Fix shellcheck warnings/errors

docker-cleanup-volumes.sh

@@ -10,9 +10,10 @@ docker_bin=$(which docker.io 2> /dev/null || which docker 2> /dev/null)
 dockerdir=/var/lib/docker
 
 # Look for an alternate docker directory with -g option
-dockerPs=`ps aux | grep $docker_bin | grep -v grep` || :
-if [[ $dockerPs =~ ' -g ' ]]; then
-	dockerdir=`echo $dockerPs | sed 's/.* -g//' | cut -d ' ' -f 2`
+
+dockerPs=$(tr "\0" " " < "/proc/$(pgrep "$docker_bin")/cmdline") || :
+if [[ $dockerPs =~ -g ]]; then
+	dockerdir=$(echo "$dockerPs" | sed 's/.* -g//' | cut -d ' ' -f 2)
 fi
 
 volumesdir=${dockerdir}/volumes
@@ -24,28 +25,29 @@ function delete_volumes() {
   targetdir=$1
   echo
   if [[ ! -d ${targetdir} ]]; then
-        echo "Directory ${targetdir} does not exist, skipping."
-        return
-  fi
-  echo "Delete unused volume directories from $targetdir"
-  for dir in $(ls -d ${targetdir}/* 2>/dev/null)
-  do
-        dir=$(basename $dir)
-        if [[ "${dir}" =~ [0-9a-f]{64} ]]; then
-                if [ ${#allvolumes[@]} -gt 0 ] && [[ ${allvolumes[@]} =~ "${dir}" ]]; then
-                        echo In use ${dir}
-                else
-                        if [ "${dryrun}" = false ]; then
-                                echo Deleting ${dir}
-                                rm -rf ${targetdir}/${dir}
-                        else
-                                echo Would have deleted ${dir}
-                        fi
-                fi
+    echo "Directory ${targetdir} does not exist, skipping."
+    return
+fi
+echo "Delete unused volume directories from $targetdir"
+for dir in ${targetdir}/*
+do
+    [[ -e $dir ]] || break
+    dir=$(basename "$dir")
+    if [[ "${dir}" =~ [0-9a-f]{64} ]]; then
+        if [ ${#allvolumes[@]} -gt 0 ] && [[ ${allvolumes[@]} =~ ${dir} ]]; then
+            echo "In use ${dir}"
         else
-                echo Not a volume ${dir}
+            if [ "${dryrun}" = false ]; then
+                echo "Deleting ${dir}"
+                rm -rf "${targetdir:?}/${dir:?}"
+            else
+                echo "Would have deleted ${dir}"
+            fi
         fi
-  done
+    else
+        echo "Not a volume ${dir}"
+    fi
+done
 }
 
 if [ $UID != 0 ]; then
@@ -59,13 +61,12 @@ if [ -z "$docker_bin" ] ; then
 fi
 
 if [ $# -gt 0 ] && [ "$1" = "--dry-run" ]; then
-        dryrun=true
-else if [ $# -gt 0 ] && [ -n "$1" ]; then
-        echo "Cleanup docker volumes: remove unused volumes."
-        echo "Usage: ${0##*/} [--dry-run]"
-        echo "   --dry-run: dry run: display what would get removed."
-        exit 1
-fi
+    dryrun=true
+elif [ $# -gt 0 ] && [ -n "$1" ]; then
+    echo "Cleanup docker volumes: remove unused volumes."
+    echo "Usage: ${0##*/} [--dry-run]"
+    echo "   --dry-run: dry run: display what would get removed."
+    exit 1
 fi
 
 # Make sure that we can talk to docker daemon. If we cannot, we fail here.
@@ -76,7 +77,7 @@ container_ids=$(${docker_bin} ps -a -q --no-trunc)
 # Check if we're running as a docker container
 if [[ ${container_ids[@]} =~ (^|[[:space:]])"$HOSTNAME" ]]; then
     # Get the dockerdir on the host from the volume mapped to /var/lib/docker
-    dockerdir_match=`${docker_bin} inspect -f '{{ index .Volumes "/var/lib/docker" }}' $HOSTNAME`
+    dockerdir_match=$(${docker_bin} inspect -f '{{ index .Volumes "/var/lib/docker" }}' "$HOSTNAME")
 else
     # Script is running standalone, dockerdir is the directory to use
     dockerdir_match=${dockerdir}
@@ -92,24 +93,24 @@ for container in $container_ids; do
         #ever exists in the volumesdir but just to be safe
         allvolumes+=${container}
         #add all volumes from this container to the list of volumes
-        for volpath in `${docker_bin} inspect --format='{{range $vol, $path := .Volumes}}{{$path}}{{"\n"}}{{end}}' ${container}`; do
+        for volpath in $(${docker_bin} inspect --format="{{range \$vol, \$path := .Volumes}}{{\$path}}{{\"\n\"}}{{end}}" "${container}"); do
 		#try to get volume id from the volume path
 		vid=$(echo "${volpath}"|sed "s|${vfsdir_match}||;s|${volumesdir_match}||;s/.*\([0-9a-f]\{64\}\).*/\1/")
                 # host daemon shows original dir path - this is why _match variables are used:
                 if [[ (${volpath} == ${vfsdir_match}* || ${volpath} == ${volumesdir_match}*) && "${vid}" =~ [0-9a-f]{64} ]]; then
-                        allvolumes+=("${vid}")
+                    allvolumes+=("${vid}")
                 else
                         #check if it's a bindmount, these have a config.json file in the ${volumesdir} but no files in ${vfsdir} (docker 1.6.2 and below)
-                        for bmv in `grep --include config.json -Rl "\"IsBindMount\":true" ${volumesdir} | xargs grep -l "\"Path\":\"${volpath}\""`; do
-                                bmv="$(basename "$(dirname "${bmv}")")"
-                                allvolumes+=("${bmv}")
+                        for bmv in $(grep --include config.json -Rl "\"IsBindMount\":true" "${volumesdir}" | xargs grep -l "\"Path\":\"${volpath}\""); do
+                            bmv="$(basename "$(dirname "${bmv}")")"
+                            allvolumes+=("${bmv}")
                                 #there should be only one config for the bindmount, delete any duplicate for the same bindmount.
                                 break
-                        done
-                fi
-        done
-done
+                            done
+                        fi
+                    done
+                done
 
-delete_volumes ${volumesdir}
-delete_volumes ${vfsdir}
+                delete_volumes "${volumesdir}"
+                delete_volumes "${vfsdir}"