Merge pull request #38 from Snawoot/docker-crosscompile

docker: crosscompile

Author: Snawoot

Dockerfile

@@ -1,10 +1,11 @@
-FROM golang AS build
+FROM --platform=$BUILDPLATFORM golang AS build
 
 ARG GIT_DESC=undefined
 
 WORKDIR /go/src/github.com/Snawoot/opera-proxy
 COPY . .
-RUN CGO_ENABLED=0 go build -a -tags netgo -ldflags '-s -w -extldflags "-static" -X main.version='"$GIT_DESC"
+ARG TARGETOS TARGETARCH
+RUN GOOS=$TARGETOS GOARCH=$TARGETARCH CGO_ENABLED=0 go build -a -tags netgo -ldflags '-s -w -extldflags "-static" -X main.version='"$GIT_DESC"
 ADD https://curl.haxx.se/ca/cacert.pem /certs.crt
 RUN chmod 0644 /certs.crt