golang docker build for linux - docker

Question

I need to compile a Golang application for Linux and I can't cross-compile under Mac, because of another library. So I decided to compile within a Docker container. This is my first time to use Docker.
This is my current directory structure:
.
├── Dockerfile
├── Gopkg.lock
├── Gopkg.toml
├── Vagrantfile
├── bootstrap.sh
├── src
│   ├── cmd
│   │   ├── build.bat
│   │   ├── build.sh
│   │   ├── config.json
│   │   ├── readme.md
│   │   └── server.go
│   ├── consumers.go
│   ├── endpoints
│   │   ├── json.go
│   │   ├── rate.go
│   │   ├── test_payment.go
│   │   └── wallet.go
│   ├── middleware
│   │   └── acl.go
│   ├── models.go
│   ├── network
│   │   └── network.go
│   ├── qr
│   │   └── qr.go
│   ├── router
│   │   └── router.go
│   ├── service
│   │   └── walletService.go
│   ├── services.go
│   ├── setup.sql
│   ├── store
│   │   └── wallet.go
│   ├── stores.go
│   └── wallet
│   ├── coin.go
│   └── ethereum.go
Dockerfile:
FROM golang:latest
WORKDIR /src/cmd
RUN ls
RUN go get github.com/go-sql-driver/mysql
RUN go build -o main ./src/cmd/server.go
CMD ["./main"]
I try to build the Docker image with:
docker build -t outyet .
This is the error it returns:
Sending build context to Docker daemon 5.505MB
Step 1/6 : FROM golang:latest
---> d0e7a411e3da
Step 2/6 : WORKDIR /src/cmd
---> Using cache
---> 0c4c2b99e294
Step 3/6 : run ls
---> Using cache
---> 23d3e491a2e1
Step 4/6 : RUN go get github.com/go-sql-driver/mysql
---> Running in f34447e51f6c
Removing intermediate container f34447e51f6c
---> 5731ab22ee43
Step 5/6 : RUN go build -o main server.go
---> Running in ecc48fcf5488
stat server.go: no such file or directory
The command '/bin/sh -c go build -o main server.go' returned a non-zero code: 1
How i can build my Golang application with docker?

Answer 1

The error you're seeing is:
stat server.go: no such file or directory
The command '/bin/sh -c go build -o main server.go' returned a non-zero code: 1
... and in other words, it's telling you that the Go compiler can't find server.go which you're trying to build. Update your Dockerfile to copy your local files into the Docker image:
FROM golang:latest
COPY . /go/src/workdir
WORKDIR /go/src/workdir
RUN go build -o main ./src/cmd/server.go
CMD ["/go/src/workdir/main"]
In your directory I spotted Gopkg.toml which is a dependency manifest used by dep. dep will use a directory called vendor to include all dependencies for your Go project. Before you build the Docker image, you need to ensure all dependencies are present with dep ensure:
$ dep ensure
$ docker build -t outyet .

Answer 2

You need to add your sources in your build container. Add this line in your Dockerfile (after FROM golang:latest for example) :
ADD src/ /src/cmd
Then, you could access files inside the container (/src/cmd) : RUN ls should now return something.