Add Dockerfile and instructions to use it.

Dockerfile

@@ -0,0 +1,19 @@
+FROM golang:1.23-alpine AS builder
+
+RUN apk --no-cache add ca-certificates
+
+WORKDIR /usr/src/app
+
+# pre-copy/cache go.mod for pre-downloading dependencies and only redownloading them in subsequent builds if they change
+COPY go.mod go.sum ./
+RUN go mod download && go mod verify
+
+COPY . .
+RUN go build -v -o /usr/src/app/dist/ ./...
+
+FROM scratch AS runtime
+
+COPY --from=builder /etc/ssl/certs/ca-certificates.crt /etc/ssl/certs/
+COPY --from=builder /usr/src/app/dist/hcloud-upload-image /bin/hcloud-upload-image
+
+ENTRYPOINT ["/bin/hcloud-upload-image"]

README.md

@@ -45,6 +45,23 @@ Use your preferred wrapper to install:
 yay -S hcloud-upload-image-bin
 ```
 
+#### Docker
+
+You can build a Docker image by cli command(from the root of this repo):
+
+```shell
+docker build -t hcloud-upload-image .
+```
+
+And the next, you can use it like this(for example):
+
+```shell
+docker run -ti --rm -e HCLOUD_TOKEN="<your token>" \
+  --image-url "https://example.com/disk-image-x86.raw.bz2" \
+  --architecture x86 \
+  --compression bz2
+```
+
 #### `go install`
 
 If you already have a recent Go toolchain installed, you can build & install the binary from source: