Add ld-cache and reduce snap size

Signed-off-by: Daniel Llewellyn <daniel@bowlhat.net>

scripts/build-ld-cache

@@ -0,0 +1,20 @@
+#!/bin/bash -ex
+
+# copying the conf dir from real /etc into $SNAP_DATA
+mkdir -p "$SNAP_DATA/etc/ld.so.conf.d"
+cp -r /etc/ld.so.conf.d/* "$SNAP_DATA/etc/ld.so.conf.d"
+cp /etc/ld.so.conf "$SNAP_DATA/etc/ld.so.conf"
+
+# delete empty entries in the LD_LIBRARY_PATH
+# i.e. change "/a/b/c:/1/2/3::/other" into "/a/b/c:/1/2/3:/other"
+# if we don't do this, then ldconfig gets confused with "" as arguments of dirs
+# to add to the cache
+LD_LIBRARY_PATH="${LD_LIBRARY_PATH//::/:}"
+
+# run ldconfig on our LD_LIBRARY_PATH lib dirs
+IFS=':' read -ra PATHS <<< "$LD_LIBRARY_PATH"
+mkdir -p "$SNAP_DATA/fake-etc"
+ldconfig -v -C "$SNAP_DATA/fake-etc/ld.so.cache" -f "$SNAP_DATA/etc/ld.so.conf" "${PATHS[@]}"
+
+# install the new ld.so.cache to the global location by just copying it
+cp "$SNAP_DATA/fake-etc/ld.so.cache" "$SNAP_DATA/etc/ld.so.cache"

scripts/check-ld-cache

@@ -0,0 +1,32 @@
+#!/bin/sh -e
+
+# save the original LD_LIBRARY_PATH, and unset it to check the cache
+ORIGINAL_LD_LIBRARY_PATH="$LD_LIBRARY_PATH"
+LD_LIBRARY_PATH=""
+export LD_LIBRARY_PATH
+
+# FINAL_BINARY should be set and exported to what the "real" final executable 
+# that's run is so we can check that
+# an alternative would be to always run the "real" final executable immediately
+# after this script in the chain, and then check "$1" here, but that is probably
+# fragile
+if [ -z "$FINAL_BINARY" ]; then
+    echo "FINAL_BINARY unset, can't check the dynamic linker cache for correctness"
+else
+    # this is a bit tricky, we want to exit 0 if we didn't find a library, but
+    # exit 1 if we didn't _not_ find a library, so use the output phrase
+    # "=> not found" as what to look for from ldd
+    # TODO: make this less of a hack?
+    if ldd "$FINAL_BINARY" | grep "=> not found" | grep -q "=> not found"; then
+        # regenerate the cache first
+        LD_LIBRARY_PATH=$ORIGINAL_LD_LIBRARY_PATH
+        export LD_LIBRARY_PATH
+        # "$SNAP/bin/build-ld-cache"
+        # # unset to continue executing the next command in the chain
+        # LD_LIBRARY_PATH=""
+        # export LD_LIBRARY_PATH
+    fi
+fi
+
+# execute the next command in the chain
+exec "$@"

scripts/makemkv-launch

@@ -0,0 +1,23 @@
+#!/bin/sh
+if [ ! -f $SNAP_USER_DATA/.MakeMKV/settings.conf ]; then
+    mkdir -p $SNAP_USER_DATA/.MakeMKV
+
+    cat > $SNAP_USER_DATA/.MakeMKV/settings.conf <<SEOF
+#
+# MakeMKV settings file, written by MakeMKV v1.14.5 linux(x64-release)
+#
+
+app_DestinationDir = ""
+app_Java = ""
+app_Key = ""
+app_PreferredLanguage = ""
+app_ccextractor = "/snap/makemkv/current/usr/bin/ccextractor"
+dvd_MinimumTitleLength = "300"
+sdf_Stop = ""
+SEOF
+
+elif grep 'app_ccextractor = ""' $SNAP_USER_DATA/.MakeMKV/settings.conf; then
+    sed -i -E 's|(app_ccextractor = )""|\1"/snap/makemkv/current/usr/bin/ccextractor"|' $SNAP_USER_DATA/.MakeMKV/settings.conf
+fi
+
+exec $@