Conditional ARG in Dockerfile?

问题

I'm trying to conditionally install vim in my docker container if I pass an optional ARG - say something like DEVBUILD. I can't find any documentation on how to use something like IF in a Dockerfile. Something like this:

FROM node:8
if $DEVBUILD {
    RUN apt-get update
    RUN apt-get --assume-yes install vim
}

Is this possible, and if so, where can find a reference on the syntax?

回答1:

Yes, it is possible. When docker builds image it uses standard shell.

Dockerfile is:

FROM node:8
ARG DEVBUILD
RUN if [ "x$DEVBUILD" != "x" ]; then apt-get update && apt-get --assume-yes install vim; fi

If you define variable DEVBUILD like, for example, DEVBUILD=true:

docker build . --no-cache --build-arg DEVBUILD=true

actions under if statement will be executed.

来源：https://stackoverflow.com/questions/48775351/conditional-arg-in-dockerfile