docker: reduce images size

By introducing multi-stage build
And switching to alpine
And using grpcurl from docker

x10 size reduction !

```
$ docker images | grep opi
opi-storage-server                      main           44996bc55718   About a minute ago   50.7MB
ghcr.io/opiproject/opi-storage-server   main           ae1f6b66da01   18 hours ago         618MB

```

Signed-off-by: Boris Glimcher <[email protected]>

server/Dockerfile

@@ -1,8 +1,7 @@
-# syntax=docker/dockerfile:1
+# SPDX-License-Identifier: Apache-2.0
+# Copyright (c) 2022 Dell Inc, or its subsidiaries.
 
-# Alpine is chosen for its small footprint
-# compared to Ubuntu
-FROM docker.io/library/golang:1.19.5-alpine
+FROM docker.io/library/golang:1.19.5-alpine as builder
 
 WORKDIR /app
 
@@ -15,5 +14,10 @@ RUN go mod download
 COPY *.go ./
 RUN go build -v -o /opi-spdk-bridge && CGO_ENABLED=0 go test -v ./...
 
+# second stage to reduce image size
+FROM alpine:3.17
+COPY --from=builder /opi-spdk-bridge /
+COPY --from=docker.io/fullstorydev/grpcurl:v1.8.7-alpine /bin/grpcurl /usr/local/bin/
 EXPOSE 50051
-CMD [ "/opi-spdk-bridge" ]
+CMD [ "/opi-spdk-bridge", "-port=50051" ]
+HEALTHCHECK CMD grpcurl -plaintext localhost:50051 list || exit 1