Error when uploading a signature to Rekor: signature already exists

[mayaCostantini]

When uploading a signature to Rekor, the following error occurs:

Signature already exists. Displaying proof
Error: signing [mayacostantini/alpine]: recursively signing: signing digest: [GET /api/v1/log/entries/{entryUUID}][404] getLogEntryByUuidNotFound 
main.go:74: error during command execution: signing [mayacostantini/alpine]: recursively signing: signing digest: [GET /api/v1/log/entries/{entryUUID}][404] getLogEntryByUuidNotFound

Getting the log info via curl -k https://rekor.ec2.internal/api/v1/log shows that no entry was uploaded:

{"inactiveShards":null,"rootHash":"e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855","signedTreeHead":"rekor-server - 8170099747802235901\n0\n47DEQpj8HBSa+/TImW+5JCeuQeRkm5NMpJWZG3hSuFU=\nTimestamp: 1690384264448029396\n\n? rekor-server rcgeOTBEAiA35EI0mfZq+BScEB5ZtGOiqVKD6vSWeWI7vC5puwBMHAIgVDURmsL5I3Dmb2RRraz8WMoi9zUEuhPzDBrkd9O7OWA=\n","treeID":"8170099747802235901","treeSize":0}

This error should not occur as the log does not have any signatures.

Full traceback from the rekor server pod logs:

2023-07-26T15:05:19.534Z	ERROR	api/error.go:72	error processing request	{"requestID": "rekor-server/QXZyBkQeAD-000037", "handler": "entries.GetLogEntryByUUID", "statusCode": 404, "clientMessage": "Not Found", "error": "grpc returned 0 leaves with success code"}
github.com/sigstore/rekor/pkg/api.handleRekorAPIError.func1
	github.com/sigstore/rekor/pkg/api/error.go:72
github.com/sigstore/rekor/pkg/api.handleRekorAPIError
	github.com/sigstore/rekor/pkg/api/error.go:89
github.com/sigstore/rekor/pkg/api.GetLogEntryByUUIDHandler
	github.com/sigstore/rekor/pkg/api/entries.go:340
github.com/sigstore/rekor/pkg/generated/restapi/operations/entries.GetLogEntryByUUIDHandlerFunc.Handle
	github.com/sigstore/rekor/pkg/generated/restapi/operations/entries/get_log_entry_by_uuid.go:35
github.com/sigstore/rekor/pkg/generated/restapi/operations/entries.(*GetLogEntryByUUID).ServeHTTP
	github.com/sigstore/rekor/pkg/generated/restapi/operations/entries/get_log_entry_by_uuid.go:71
github.com/go-chi/chi/middleware.NoCache.func1
	github.com/go-chi/chi@v4.1.2+incompatible/middleware/nocache.go:54
net/http.HandlerFunc.ServeHTTP
	net/http/server.go:2109
github.com/sigstore/rekor/pkg/generated/restapi.recordMetricsForAPI.func1.1
	github.com/sigstore/rekor/pkg/generated/restapi/configure_rekor_server.go:222
net/http.HandlerFunc.ServeHTTP
	net/http/server.go:2109
github.com/go-openapi/runtime/middleware.NewOperationExecutor.func1
	github.com/go-openapi/runtime@v0.24.1/middleware/operation.go:28
net/http.HandlerFunc.ServeHTTP
	net/http/server.go:2109
github.com/go-openapi/runtime/middleware.NewRouter.func1
	github.com/go-openapi/runtime@v0.24.1/middleware/router.go:78
net/http.HandlerFunc.ServeHTTP
	net/http/server.go:2109
github.com/go-openapi/runtime/middleware.Redoc.func1
	github.com/go-openapi/runtime@v0.24.1/middleware/redoc.go:72
net/http.HandlerFunc.ServeHTTP
	net/http/server.go:2109
github.com/go-openapi/runtime/middleware.Spec.func1
	github.com/go-openapi/runtime@v0.24.1/middleware/spec.go:46
net/http.HandlerFunc.ServeHTTP
	net/http/server.go:2109
github.com/go-chi/chi/middleware.RequestLogger.func1.1
	github.com/go-chi/chi@v4.1.2+incompatible/middleware/logger.go:46
net/http.HandlerFunc.ServeHTTP
	net/http/server.go:2109
github.com/go-chi/chi/middleware.Recoverer.func1
	github.com/go-chi/chi@v4.1.2+incompatible/middleware/recoverer.go:37
net/http.HandlerFunc.ServeHTTP
	net/http/server.go:2109
github.com/go-chi/chi/middleware.Heartbeat.func1.1
	github.com/go-chi/chi@v4.1.2+incompatible/middleware/heartbeat.go:21
net/http.HandlerFunc.ServeHTTP
	net/http/server.go:2109
github.com/sigstore/rekor/pkg/generated/restapi.serveStaticContent.func1
	github.com/sigstore/rekor/pkg/generated/restapi/configure_rekor_server.go:296
net/http.HandlerFunc.ServeHTTP
	net/http/server.go:2109
github.com/rs/cors.(*Cors).Handler.func1
	github.com/rs/cors@v1.8.2/cors.go:231
net/http.HandlerFunc.ServeHTTP
	net/http/server.go:2109
github.com/sigstore/rekor/pkg/generated/restapi.wrapMetrics.func1
	github.com/sigstore/rekor/pkg/generated/restapi/configure_rekor_server.go:266
net/http.HandlerFunc.ServeHTTP
	net/http/server.go:2109
github.com/sigstore/rekor/pkg/generated/restapi.setupGlobalMiddleware.func1
	github.com/sigstore/rekor/pkg/generated/restapi/configure_rekor_server.go:207
net/http.HandlerFunc.ServeHTTP
	net/http/server.go:2109
github.com/go-chi/chi/middleware.RequestID.func1
	github.com/go-chi/chi@v4.1.2+incompatible/middleware/request_id.go:76
net/http.HandlerFunc.ServeHTTP
	net/http/server.go:2109
net/http.serverHandler.ServeHTTP
	net/http/server.go:2947
net/http.(*conn).serve
	net/http/server.go:1991
2023-07-26T15:05:19.534Z	DEBUG	api/error.go:75	map[EntryUUID:e377b0a5758ae3e455062eaa132f349325b294a27171c760db42b759d44ddb19 HTTPRequest:0xc0000a4700]	{"requestID": "rekor-server/QXZyBkQeAD-000037"}
2023-07-26T15:05:19.534Z	INFO	restapi/configure_rekor_server.go:182	[rekor-server/QXZyBkQeAD-000037] "GET http://rekor.ec2.internal/api/v1/log/entries/e377b0a5758ae3e455062eaa132f349325b294a27171c760db42b759d44ddb19 HTTP/1.1" from 10.89.0.19:40434 - 404 0B in 5.45037ms