barriers: reveal more safe details about the masked error

This commit extracts more safe details for the error hidden behind a
barrier. It achieves this using the new `SafeFormatError()` API via
the `redact` package.

As a side effect, this guarantees that a sentry report for a
barrier (including, but not limited to, assertion failures constructed
with errors.NewAssertionErrorWithWrappedErrf) now always spells out
the type of the error behind the barrier. It also includes any
safe-for-reporting strings that the hidden error object would report
when printed out via `%+v`.

Note that this patch is a band-aid: this is really adding more
complexity to the `SafeDetails()` API, which is arguably somewhat
obsolete now that the `errors` and `redact` packages collaborate to
extract safe strings. However, there is some marginal utility
remaining, in the particular case of an error object transported over
the wire where the target server doesn't know how to decode the error
behind the barrier; in this case, the approach taken here ensures that
a modicum of reportable structure is still included.

barriers/barriers.go

@@ -19,6 +19,7 @@ import (
 	"fmt"
 
 	"github.com/cockroachdb/errors/errbase"
+	"github.com/cockroachdb/redact"
 	"github.com/gogo/protobuf/proto"
 )
 
@@ -88,6 +89,7 @@ func (e *barrierError) SafeDetails() []string {
 		sd := errbase.GetSafeDetails(err)
 		details = sd.Fill(details)
 	}
+	details = append(details, redact.Sprintf("masked error: %+v", e.maskedErr).Redact().StripMarkers())
 	return details
 }
 

fmttests/testdata/format/wrap-fmt

@@ -137,9 +137,18 @@ Error types: (1) *assert.withAssertionFailure (2) *withstack.withStack (3) *barr
 <path>:<lineno>: ×
 ×
 --
-*barriers.barrierError
+*barriers.barrierError: masked error: × (1)
 <path>:<lineno>: *withstack.withStack (top exception)
 *assert.withAssertionFailure
+(check the extra data payloads)
+== Extra "1: details"
+masked error: ×
+   (1) ××
+   ×
+   ×
+   ×
+   ×
+   Error types: (1) *fmttests.errFmt
 == Extra "error types"
 github.com/cockroachdb/errors/barriers/*barriers.barrierError (*::)
 github.com/cockroachdb/errors/withstack/*withstack.withStack (*::)
@@ -324,12 +333,20 @@ Error types: (1) *assert.withAssertionFailure (2) *withstack.withStack (3) *erru
 ×: ×
 ×
 --
-*barriers.barrierError
-*errutil.withPrefix: assertmsg: × (1)
+*barriers.barrierError: masked error: × (1)
+*errutil.withPrefix: assertmsg: × (2)
 <path>:<lineno>: *withstack.withStack (top exception)
 *assert.withAssertionFailure
 (check the extra data payloads)
 == Extra "1: details"
+masked error: ×
+   (1) ××
+   ×
+   ×
+   ×
+   ×
+   Error types: (1) *fmttests.errFmt
+== Extra "2: details"
 assertmsg: ×
    ×
 == Extra "error types"
@@ -440,7 +457,16 @@ Error types: (1) *barriers.barrierError
 ×
 ×
 --
-*barriers.barrierError
+*barriers.barrierError: masked error: × (1)
+(check the extra data payloads)
+== Extra "1: details"
+masked error: ×
+   (1) ××
+   ×
+   ×
+   ×
+   ×
+   Error types: (1) *fmttests.errFmt
 == Extra "error types"
 github.com/cockroachdb/errors/barriers/*barriers.barrierError (*::)
 == Exception 1 (Module: "error domain: <none>")
@@ -1528,10 +1554,18 @@ Error types: (1) *domains.withDomain (2) *barriers.barrierError
 ×
 ×
 --
-*barriers.barrierError
-*domains.withDomain: error domain: pkg <path> (1)
+*barriers.barrierError: masked error: × (1)
+*domains.withDomain: error domain: pkg <path> (2)
 (check the extra data payloads)
 == Extra "1: details"
+masked error: ×
+   (1) ××
+   ×
+   ×
+   ×
+   ×
+   Error types: (1) *fmttests.errFmt
+== Extra "2: details"
 error domain: pkg <path>
 == Extra "error types"
 github.com/cockroachdb/errors/barriers/*barriers.barrierError (*::)

fmttests/testdata/format/wrap-fmt-via-network

@@ -172,9 +172,18 @@ Error types: (1) *assert.withAssertionFailure (2) *errbase.opaqueWrapper (3) *ba
 <path>:<lineno>: ×
 ×
 --
-*barriers.barrierError
+*barriers.barrierError: masked error: × (1)
 <path>:<lineno>: *withstack.withStack (top exception)
 *assert.withAssertionFailure
+(check the extra data payloads)
+== Extra "1: details"
+masked error: ×
+   (1) ×
+     | ×
+     |
+     | (opaque error leaf)
+     | type name: github.com/cockroachdb/errors/fmttests/*fmttests.errFmt
+   Error types: (1) *errbase.opaqueLeaf
 == Extra "error types"
 github.com/cockroachdb/errors/barriers/*barriers.barrierError (*::)
 github.com/cockroachdb/errors/withstack/*withstack.withStack (*::)
@@ -394,12 +403,20 @@ Error types: (1) *assert.withAssertionFailure (2) *errbase.opaqueWrapper (3) *er
 ×: ×
 ×
 --
-*barriers.barrierError
-*errutil.withPrefix: assertmsg: × (1)
+*barriers.barrierError: masked error: × (1)
+*errutil.withPrefix: assertmsg: × (2)
 <path>:<lineno>: *withstack.withStack (top exception)
 *assert.withAssertionFailure
 (check the extra data payloads)
 == Extra "1: details"
+masked error: ×
+   (1) ×
+     | ×
+     |
+     | (opaque error leaf)
+     | type name: github.com/cockroachdb/errors/fmttests/*fmttests.errFmt
+   Error types: (1) *errbase.opaqueLeaf
+== Extra "2: details"
 assertmsg: ×
    ×
 == Extra "error types"
@@ -527,7 +544,16 @@ Error types: (1) *barriers.barrierError
 ×
 ×
 --
-*barriers.barrierError
+*barriers.barrierError: masked error: × (1)
+(check the extra data payloads)
+== Extra "1: details"
+masked error: ×
+   (1) ×
+     | ×
+     |
+     | (opaque error leaf)
+     | type name: github.com/cockroachdb/errors/fmttests/*fmttests.errFmt
+   Error types: (1) *errbase.opaqueLeaf
 == Extra "error types"
 github.com/cockroachdb/errors/barriers/*barriers.barrierError (*::)
 == Exception 1 (Module: "error domain: <none>")
@@ -1965,10 +1991,18 @@ Error types: (1) *domains.withDomain (2) *barriers.barrierError
 ×
 ×
 --
-*barriers.barrierError
-*domains.withDomain: error domain: pkg <path> (1)
+*barriers.barrierError: masked error: × (1)
+*domains.withDomain: error domain: pkg <path> (2)
 (check the extra data payloads)
 == Extra "1: details"
+masked error: ×
+   (1) ×
+     | ×
+     |
+     | (opaque error leaf)
+     | type name: github.com/cockroachdb/errors/fmttests/*fmttests.errFmt
+   Error types: (1) *errbase.opaqueLeaf
+== Extra "2: details"
 error domain: pkg <path>
 == Extra "error types"
 github.com/cockroachdb/errors/barriers/*barriers.barrierError (*::)

fmttests/testdata/format/wrap-goerr

@@ -131,9 +131,15 @@ Error types: (1) *assert.withAssertionFailure (2) *withstack.withStack (3) *barr
 <path>:<lineno>: ×
 ×
 --
-*barriers.barrierError
+*barriers.barrierError: masked error: × (1)
 <path>:<lineno>: *withstack.withStack (top exception)
 *assert.withAssertionFailure
+(check the extra data payloads)
+== Extra "1: details"
+masked error: ×
+   (1) ××
+   ×
+   Error types: (1) *errors.errorString
 == Extra "error types"
 github.com/cockroachdb/errors/barriers/*barriers.barrierError (*::)
 github.com/cockroachdb/errors/withstack/*withstack.withStack (*::)
@@ -312,12 +318,17 @@ Error types: (1) *assert.withAssertionFailure (2) *withstack.withStack (3) *erru
 ×: ×
 ×
 --
-*barriers.barrierError
-*errutil.withPrefix: assertmsg: × (1)
+*barriers.barrierError: masked error: × (1)
+*errutil.withPrefix: assertmsg: × (2)
 <path>:<lineno>: *withstack.withStack (top exception)
 *assert.withAssertionFailure
 (check the extra data payloads)
 == Extra "1: details"
+masked error: ×
+   (1) ××
+   ×
+   Error types: (1) *errors.errorString
+== Extra "2: details"
 assertmsg: ×
    ×
 == Extra "error types"
@@ -422,7 +433,13 @@ Error types: (1) *barriers.barrierError
 ×
 ×
 --
-*barriers.barrierError
+*barriers.barrierError: masked error: × (1)
+(check the extra data payloads)
+== Extra "1: details"
+masked error: ×
+   (1) ××
+   ×
+   Error types: (1) *errors.errorString
 == Extra "error types"
 github.com/cockroachdb/errors/barriers/*barriers.barrierError (*::)
 == Exception 1 (Module: "error domain: <none>")
@@ -1422,10 +1439,15 @@ Error types: (1) *domains.withDomain (2) *barriers.barrierError
 ×
 ×
 --
-*barriers.barrierError
-*domains.withDomain: error domain: pkg <path> (1)
+*barriers.barrierError: masked error: × (1)
+*domains.withDomain: error domain: pkg <path> (2)
 (check the extra data payloads)
 == Extra "1: details"
+masked error: ×
+   (1) ××
+   ×
+   Error types: (1) *errors.errorString
+== Extra "2: details"
 error domain: pkg <path>
 == Extra "error types"
 github.com/cockroachdb/errors/barriers/*barriers.barrierError (*::)

fmttests/testdata/format/wrap-goerr-via-network

@@ -150,9 +150,15 @@ Error types: (1) *assert.withAssertionFailure (2) *errbase.opaqueWrapper (3) *ba
 <path>:<lineno>: ×
 ×
 --
-*barriers.barrierError
+*barriers.barrierError: masked error: × (1)
 <path>:<lineno>: *withstack.withStack (top exception)
 *assert.withAssertionFailure
+(check the extra data payloads)
+== Extra "1: details"
+masked error: ×
+   (1) ××
+   ×
+   Error types: (1) *errors.errorString
 == Extra "error types"
 github.com/cockroachdb/errors/barriers/*barriers.barrierError (*::)
 github.com/cockroachdb/errors/withstack/*withstack.withStack (*::)
@@ -350,12 +356,17 @@ Error types: (1) *assert.withAssertionFailure (2) *errbase.opaqueWrapper (3) *er
 ×: ×
 ×
 --
-*barriers.barrierError
-*errutil.withPrefix: assertmsg: × (1)
+*barriers.barrierError: masked error: × (1)
+*errutil.withPrefix: assertmsg: × (2)
 <path>:<lineno>: *withstack.withStack (top exception)
 *assert.withAssertionFailure
 (check the extra data payloads)
 == Extra "1: details"
+masked error: ×
+   (1) ××
+   ×
+   Error types: (1) *errors.errorString
+== Extra "2: details"
 assertmsg: ×
    ×
 == Extra "error types"
@@ -461,7 +472,13 @@ Error types: (1) *barriers.barrierError
 ×
 ×
 --
-*barriers.barrierError
+*barriers.barrierError: masked error: × (1)
+(check the extra data payloads)
+== Extra "1: details"
+masked error: ×
+   (1) ××
+   ×
+   Error types: (1) *errors.errorString
 == Extra "error types"
 github.com/cockroachdb/errors/barriers/*barriers.barrierError (*::)
 == Exception 1 (Module: "error domain: <none>")
@@ -1613,10 +1630,15 @@ Error types: (1) *domains.withDomain (2) *barriers.barrierError
 ×
 ×
 --
-*barriers.barrierError
-*domains.withDomain: error domain: pkg <path> (1)
+*barriers.barrierError: masked error: × (1)
+*domains.withDomain: error domain: pkg <path> (2)
 (check the extra data payloads)
 == Extra "1: details"
+masked error: ×
+   (1) ××
+   ×
+   Error types: (1) *errors.errorString
+== Extra "2: details"
 error domain: pkg <path>
 == Extra "error types"
 github.com/cockroachdb/errors/barriers/*barriers.barrierError (*::)