Add build and upload scripts, documentation and GH workflow

Author: tomaszn

.github/workflows/ci.yml

@@ -0,0 +1,60 @@
+name: CI
+
+on: [push]
+
+jobs:
+  create_release:
+    name: create_release
+    runs-on: ubuntu-18.04
+    steps:
+      - name: Check out code
+        uses: actions/checkout@v1
+      - name: create release
+        id: create_release
+        uses: actions/create-release@v1
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        with:
+          tag_name: ${{ github.ref }}
+          release_name: Release ${{ github.ref }}
+          draft: false
+          prerelease: false
+      - name: Output Release URL File
+        run: echo "${{ steps.create_release.outputs.upload_url }}" > release_url.txt
+      - name: Save Release URL File for publish
+        uses: actions/upload-artifact@v1
+        with:
+          name: release_url
+          path: release_url.txt
+
+  build_and_release:
+    needs: [create_release]
+    strategy:
+      matrix:
+        runtime:
+          - python3.6
+          - python3.7
+          - python3.8
+    runs-on: ubuntu-18.04
+    steps:
+      - uses: actions/checkout@v1
+      - run: ./make_layer.sh ${{ matrix.runtime }}
+      - name: Load Release URL File from release job
+        uses: actions/download-artifact@v1
+        with:
+          name: release_url
+      - name: Get Release File Name & Upload URL
+        id: get_release_info
+        run: |
+          value=`cat release_url/release_url.txt`
+          echo ::set-output name=upload_url::$value
+      - name: Upload Release Asset
+        id: upload-release-asset 
+        uses: actions/upload-release-asset@v1.0.1
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        with:
+          upload_url: ${{ steps.get_release_info.outputs.upload_url }}
+          asset_path: ./layer_diffoscope_${{ matrix.runtime }}.zip
+          asset_name: layer_diffoscope_${{ matrix.runtime }}.zip
+          asset_content_type: application/zip

README.md

@@ -1,2 +1,33 @@
 # diffoscope-aws-lambda-layer
-AWS Lambda layer with diffoscope and everything it needs
+
+A script that prepares an AWS Lambda layer with diffoscope and some tools it needs.
+
+## How to build
+
+```bash
+./make_layer.sh python3.6
+./upload_layer.sh python3.6 # requires properly configured "aws" command
+```
+
+## How to use in Lambda
+
+```python
+from diffoscope.logging import line_eraser, setup_logging
+from diffoscope.main import create_parser, run_diffoscope
+from diffoscope.profiling import ProfileManager, profile
+from diffoscope.progress import ProgressManager, Progress
+
+
+def handler(event, context):
+    # ...
+    args = [files[v1], files[v2], "--html", output_file]
+    with profile("main", "parse_args"):
+        parser, post_parse = create_parser()
+        parsed_args = parser.parse_args(args)
+        print(parsed_args)
+    log_handler = ProgressManager().setup(parsed_args)
+    with setup_logging(parsed_args.debug, log_handler) as logger:
+        post_parse(parsed_args)
+        run_diffoscope(parsed_args)
+    # serve output_file as text/html
+```

make_layer.sh

@@ -0,0 +1,31 @@
+#!/bin/bash
+
+# TODO
+# add zipnote to bin/ (zip package)
+# add libarchive-tools
+
+RUNTIME=${1:-python3.6}
+PKG_DIR=$(mktemp -d ./d.XXXXXX)
+trap 'rm -rf "$PKG_DIR"' EXIT
+mkdir $PKG_DIR/bin $PKG_DIR/lib
+TARGET="layer_diffoscope_$RUNTIME.zip"
+rm $TARGET
+
+docker run --rm -v $(pwd):/foo -w /foo lambci/lambda:build-$RUNTIME \
+    sh -c " \
+      yum --assumeyes install vim-common && \
+      cp /usr/bin/xxd ${PKG_DIR}/bin && \
+      yum --assumeyes install libarchive && \
+      cp --verbose /usr/lib64/libarchive.so.13 ${PKG_DIR}/lib/libarchive.so && \
+      cp --verbose /usr/lib64/liblzo2.so.2 ${PKG_DIR}/lib/ && \
+      chown --verbose $(id --user):$(id --group) ${PKG_DIR}/lib/* \
+    "
+docker run --user $(id --user):$(id --group) --rm -v $(pwd):/foo -w /foo lambci/lambda:build-$RUNTIME \
+    sh -c " \
+      pip install diffoscope jsbeautifier jsondiff -t ${PKG_DIR}/python --no-cache-dir && \
+      cp --verbose ${PKG_DIR}/python/bin/* ${PKG_DIR}/bin/ \
+    "
+
+cd $PKG_DIR
+zip -r --move ../$TARGET *
+cd ..

upload_layer.sh

@@ -0,0 +1,7 @@
+#!/bin/bash
+
+RUNTIME=${1:-python3.6}
+TARGET="layer_diffoscope_$RUNTIME.zip"
+
+DESCRIPTION=$(unzip -p $TARGET '*/diffoscope*/METADATA' | grep '^Version')
+aws lambda publish-layer-version --layer-name diffoscope --description "$DESCRIPTION" --zip-file fileb://$TARGET --compatible-runtimes $RUNTIME