Add a new Dockerfile for building Swift-DocC-Render-Artifact

Adds a new Dockerfile that can be used to generate a built version of Swift-DocC-Render in isolation. This allows developers interested in having an up-to-date version of Swift-DocC-Render to build one in an automated way without installing Node.

Developers can build a copy of Swift-DocC-Render at the given branch with the included helper script by running something like the following:

    ./build-swift-docc-render.sh \
        --branch <branch-in-swift-docc-render-repo> \
        --output-path <path-to-output-directory>

The helper script starts by building a new version of the included Docker container with caching disabled. It then copies out the built artifact to the given output directory, and deletes the created Docker container.

Resolves r81634420.

Author: ethan-kusters

swift-ci/README.md

@@ -11,6 +11,8 @@ The Dockerfiles used for Continuous Integration are layed out under the top leve
 Under that, we have a directory for each of the target branches, e.g.
 Continuous Integration for Swift's `master` branch uses the `swift-ci/master` Dockerfiles.
 
+There is also a specific directory (`swift-docc-render`) for the Dockerfile used to build Swift-DocC-Render. Swift-DocC-Render builds separately from the rest of the projects in the Swift toolchain and ships a pre-built copy for use in the toolchain in the Swift-DocC-Render-Artifact repository.
+
 ## Continuous Integration
 
 This system is designed to support many distributions.

swift-ci/swift-docc-render/Dockerfile

@@ -0,0 +1,15 @@
+FROM node:14.17.4
+
+ARG SWIFT_DOCC_RENDER_BRANCH=main
+
+RUN groupadd -g 998 build-user && \
+    useradd -m -r -u 998 -g build-user build-user
+
+USER build-user
+
+WORKDIR /home/build-user
+
+RUN git clone https://github.com/apple/swift-docc-render.git
+RUN cd swift-docc-render && git checkout $SWIFT_DOCC_RENDER_BRANCH
+RUN /home/build-user/swift-docc-render/build-script-helper.py build --verbose
+RUN /home/build-user/swift-docc-render/build-script-helper.py test --verbose

swift-ci/swift-docc-render/build-swift-docc-render.sh

@@ -0,0 +1,78 @@
+#!/bin/bash
+#
+# This source file is part of the Swift.org open source project
+#
+# Copyright (c) 2021 Apple Inc. and the Swift project authors
+# Licensed under Apache License v2.0 with Runtime Library Exception
+#
+# See https://swift.org/LICENSE.txt for license information
+# See https://swift.org/CONTRIBUTORS.txt for Swift project authors
+
+
+set -e
+
+function usage() {
+  echo "$0 --output-path <output_path> [OPTIONS]"
+  echo ""
+  echo "<output_path> - Path to the directory where the built Swift-DocC-Render will be copied"
+  echo ""
+  echo "OPTIONS"
+  echo ""
+  echo "-h --help"
+  echo "Show help information."
+  echo ""
+  echo "-b --branch"
+  echo "The branch of Swift-DocC-Render to build."
+  echo ""
+}
+
+OUTPUT_PATH=
+BRANCH=main
+
+while [ $# -ne 0 ]; do
+  case "$1" in
+  -o|--output-path)
+    shift
+    OUTPUT_PATH="$1"
+  ;;
+  -b|--branch)
+    shift
+    BRANCH="$1"
+  ;;
+  -h|--help)
+    usage
+    exit 0
+  ;;
+  *)
+    echo "Unrecognised argument \"$1\""
+    echo ""
+    usage
+    exit 1
+  ;;
+  esac
+shift
+done
+
+if [ -z "${OUTPUT_PATH}" ]; then
+echo "Output path cannot be empty. See $0 --help"
+exit 1
+fi
+
+function filepath() {
+  [[ $1 = /* ]] && echo "$1" || echo "$PWD/${1#./}"
+}
+
+DIRECTORY_ROOT="$(dirname $(filepath $0))"
+DOCKERFILE_PATH="$DIRECTORY_ROOT"/Dockerfile
+
+docker build -t swift-docc-render:latest \
+  --no-cache \
+  --build-arg SWIFT_DOCC_RENDER_BRANCH="$BRANCH" \
+  -f "$DOCKERFILE_PATH" \
+  "$DIRECTORY_ROOT" 
+
+CONTAINER_ID=$(docker create swift-docc-render:latest)
+
+docker cp -a $CONTAINER_ID:/home/build-user/swift-docc-render/dist/. "$OUTPUT_PATH"
+ 
+docker rm $CONTAINER_ID