add grpc, otel, metrics helpers

cobrautil.go

@@ -2,8 +2,14 @@ package cobrautil
 
 import (
 	"fmt"
+	"net/http"
+	"net/http/pprof"
+	"os"
 	"strings"
+	"time"
 
+	"github.com/mattn/go-isatty"
+	"github.com/prometheus/client_golang/prometheus/promhttp"
 	"github.com/rs/zerolog"
 	"github.com/rs/zerolog/log"
 	"github.com/spf13/cobra"
@@ -15,6 +21,9 @@ import (
 	"go.opentelemetry.io/otel/sdk/resource"
 	"go.opentelemetry.io/otel/sdk/trace"
 	semconv "go.opentelemetry.io/otel/semconv/v1.4.0"
+	"google.golang.org/grpc"
+	"google.golang.org/grpc/credentials"
+	"google.golang.org/grpc/keepalive"
 )
 
 // SyncViperPreRunE returns a Cobra run func that synchronizes Viper environment
@@ -24,6 +33,10 @@ import (
 func SyncViperPreRunE(prefix string) func(cmd *cobra.Command, args []string) error {
 	prefix = strings.ReplaceAll(strings.ToUpper(prefix), "-", "_")
 	return func(cmd *cobra.Command, args []string) error {
+		if cmd.Use == "help [command]" {
+			return nil // No-op the help command
+		}
+
 		v := viper.New()
 		viper.SetEnvPrefix(prefix)
 
@@ -58,7 +71,8 @@ func CommandStack(cmdfns ...CobraRunFunc) CobraRunFunc {
 
 // RegisterZeroLogFlags adds a "log-level" flag for use in with ZeroLogPreRunE.
 func RegisterZeroLogFlags(flags *pflag.FlagSet) {
-	flags.String("log-level", "info", "verbosity of logging (trace, debug, info, warn, error, fatal, panic)")
+	flags.String("log-level", "info", `verbosity of logging ("trace", "debug", "info", "warn", "error")`)
+	flags.String("log-format", "auto", `format of logs ("auto", "human", "json")`)
 }
 
 // ZeroLogPreRunE reads the provided command's flags and configures the
@@ -67,6 +81,15 @@ func RegisterZeroLogFlags(flags *pflag.FlagSet) {
 //
 // This function exits with log.Fatal on failure.
 func ZeroLogPreRunE(cmd *cobra.Command, args []string) error {
+	if cmd.Use == "help [command]" {
+		return nil // No-op the help command
+	}
+
+	format := MustGetString(cmd, "log-format")
+	if format == "human" || (format == "auto" && isatty.IsTerminal(os.Stdout.Fd())) {
+		log.Logger = log.Output(zerolog.ConsoleWriter{Out: os.Stdout})
+	}
+
 	level := strings.ToLower(MustGetString(cmd, "log-level"))
 	switch level {
 	case "trace":
@@ -97,7 +120,7 @@ func ZeroLogPreRunE(cmd *cobra.Command, args []string) error {
 // - "otel-jaeger-endpoint"
 // - "otel-jaeger-service-name"
 func RegisterOpenTelemetryFlags(flags *pflag.FlagSet, serviceName string) {
-	flags.String("otel-provider", "none", "opentelemetry provider for tracing (none, jaeger)")
+	flags.String("otel-provider", "none", `opentelemetry provider for tracing ("none", "jaeger")`)
 	flags.String("otel-jaeger-endpoint", "http://jaeger:14268/api/traces", "jaeger collector endpoint")
 	flags.String("otel-jaeger-service-name", serviceName, "jaeger service name for trace data")
 }
@@ -106,6 +129,10 @@ func RegisterOpenTelemetryFlags(flags *pflag.FlagSet, serviceName string) {
 // corresponding tracing provider. The required flags can be added to a command
 // by using RegisterTracingPersistentFlags().
 func OpenTelemetryPreRunE(cmd *cobra.Command, args []string) error {
+	if cmd.Use == "help [command]" {
+		return nil // No-op the help command
+	}
+
 	provider := strings.ToLower(MustGetString(cmd, "otel-provider"))
 	switch provider {
 	case "none":
@@ -144,3 +171,61 @@ func initJaegerTracer(endpoint, serviceName string) error {
 	otel.SetTextMapPropagator(propagation.TraceContext{})
 	return nil
 }
+
+// RegisterGrpcServerFlags adds the following flags for use with
+// GrpcServerFromFlags:
+// - "grpc-addr"
+// - "grpc-no-tls"
+// - "grpc-cert-path"
+// - "grpc-key-path"
+// - "grpc-max-conn-age"
+func RegisterGrpcServerFlags(flags *pflag.FlagSet) {
+	flags.String("grpc-addr", ":50051", "address to listen on for serving gRPC services")
+	flags.String("grpc-cert-path", "", "local path to the TLS certificate used to serve gRPC services")
+	flags.String("grpc-key-path", "", "local path to the TLS key used to serve gRPC services")
+	flags.Bool("grpc-no-tls", false, "serve unencrypted gRPC services")
+	flags.Duration("grpc-max-conn-age", 30*time.Second, "how long a connection should be able to live")
+}
+
+func GrpcServerFromFlags(cmd *cobra.Command, opts ...grpc.ServerOption) (*grpc.Server, error) {
+	opts = append(opts, grpc.KeepaliveParams(keepalive.ServerParameters{
+		MaxConnectionAge: MustGetDuration(cmd, "grpc-max-conn-age"),
+	}))
+
+	if MustGetBool(cmd, "grpc-no-tls") {
+		return grpc.NewServer(opts...), nil
+	}
+
+	certPath := MustGetStringExpanded(cmd, "grpc-cert-path")
+	keyPath := MustGetStringExpanded(cmd, "grpc-key-path")
+	if certPath == "" || keyPath == "" {
+		return nil, fmt.Errorf("failed to start gRPC server: must provide either --grpc-no-tls or --grpc-cert-path and --grpc-key-path")
+	}
+
+	creds, err := credentials.NewServerTLSFromFile(certPath, keyPath)
+	if err != nil {
+		return nil, err
+	}
+	opts = append(opts, grpc.Creds(creds))
+
+	return grpc.NewServer(opts...), nil
+}
+
+func RegisterMetricsServerFlags(flags *pflag.FlagSet) {
+	flags.String("metrics-addr", ":9090", "address on which to serve metrics and runtime profiles")
+}
+
+func MetricsServerFromFlags(cmd *cobra.Command) *http.Server {
+	mux := http.NewServeMux()
+	mux.Handle("/metrics", promhttp.Handler())
+	mux.HandleFunc("/debug/pprof/", pprof.Index)
+	mux.HandleFunc("/debug/pprof/cmdline", pprof.Cmdline)
+	mux.HandleFunc("/debug/pprof/profile", pprof.Profile)
+	mux.HandleFunc("/debug/pprof/symbol", pprof.Symbol)
+	mux.HandleFunc("/debug/pprof/trace", pprof.Trace)
+
+	return &http.Server{
+		Addr:    MustGetString(cmd, "metrics-addr"),
+		Handler: mux,
+	}
+}

go.mod

@@ -3,11 +3,14 @@ module github.com/jzelinskie/cobrautil
 go 1.16
 
 require (
+	github.com/mattn/go-isatty v0.0.3
+	github.com/prometheus/client_golang v0.9.3
 	github.com/rs/zerolog v1.23.0
 	github.com/spf13/cobra v1.1.3
 	github.com/spf13/pflag v1.0.5
 	github.com/spf13/viper v1.7.1
 	go.opentelemetry.io/otel v1.0.0-RC2
 	go.opentelemetry.io/otel/exporters/jaeger v1.0.0-RC2
 	go.opentelemetry.io/otel/sdk v1.0.0-RC2
+	google.golang.org/grpc v1.21.1
 )

go.sum

@@ -21,6 +21,7 @@ github.com/armon/circbuf v0.0.0-20150827004946-bbbad097214e/go.mod h1:3U/XgcO3hC
 github.com/armon/go-metrics v0.0.0-20180917152333-f0300d1749da/go.mod h1:Q73ZrmVTwzkszR9V5SSuryQ31EELlFMUz1kKyl939pY=
 github.com/armon/go-radix v0.0.0-20180808171621-7fddfc383310/go.mod h1:ufUuZ+zHj4x4TnLV4JWEpy2hxWSpsRywHrMgIH9cCH8=
 github.com/beorn7/perks v0.0.0-20180321164747-3a771d992973/go.mod h1:Dwedo/Wpr24TaqPxmxbtue+5NUziq4I4S80YR8gNf3Q=
+github.com/beorn7/perks v1.0.0 h1:HWo1m869IqiPhD389kmkxeTalrjNbbJTC8LXupb+sl0=
 github.com/beorn7/perks v1.0.0/go.mod h1:KWe93zE9D1o94FZ5RNwFwVgaQK1VOXiVxmqh+CedLV8=
 github.com/bgentry/speakeasy v0.1.0/go.mod h1:+zsyZBPWlz7T6j88CTgSN5bM796AkVf0kBD4zp0CCIs=
 github.com/bketelsen/crypt v0.0.3-0.20200106085610-5cbc8cc4026c/go.mod h1:MKsuJmJgSg28kpZDP6UIiPt0e0Oz0kqKNGyRaWEPv84=
@@ -50,13 +51,15 @@ github.com/go-stack/stack v1.8.0/go.mod h1:v0f6uXyyMGvRgIKkXu+yp6POWl0qKG85gN/me
 github.com/godbus/dbus/v5 v5.0.4/go.mod h1:xhWf0FNVPg57R7Z0UbKHbJfkEywrmjJnf7w5xrFpKfA=
 github.com/gogo/protobuf v1.1.1/go.mod h1:r8qH/GZQm5c6nD/R0oafs1akxWv10x8SbQlK7atdtwQ=
 github.com/gogo/protobuf v1.2.1/go.mod h1:hp+jE20tsWTFYpLwKvXlhS1hjn+gTNwPg2I6zVXpSg4=
+github.com/golang/glog v0.0.0-20160126235308-23def4e6c14b h1:VKtxabqXZkF25pY9ekfRL6a582T4P37/31XEstQ5p58=
 github.com/golang/glog v0.0.0-20160126235308-23def4e6c14b/go.mod h1:SBH7ygxi8pfUlaOkMMuAQtPIUF8ecWP5IEl/CR7VP2Q=
 github.com/golang/groupcache v0.0.0-20190129154638-5b532d6fd5ef/go.mod h1:cIg4eruTrX1D+g88fzRXU5OdNfaM+9IcxsU14FzY7Hc=
 github.com/golang/mock v1.1.1/go.mod h1:oTYuIxOrZwtPieC+H1uAHpcLFnEyAGVDL/k47Jfbm0A=
 github.com/golang/mock v1.2.0/go.mod h1:oTYuIxOrZwtPieC+H1uAHpcLFnEyAGVDL/k47Jfbm0A=
 github.com/golang/mock v1.3.1/go.mod h1:sBzyDLLjw3U8JLTeZvSv8jJB+tU5PVekmnlKIyFUx0Y=
 github.com/golang/protobuf v1.2.0/go.mod h1:6lQm79b+lXiMfvg/cZm0SGofjICqVBUtrP5yJMmIC1U=
 github.com/golang/protobuf v1.3.1/go.mod h1:6lQm79b+lXiMfvg/cZm0SGofjICqVBUtrP5yJMmIC1U=
+github.com/golang/protobuf v1.3.2 h1:6nsPYzhq5kReh6QImI3k5qWzO4PEbvbIW2cwSfR/6xs=
 github.com/golang/protobuf v1.3.2/go.mod h1:6lQm79b+lXiMfvg/cZm0SGofjICqVBUtrP5yJMmIC1U=
 github.com/google/btree v0.0.0-20180813153112-4030bb1f1f0c/go.mod h1:lNA+9X1NB3Zf8V7Ke586lFgjr2dZNuvo3lPJSGZ5JPQ=
 github.com/google/btree v1.0.0/go.mod h1:lNA+9X1NB3Zf8V7Ke586lFgjr2dZNuvo3lPJSGZ5JPQ=
@@ -117,7 +120,9 @@ github.com/kr/text v0.1.0/go.mod h1:4Jbv+DJW3UT/LiOwJeYQe1efqtUx/iVham/4vfdArNI=
 github.com/magiconair/properties v1.8.1 h1:ZC2Vc7/ZFkGmsVC9KvOjumD+G5lXy2RtTKyzRKO2BQ4=
 github.com/magiconair/properties v1.8.1/go.mod h1:PppfXfuXeibc/6YijjN8zIbojt8czPbwD3XqdrwzmxQ=
 github.com/mattn/go-colorable v0.0.9/go.mod h1:9vuHe8Xs5qXnSaW/c/ABM9alt+Vo+STaOChaDxuIBZU=
+github.com/mattn/go-isatty v0.0.3 h1:ns/ykhmWi7G9O+8a448SecJU3nSMBXJfqQkl0upE1jI=
 github.com/mattn/go-isatty v0.0.3/go.mod h1:M+lRXTBqGeGNdLjl/ufCoiOlB5xdOkqRJdNxMWT7Zi4=
+github.com/matttproud/golang_protobuf_extensions v1.0.1 h1:4hp9jkHxhMHkqkrB3Ix0jegS5sx/RkqARlsWZ6pIwiU=
 github.com/matttproud/golang_protobuf_extensions v1.0.1/go.mod h1:D8He9yQNgCq6Z5Ld7szi9bcBfOoFv/3dc6xSMkL2PC0=
 github.com/miekg/dns v1.0.14/go.mod h1:W1PPwlIAgtquWBMBEV9nkV9Cazfe8ScdGz/Lj7v3Nrg=
 github.com/mitchellh/cli v1.0.0/go.mod h1:hNIlj7HEI86fIcpObd7a0FcrxTWetlwJDGcceTlRvqc=
@@ -143,12 +148,16 @@ github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZb
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/posener/complete v1.1.1/go.mod h1:em0nMJCgc9GFtwrmVmEMR/ZL6WyhyjMBndrE9hABlRI=
 github.com/prometheus/client_golang v0.9.1/go.mod h1:7SWBe2y4D6OKWSNQJUaRYU/AaXPKyh/dDVn+NZz0KFw=
+github.com/prometheus/client_golang v0.9.3 h1:9iH4JKXLzFbOAdtqv/a+j8aewx2Y8lAjAydhbaScPF8=
 github.com/prometheus/client_golang v0.9.3/go.mod h1:/TN21ttK/J9q6uSwhBd54HahCDft0ttaMvbicHlPoso=
 github.com/prometheus/client_model v0.0.0-20180712105110-5c3871d89910/go.mod h1:MbSGuTsp3dbXC40dX6PRTWyKYBIrTGTE9sqQNg2J8bo=
+github.com/prometheus/client_model v0.0.0-20190129233127-fd36f4220a90 h1:S/YWwWx/RA8rT8tKFRuGUZhuA90OyIBpPCXkcbwU8DE=
 github.com/prometheus/client_model v0.0.0-20190129233127-fd36f4220a90/go.mod h1:xMI15A0UPsDsEKsMN9yxemIoYk6Tm2C1GtYGdfGttqA=
 github.com/prometheus/common v0.0.0-20181113130724-41aa239b4cce/go.mod h1:daVV7qP5qjZbuso7PdcryaAu0sAZbrN9i7WWcTMWvro=
+github.com/prometheus/common v0.4.0 h1:7etb9YClo3a6HjLzfl6rIQaU+FDfi0VSX39io3aQ+DM=
 github.com/prometheus/common v0.4.0/go.mod h1:TNfzLD0ON7rHzMJeJkieUDPYmFC7Snx/y86RQel1bk4=
 github.com/prometheus/procfs v0.0.0-20181005140218-185b4288413d/go.mod h1:c3At6R/oaqEKCNdg8wHV1ftS6bRYblBhIjjI8uT2IGk=
+github.com/prometheus/procfs v0.0.0-20190507164030-5867b95ac084 h1:sofwID9zm4tzrgykg80hfFph1mryUeLRsUfoocVVmRY=
 github.com/prometheus/procfs v0.0.0-20190507164030-5867b95ac084/go.mod h1:TjEm7ze935MbeOT/UhFTIMYKhuLP4wbCsTZCD3I8kEA=
 github.com/prometheus/tsdb v0.7.1/go.mod h1:qhTCs0VvXwvX/y3TZrWD7rabWM+ijKTux40TwIPHuXU=
 github.com/rogpeppe/fastuuid v0.0.0-20150106093220-6724a57986af/go.mod h1:XWv6SoW27p1b0cqNHllgS5HIMJraePCO15w5zCzIWYg=
@@ -247,6 +256,7 @@ golang.org/x/net v0.0.0-20190501004415-9ce7a6920f09/go.mod h1:t9HGtf8HONx5eT2rtn
 golang.org/x/net v0.0.0-20190503192946-f4e77d36d62c/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
 golang.org/x/net v0.0.0-20190603091049-60506f45cf65/go.mod h1:HSz+uSET+XFnRR8LxR5pz3Of3rY3CfYBVs4xY44aLks=
 golang.org/x/net v0.0.0-20190620200207-3b0461eec859/go.mod h1:z5CRVTTTmAJ677TzLLGU+0bjPO0LkuOLi4/5GtJWs/s=
+golang.org/x/net v0.0.0-20201021035429-f5854403a974 h1:IX6qOQeG5uLjB/hjjwjedwfjND0hgjPMMyO1RoIXQNI=
 golang.org/x/net v0.0.0-20201021035429-f5854403a974/go.mod h1:sp8m0HH+o8qH0wwXwYZr8TS3Oi6o0r6Gce1SSxlDquU=
 golang.org/x/oauth2 v0.0.0-20180821212333-d2e6202438be/go.mod h1:N/0e6XlmueqKjAGxoOufVs8QHGRruUQn6yWY3a++T0U=
 golang.org/x/oauth2 v0.0.0-20190226205417-e64efc72b421/go.mod h1:gOpvHmFTYa4IltrdGE7lF6nIHvwfUNPOp7c8zoXwtLw=
@@ -321,9 +331,11 @@ google.golang.org/genproto v0.0.0-20190502173448-54afdca5d873/go.mod h1:VzzqZJRn
 google.golang.org/genproto v0.0.0-20190801165951-fa694d86fc64/go.mod h1:DMBHOl98Agz4BDEuKkezgsaosCRResVns1a3J2ZsMNc=
 google.golang.org/genproto v0.0.0-20190819201941-24fa4b261c55/go.mod h1:DMBHOl98Agz4BDEuKkezgsaosCRResVns1a3J2ZsMNc=
 google.golang.org/genproto v0.0.0-20190911173649-1774047e7e51/go.mod h1:IbNlFCBrqXvoKpeg0TB2l7cyZUmoaFKYIwrEpbDKLA8=
+google.golang.org/genproto v0.0.0-20191108220845-16a3f7862a1a h1:Ob5/580gVHBJZgXnff1cZDbG+xLtMVE5mDRTe+nIsX4=
 google.golang.org/genproto v0.0.0-20191108220845-16a3f7862a1a/go.mod h1:n3cpQtvxv34hfy77yVDNjmbRyujviMdxYliBSkLhpCc=
 google.golang.org/grpc v1.19.0/go.mod h1:mqu4LbDTu4XGKhr4mRzUsmM4RtVoemTSY81AxZiDr8c=
 google.golang.org/grpc v1.20.1/go.mod h1:10oTOabMzJvdu6/UiuZezV6QK5dSlG84ov/aaiqXj38=
+google.golang.org/grpc v1.21.1 h1:j6XxA85m/6txkUCHvzlV5f+HBNl/1r5cZ2A/3IEFOO8=
 google.golang.org/grpc v1.21.1/go.mod h1:oYelfM1adQP15Ek0mdvEgi9Df8B9CZIaU1084ijfRaM=
 gopkg.in/alecthomas/kingpin.v2 v2.2.6/go.mod h1:FMv+mEhP44yOT+4EoQTLFTRgOQ1FBLkstjWtayDeSgw=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=