Add Dockerfile support

Dockerfile

@@ -0,0 +1,12 @@
+FROM golang:1.11-alpine as builder
+ADD . /go/src/github.com/shizhMSFT/oras
+WORKDIR /go/src/github.com/shizhMSFT/oras
+RUN go install github.com/shizhMSFT/oras/cmd/oras
+
+FROM alpine
+LABEL maintainer="[email protected]"
+RUN apk --update add ca-certificates
+COPY --from=builder /go/bin/oras /bin/oras
+RUN mkdir /workplace
+WORKDIR /workplace 
+ENTRYPOINT  ["/bin/oras"]

README.md

@@ -20,3 +20,24 @@ oras pull localhost:5000/hello:latest
 ```
 oras pull -u username -p password myregistry.io/myimage:latest
 ```
+
+## Running in Docker
+### Build the image
+```
+docker build -t oras .
+```
+
+### Run on Linux
+```
+docker run --rm -it -v $(pwd):/workplace oras pull localhost:5000/hello:latest
+```
+
+### Run on Windows PowerShell
+```
+docker run --rm -it -v ${pwd}:/workplace oras pull localhost:5000/hello:latest
+```
+
+### Run on Windows Commands
+```
+docker run --rm -it -v %cd%:/workplace oras pull localhost:5000/hello:latest
+```