Why does apt-get exit without an error during Dockerfile build? - docker

Question

For some reason, I've been unable to complete a docker build without the process stopping and no error being provided. I've googled around, and no-one appears to have the same issue.
The first (and salient) part of the Dockerfile config I'm using:
FROM java:8-jre
ENV DEBIAN_FRONTEND noninteractive
# Install needed packages
RUN apt-get update
RUN apt-get install -y \
cron
The command I'm using to execute the build (build.cmd):
#ECHO OFF
docker --debug --log-level debug build . ^
--build-arg http_proxy=%http_proxy% ^
--build-arg https_proxy=%https_proxy% ^
--build-arg no_proxy=%no_proxy% ^
--tag "bravura/jfrog-mission-control:latest" ^
%*
The result of running it:
Sending build context to Docker daemon 133.9MB
Step 1/7 : FROM java:8-jre
---> e44d62cf8862
Step 2/7 : ENV DEBIAN_FRONTEND noninteractive
---> Using cache
---> f30e6ab20920
Step 3/7 : RUN apt-get update
---> Running in 677bd445e48c
Get:1 http://security.debian.org jessie/updates InRelease [63.1 kB]
Get:2 http://security.debian.org jessie/updates/main amd64 Packages [508 kB]
Ign http://deb.debian.org jessie InRelease
Get:3 http://deb.debian.org jessie-updates InRelease [145 kB]
Get:4 http://deb.debian.org jessie-backports InRelease [166 kB]
Get:5 http://deb.debian.org jessie Release.gpg [2373 B]
Get:6 http://deb.debian.org jessie Release [148 kB]
Get:7 http://deb.debian.org jessie-updates/main amd64 Packages [17.6 kB]
Get:8 http://deb.debian.org jessie-backports/main amd64 Packages [1150 kB]
Get:9 http://deb.debian.org jessie/main amd64 Packages [9065 kB]
Fetched 11.3 MB in 6s (1829 kB/s)
Reading package lists...
SECURITY WARNING: You are building a Docker image from Windows against a non-Windows Docker host. All files and directories added to build context will have '-rwxr-xr-x' permissions. It is recommended to double check and reset permissions for sensitive files and directories.
Here's the big one: Running the same set of commands in a shell brought up by running docker run -it --rm java:8-jre /bin/bash works perfectly fine.
The other interesting bit: Concatenating the two commands together (with &&) defers the exit to the end of both executions. In fact, no errors are actually produced, so appending additional commands to the end works just fine (e.g. apt-get update && apt-get install -y cron && echo "Done!")
Any help even identifying where the issue could be reported would be greatly appreciated.
Update: As is the way with these things, I thought to look in the service logs as soon as I posted this. Found the following tidbits that might point me in the right direction:
[13:50:31.818][ApiProxy ][Info ] error copying response body from Docker: unexpected EOF
[13:50:31.818][ApiProxy ][Info ] error closing response body from Docker: unexpected EOF
Still no real idea what it means, however. Might just be another symptom rather than a cause.
Update: Just ran the build again to double-check the submitted responses, and without changes to my Dockerfile, everything is now working beautifully. One possible option is that the issue was silently fixed in the last update (which I installed today). I don't really have time to revert and re-test, so this is it until I run into the issue again, or someone else gets the same thing.

Answer 1

unexpected EOF (end of file). it seems you forgot the "\" at the end of your RUN command.
RUN apt-get update && apt-get install -y cron && echo "Done!" \
or
RUN apt-get update && \
apt-get install -y cron && \
echo "Done!" \

Answer 2

#Tzrlk are you working behind the corporate proxy? Try running this command directly in your terminal first and then use the docker build command and see.
export http_proxy=http://your proxy here:port here
export https_proxy=http://your proxy here:port here