singcvmfs

#!/bin/bash
# Run a singularity container including cvmfs repositories mounted
#   with the singularity --fusemount option.
# Written by Dave Dykstra March 2020

VERSION=4.42

ME="`basename $0`"

usage()
{
cat <<!EOF!
Usage: singcvmfs [-V] [global options] [command]
    -V:   print current $ME version and exit
    global options: singularity global options (prior to its command)
    If command starts with one of these singularity commands
        exec
        instance
        run
        shell
        version
    then the entire command is passed directly to singularity along
    with options to mount cvmfs repositories when appropiate.
    Otherwise the command is a shell command to run inside the chosen
    container image, which may contain whitespace.
    If command is missing then the shell is run.

Required environment variable:
    SINGCVMFS_REPOSITORIES  Comma-separated cvmfs repositories to mount
Required environment variable when singularity command not given:
    SINGCVMFS_IMAGE         singularity container path or URL

Optional environment variables:
    SINGCVMFS_CACHEDIR      Source directory for the cvmfs cache
    SINGCVMFS_CACHEIMAGE    Ext3 image file for the cvmfs cache
                            - If set, then ${SINGCVMFS_CACHEDIR:-/} is the
                              directory within the image used for the cache,
                              which must be writable by the user or contain
                              a 'shared' directory writable by the user
    SINGCVMFS_OPTSFILE      CVMFS options file (default.local)
                            - should set at least CVMFS_HTTP_PROXY
    SINGCVMFS_SINGOPTS      Extra singularity command options
    SINGCVMFS_LOGDIR        Directory for the cvmfs logs
    SINGCVMFS_LOGLEVEL      Set to debug to enable cvmfs debugging
!EOF!
    exit 1
} >&2

HERE="$(cd `dirname $0` && pwd)"

ORIGPWD=$PWD

if [ "$1" = "-V" ]; then
    echo "$VERSION"
    exit
fi

if [ ! -f $HERE/dist/usr/lib*/libcvmfs_fuse3.so ]; then
    echo "$ME: Must be run from where cvmfs distribution was made by 'makedist -s'" >&2
    exit 1
fi

if [ -z "$SINGCVMFS_REPOSITORIES" ]; then
    echo "$ME: SINGCVMFS_REPOSITORIES not set" >&2
    usage
    exit 1
fi

REPOS="$SINGCVMFS_REPOSITORIES"
# Add the config repo if not already asked for
CONFIG_REPO="`grep -h '^CVMFS_CONFIG_REPOSITORY=' $HERE/dist/etc/cvmfs/default.d/*.conf 2>/dev/null|tail -1|sed 's/^CVMFS_CONFIG_REPOSITORY=//'`"
if [[ ",$REPOS," != *",$CONFIG_REPO,"* ]]; then
    REPOS="$CONFIG_REPO,$REPOS"
fi

CVMFSDEBUG=""
EXEC=exec
DEBUGCONF=$HERE/dist/etc/cvmfs/default.d/00-debug.conf
if [ "$SINGCVMFS_LOGLEVEL" = "debug" ]; then
    CVMFSDEBUG="-o debug"
    echo "CVMFS_DEBUGLOG=/var/log/cvmfs/@fqrn@-debug.log" >$DEBUGCONF
    # would rather not leave this around because it interferes with
    #  use of cvmfsexec in same directory.
    EXEC=""
    trap "rm -f $DEBUGCONF" 0
else
    rm -f $DEBUGCONF
fi

declare -a MOUNT_ARGS
for R in ${REPOS//,/ }; do
    MOUNT_ARGS+=(--fusemount "\"container:cvmfs2-wrapper $CVMFSDEBUG $R /cvmfs/$R\"")
done
if [ -n "$APPTAINER_BINDPATH" ]; then
    SINGULARITY_BINDPATH="$APPTAINER_BINDPATH"
fi
SINGULARITY_BINDPATH="$SINGULARITY_BINDPATH,$HERE/cvmfs2-wrapper:/usr/bin/cvmfs2-wrapper"

cd $HERE/dist

if [ -n "$SINGCVMFS_OPTSFILE" ]; then
    cp $SINGCVMFS_OPTSFILE etc/cvmfs/default.local
fi

echo "CVMFS_NFILES=`ulimit -Hn`" >etc/cvmfs/default.d/00-nfiles.conf
echo "CVMFS_USYSLOG=/var/log/cvmfs/@fqrn@.log" >etc/cvmfs/default.d/00-usyslog.conf
if [ -n "$SINGCVMFS_LOGDIR" ]; then
  LOGDIR=$SINGCVMFS_LOGDIR
else
  LOGDIR=$HERE/log
fi
mkdir -p $LOGDIR
SINGULARITY_BINDPATH="$SINGULARITY_BINDPATH,$LOGDIR:/var/log/cvmfs"

for P in `find * ! -type d ! -path '*/doc/*' ! -path 'var/lib/cvmfs/*'| \
        sed 's,/cvmfs/.*,/cvmfs,'|uniq`; do
    SINGULARITY_BINDPATH="$SINGULARITY_BINDPATH,$PWD/$P:/$P"
done
SINGULARITY_BINDPATH="${SINGULARITY_BINDPATH#,}" # remove leading comma
export SINGULARITY_BINDPATH
export APPTAINER_BINDPATH="$SINGULARITY_BINDPATH"

CACHEBIND=""
if [ -n "$SINGCVMFS_CACHEIMAGE" ]; then
    CACHEBIND="$SINGCVMFS_CACHEIMAGE:/var/lib/cvmfs:image-src=${SINGCVMFS_CACHEDIR:-/}"
else
    CACHEBIND="${SINGCVMFS_CACHEDIR:-$PWD/var/lib/cvmfs}:/var/lib/cvmfs"
fi

cd $ORIGPWD

SINGGLOBALOPTS=""
while [ $# -gt 0 ]; do
    if [[ "$1" = -* ]]; then
        SINGGLOBALOPTS="$SINGGLOBALOPTS $1"
        shift
    else
        break
    fi
done

SINGCMD=""
SINGINSTCMD=""
case "$1" in
    version)
        exec singularity $SINGGLOBALOPTS "$@"
        ;;
    version|exec|run|shell)
        SINGCMD="$1"
        shift
        SINGCVMFS_IMAGE="" # just in case it is set
        ;;
    instance)
        SINGCMD="$1"
        shift
        # consume subcommand for instance
        SINGINSTCMD=$1
        shift
        SINGCVMFS_IMAGE="" # just in case it is set
        ;;
    *)  if [ -z "$SINGCVMFS_IMAGE" ]; then
            echo "$ME: SINGCVMFS_IMAGE not set" >&2
            usage
            exit 1
        fi
        SINGCMD=run
        ;;
esac

if [ "$SINGCMD" = instance -a "$SINGINSTCMD" != start ];
then
    $EXEC singularity $SINGGLOBALOPTS $SINGCMD $SINGINSTCMD "$@"
else
    $EXEC singularity $SINGGLOBALOPTS $SINGCMD $SINGINSTCMD \
        -S /var/run/cvmfs -B $CACHEBIND \
        "${MOUNT_ARGS[@]}" ${SINGCVMFS_SINGOPTS[@]} $SINGCVMFS_IMAGE "$@"
fi