feat: add healthcheck

.gitignore

@@ -1,4 +1,5 @@
 client_secret.json
+.env
 
 # If you prefer the allow list template instead of the deny list, see community template:
 # https://github.com/github/gitignore/blob/main/community/Golang/Go.AllowList.gitignore

cmd/server/main.go

@@ -13,6 +13,7 @@ import (
 	"golang.org/x/oauth2/google"
 	"gopkg.in/Iwark/spreadsheet.v2"
 
+	grpchealth "github.com/bufbuild/connect-grpchealth-go"
 	"github.com/stillmatic/featuresheet"
 	fsv1 "github.com/stillmatic/featuresheet/gen/featuresheet/v1"
 	"github.com/stillmatic/featuresheet/gen/featuresheet/v1/featuresheetv1connect"
@@ -47,6 +48,9 @@ func (s *FeatureSheetServer) Evaluate(
 
 func main() {
 	// copy these from client_secret.json
+	if os.Getenv("GCP_PROJECT_ID") == "" {
+		panic("GCP_PROJECT_ID env var must be set")
+	}
 	serviceAccountJSON := map[string]interface{}{
 		"type":                        "service_account",
 		"project_id":                  os.Getenv("GCP_PROJECT_ID"),
@@ -59,12 +63,10 @@ func main() {
 		"auth_provider_x509_cert_url": os.Getenv("GCP_AUTH_PROVIDER_CERT_URL"),
 		"client_x509_cert_url":        os.Getenv("GCP_CLIENT_CERT_URL"),
 	}
-
 	serviceAccountJSONBytes, err := json.Marshal(serviceAccountJSON)
 	if err != nil {
 		panic(err)
 	}
-
 	conf, err := google.JWTConfigFromJSON(serviceAccountJSONBytes, spreadsheet.Scope)
 	if err != nil {
 		panic(err)
@@ -80,12 +82,18 @@ func main() {
 	if err != nil {
 		panic(err)
 	}
+
+	// serving
 	s := &FeatureSheetServer{
 		fs: fs,
 	}
 	mux := http.NewServeMux()
 	path, handler := featuresheetv1connect.NewFeatureSheetServiceHandler(s)
 	mux.Handle(path, handler)
+	checker := grpchealth.NewStaticChecker(
+		"featuresheet.v1.FeatureSheetService",
+	)
+	mux.Handle(grpchealth.NewHandler(checker))
 	portNum := os.Getenv("PORT")
 	if portNum == "" {
 		portNum = "8080"

go.mod

@@ -12,6 +12,7 @@ require (
 require (
 	cloud.google.com/go/compute/metadata v0.2.0 // indirect
 	github.com/bufbuild/connect-go v1.9.0 // indirect
+	github.com/bufbuild/connect-grpchealth-go v1.1.1 // indirect
 	github.com/davecgh/go-spew v1.1.1 // indirect
 	github.com/golang/protobuf v1.5.2 // indirect
 	github.com/pmezard/go-difflib v1.0.0 // indirect

go.sum

@@ -2,6 +2,8 @@ cloud.google.com/go/compute/metadata v0.2.0 h1:nBbNSZyDpkNlo3DepaaLKVuO7ClyifSAm
 cloud.google.com/go/compute/metadata v0.2.0/go.mod h1:zFmK7XCadkQkj6TtorcaGlCW1hT1fIilQDwofLpJ20k=
 github.com/bufbuild/connect-go v1.9.0 h1:JIgAeNuFpo+SUPfU19Yt5TcWlznsN5Bv10/gI/6Pjoc=
 github.com/bufbuild/connect-go v1.9.0/go.mod h1:CAIePUgkDR5pAFaylSMtNK45ANQjp9JvpluG20rhpV8=
+github.com/bufbuild/connect-grpchealth-go v1.1.1 h1:ldceS3m7+Qvl3GI4yzB4oCg3uOdD+Y1bytc/5xuMpqo=
+github.com/bufbuild/connect-grpchealth-go v1.1.1/go.mod h1:9KbkogLoUIxOTPKyWDv5evkawr1IYXaHax4XoUHCgoQ=
 github.com/datadog/mmh3 v0.0.0-20210722141835-012dc69a9e49 h1:9ppqviquwkVpmVM19utHENs1+Ugp4odEBUbFsqP2f/M=
 github.com/datadog/mmh3 v0.0.0-20210722141835-012dc69a9e49/go.mod h1:NoK5OFSzgNJ9DLcHQ3hhbZKeJZioh9B8G59FOAlytYU=
 github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=