ioc: prune shared libraries from non-static builds.

Shared libraries may be installed either in /opt or /usr/local/lib but
may not be used by the target binaries from the IOC image. Remove them
during the prune phase before copying both directories to resulting
image to shrink the final image size.

A regular expression is needed to filter the existing libraries, as
Solaris configuration files match the trivial ".so*" expression.

base/lnls-prune-artifacts.sh

@@ -3,6 +3,22 @@
 set -eu
 
 
+get_linked_libraries() {
+    targets=$@
+
+    executables=$(find $targets -type f -executable)
+
+    # Depend on the glibc-specific behavior of supporting multiple executables
+    # to be queried at once
+    libs="$(ldd $executables 2>/dev/null | grep '=>' | cut -d'=' -f 1)"
+
+    for lib in $libs; do
+        # Strip version from soname so that we match any version of the library
+        # in use
+        echo ${lib%.so*}.so
+    done | sort -u
+}
+
 get_used_epics_modules() {
     targets=$@
 
@@ -42,6 +58,26 @@ remove_static_libs() {
     done
 }
 
+remove_unused_shared_libs() {
+    targets=$@
+
+    used_libs=$(get_linked_libraries $targets)
+
+    remove_libs=$(find /opt /usr/local -type f -executable -name *.so*)
+    remove_libs=$(echo "$remove_libs" | grep -E "*.so(.[0-9]+)*$" | sort -u)
+
+    for lib in $used_libs; do
+        remove_libs=$(echo "$remove_libs" | grep -v $lib)
+    done
+
+    for lib in $remove_libs; do
+        size=$(du -hs $lib | cut -f 1)
+
+        echo "Removing shared library '$lib' ($size)"
+        rm -f $lib
+    done
+}
+
 remove_unused_epics_modules() {
     targets=$@
 
@@ -59,3 +95,4 @@ remove_unused_epics_modules() {
 
 remove_unused_epics_modules $@
 remove_static_libs /opt
+remove_unused_shared_libs $@