fix(deploy): unblock fake-exporter rebuild — proto bindings + sketchlib-go rename adaptation

PROGRESS.md

@@ -424,6 +424,25 @@ deploy/scripts/run_e2e_sweep.sh --out-dir /tmp/sweep-$(date +%s) --soak-secs 120
    commits and have been intentionally excluded from PRs since
    #204. Decision still pending — either commit a clean bump as
    its own PR or revert.
+9. ~~**`asap/fake-exporter:dev` rebuild broken from upstream drift.**~~
+   **Done (2026-05-05).** The patched OTLP proto bindings (mpb.DDSketch /
+   KLLSketch / CountSketch / CountMinSketch / HLLSketch) were never
+   committed under `opentelemetry-proto-patch/gen/go/...`, so any rebuild
+   hit `undefined: mpb.*` symbols. Separately, the patch dir's transform
+   files referenced `metricdata.*EncodingGob` enum names that the metric-
+   data package had renamed to `*EncodingProto` / `*EncodingDelta`. Fixed:
+   (a) regenerated the Go bindings via the upstream Makefile recipe and
+   committed them under `opentelemetry-proto-patch/gen/go/`; (b) added a
+   `go.opentelemetry.io/proto/otlp` replace to `deploy/fake-exporter/go.mod`
+   pointing at the patch's gen tree; (c) updated the http+grpc transform
+   files to use the post-rename `*EncodingProto` / `*EncodingDelta`
+   metricdata enums and `*_ENCODING_PROTO` / `*_ENCODING_DELTA` mpb enums;
+   (d) updated `Dockerfile.fake-exporter` to copy `opentelemetry-proto/`
+   into the build context. Regen recipe lives at
+   `opentelemetry-proto-patch/REGEN.md`. The companion sketchlib-go PR #53
+   rename refactor (Add/Insert/InsertValue/EstimateCardinality/
+   GetValueAtQuantile → Update/UpdateValue/Estimate/Quantile) was already
+   absorbed into the patch dir before this round; the build verifies it.
 
 ---
 

deploy/docker/Dockerfile.fake-exporter

@@ -6,13 +6,19 @@
 # aggregators — see docs/sdk-cost-evaluation.md) and
 # the sketchlib-go sibling repo.
 #
-# ## Prereq: combine the patch onto the upstream tree
+# ## Prereq: combine the patches onto the upstream trees
 #
 #   ./restore_opentelemetry_go_patches.sh
+#   ./restore_otel_proto_patches.sh
 #
-# That walks the `opentelemetry-go-patch/` directory and copies its
-# contents on top of `opentelemetry-go/`. The combined tree is what
-# the go.mod replaces point at.
+# Those walk the `opentelemetry-go-patch/` and `opentelemetry-proto-patch/`
+# directories and copy their contents on top of `opentelemetry-go/` and
+# `opentelemetry-proto/` respectively. The combined trees are what the
+# `go.mod` replaces point at. The proto-patch carries the patched `.proto`
+# sources AND the regenerated `gen/go/...` Go bindings (mpb.DDSketch,
+# mpb.KLLSketch, mpb.CountSketch, mpb.CountMinSketch, mpb.HLLSketch types
+# + the `MetricsService` gRPC client). See
+# `opentelemetry-proto-patch/REGEN.md` for the regeneration recipe.
 #
 # ## Build
 #
@@ -31,9 +37,14 @@
 FROM golang:1.25-bookworm AS build
 WORKDIR /src
 
-# Main repo tree (contains opentelemetry-go with patches applied and
-# deploy/fake-exporter source).
+# Main repo tree (contains opentelemetry-go and opentelemetry-proto with
+# patches applied and deploy/fake-exporter source). The replace directives
+# in opentelemetry-go's exporter go.mod files point at
+# ../../../../../opentelemetry-proto/gen/go/go.opentelemetry.io/proto/otlp,
+# so opentelemetry-proto/ must be present alongside opentelemetry-go/ in the
+# build context root.
 COPY opentelemetry-go     /src/opentelemetry-go
+COPY opentelemetry-proto  /src/opentelemetry-proto
 COPY deploy/fake-exporter /src/deploy/fake-exporter
 
 # Sketchlib-go pulled via named build context to avoid a submodule

deploy/fake-exporter/go.mod

@@ -53,4 +53,9 @@ replace (
 	go.opentelemetry.io/otel/sdk => ../../opentelemetry-go/sdk
 	go.opentelemetry.io/otel/sdk/metric => ../../opentelemetry-go/sdk/metric
 	go.opentelemetry.io/otel/trace => ../../opentelemetry-go/trace
+	// The patched OTLP proto bindings (mpb.DDSketch / KLLSketch / CountSketch
+	// / CountMinSketch / HLLSketch types added on top of upstream v1.9.0)
+	// are regenerated under opentelemetry-proto/gen/go/... by
+	// restore_otel_proto_patches.sh. See opentelemetry-proto-patch/REGEN.md.
+	go.opentelemetry.io/proto/otlp => ../../opentelemetry-proto/gen/go/go.opentelemetry.io/proto/otlp
 )

opentelemetry-proto-patch/.gitignore

@@ -18,12 +18,12 @@
 # Vim
 .swp
 
-# Generated code
-/gen/
+# Generated code: track the regenerated Go bindings under
+# gen/go/go.opentelemetry.io/proto/otlp/. Other languages' gen/* output is
+# ignored. See REGEN.md for the regeneration recipe.
+/gen/*
 !/gen/go/
+/gen/go/*
 !/gen/go/go.opentelemetry.io/
-!/gen/go/go.opentelemetry.io/proto/
-!/gen/go/go.opentelemetry.io/proto/otlp/
-!/gen/go/go.opentelemetry.io/proto/otlp/go.mod
 
 node_modules

opentelemetry-proto-patch/REGEN.md

@@ -0,0 +1,86 @@
+# Regenerating the patched OTLP Go bindings
+
+The ASAP-patched `metrics.proto` adds five sketch message types (`DDSketch`,
+`KLLSketch`, `CountSketch`, `CountMinSketch`, `HLLSketch`) plus their
+`*DataPoint` and `*Encoding` enums on top of upstream
+[`opentelemetry-proto` v1.9.0]. The Go bindings under
+`gen/go/go.opentelemetry.io/proto/otlp/` are committed to this repo so the
+fake-exporter / sketchcol Docker builds don't have to reinvent a protoc
+toolchain at build time. The `replace` directives in
+`opentelemetry-go-patch/exporters/otlp/otlpmetric/{otlpmetricgrpc,otlpmetrichttp}/go.mod`
+and `deploy/fake-exporter/go.mod` point at this gen tree.
+
+## When to regenerate
+
+Whenever any `.proto` file under `opentelemetry-proto-patch/opentelemetry/`
+changes. Both the patched files (carried in this directory) AND any
+upstream-only files transitively imported by them
+(`common.proto`, `resource.proto`, etc.) must be passed to `protoc`.
+
+## Recipe
+
+The repo pins upstream proto to `v1.9.0` (commit
+`a8951735f7801e8adfaec5c0ace9262771cfec6e`). The recipe overlays this
+patch's `.proto` files on top of a clean v1.9.0 checkout, then runs
+`protoc-gen-go` (with `plugins=grpc`) per upstream's Makefile target
+`gen-go`.
+
+```bash
+# 1. Get a clean v1.9.0 of upstream opentelemetry-proto.
+PROTO_BUILD=/tmp/proto-build
+rm -rf "$PROTO_BUILD"
+git clone --depth 1 --branch v1.9.0 \
+    https://github.com/open-telemetry/opentelemetry-proto.git "$PROTO_BUILD"
+
+# 2. Overlay the patched .proto files.
+REPO_ROOT="$(git rev-parse --show-toplevel)"
+cp "$REPO_ROOT/opentelemetry-proto-patch/opentelemetry/proto/metrics/v1/metrics.proto" \
+   "$PROTO_BUILD/opentelemetry/proto/metrics/v1/metrics.proto"
+cp "$REPO_ROOT/opentelemetry-proto-patch/opentelemetry/proto/collector/metrics/v1/metrics_service.proto" \
+   "$PROTO_BUILD/opentelemetry/proto/collector/metrics/v1/metrics_service.proto"
+
+# 3. Run protoc-gen-go (with grpc plugin) via the otel/build-protobuf
+#    image — the same image upstream uses for `make gen-go`.
+cd "$PROTO_BUILD"
+rm -rf gen/go && mkdir -p gen/go
+for f in $(find opentelemetry/proto -name '*.proto'); do
+    docker run --rm -u "$(id -u)" -v "${PWD}:${PWD}" -w "${PWD}" \
+        otel/build-protobuf:0.9.0 \
+        --proto_path="${PWD}" \
+        --go_out=plugins=grpc:./gen/go \
+        "$f"
+done
+
+# 4. Copy the generated tree back into the patch repo.
+rm -rf "$REPO_ROOT/opentelemetry-proto-patch/gen/go/go.opentelemetry.io/proto/otlp"/*
+cp -r gen/go/go.opentelemetry.io/proto/otlp/* \
+      "$REPO_ROOT/opentelemetry-proto-patch/gen/go/go.opentelemetry.io/proto/otlp/"
+
+# 5. Confirm the new sketch types are present:
+grep -c "DDSketchDataPoint\|KLLSketchDataPoint\|CountSketchDataPoint\|CountMinSketchDataPoint\|HLLSketchDataPoint" \
+    "$REPO_ROOT/opentelemetry-proto-patch/gen/go/go.opentelemetry.io/proto/otlp/metrics/v1/metrics.pb.go"
+```
+
+The `gen/go/go.opentelemetry.io/proto/otlp/go.mod` is hand-maintained
+(modeled on upstream) and pins protobuf / gRPC / grpc-gateway versions
+that match `deploy/fake-exporter/go.sum`. Update it only when those pins
+shift (rare).
+
+## Build wiring
+
+`restore_otel_proto_patches.sh` (in the repo root) copies this entire
+directory tree, including `gen/go/...`, on top of the
+`opentelemetry-proto/` submodule. The Docker build for fake-exporter
+copies `opentelemetry-proto/` into the build context, and
+`deploy/fake-exporter/go.mod` has a
+`replace go.opentelemetry.io/proto/otlp => ../../opentelemetry-proto/gen/go/go.opentelemetry.io/proto/otlp`
+that picks up the regenerated bindings.
+
+## Why the bindings are committed (not generated at build time)
+
+- The Docker build runs `golang:1.25-bookworm` (no protoc, no Docker-in-
+  Docker for the otel/build-protobuf image). Pulling the toolchain
+  inside the build would add 200+ MB of layers and a Docker socket
+  mount. Easier to commit ~10 KLOC of generated `.pb.go`.
+- Upstream `opentelemetry-proto` itself commits its `gen/...` outputs,
+  so we follow the same pattern.