x/U+Is=
 github.com/rcrowley/go-metrics v0.0.0-20181016184325-3113b8401b8a/go.mod h1:bCqnVzQkZxMG4s8nGwiZ5l3QUCyqpo9Y+/ZMZ9VjZe4=
 github.com/redis/go-redis/v9 v9.8.0 h1:q3nRvjrlge/6UD7eTu/DSg2uYiU2mCL0G/uzBWqhicI=
 github.com/redis/go-redis/v9 v9.8.0/go.mod h1:huWgSWd8mW6+m0VPhJjSSQ+d6Nh1VICQ6Q5lHuCH/Iw=

google/cmd/prw2gcm/Makefile

@@ -0,0 +1,35 @@
+# Copyright 2025 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     https:#www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+.PHONY: proto
+proto: ## Regenerate Go from proto
+proto: $(BUF)
+	@echo ">> regenerating Prometheus proto"
+	@$(BUF) generate
+	@# For some reasons buf generates this unused import, kill it manually for now and reformat.
+	@find io/prometheus/write/v2/ -type f -exec sed -i '' 's/_ "github.com\/gogo\/protobuf\/gogoproto"#g' {} \;
+	@go fmt ./io/prometheus/write/v2/...
+
+BUF = buf
+$(BUF):
+	@go install github.com/bufbuild/buf/cmd/buf@v1.39.0
+
+GCM_SECRET?=
+.PHONY: test
+test:  ## Run special proxy unit tests that will use GCM if GCM_SECRET is present.
+ifneq ($(GCM_SECRET),)
+	go test -tags gcme2e -v ./...
+else
+	@echo "Secret not provided, skipping!"
+endif

google/cmd/prw2gcm/buf.gen.yaml

@@ -0,0 +1,21 @@
+# buf.gen.yaml
+version: v2
+
+plugins:
+- remote: buf.build/protocolbuffers/go:v1.31.0
+  out: .
+  opt:
+  - Mio/prometheus/write/v2/types.proto=io/prometheus/write/v2
+
+# vtproto for efficiency utilities like pooling etc.
+# https://buf.build/community/planetscale-vtprotobuf?version=v0.6.0
+- remote: buf.build/community/planetscale-vtprotobuf:v0.6.0
+  out: .
+  opt:
+  - Mio/prometheus/write/v2/types.proto=io/prometheus/write/v2
+  - features=marshal+unmarshal+size+clone
+
+inputs:
+- module: buf.build/prometheus/prometheus:7dec989b8d3a49e6bbe6d7221400e8f8 # (bwplotka-experiment1 label).
+  types:
+  - "io.prometheus.write.v2.Request"