Fix layer for python3.8 and more debug output

Author: tomaszn

README.md

@@ -11,6 +11,13 @@ A script that prepares an AWS Lambda layer with diffoscope and some tools it nee
 
 ## How to use in Lambda
 
+First, you need to set two environment variables:
+```bash
+MAGIC=/usr/share/misc/magic:/opt/magic
+LD_PRELOAD=/opt/lib/libarchive.so
+```
+
+Second, use this snippet to run diffoscope:
 ```python
 from diffoscope.logging import line_eraser, setup_logging
 from diffoscope.main import create_parser, run_diffoscope

make_layer.sh

@@ -18,10 +18,13 @@ docker run --rm -v $(pwd):/foo -w /foo lambci/lambda:build-$RUNTIME \
       cp --verbose /usr/bin/zipnote bin/ && \
       yum --assumeyes install libarchive && \
       cp --verbose /usr/lib64/libarchive.so.13 lib/libarchive.so && \
-      cp --verbose /usr/lib64/libarchive.so.13 lib/libarchive.so.13 && \
       cp --verbose /usr/lib64/liblzo2.so.2 lib/ && \
-      ([[ $RUNTIME == 'python3.8' ]] && cp --verbose /usr/lib64/libmagic.so.1 lib/) && \
-      ([[ $RUNTIME == 'python3.8' ]] && cp --verbose /usr/lib64/libcrypto.so.10 lib/) && \
+      ([[ $RUNTIME == 'python3.8' ]] && cp --verbose /usr/bin/cmp bin/) && \
+      ([[ $RUNTIME == 'python3.8' ]] && cp --verbose /usr/bin/diff bin/) && \
+      ([[ $RUNTIME == 'python3.8' ]] && cp --verbose /usr/bin/file bin/) && \
+      ([[ $RUNTIME == 'python3.8' ]] && cp --verbose /usr/bin/zipinfo bin/) && \
+      ([[ $RUNTIME == 'python3.8' ]] && cp --verbose /usr/lib64/libxml2.so.2 lib/) && \
+      ([[ $RUNTIME == 'python3.8' ]] && curl 'https://kojipkgs.fedoraproject.org//packages/file/5.36/5.fc30/x86_64/file-libs-5.36-5.fc30.x86_64.rpm' --output - | rpm2cpio | cpio -idv && cp --verbose usr/share/misc/magic . && cp usr/lib64/libmagic.so.1 lib/) && \
       chown --verbose $(id --user):$(id --group) lib/* \
     "
 docker run --user $(id --user):$(id --group) --rm -v $(pwd):/foo -w /foo lambci/lambda:build-$RUNTIME \

run_tests.sh

@@ -1,4 +1,5 @@
 #!/bin/sh
+set -x
 RUNTIME=${1:-python3.6}
 
 rm -r opt
@@ -9,6 +10,6 @@ ldd bin/* || true
 ldd lib/* || true
 cd ..
 ls -l
-docker run -e DOCKER_LAMBDA_DEBUG=1 --rm -v "$PWD":/var/task:ro,delegated -v "$PWD"/opt/:/opt:ro,delegated lambci/lambda:$RUNTIME tests.run 2> /tmp/test_results
+docker run -e MAGIC=/usr/share/misc/magic:/opt/magic -e LD_PRELOAD=/opt/lib/libarchive.so -e DOCKER_LAMBDA_DEBUG=1 --rm -v "$PWD":/var/task:ro,delegated -v "$PWD"/opt/:/opt:ro,delegated lambci/lambda:$RUNTIME tests.run 2> /tmp/test_results
 cat /tmp/test_results
 grep '^OK$' /tmp/test_results

tests.py

@@ -19,6 +19,7 @@ def setUpClass(cls):
                 "test/extension_2020_1_13_0.crx",
                 "--text",
                 report_file,
+                "--debug",
             ]
         )
         with open(report_file) as f: