Tips for running Go with docker

docker image

Reference of patterns using go mod

#build image
FROM golang:1.13 AS builder

WORKDIR /go/src

##Download dependent libraries(I want to use the cache, so I'll do this first)
ENV GO111MODULE=on
COPY go.mod go.sum ./
RUN go mod download

ADD . /myapp
WORKDIR /myapp

## main.Compile go and save the executable binary
RUN CGO_ENABLED=0 GOOS=linux go build -o server ../myapp/cmd/main.go

# run-time image
FROM alpine:3.10
COPY --from=builder /myapp/server /app
EXPOSE 50051
ENTRYPOINT ["/app"]

Reference of patterns using dep

#build image
FROM golang:1.13 AS builder
ADD . /go/src/github.com/myself/myapp
WORKDIR /go/src/github.com/myself/myapp

##Install dep and resolve dependencies
RUN go get github.com/golang/dep/cmd/dep
RUN dep ensure

## main.Compile go and save the executable binary
RUN CGO_ENABLED=0 GOOS=linux go build -o server /myapp/cmd/main.go

# run-time image
FROM alpine:3.10
COPY --from=builder /go/src/github.com/myself/myapp/server /app
EXPOSE 50051
ENTRYPOINT ["/app"]

Clogged points

cannot find package error in go build

--Most likely the path is wrong or the file is missing

packages founded A and B error in go build

--There are multiple packages in the same directory --The following is a compilation error --Place multiple main package modules under the target directory --Put modules with different name package declarations in the same directory --Files ending in _test are interpreted as test code, so they can be placed as multiple files as an exception. --By the way, it is safe to declare the package with a different name from the directory. --Because it imports on a path basis instead of a package name

In go get, XX is not using a known version control system error

• https://github.com/gobuffalo/buffalo/issues/694#issuecomment-337032375 --Based on the above, I deleted the target files under / vendor and it worked for some reason.

dep ensure / hoge is not within a known GOPATH / src error

――I don't know, but the directory structure seems to be useless. --A feature of Go's directory structure is that all source code is placed under the environment variable $ GOPATH / src. --There are two solutions: --Place the repository under / go / src in the container --Put a symbolic link

dep ensure root project import: dep does not currently support using GOPATH / src as the project root error

--The workdir was specified as GOPATH / src, but it was fixed by changing it to GOPATH / src / app.

With dep ensure at docker build, I get angry because I can't access github like fatal: could not read Username for'https://github.com'~

--When you take resources from private repository, you have to use github token etc. ――However, you should be able to use the local path when taking resources from your repository. If you can't get it, it's likely that the path is wrong --In fact, I was able to change docker's workdir from go / src / app to /go/src/github.com/myself/my-app

When I do docker run, I get angry with ʻexec user process caused "no such file or directory" `

--Recent Go binaries seem to do a Dynamic link, which seems to be caused by the lack of the link target. --You can add CGO_ENABLED = 0 at build time - CGO_ENABLED=0 go build