Added Prometheus Metrics

cmd/server/server.go

@@ -7,9 +7,11 @@ import (
 	"github.com/flatheadmill/tang-encryption-provider/crypter"
 	"github.com/gorilla/mux"
 	"github.com/pkg/errors"
+	"github.com/prometheus/client_golang/prometheus/promhttp"
 	"net/http"
 	"os"
 	"os/signal"
+	"runtime"
 	"syscall"
 	"time"
 
@@ -36,17 +38,17 @@ const (
 func main() {
 	var spec Specification
 	try.To(envconfig.Process("tang_kms", &spec))
-	log := logger.New(os.Stdout)
+	log := logger.New(os.Stdout).WithFields(map[string]interface{}{"go_version": runtime.Version(), "env": spec.Env})
 	if spec.Env == EnvLocal {
 		log.Console()
 	}
 
 	log.MsgWithFields(map[string]interface{}{"thumbprint": spec.Thumbprint, "unix_socket": spec.UnixSocket}, "")
 	crypt := try.To1(crypter.NewCrypter(spec.ServerUrl, spec.Thumbprint))
+	plugin := try.To1(plugin.New(log, crypt, spec.UnixSocket))
+	httpSvr := setupHttpServer(log, []HealthComponent{NewHealthComponent(plugin, "tang-encryption-provider plugin")}, spec.HttpPort)
 
-	httpSvr := setupHttpServer(log, []HealthComponent{NewHealthComponent(crypt, "tang_crypter")}, spec.HttpPort)
-
-	err := run(log, try.To1(plugin.New(log, crypt, spec.UnixSocket)), httpSvr)
+	err := run(log, plugin, httpSvr)
 	if err != nil {
 		fmt.Printf("exited with error: %T %v\n", err, err)
 	}
@@ -85,6 +87,7 @@ func setupHttpServer(l logger.Logger, components []HealthComponent, httpPort str
 	r := mux.NewRouter()
 	r.HandleFunc("/livez", healthAPI.Health)
 	r.HandleFunc("/readyz", healthAPI.Health)
+	r.Handle("/metrics", promhttp.Handler())
 
 	return &http.Server{Addr: ":" + httpPort, Handler: r}
 }

crypter/crypter.go

@@ -114,8 +114,8 @@ func NewCrypter(url string, thumbprint string) (crypter *Crypter, err error) {
 }
 
 func (c *Crypter) Encrypt(plain []byte) (cipher []byte, err error) {
-	defer err2.Handle(&err, handler.Handler(&err))
-	return try.To1(jwe.Encrypt(plain, jwa.ECDH_ES, c.exchangeKey, jwa.A256GCM, jwa.NoCompress, jwe.WithProtectedHeaders(c.headers))), nil
+	cipher, err = jwe.Encrypt(plain, jwa.ECDH_ES, c.exchangeKey, jwa.A256GCM, jwa.NoCompress, jwe.WithProtectedHeaders(c.headers))
+	return cipher, errors.Wrap(err, "failed to encrypt plaintext locally with JWE")
 }
 
 func (c *Crypter) Decrypt(cipher []byte) (plain []byte, err error) {
@@ -124,12 +124,12 @@ func (c *Crypter) Decrypt(cipher []byte) (plain []byte, err error) {
 
 func Decrypt(cipher []byte) (plain []byte, err error) {
 	plain, err = clevis.Decrypt(cipher)
-	err = errors.Wrap(err, "failed to decrypt cipher")
+	err = errors.Wrap(err, "failed to decrypt cipher with clevis")
 	return
 }
 
 func (c Crypter) Health() error {
-	randomPlaintext := RandomHex(8)
+	randomPlaintext := randomHex(8)
 	cipher, err := c.Encrypt([]byte(randomPlaintext))
 	if err != nil {
 		return errors.Wrap(err, "failed to encrypt random text")
@@ -149,7 +149,7 @@ func init() {
 	rand.Seed(time.Now().UnixNano())
 }
 
-func RandomHex(n int) string {
+func randomHex(n int) string {
 	if n <= 0 {
 		return ""
 	}

go.mod

@@ -4,25 +4,26 @@ go 1.18
 
 require (
 	github.com/anatol/clevis.go v0.0.0-20220325231436-1877edc32744
-	github.com/flatheadmill/go-jose/v3 v3.0.2
 	github.com/gogo/protobuf v1.3.2
 	github.com/gorilla/mux v1.8.0
 	github.com/goware/urlx v0.3.1
 	github.com/kelseyhightower/envconfig v1.4.0
 	github.com/lainio/err2 v0.8.0
 	github.com/lestrrat-go/jwx v1.2.20
 	github.com/pkg/errors v0.9.1
+	github.com/prometheus/client_golang v1.12.1
 	github.com/rs/zerolog v1.26.1
-	golang.org/x/net v0.0.0-20211209124913-491a49abca63
+	golang.org/x/net v0.0.0-20220225172249-27dd8689420f
 	google.golang.org/grpc v1.45.0
 	k8s.io/apiserver v0.23.5
 )
 
 require (
 	github.com/PuerkitoBio/purell v1.1.1 // indirect
 	github.com/PuerkitoBio/urlesc v0.0.0-20170810143723-de5bf2ad4578 // indirect
+	github.com/beorn7/perks v1.0.1 // indirect
+	github.com/cespare/xxhash/v2 v2.1.2 // indirect
 	github.com/decred/dcrd/dcrec/secp256k1/v4 v4.0.1 // indirect
-	github.com/go-jose/go-jose/v3 v3.0.0 // indirect
 	github.com/goccy/go-json v0.9.5 // indirect
 	github.com/golang/protobuf v1.5.2 // indirect
 	github.com/google/go-tpm v0.3.3 // indirect
@@ -31,9 +32,13 @@ require (
 	github.com/lestrrat-go/httpcc v1.0.0 // indirect
 	github.com/lestrrat-go/iter v1.0.1 // indirect
 	github.com/lestrrat-go/option v1.0.0 // indirect
+	github.com/matttproud/golang_protobuf_extensions v1.0.2-0.20181231171920-c182affec369 // indirect
+	github.com/prometheus/client_model v0.2.0 // indirect
+	github.com/prometheus/common v0.34.0 // indirect
+	github.com/prometheus/procfs v0.7.3 // indirect
 	golang.org/x/crypto v0.0.0-20220315160706-3147a52a75dd // indirect
-	golang.org/x/sys v0.0.0-20220315194320-039c03cc5b86 // indirect
+	golang.org/x/sys v0.0.0-20220503163025-988cb79eb6c6 // indirect
 	golang.org/x/text v0.3.7 // indirect
 	google.golang.org/genproto v0.0.0-20210831024726-fe130286e0e2 // indirect
-	google.golang.org/protobuf v1.27.1 // indirect
+	google.golang.org/protobuf v1.28.0 // indirect
 )