build: publish stamped controller release manifest

Makefile

@@ -1,6 +1,6 @@
 .DEFAULT_GOAL := verify
 
-.PHONY: build build-controller build-garm-derivative fmt-check garm-derivative-script test test-race vet verify
+.PHONY: build build-controller controller-release build-garm-derivative fmt-check garm-derivative-script test test-controller-release-manifest test-race vet verify
 
 # The controller, observer, cache broker and pressure observer that ship to
 # the hosts. Stamped, because an unstamped binary reports `version: dev,
@@ -31,9 +31,19 @@ build-controller:
 	CGO_ENABLED=0 go build -trimpath -buildvcs=false -ldflags "$(CONTROLLER_LDFLAGS)" -o dist/gha-fleet-observer ./cmd/gha-fleet-observer
 	CGO_ENABLED=0 go build -trimpath -buildvcs=false -ldflags "$(CONTROLLER_LDFLAGS)" -o dist/gha-cache-broker ./cmd/gha-cache-broker
 	CGO_ENABLED=0 go build -trimpath -buildvcs=false -ldflags "$(CONTROLLER_LDFLAGS)" -o dist/gha-pressure-observer ./cmd/gha-pressure-observer
+	CGO_ENABLED=0 go build -trimpath -buildvcs=false -ldflags "$(CONTROLLER_LDFLAGS)" -o dist/gha-diagnostic-exporter ./cmd/gha-diagnostic-exporter
 	@./dist/gha-fleet version
+	@./dist/gha-fleet-observer --version
 	@./dist/gha-cache-broker -version
 	@./dist/gha-pressure-observer --version
+	@./dist/gha-diagnostic-exporter --version
+
+# The only supported deployable controller build. The manifest binds every
+# artifact to the exact source tree and build inputs consumed by the estate.
+controller-release: build-controller
+	@./scripts/write-controller-release-manifest.sh \
+		"$(CONTROLLER_VERSION)" "$(CONTROLLER_COMMIT)" dist/controller-release.json dist/gha-fleet \
+		dist/gha-fleet-observer dist/gha-cache-broker dist/gha-pressure-observer dist/gha-diagnostic-exporter
 
 garm-derivative-script:
 	go run ./cmd/gha-fleet render-garm-build
@@ -50,10 +60,13 @@ fmt-check:
 test:
 	go test ./...
 
+test-controller-release-manifest:
+	./scripts/test-controller-release-manifest.sh
+
 test-race:
 	go test -race ./...
 
 vet:
 	go vet ./...
 
-verify: fmt-check vet test-race build
+verify: fmt-check vet test-race test-controller-release-manifest build

scripts/test-controller-release-manifest.sh

@@ -0,0 +1,33 @@
+#!/usr/bin/env bash
+set -Eeuo pipefail
+
+repo_root=$(git rev-parse --show-toplevel)
+scratch=$(mktemp -d)
+trap 'rm -rf -- "${scratch}"' EXIT
+
+printf '#!/usr/bin/env bash\nexit 0\n' >"${scratch}/one"
+printf '#!/usr/bin/env bash\nexit 0\n# two\n' >"${scratch}/two"
+chmod +x "${scratch}/one" "${scratch}/two"
+
+"${repo_root}/scripts/write-controller-release-manifest.sh" \
+  v1.2.3 0123456789abcdef0123456789abcdef01234567 "${scratch}/manifest.json" \
+  "${scratch}/one" "${scratch}/two"
+
+python3 - "${scratch}/manifest.json" "${scratch}/one" "${scratch}/two" <<'PY'
+import hashlib
+import json
+from pathlib import Path
+import sys
+
+manifest = json.loads(Path(sys.argv[1]).read_text(encoding="utf-8"))
+assert manifest["schema_version"] == 1
+assert manifest["version"] == "v1.2.3"
+assert manifest["source_commit"] == "0123456789abcdef0123456789abcdef01234567"
+assert manifest["build"]["cgo_enabled"] is False
+assert manifest["build"]["trimpath"] is True
+assert manifest["build"]["buildvcs"] is False
+for path_text in sys.argv[2:]:
+    path = Path(path_text)
+    digest = hashlib.sha256(path.read_bytes()).hexdigest()
+    assert manifest["binaries"][path.name] == f"sha256:{digest}"
+PY

scripts/write-controller-release-manifest.sh

@@ -0,0 +1,47 @@
+#!/usr/bin/env bash
+set -Eeuo pipefail
+
+version=${1:?usage: write-controller-release-manifest.sh <version> <commit> <output> <binary>...}
+commit=${2:?usage: write-controller-release-manifest.sh <version> <commit> <output> <binary>...}
+output=${3:?usage: write-controller-release-manifest.sh <version> <commit> <output> <binary>...}
+shift 3
+
+(( $# > 0 )) || { echo "controller release has no binaries" >&2; exit 1; }
+[[ "${commit}" =~ ^[0-9a-f]{40}$ ]] || { echo "invalid controller source commit: ${commit}" >&2; exit 1; }
+
+for binary in "$@"; do
+  [[ -x "${binary}" ]] || { echo "controller binary is absent or not executable: ${binary}" >&2; exit 1; }
+done
+
+temporary="${output}.tmp"
+trap 'rm -f -- "${temporary}"' EXIT
+
+{
+  printf '{\n'
+  printf '  "schema_version": 1,\n'
+  printf '  "version": "%s",\n' "${version}"
+  printf '  "source_commit": "%s",\n' "${commit}"
+  printf '  "build": {\n'
+  printf '    "go_version": "%s",\n' "$(go env GOVERSION)"
+  printf '    "goos": "%s",\n' "$(go env GOOS)"
+  printf '    "goarch": "%s",\n' "$(go env GOARCH)"
+  printf '    "cgo_enabled": false,\n'
+  printf '    "trimpath": true,\n'
+  printf '    "buildvcs": false,\n'
+  printf '    "build_id": ""\n'
+  printf '  },\n'
+  printf '  "binaries": {\n'
+  index=0
+  count=$#
+  for binary in "$@"; do
+    index=$((index + 1))
+    separator=,
+    if (( index == count )); then separator=; fi
+    printf '    "%s": "sha256:%s"%s\n' "$(basename -- "${binary}")" "$(sha256sum "${binary}" | awk '{print $1}')" "${separator}"
+  done
+  printf '  }\n'
+  printf '}\n'
+} >"${temporary}"
+
+mv -- "${temporary}" "${output}"
+trap - EXIT