Add support for prometheus

This is blocked on prometheus/procfs#553 being merged and released.

Makefile

@@ -16,7 +16,7 @@ BUILD_USER ?= $(shell whoami)
 BUILD_HOST ?= $(shell hostname)
 BUILD_DATE ?= $(shell /bin/date -u "+%Y-%m-%d %H:%M:%S")
 BUILD_EPOCH := $(shell /bin/date -u "+%s")
-BUILD_TAGS = linkramsize,linkramstart,disable_fr_auth,linkprintk
+BUILD_TAGS = linkramsize,linkramstart,disable_fr_auth,linkprintk,nostatfs
 BUILD = ${BUILD_USER}@${BUILD_HOST} on ${BUILD_DATE}
 REV = $(shell git rev-parse --short HEAD 2> /dev/null)
 

go.mod

@@ -6,6 +6,7 @@ require (
 	github.com/beevik/ntp v1.2.0
 	github.com/golang/glog v1.1.1
 	github.com/google/go-cmp v0.5.9
+	github.com/prometheus/client_golang v1.16.0
 	github.com/transparency-dev/armored-witness-os v0.0.0-20230608161615-85a962a3140d
 	github.com/transparency-dev/witness v0.0.0-20230626165226-5051f84409bc
 	github.com/usbarmory/GoTEE v0.0.0-20230717085113-1beadf7e5429
@@ -22,7 +23,9 @@ require (
 )
 
 require (
+	github.com/beorn7/perks v1.0.1 // indirect
 	github.com/cenkalti/backoff/v4 v4.2.1 // indirect
+	github.com/cespare/xxhash/v2 v2.2.0 // indirect
 	github.com/golang/protobuf v1.5.3 // indirect
 	github.com/google/btree v1.1.2 // indirect
 	github.com/google/go-github/v39 v39.2.0 // indirect
@@ -31,6 +34,10 @@ require (
 	github.com/gorilla/mux v1.8.0 // indirect
 	github.com/gsora/fidati v0.0.0-20220824075547-eeb0a5f7d6c3 // indirect
 	github.com/kr/text v0.2.0 // indirect
+	github.com/matttproud/golang_protobuf_extensions v1.0.4 // indirect
+	github.com/prometheus/client_model v0.3.0 // indirect
+	github.com/prometheus/common v0.42.0 // indirect
+	github.com/prometheus/procfs v0.10.1 // indirect
 	github.com/transparency-dev/formats v0.0.0-20230607101544-c064fae4cff6 // indirect
 	github.com/transparency-dev/merkle v0.0.2 // indirect
 	golang.org/x/net v0.11.0 // indirect
@@ -41,3 +48,5 @@ require (
 	google.golang.org/appengine v1.6.7 // indirect
 	google.golang.org/genproto v0.0.0-20230410155749-daa745c078e1 // indirect
 )
+
+replace github.com/prometheus/procfs => ../procfs

go.sum

@@ -1,15 +1,21 @@
 github.com/beevik/ntp v1.2.0 h1:n1teVGbd4YM36FlGvWYfccBIdGzeaakHrTlo6RSL8mw=
 github.com/beevik/ntp v1.2.0/go.mod h1:vD6h1um4kzXpqmLTuu0cCLcC+NfvC0IC+ltmEDA8E78=
+github.com/beorn7/perks v1.0.1 h1:VlbKKnNfV8bJzeqoa4cOKqO6bYr3WgKZxO8Z16+hsOM=
+github.com/beorn7/perks v1.0.1/go.mod h1:G2ZrVWU2WbWT9wwq4/hrbKbnv/1ERSJQ0ibhJ6rlkpw=
 github.com/cenkalti/backoff/v4 v4.2.1 h1:y4OZtCnogmCPw98Zjyt5a6+QwPLGkiQsYW5oUqylYbM=
 github.com/cenkalti/backoff/v4 v4.2.1/go.mod h1:Y3VNntkOUPxTVeUxJ/G5vcM//AlwfmyYozVcomhLiZE=
+github.com/cespare/xxhash/v2 v2.2.0 h1:DC2CZ1Ep5Y4k3ZQ899DldepgrayRUGE6BBZ/cd9Cj44=
+github.com/cespare/xxhash/v2 v2.2.0/go.mod h1:VGX0DQ3Q6kWi7AoAeZDth3/j3BFtOZR5XLFGgcrjCOs=
 github.com/creack/pty v1.1.9/go.mod h1:oKZEueFk5CKHvIhNR5MUki03XCEU+Q6VDXinZuGJ33E=
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/golang/glog v1.1.1 h1:jxpi2eWoU84wbX9iIEyAeeoac3FLuifZpY9tcNUD9kw=
 github.com/golang/glog v1.1.1/go.mod h1:zR+okUeTbrL6EL3xHUDxZuEtGv04p5shwip1+mL/rLQ=
+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/go.mod h1:6lQm79b+lXiMfvg/cZm0SGofjICqVBUtrP5yJMmIC1U=
+github.com/golang/protobuf v1.3.5/go.mod h1:6O5/vntMXwX2lRkT1hjjk0nAC1IDOTvTlVgjlRvqsdk=
 github.com/golang/protobuf v1.5.0/go.mod h1:FsONVRAS9T7sI+LIUmWTfcYkHO4aIWwzhcaSAoJOfIk=
 github.com/golang/protobuf v1.5.3 h1:KhyjKVUg7Usr/dYsdSqoFveMYd5ko72D+zANwlG1mmg=
 github.com/golang/protobuf v1.5.3/go.mod h1:XVQd3VNwM+JqD3oG2Ue2ip4fOMUkwXdXDdiuN0vRsmY=
@@ -34,8 +40,16 @@ github.com/kr/pretty v0.3.1 h1:flRD4NNwYAUpkphVc1HcthR4KEIFJ65n8Mw5qdRn3LE=
 github.com/kr/text v0.2.0 h1:5Nx0Ya0ZqY2ygV366QzturHI13Jq95ApcVaJBhpS+AY=
 github.com/kr/text v0.2.0/go.mod h1:eLer722TekiGuMkidMxC/pM04lWEeraHUUmBw8l2grE=
 github.com/mattn/go-sqlite3 v1.14.17 h1:mCRHCLDUBXgpKAqIKsaAaAsrAlbkeomtRFKXh2L6YIM=
+github.com/matttproud/golang_protobuf_extensions v1.0.4 h1:mmDVorXM7PCGKw94cs5zkfA9PSy5pEvNWRP0ET0TIVo=
+github.com/matttproud/golang_protobuf_extensions v1.0.4/go.mod h1:BSXmuO+STAnVfrANrmjBb36TMTDstsz7MSK+HVaYKv4=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/prometheus/client_golang v1.16.0 h1:yk/hx9hDbrGHovbci4BY+pRMfSuuat626eFsHb7tmT8=
+github.com/prometheus/client_golang v1.16.0/go.mod h1:Zsulrv/L9oM40tJ7T815tM89lFEugiJ9HzIqaAx4LKc=
+github.com/prometheus/client_model v0.3.0 h1:UBgGFHqYdG/TPFD1B1ogZywDqEkwp3fBMvqdiQ7Xew4=
+github.com/prometheus/client_model v0.3.0/go.mod h1:LDGWKZIo7rky3hgvBe+caln+Dr3dPggB5dvjtD7w9+w=
+github.com/prometheus/common v0.42.0 h1:EKsfXEYo4JpWMHH5cg+KOUWeuJSov1Id8zGR8eeI1YM=
+github.com/prometheus/common v0.42.0/go.mod h1:xBwqVerjNdUDjgODMpudtOMwlOwf2SaTr1yjz4b7Zbc=
 github.com/rakyll/statik v0.1.7/go.mod h1:AlZONWzMtEnMs7W4e/1LURLiI49pIMmp6V9Unghqrcc=
 github.com/rogpeppe/go-internal v1.10.0 h1:TMyTOH3F/DB16zRVcYyreMH6GnZZrwQVAoYjRBZyWFQ=
 github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
@@ -84,6 +98,7 @@ golang.org/x/net v0.11.0/go.mod h1:2L/ixqYpgIVXmeoSA/4Lu7BzTG4KIyPIryS4IsOd1oQ=
 golang.org/x/oauth2 v0.0.0-20180821212333-d2e6202438be/go.mod h1:N/0e6XlmueqKjAGxoOufVs8QHGRruUQn6yWY3a++T0U=
 golang.org/x/oauth2 v0.9.0 h1:BPpt2kU7oMRq3kCHAA1tbSEshXRw1LpG2ztgDwrzuAs=
 golang.org/x/oauth2 v0.9.0/go.mod h1:qYgFZaFiu6Wg24azG8bdV52QJXJGbZzIIsRCdVKzbLw=
+golang.org/x/sync v0.0.0-20181221193216-37e7f081c4d4/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sync v0.0.0-20190423024810-112230192c58/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sync v0.0.0-20220722155255-886fb9371eb4/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sync v0.1.0/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=

trusted_applet/main.go

@@ -26,6 +26,7 @@ import (
 	"strings"
 	"time"
 
+	"github.com/prometheus/client_golang/prometheus/promhttp"
 	"github.com/usbarmory/GoTEE/applet"
 	"github.com/usbarmory/GoTEE/syscall"
 	"github.com/usbarmory/tamago/soc/nxp/usdhc"
@@ -40,6 +41,7 @@ import (
 
 	"github.com/golang/glog"
 	"github.com/transparency-dev/witness/monitoring"
+	"github.com/transparency-dev/witness/monitoring/prometheus"
 	"github.com/transparency-dev/witness/omniwitness"
 	"golang.org/x/mod/sumdb/note"
 
@@ -92,7 +94,10 @@ func main() {
 	ctx := context.Background()
 	defer applet.Exit()
 
-	monitoring.SetMetricFactory(monitoring.InertMetricFactory{})
+	mf := prometheus.MetricFactory{
+		Prefix: "omniwitness_",
+	}
+	monitoring.SetMetricFactory(mf)
 
 	log.Printf("%s/%s (%s) • TEE user applet • %s %s",
 		runtime.GOOS, runtime.GOARCH, runtime.Version(),
@@ -224,18 +229,40 @@ func runWithNetworking(ctx context.Context) error {
 
 	listenCfg := &net.ListenConfig{}
 
-	listener, err := listenCfg.Listen(ctx, "tcp", ":22")
+	sshListener, err := listenCfg.Listen(ctx, "tcp", ":22")
 	if err != nil {
 		return fmt.Errorf("TA could not initialize SSH listener, %v", err)
 	}
 	defer func() {
 		log.Println("Closing ssh port")
-		if err := listener.Close(); err != nil {
+		if err := sshListener.Close(); err != nil {
 			log.Printf("Error closing ssh port: %v", err)
 		}
 	}()
+	go startSSHServer(ctx, sshListener, addr.Address.String(), 22, cmd.Console)
 
-	go startSSHServer(ctx, listener, addr.Address.String(), 22, cmd.Console)
+	metricsListener, err := listenCfg.Listen(ctx, "tcp", ":8081")
+	if err != nil {
+		return fmt.Errorf("TA could not initialize metrics listener, %v", err)
+	}
+	defer func() {
+		log.Println("Closing metrics port (8081)")
+		if err := metricsListener.Close(); err != nil {
+			log.Printf("Error closing ssh port: %v", err)
+		}
+	}()
+	go func() {
+		srvMux := http.NewServeMux()
+		srvMux.Handle("/metrics", promhttp.Handler())
+		srv := &http.Server{
+			ReadTimeout:  5 * time.Second,
+			WriteTimeout: 10 * time.Second,
+			Handler:      srvMux,
+		}
+		if err := srv.Serve(metricsListener); err != http.ErrServerClosed {
+			glog.Errorf("Error serving metrics: %v", err)
+		}
+	}()
 
 	// Set up and start omniwitness
 	signer, err := note.NewSigner(signingKey)