[codex] Add Foundry service chassis

MODULE.bazel

@@ -5,10 +5,10 @@ module(
 )
 
 # Go rules for building Go code
-bazel_dep(name = "rules_go", version = "0.56.1")
+bazel_dep(name = "rules_go", version = "0.60.0")
 
 # Gazelle for generating BUILD files automatically
-bazel_dep(name = "gazelle", version = "0.44.0")
+bazel_dep(name = "gazelle", version = "0.50.0")
 
 # Rust rules for building Rust code
 bazel_dep(name = "rules_rust", version = "0.67.0")
@@ -17,12 +17,12 @@ bazel_dep(name = "rules_rust", version = "0.67.0")
 bazel_dep(name = "rules_rust_prost", version = "0.67.0")
 
 # Proto rules for protocol buffers
-bazel_dep(name = "rules_proto", version = "6.0.2")
-bazel_dep(name = "protobuf", version = "29.0")
+bazel_dep(name = "rules_proto", version = "7.1.0")
+bazel_dep(name = "protobuf", version = "29.1")
 
 # Configure Go SDK
 go_sdk = use_extension("@rules_go//go:extensions.bzl", "go_sdk")
-go_sdk.download(version = "1.24.6")
+go_sdk.download(version = "1.24.13")
 
 # Configure Go dependencies from go.work
 go_deps = use_extension("@gazelle//:extensions.bzl", "go_deps")
@@ -34,7 +34,16 @@ go_deps.config(
         "GOPROXY": "https://proxy.golang.org,direct",
     },
 )
-use_repo(go_deps, "org_golang_google_grpc")
+use_repo(
+    go_deps,
+    "com_github_grpc_ecosystem_go_grpc_middleware_providers_prometheus",
+    "com_github_grpc_ecosystem_go_grpc_middleware_v2",
+    "com_github_open_feature_go_sdk",
+    "com_github_prometheus_client_golang",
+    "io_opencensus_go",
+    "org_golang_google_grpc",
+    "org_golang_google_protobuf",
+)
 
 # Configure Rust toolchain
 rust = use_extension("@rules_rust//rust:extensions.bzl", "rust")
@@ -57,4 +66,4 @@ rust.toolchain(edition = "2024")
 # crate.from_specs(
 #     cargo_lockfile = "//:Cargo.Bazel.lock",
 # )
-# use_repo(crate, "crates")
+# use_repo(crate, "crates")

README.md

@@ -15,11 +15,16 @@
   - Go client and server
   - Rust client and server
   - Shared protobuf definitions with automatic code generation
+- **foundry/**: Production-style Go/Kubernetes service chassis
+  - gRPC service with health, reflection, channelz, and OpenFeature experiments
+  - JSON logs, Prometheus metrics, pprof, expvar, and zPage-style debugging
+  - Kubernetes Deployment, Service, ServiceMonitor, and canary examples
 - **Bazel configuration**: Pre-configured rules for Go (`rules_go`), Rust (`rules_rust`), and protobuf code generation
 
 ## Use Cases
 
 - Starting a polyglot microservices project
 - Learning how to structure multi-language Bazel workspaces
 - Understanding gRPC service implementations across different languages
-- Evaluating Bazel for multi-language projects
+- Starting a Go service on Kubernetes with practical observability and debugging defaults
+- Evaluating Bazel for multi-language projects

foundry/BUILD.bazel

@@ -0,0 +1,5 @@
+alias(
+    name = "foundryd",
+    actual = "//foundry/cmd/foundryd:foundryd",
+    visibility = ["//visibility:public"],
+)

foundry/Dockerfile

@@ -0,0 +1,14 @@
+FROM golang:1.24 AS build
+
+WORKDIR /src
+COPY foundry/go.mod foundry/go.sum ./
+RUN go mod download
+COPY foundry/ ./
+RUN CGO_ENABLED=0 GOOS=linux GOARCH=amd64 go build -trimpath -ldflags="-s -w" -o /out/foundryd ./cmd/foundryd
+
+FROM gcr.io/distroless/static-debian12:nonroot
+
+COPY --from=build /out/foundryd /foundryd
+USER nonroot:nonroot
+EXPOSE 50051 8080
+ENTRYPOINT ["/foundryd"]

foundry/README.md

@@ -0,0 +1,132 @@
+# Foundry
+
+Foundry is a Go/Kubernetes service chassis: a small, explicit reference implementation for running a production-style gRPC service with debugging, metrics, structured logs, health, and feature flags.
+
+It intentionally keeps the middleware stack visible instead of hiding it behind a framework. The goal is to show the operating model a team can copy into a real service.
+
+## What It Includes
+
+- gRPC API: `foundry.v1.FoundryService`
+- Example RPCs: `SayHello`, `GetExperiment`, `GetRuntimeInfo`
+- gRPC health, reflection, and channelz
+- JSON `slog` access logs with request IDs, status codes, latency, service metadata, and flag decisions
+- Prometheus metrics for Go/process runtime and gRPC golden signals
+- HTTP admin/debug port with `/admin`, `/metrics`, `/debug/pprof/`, `/debug/vars`, `/debug/rpcz`, and `/debug/tracez`
+- OpenFeature local feature flag provider with `foundry.new_greeting`
+- Kubernetes manifests with probes, resources, security context, ServiceMonitor, and stable/canary examples
+- A feature matrix comparing Foundry with Kratos, Go kit, go-zero, Encore.go, Service Weaver, Spring Boot Actuator, App Engine, Cloud Run, Dapr, Envoy, Istio, and Linkerd
+
+## Run Locally
+
+From this directory:
+
+```bash
+go run ./cmd/foundryd
+```
+
+The service listens on:
+
+- gRPC: `localhost:50051`
+- Admin/debug HTTP: `localhost:8080`
+
+Example calls:
+
+```bash
+grpcurl -plaintext -d '{"name":"Ada"}' localhost:50051 foundry.v1.FoundryService/SayHello
+grpcurl -plaintext -d '{}' localhost:50051 foundry.v1.FoundryService/GetExperiment
+grpcurl -plaintext -d '{}' localhost:50051 foundry.v1.FoundryService/GetRuntimeInfo
+grpcurl -plaintext localhost:50051 grpc.health.v1.Health/Check
+```
+
+Enable the sample experiment:
+
+```bash
+FEATURE_FOUNDRY_NEW_GREETING=true go run ./cmd/foundryd
+```
+
+## Debug Surface
+
+The admin port is designed for internal access and port-forwarding, not public ingress.
+
+```bash
+curl localhost:8080/admin
+curl localhost:8080/admin/info
+curl localhost:8080/admin/ready
+curl localhost:8080/metrics
+go tool pprof http://localhost:8080/debug/pprof/profile
+```
+
+Legacy OpenCensus zPages are available at:
+
+- `http://localhost:8080/debug/rpcz`
+- `http://localhost:8080/debug/tracez`
+
+They are included as a compatibility/debug reference because the request explicitly asked for a zPage-like interface. New instrumentation should prefer Prometheus/OpenTelemetry-compatible metrics and gRPC channelz/reflection.
+
+## Configuration
+
+| Environment variable | Default | Purpose |
+| --- | --- | --- |
+| `FOUNDRY_SERVICE_NAME` | `foundry` | Service name in logs, metrics, and runtime info |
+| `FOUNDRY_VERSION` | `dev` | Version label |
+| `FOUNDRY_COMMIT` | `unknown` | Build commit label |
+| `FOUNDRY_ENVIRONMENT` | `local` | Environment label |
+| `FOUNDRY_REVISION` | `local` | Revision/canary label |
+| `FOUNDRY_GRPC_ADDR` | `:50051` | gRPC listen address |
+| `FOUNDRY_HTTP_ADDR` | `:8080` | Admin/debug HTTP listen address |
+| `FOUNDRY_LOG_LEVEL` | `info` | `debug`, `info`, `warn`, or `error` |
+| `FEATURE_FOUNDRY_NEW_GREETING` | `false` | OpenFeature-backed sample experiment |
+| `FOUNDRY_SHUTDOWN_GRACE_PERIOD` | `20s` | Graceful shutdown timeout |
+
+## Kubernetes
+
+Apply the reference manifests:
+
+```bash
+kubectl apply -f k8s/configmap.yaml
+kubectl apply -f k8s/deployment.yaml
+kubectl apply -f k8s/service.yaml
+```
+
+If Prometheus Operator is installed:
+
+```bash
+kubectl apply -f k8s/servicemonitor.yaml
+```
+
+Canary example:
+
+```bash
+kubectl apply -f k8s/canary.yaml
+```
+
+Port-forward the internal admin port:
+
+```bash
+kubectl port-forward deploy/foundry 8080:8080
+```
+
+## Development
+
+Regenerate protobuf bindings after editing `proto/foundry/v1/foundry.proto`:
+
+```bash
+PATH="$(go env GOPATH)/bin:$PATH" buf generate
+```
+
+Run tests:
+
+```bash
+go test ./...
+```
+
+Bazel target:
+
+```bash
+bazel build //foundry:foundryd
+```
+
+## Related Docs
+
+- [Feature matrix](docs/feature-matrix.md)
+- [Research notes](docs/research-notes.md)

foundry/buf.gen.yaml

@@ -0,0 +1,10 @@
+version: v1
+plugins:
+  - plugin: go
+    out: .
+    opt:
+      - paths=source_relative
+  - plugin: go-grpc
+    out: .
+    opt:
+      - paths=source_relative

foundry/buf.yaml

@@ -0,0 +1,9 @@
+version: v1
+lint:
+  use:
+    - DEFAULT
+  except:
+    - PACKAGE_DIRECTORY_MATCH
+breaking:
+  use:
+    - FILE

foundry/cmd/foundryd/BUILD.bazel

@@ -0,0 +1,31 @@
+load("@rules_go//go:def.bzl", "go_binary", "go_library")
+
+go_library(
+    name = "foundryd_lib",
+    srcs = ["main.go"],
+    importpath = "github.com/bazelment/hajime/foundry/cmd/foundryd",
+    visibility = ["//visibility:private"],
+    deps = [
+        "//foundry/internal/admin",
+        "//foundry/internal/config",
+        "//foundry/internal/feature",
+        "//foundry/internal/observability",
+        "//foundry/internal/service",
+        "//foundry/proto/foundry/v1:foundry_go_proto",
+        "@com_github_grpc_ecosystem_go_grpc_middleware_v2//interceptors/logging",
+        "@com_github_grpc_ecosystem_go_grpc_middleware_v2//interceptors/recovery",
+        "@org_golang_google_grpc//:grpc",
+        "@org_golang_google_grpc//channelz/service",
+        "@org_golang_google_grpc//codes",
+        "@org_golang_google_grpc//health",
+        "@org_golang_google_grpc//health/grpc_health_v1",
+        "@org_golang_google_grpc//reflection",
+        "@org_golang_google_grpc//status",
+    ],
+)
+
+go_binary(
+    name = "foundryd",
+    embed = [":foundryd_lib"],
+    visibility = ["//visibility:public"],
+)