Add server scripts to repo (closes #4302) (#4303)

* Add existing server scripts
* Update thumbnail script to update any time the PDF is newer than the thumbnail

bin/build-thumbnails.sh

@@ -0,0 +1,50 @@
+# Requires $PREVIEW_DIR to be set.
+#!/bin/bash
+
+# Builds thumbnails for files. There are two use cases:
+# 1. If no arguments are supplied, will do so for all Anthology files.
+#
+#    Example:
+#
+#        build_thumbnails.sh
+#
+# 2. If two arguments are supplied, will read the first file and write
+#    to the second.
+#
+#    Example:
+#
+#        build_thumbnails ~/anthology-files/pdf/W/W19/W19-5605.pdf \
+#          ~/anthology-files/thumb/W/W19/W19-5606-thumb.pdf
+#
+# The first use case recurses to the second.
+
+# The base directory of Anthology object files (contains pdf/ and thumb/)
+ANTHOLOGYFILES=$HOME/anthology-files
+
+# Where to write thumbnails
+THUMBDIR=${ANTHOLOGYFILES}/thumb
+
+# Thumbnail dimensions
+DIM=600
+
+if [[ -z $2 ]]; then
+    [[ ! -e $THUMBDIR ]] && mkdir -p $THUMBDIR
+
+    inputdir=${1:-$ANTHOLOGYFILES/pdf/}
+    echo "Looking for PDFs in $inputdir..."
+    for pdf in $(find $inputdir -type f -name '*.pdf'); do
+        outfile=$THUMBDIR/$(basename $pdf .pdf).jpg
+        # update if outfile doesn't exist or has an older timestamp
+        if [[ ! -e $outfile || $pdf -nt $outfile ]]; then
+          echo "$pdf -> $outfile"
+          bash $0 $pdf $outfile
+        fi
+    done
+else
+    pdffile=$1
+    outfile=$2
+
+    cmd="convert $pdffile[0] -background white -flatten -resize x${DIM}^ -gravity North -crop ${DIM}x${DIM}+0+10 -colorspace Gray $outfile"
+#    echo $cmd
+    $cmd
+fi

bin/remove-previews.sh

@@ -0,0 +1,17 @@
+#!/bin/bash
+
+# Removes previews of branches that have been deleted on Github.
+
+export PREVIEW_DIR="/var/www/preview.aclanthology.org"
+
+set -u
+
+if [[ -d $PREVIEW_DIR ]]; then
+	cd $PREVIEW_DIR
+	for branch in *; do
+		if ! curl -s -o /dev/null -f https://github.com/acl-org/acl-anthology/tree/$branch; then
+			echo "* Removing Anthology preview $branch"
+			rm -rf "./$branch"
+		fi
+	done
+fi