core: Move canceled.Is to core.IsCanceled (#7831)

Small refactor to use errors.Is() rather than the equality operator.
Also moves this utility function into core.

core/util.go

@@ -1,6 +1,7 @@
 package core
 
 import (
+	"context"
 	"crypto"
 	"crypto/ecdsa"
 	"crypto/rand"
@@ -27,9 +28,12 @@ import (
 	"unicode"
 
 	"github.com/go-jose/go-jose/v4"
-	"github.com/letsencrypt/boulder/identifier"
+	"google.golang.org/grpc/codes"
+	"google.golang.org/grpc/status"
 	"google.golang.org/protobuf/types/known/durationpb"
 	"google.golang.org/protobuf/types/known/timestamppb"
+
+	"github.com/letsencrypt/boulder/identifier"
 )
 
 const Unspecified = "Unspecified"
@@ -395,6 +399,14 @@ func IsASCII(str string) bool {
 	return true
 }
 
+// IsCanceled returns true if err is non-nil and is either context.Canceled, or
+// has a grpc code of Canceled. This is useful because cancellations propagate
+// through gRPC boundaries, and if we choose to treat in-process cancellations a
+// certain way, we usually want to treat cross-process cancellations the same way.
+func IsCanceled(err error) bool {
+	return errors.Is(err, context.Canceled) || status.Code(err) == codes.Canceled
+}
+
 func Command() string {
 	return path.Base(os.Args[0])
 }

core/util_test.go

@@ -2,7 +2,9 @@ package core
 
 import (
 	"bytes"
+	"context"
 	"encoding/json"
+	"errors"
 	"fmt"
 	"math"
 	"math/big"
@@ -13,6 +15,8 @@ import (
 	"time"
 
 	"github.com/go-jose/go-jose/v4"
+	"google.golang.org/grpc/codes"
+	"google.golang.org/grpc/status"
 	"google.golang.org/protobuf/types/known/durationpb"
 	"google.golang.org/protobuf/types/known/timestamppb"
 
@@ -362,3 +366,15 @@ func TestHashNames(t *testing.T) {
 	h2 = HashNames([]string{"a"})
 	test.AssertByteEquals(t, h1, h2)
 }
+
+func TestIsCanceled(t *testing.T) {
+	if !IsCanceled(context.Canceled) {
+		t.Errorf("Expected context.Canceled to be canceled, but wasn't.")
+	}
+	if !IsCanceled(status.Errorf(codes.Canceled, "hi")) {
+		t.Errorf("Expected gRPC cancellation to be canceled, but wasn't.")
+	}
+	if IsCanceled(errors.New("hi")) {
+		t.Errorf("Expected random error to not be canceled, but was.")
+	}
+}

publisher/publisher.go

@@ -25,7 +25,6 @@ import (
 	cttls "github.com/google/certificate-transparency-go/tls"
 	"github.com/prometheus/client_golang/prometheus"
 
-	"github.com/letsencrypt/boulder/canceled"
 	"github.com/letsencrypt/boulder/core"
 	"github.com/letsencrypt/boulder/issuance"
 	blog "github.com/letsencrypt/boulder/log"
@@ -261,7 +260,7 @@ func (pub *Impl) SubmitToSingleCTWithResult(ctx context.Context, req *pubpb.Requ
 
 	sct, err := pub.singleLogSubmit(ctx, chain, req.Kind, ctLog)
 	if err != nil {
-		if canceled.Is(err) {
+		if core.IsCanceled(err) {
 			return nil, err
 		}
 		var body string
@@ -297,7 +296,7 @@ func (pub *Impl) singleLogSubmit(
 	took := time.Since(start).Seconds()
 	if err != nil {
 		status := "error"
-		if canceled.Is(err) {
+		if core.IsCanceled(err) {
 			status = "canceled"
 		}
 		httpStatus := ""

va/caa.go

@@ -13,7 +13,6 @@ import (
 	"github.com/miekg/dns"
 
 	"github.com/letsencrypt/boulder/bdns"
-	"github.com/letsencrypt/boulder/canceled"
 	"github.com/letsencrypt/boulder/core"
 	corepb "github.com/letsencrypt/boulder/core/proto"
 	berrors "github.com/letsencrypt/boulder/errors"
@@ -234,7 +233,7 @@ func (va *ValidationAuthorityImpl) processRemoteCAAResults(
 // the number of remote VAs. The CAA checks will be performed in separate
 // go-routines. If the result `error` from a remote `isCAAValid` RPC is nil or a
 // nil `ProblemDetails` instance it is written directly to the `results` chan.
-// If the err is a cancelled error it is treated as a nil error. Otherwise the
+// If the err is a canceled error it is treated as a nil error. Otherwise the
 // error/problem is written to the results channel as-is.
 func (va *ValidationAuthorityImpl) performRemoteCAACheck(
 	ctx context.Context,
@@ -248,9 +247,9 @@ func (va *ValidationAuthorityImpl) performRemoteCAACheck(
 			}
 			res, err := rva.IsCAAValid(ctx, req)
 			if err != nil {
-				if canceled.Is(err) {
+				if core.IsCanceled(err) {
 					// Handle the cancellation error.
-					result.Problem = probs.ServerInternal("Remote VA IsCAAValid RPC cancelled")
+					result.Problem = probs.ServerInternal("Remote VA IsCAAValid RPC canceled")
 				} else {
 					// Handle validation error.
 					va.log.Errf("Remote VA %q.IsCAAValid failed: %s", rva.Address, err)

va/va.go

@@ -20,7 +20,6 @@ import (
 	"github.com/prometheus/client_golang/prometheus"
 
 	"github.com/letsencrypt/boulder/bdns"
-	"github.com/letsencrypt/boulder/canceled"
 	"github.com/letsencrypt/boulder/core"
 	berrors "github.com/letsencrypt/boulder/errors"
 	bgrpc "github.com/letsencrypt/boulder/grpc"
@@ -485,7 +484,7 @@ func (va *ValidationAuthorityImpl) performRemoteValidation(
 			// Failed to communicate with the remote VA.
 			failed = append(failed, resp.addr)
 
-			if canceled.Is(resp.err) {
+			if core.IsCanceled(resp.err) {
 				currProb = probs.ServerInternal("Remote PerformValidation RPC canceled")
 			} else {
 				va.log.Errf("Remote VA %q.PerformValidation failed: %s", resp.addr, resp.err)