Using go mod download to speed up Golang Docker builds

The build time of Golang Docker images always frustrated me as there was always a need to do the go get ./... before we started building the binary. This resulted in fetching the dependencies every time we wanted to build the image. The Dockerfile then looked like this: FROM golang:alpine AS build-envCOPY . $GOPATH/src/mypackage/myapp/ WORKDIR $GOPATH/src/mypackage/myapp/# go get and build <-- THI

[castaneai]

先に go mod download レイヤーをキャッシュしておこうね

[withnic]

もう対応してる所のをみると当たり前に書いてあったりするけど。