Copy go package from previous stage based go image?

Question

In image based Python, I want to run one command (*) using go package gnostic:

RUN gnostic --grpc-out=test test/openapi/loyalty-bff.yaml

I did wrote following dockerfile:

FROM golang:1.17 AS golang
RUN go get -u github.com/google/gnostic@latest
RUN go get -u github.com/googleapis/gnostic-grpc@latest

FROM python:3.7.10
WORKDIR /app
ADD requirements.txt /app/
RUN pip install -r requirements.txt
ADD . /app/
COPY --from=golang /go/bin/gnostic /go/bin/gnostic-grpc
CMD ["uvicorn", "main:app", "--host", "0.0.0.0", "--port", "5000"]

I got error when run the command (*):

Command 'gnostic --grpc-out=loyalty-bff-1634180849463365375 loyalty-bff-1634180849463365375/loyalty-bff.yaml' returned non-zero exit status 127.

On the other hand, i can run when not use multi stages. Replace by install python in image based go, but building time is very long:

FROM golang:1.17
WORKDIR /app
RUN go get -u github.com/google/gnostic@latest
RUN go get -u github.com/googleapis/gnostic-grpc@latest
RUN apt-get update
RUN apt-get install -y build-essential zlib1g-dev libncurses5-dev libgdbm-dev libnss3-dev libssl-dev libsqlite3-dev libreadline-dev libffi-dev wget libbz2-dev
RUN wget https://www.python.org/ftp/python/3.7.8/Python-3.7.8.tgz
RUN tar -xf Python-3.7.8.tgz
RUN cd Python-3.7.8 \
    && ./configure --enable-shared \
    && make && make install
RUN apt-get install python3-pip -y

ADD requirements.txt /app/
RUN pip3 install -r requirements.txt
ADD . /app/
CMD ["uvicorn", "main:app", "--host", "0.0.0.0", "--port", "5000"]

Answer 1

Exit code 127 usually means can't find the executable.

If you have a look for env of golang:1.17, you could see by default the PATH has /go/bin:

$ docker run --rm -it golang:1.17 env
PATH=/go/bin:/usr/local/go/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin
HOSTNAME=a9b7efb588ea
TERM=xterm
GOLANG_VERSION=1.17.2
GOPATH=/go
HOME=/root

This is the reason why you could find gnostic in golang based container.

But, in python:3.7.10, it's next:

$ docker run --rm -it python:3.7.10 env
PATH=/usr/local/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin

So, for your scenario, change the copy to next could make it work:

COPY --from=golang /go/bin/gnostic /go/bin/gnostic-grpc /usr/local/bin/