[AWS Block Support] Invalid memory address or nil pointer dereference for AWS Volume Updation

[himanshuvar]

Issue/Feature Description: AWS Block Updation is failing with the following reason:

Invalid memory address or nil pointer dereference

Error logs:

[2020-09-28T12:21:54+05:30] [ERROR] [/root/gopath/src/github.com/opensds/multi-cloud/contrib/datastore/block/aws/aws.go] [aws.(*AwsAdapter).UpdateVolume():322] [PID:1] InvalidParameterValue: Iops to volume size ratio of Infinity is too high; maximum is 50
        status code: 400, request id: 18be4668-5783-4856-80db-4b3554c6a256
[2020-09-28T12:21:54+05:30] [ERROR] [/root/gopath/src/github.com/opensds/multi-cloud/block/pkg/service/service.go] [service.(*blockService).UpdateVolume():285] [PID:1] Received error in updating volumes at backend, error: Get object from backend failed.
2020-09-28 12:21:54  file=grpc.go:372 level=error panic recovered: runtime error: invalid memory address or nil pointer dereference
2020-09-28 12:21:54  file=grpc.go:373 level=error goroutine 18086 [running]:
runtime/debug.Stack(0xc00000c4e0, 0xc000951a02, 0xc000951a80)
        /usr/local/go/src/runtime/debug/stack.go:24 +0x9d
github.com/micro/go-micro/v2/server/grpc.(*grpcServer).processRequest.func1.1(0xc0005e7250)
        /root/gopath/pkg/mod/github.com/micro/go-micro/v2@v2.6.0/server/grpc/grpc.go:373 +0x2cf
panic(0x1838480, 0x2c43360)
        /usr/local/go/src/runtime/panic.go:679 +0x1b2
github.com/opensds/multi-cloud/block/pkg/service.(*blockService).UpdateVolume(0xc0005651c0, 0x1ef09c0, 0xc000634390, 0xc000808640, 0xc000634150, 0x498f1c, 0x193d700)
        /root/gopath/src/github.com/opensds/multi-cloud/block/pkg/service/service.go:286 +0x51a
github.com/opensds/multi-cloud/block/proto.(*blockHandler).UpdateVolume(0xc0007d10e0, 0x1ef09c0, 0xc000634390, 0xc000808640, 0xc000634150, 0x7f5223ccb008, 0x0)
        /root/gopath/src/github.com/opensds/multi-cloud/block/proto/block.pb.micro.go:157 +0x5b
reflect.Value.call(0xc0007d2900, 0xc0008302d8, 0x13, 0x1b16bcc, 0x4, 0xc00001f1b0, 0x4, 0x4, 0x16, 0x19830c0, ...)
        /usr/local/go/src/reflect/value.go:460 +0x5f6
reflect.Value.Call(0xc0007d2900, 0xc0008302d8, 0x13, 0xc00001f1b0, 0x4, 0x4, 0x203000, 0xc00001f1b0, 0x40c1d6)
        /usr/local/go/src/reflect/value.go:321 +0xb4
github.com/micro/go-micro/v2/server/grpc.(*grpcServer).processRequest.func1(0x1ef09c0, 0xc000634390, 0x1f06e20, 0xc000a6d080, 0x193d700, 0xc000634150, 0x0, 0x0)
        /root/gopath/pkg/mod/github.com/micro/go-micro/v2@v2.6.0/server/grpc/grpc.go:378 +0x303
github.com/micro/go-micro/v2/util/wrapper.AuthHandler.func1.1(0x1ef09c0, 0xc000634330, 0x1f06e20, 0xc000a6d080, 0x193d700, 0xc000634150, 0xc000634330, 0xc0001c65b0)
        /root/gopath/pkg/mod/github.com/micro/go-micro/v2@v2.6.0/util/wrapper/wrapper.go:282 +0x5e3
github.com/micro/go-micro/v2/util/wrapper.TraceHandler.func1.1(0x1ef0900, 0xc000808600, 0x1f06e20, 0xc000a6d080, 0x193d700, 0xc000634150, 0x16, 0x193d700)
        /root/gopath/pkg/mod/github.com/micro/go-micro/v2@v2.6.0/util/wrapper/wrapper.go:122 +0x1c6
github.com/micro/go-micro/v2/util/wrapper.HandlerStats.func1.1(0x1ef0900, 0xc000808600, 0x1f06e20, 0xc000a6d080, 0x193d700, 0xc000634150, 0x12, 0x0)
        /root/gopath/pkg/mod/github.com/micro/go-micro/v2@v2.6.0/util/wrapper/wrapper.go:67 +0x83
github.com/micro/go-micro/v2/server/grpc.(*grpcServer).processRequest(0xc0001ef380, 0x1efc7a0, 0xc0005480c0, 0xc0008455c0, 0xc0007e6360, 0xc0009ee2c0, 0x16, 0x1ef0900, 0xc000808600, 0xc000589c00, ...)
        /root/gopath/pkg/mod/github.com/micro/go-micro/v2@v2.6.0/server/grpc/grpc.go:395 +0x7ee
github.com/micro/go-micro/v2/server/grpc.(*grpcServer).handler(0xc0001ef380, 0x0, 0x0, 0x1efc7a0, 0xc0005480c0, 0x0, 0x0)
        /root/gopath/pkg/mod/github.com/micro/go-micro/v2@v2.6.0/server/grpc/grpc.go:314 +0x77f
google.golang.org/grpc.(*Server).processStreamingRPC(0xc000814300, 0x1f06e80, 0xc0002c3080, 0xc000890200, 0x0, 0xc0005650e0, 0x0, 0x0, 0x0)
        /root/gopath/pkg/mod/google.golang.org/grpc@v1.26.0/server.go:1237 +0xb42
google.golang.org/grpc.(*Server).handleStream(0xc000814300, 0x1f06e80, 0xc0002c3080, 0xc000890200, 0x0)
        /root/gopath/pkg/mod/google.golang.org/grpc@v1.26.0/server.go:1323 +0xc0a
google.golang.org/grpc.(*Server).serveStreams.func1.1(0xc000042690, 0xc000814300, 0x1f06e80, 0xc0002c3080, 0xc000890200)
        /root/gopath/pkg/mod/google.golang.org/grpc@v1.26.0/server.go:722 +0xbb
created by google.golang.org/grpc.(*Server).serveStreams.func1
        /root/gopath/pkg/mod/google.golang.org/grpc@v1.26.0/server.go:720 +0xa1

Why this issue to fixed / feature is needed(give scenarios or use cases): To Support AWS Volume Updation with proper Error Handling

How to reproduce, in case of a bug:

1. Create AWS Backend for block service
2. Update AWS with 1 Bytes Size

Other Notes / Environment Information: (Please give the env information, log link or any useful information for this issue)

[himanshuvar]

PR merged