Docker Compose libcups.so.2

[danielchild1]

When I use docker compose up I get caught on the the error error while loading shared libraries: libcups.so.2: cannot open shared object file: No such file or directory. So I go into the Dockerfile and add libcups2 to the end of the apt-get install -y line. Once I rebuild and run it gives me a symbol lookup error: /usr/sbin/cupsd: undefined symbol: _cupsArrayStrcmp Error.

I am wondering if I am needing to do some more prepwork before running this docker container. Is there documentation for the docker-compose.yml? I cannot find it. Thank you!

[coolstuff99]

Hey @danielchild1 I am having same issue... did you find way to solve it?

[coolstuff99]

@michaelrsweet by any chance can you bring us some light here? Thank you so much.

[michaelrsweet]

The current Github master code should work better. Linux needs the "ldconfig" command to be run, otherwise the cache of symbols in libcups.so.2 isn't updated, and that can prevent programs using the newer functions from working. I also cleaned up the Docker stuff so that it would build properly (although a fully-functional Docker image will really depend on more of the OpenPrinting components...)

[anony253]

I also have this problem, can you please explain in a bit more detail how is this exactly intended to be used, as I have no clue where to run the "ldconfig" command, on the host, or in the container? If in the container, at which point, since it is impossible to even start this container in the first place. I have tried both in Dockerfile and in docker-compose.yaml but with no success

[michaelrsweet]

@anony253 Can you provide more information? What errors are you seeing when you try building and running the container?

[anony253]

Exactly what the original ticket was for:
error while loading shared libraries: libcups.so.2: cannot open shared object file: No such file or directory

[Magniveo]

May be will help, change pathtolib where you install cups.

#!/bin/bash
#set -x
# Set environment variables
export CUPS_SERVERBIN="/home/pathtolib/usr/local/lib64/cups"
export LD_LIBRARY_PATH="/home/pathtolib/usr/local/lib64:$LD_LIBRARY_PATH"
export CUPS_DATADIR="/home/pathtolib/usr/local/share/cups"
export CUPS_REQUESTROOT="/home/pathtolib/var/run/cups"
export CUPS_STATEDIR="/home/pathtolib/var/run/cups"
export CUPS_FONTPATH="/home/pathtolib/usr/local/share/cups/fonts"


# Test configuration file
/home/pathtolib/usr/local/sbin/cupsd -t -c /home/pathtolib/usr/local/etc/cups/cupsd.conf
if [ $? -ne 0 ]; then
  echo "Configuration file test failed. Exiting."
  exit 1
fi

# Run cupsd in foreground mode for debugging
echo "Starting cupsd..."
# Run cupsd with a custom config file
/home/pathtolib/usr/local/sbin/cupsd -f -l -c /home/pathtolib/usr/local/etc/cups/cupsd.conf

[SeanTasker]

I ran into this issue be the case on both 2.4.x and master. Which I later realised were the same revision. The instructions below can help you fix the problem but I also ran into further issues with an assertion cupsd: browser.c:245: avahi_domain_browser_free: Assertion b' failed.(I had to drop into an interactive shell then run/usr/sbin/cupsd -f` to see this error. If below is all that was required to fix this issue I would have been happy to open a pull request.

I had more luck running olbat/cupsd instead of building from source.

docker run -d -p 631:631 -v /var/run/dbus:/var/run/dbus --name cupsd olbat/cupsd

Fixes

There are two fixes that should resolve libraries not being found. Modify Makedefs.in to make ALL_LDFLAGS include the flags for LDFLAGS or modify Dockerfile.

Dockerfile change

-RUN ./configure --prefix=/usr --sysconfdir=/etc --localstatedir=/var && make clean && make && make install
+RUN LDFLAGS='-Wl,-rpath=${libdir}' ./configure --prefix=/usr --sysconfdir=/etc --localstatedir=/var && make clean && make && make install

Makedefs.in version

-ALL_LDFLAGS    =       -L../cups @LDARCHFLAGS@ @RELROFLAGS@ $(LDFLAGS)  \
+ALL_LDFLAGS    =       -L../cups -Wl,-rpath=${libdir} @LDARCHFLAGS@ @RELROFLAGS@ $(LDFLAGS)  \

The Dockerfile change should source rebuild when you when you run docker build . again but the second change may require cleaning your docker cache.

To Clean

This assumes you only have one image with "cups-cups" in the name

# Remove containers referencing the cups image
docker container ls -a | grep 'cups-cups' | awk '{print $1}' | xargs -I{} docker container rm "{}"
# Remove cups image
docker image rm cups-cups
docker system prune

Otherwise run docker container ls -a and then docker container rm containerID for each container that references the cups image before pruning. Run docker build . when you've made the change required.