[SR-9523] Separate dev/runtime images

[swift-ci]

Previous ID	SR-9523
Radar	None
Original Reporter	kiliankoe (JIRA User)
Type	New Feature

Additional Detail from JIRA

Votes	0
Component/s	Docker
Labels	New Feature
Assignee	@shahmishal
Priority	Medium

md5: 7e97e3cc837416fd372064aed8cdcd0b

Issue Description:

It would be great to have separate docker images for bundling the necessary dependencies to build Swift tools and to run them, the later hopefully being quite a bit smaller since they don't have to bundle swiftc and everything that's necessary for that.

[swift-ci]

Comment by Michael Bates (JIRA)

Would this be any different from using multi-phase docker builds? i.e., couldn't you build your project in one phase using`FROM swift`, then copy the executable(s) to a the final image using `FROM ubuntu:16.04`

FROM swift AS builder_image
WORKDIR /app
COPY ./ ./
RUN swift build

FROM ubuntu:16.04
copy --from=builder_image /app/.build/debug/latest/app_executable .
CMD ./app_executable

The output of this would be a basic ubuntu image with just the `app_executable` binary.

[swift-ci]

Comment by Kilian Koeltzsch (JIRA)

mklbtz (JIRA User) In theory, yes, that's exactly what I was looking for. A base ubuntu image however unfortunately is not enough to run a swift binary. I haven't played with this for a small while, but a "runtime image" tended to look more like the following.

FROM swift:latest as build
RUN mkdir -p /build/lib && cp -R /usr/lib/swift/linux/*.so /build/lib

FROM ubuntu:16.04
COPY --from=build /build/lib/* /usr/lib/

RUN apt-get -q update && \
    apt-get -q install -y --no-install-recommends \
    libatomic1 \
    libbsd0 \
    libcurl3 \
    libicu55 \
    libxml2 \
    && rm -r /var/lib/apt/lists/*