Context: phalanx with file storage configured
When I made a call to create index with minio & etcd took down whole phalanx with panic error:

phalanx {"_level_":"info","_timestamp_":"2022-09-28T08:19:20.986Z","_name_":"phalanx","_caller_":"server/index_service.go:198","_message_":"opening index writers"} phalanx {"_level_":"error","_timestamp_":"2022-09-28T08:19:20.986Z","_name_":"phalanx.manager.writer.directory","_caller_":"directory/directory_minio.go:48","_message_":"Endpoint: does not follow ip address or domain name standards.","uri":"minio://phalanx/indexes/product/shard-2qpDDnjJ"} phalanx panic: runtime error: invalid memory address or nil pointer dereference phalanx [signal SIGSEGV: segmentation violation code=0x1 addr=0x28 pc=0x11ea50d] phalanx phalanx goroutine 49 [running]: phalanx github.com/mosuka/phalanx/directory.(*MinioDirectory).exists(0x0) phalanx /go/src/github.com/mosuka/phalanx/directory/directory_minio.go:77 +0x4d phalanx github.com/mosuka/phalanx/directory.(*MinioDirectory).Setup(0x0, 0xb) phalanx /go/src/github.com/mosuka/phalanx/directory/directory_minio.go:95 +0x53 phalanx github.com/blugelabs/bluge/index.OpenWriter({{0x15b6c0b, 0x3}, 0x1, 0xc0002263c0, 0x0, 0x0, 0x0, {0xa, 0x4c4b40, 0x4024000000000000, ...}, ...}) phalanx /go/pkg/mod/github.com/blugelabs/bluge@v0.1.9/index/writer.go:85 +0x394 phalanx github.com/blugelabs/bluge.OpenWriter({{{0x15b6c0b, 0x3}, 0x1, 0xc0002263c0, 0x0, 0x0, 0x0, {0xa, 0x4c4b40, 0x4024000000000000, ...}, ...}, ...}) phalanx /go/pkg/mod/github.com/blugelabs/bluge@v0.1.9/writer.go:36 +0xb8 phalanx github.com/mosuka/phalanx/index.(*IndexWriters).open(0xc00020b4a0, {0xc0005fc88a, 0x7}, {0xc0003a9a62, 0xe}, 0xc0005fe5a0, 0xc0001a8b00) phalanx /go/src/github.com/mosuka/phalanx/index/writer.go:107 +0x3b8 phalanx github.com/mosuka/phalanx/index.(*IndexWriters).Open(0xc00020b4a0, {0xc0005fc88a, 0x7}, {0xc0003a9a62, 0xe}, 0x0, 0x0) phalanx /go/src/github.com/mosuka/phalanx/index/writer.go:128 +0xe7 phalanx github.com/mosuka/phalanx/server.(*IndexService).assignShardsToNode(0xc000124a80) phalanx /go/src/github.com/mosuka/phalanx/server/index_service.go:216 +0x3ce5 phalanx github.com/mosuka/phalanx/server.(*IndexService).Start.func1() phalanx /go/src/github.com/mosuka/phalanx/server/index_service.go:114 +0x692 phalanx created by github.com/mosuka/phalanx/server.(*IndexService).Start phalanx /go/src/github.com/mosuka/phalanx/server/index_service.go:86 +0x5b

The expected behaviour should be an appropriate HTTP error code returned, index creation attempt should not happened and the application should be functional