Dockerfile and drone config for build & publish to ghcr

Dockerfile

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+# Build the project
+FROM golang:1.19 as builder
+
+LABEL org.opencontainers.image.source="https://github.com/KevinMidboe/planetposen-images"
+
+WORKDIR /go/src/github.com/kevinmidboe/planetposen-images
+ADD . .
+
+RUN make build
+# RUN make test
+
+# Create production image for application with needed files
+FROM golang:1.19-alpine
+
+EXPOSE 8000
+
+RUN apk add --no-cache ca-certificates
+
+COPY --from=builder /go/src/github.com/kevinmidboe/planetposen-images .
+
+CMD ["./main"]