Create a minimal Linux binary distribution (fixes #352)

This is suitable for use as a Lambda layer in AWS, inclusion in a
docker container, or other places where a minimal binary distribution
is desired.

4 files changed, 24 insertions, 1 deletions

diff --git a/ChangeLog b/ChangeLog
index 3c748cc3..8d772d91 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,14 @@
+2020-10-21  Jay Berkenbilt  <ejb@ql.org>
+
+	* Add qpdf-<version>-linux-x86_64.zip to the list of built
+	distributions. This is a simple zip file that contains just the
+	qpdf executables and the dependent shared libraries that would not
+	ordinarily be present on a base system. This minimal binary
+	distribution works as is when used as a Lambda layer in AWS and
+	could be suitable for inclusion in a docker image or other
+	standalone Linux/x86_64 environment where you want minimal support
+	for running the qpdf executable. Fixes #352.
+
 2020-10-20  Jay Berkenbilt  <ejb@ql.org>
 
 	* Add --warning-exit-0 option to the qpdf command line. When
diff --git a/TODO b/TODO
index 98512644..2e76e5f8 100644
--- a/TODO
+++ b/TODO
@@ -2,7 +2,6 @@ Candidates for upcoming release
 ===============================
 
 * Easy build/test
-  * #352: building standalone executables (lambda layer)
   * #460: potential malware in fuzzer seed corpus
   * Consider building workflow on a schedule to detect build rot. This
     may enable safe use of *-latest especially if Windows wildcard is
diff --git a/build-scripts/build-appimage b/build-scripts/build-appimage
index 8a614701..3ba7175e 100755
--- a/build-scripts/build-appimage
+++ b/build-scripts/build-appimage
@@ -19,4 +19,15 @@ cp -p appimage/build/qpdf/appimage/build/qpdf*AppImage* distribution
 for i in distribution/*; do
     mv $i $(echo $i | sed -e 's/\.AppImage/-ci.AppImage/')
 done
+
+# Extract a standalone copy of binaries and libraries from the
+# AppImage. This is suitable for use in AWS Lambda, docker, or other
+# self-contained environments.
+version=$(basename distribution/qpdf*AppImage | cut -d- -f 2)
+./distribution/qpdf*AppImage --appimage-extract
+D=$PWD/distribution
+(cd squashfs-root/usr; \
+ zip -9 --symlinks $D/qpdf-$version-bin-linux-x86_64-ci.zip \
+     bin/{qpdf,fix-qdf,zlib-flate} lib/*)
+
 sha256sum distribution/*
diff --git a/make/libtool.mk b/make/libtool.mk
index 6a2bbc1a..a259afe0 100644
--- a/make/libtool.mk
+++ b/make/libtool.mk
@@ -106,6 +106,8 @@ endef
 
 # Install target
 
+# NOTE: If installing any new executables, remember to update the
+# lambda layer code in build-scripts/build-appimage.
 install: all
 	./mkinstalldirs -m 0755 $(DESTDIR)$(libdir)/pkgconfig
 	./mkinstalldirs -m 0755 $(DESTDIR)$(bindir)