Race condition when using cache-mounts with multi-arch builds. #549
Comments
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You can't use variables in |
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@tonistiigi I take it then that it's impossible to use a |
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The simplest is to put your cache in a subdir of the mount so it doesn't collide. Another way is to use |
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RUN rm -f /etc/apt/apt.conf.d/docker-clean; echo 'Binary::apt::APT::Keep-Downloaded-Packages "true";' > /etc/apt/apt.conf.d/keep-cache
...
RUN --mount=type=cache,target=/var/cache/apt,sharing=private \
echo "[+] Installing APT base system dependencies for $TARGETPLATFORM..." \
&& apt-get update -qq \
&& apt-get install -qq -y --no-install-recommends \
apt-transport-https ca-certificates apt-utils gnupg2 curl wget \
...
&& rm -rf /var/lib/apt/lists/*
More info here: moby/buildkit#1673 With these changes I achieved a >20x speed gain when rebuilding a frequently changed complex docker image with lots of apt lines. |
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@pirate If you are using this pattern for multi-platform then add |
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Cool! Just noticed they merged support for variables in mount arguments: moby/buildkit#815 So the updated version would look like this? I added the ARG TARGETPLATFORM
ARG TARGETOS
ARG TARGETARCH
ARG TARGETVARIANT
...
RUN rm -f /etc/apt/apt.conf.d/docker-clean; echo 'Binary::apt::APT::Keep-Downloaded-Packages "true";' > /etc/apt/apt.conf.d/keep-cache
...
RUN --mount=type=cache,id=apt-$TARGETARCH$TARGETVARIANT,sharing=locked,target=/var/cache/apt \
&& apt-get update -qq \
&& apt-get install -qq -y --no-install-recommends \
apt-transport-https ca-certificates apt-utils gnupg2 curl wget ... \
&& rm -rf /var/lib/apt/lists/*Edit: confirmed this works 👍 (build speeds are now 20x faster for small changes) and is now how we do it in ArchiveBox's Dockerfile |
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@pirate In your latest example you are using |
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Yes, following @tonistiigi's comment the additional cache keys allow us to go back to using |
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@pirate If you put the |
Issue
I've encountered intermittent failures using
--mount=type=cacheto shareapkpackage manager cache when doing multi-platform builds usingbuildxwith thedocker-containerdriver. It appearsbuildxattempts to use the same cache even though they have different identifiers resulting in a failure for the package manager as it expects the files in the cached folder to be platform specific. This is intermittent though there are times where inbuildxcorrectly creates two separate caches and the build is successful.System Info
Steps to reproduce.
Setup the builder:
Enable multi-arch builds via Qemu:
Attempt to build:
See the error in the logs in which
apkcannot be shared across architectures.Note the outputs of
ls -lah /var/cache/apkdiffers asamd64wrote to the directory beforearm64read from it.The text was updated successfully, but these errors were encountered: