[5.2] Add Ubuntu 20.04 slim dockerfile

Author: shahmishal

5.2/ubuntu/20.04/slim/Dockerfile

@@ -0,0 +1,45 @@
+FROM ubuntu:20.04
+LABEL maintainer="Swift Infrastructure <swift-infrastructure@swift.org>"
+LABEL description="Docker Container for the Swift programming language"
+
+RUN export DEBIAN_FRONTEND=noninteractive DEBCONF_NONINTERACTIVE_SEEN=true && apt-get -q update && \
+    apt-get -q install -y \
+    libcurl4 \
+    libxml2 \
+    tzdata \
+    && rm -r /var/lib/apt/lists/*
+
+# Everything up to here should cache nicely between Swift versions, assuming dev dependencies change little
+
+# pub   4096R/ED3D1561 2019-03-22 [expires: 2021-03-21]
+#       Key fingerprint = A62A E125 BBBF BB96 A6E0  42EC 925C C1CC ED3D 1561
+# uid                  Swift 5.x Release Signing Key <swift-infrastructure@swift.org
+ARG SWIFT_SIGNING_KEY=A62AE125BBBFBB96A6E042EC925CC1CCED3D1561
+ARG SWIFT_PLATFORM=ubuntu20.04
+ARG SWIFT_BRANCH=swift-5.2.4-release
+ARG SWIFT_VERSION=swift-5.2.4-RELEASE
+ARG SWIFT_WEBROOT=https://swift.org/builds/
+
+ENV SWIFT_SIGNING_KEY=$SWIFT_SIGNING_KEY \
+    SWIFT_PLATFORM=$SWIFT_PLATFORM \
+    SWIFT_BRANCH=$SWIFT_BRANCH \
+    SWIFT_VERSION=$SWIFT_VERSION \
+    SWIFT_WEBROOT=$SWIFT_WEBROOT
+
+RUN set -e; \
+    SWIFT_WEBDIR="$SWIFT_WEBROOT/$SWIFT_BRANCH/$(echo $SWIFT_PLATFORM | tr -d .)/" \
+    && SWIFT_BIN_URL="$SWIFT_WEBDIR/$SWIFT_VERSION/$SWIFT_VERSION-$SWIFT_PLATFORM.tar.gz" \
+    && SWIFT_SIG_URL="$SWIFT_BIN_URL.sig" \
+    # - Grab curl and gpg here so we cache better up above
+    && export DEBIAN_FRONTEND=noninteractive \
+    && apt-get -q update && apt-get -q install -y curl gnupg && rm -rf /var/lib/apt/lists/* \
+    # - Download the GPG keys, Swift toolchain, and toolchain signature, and verify.
+    && export GNUPGHOME="$(mktemp -d)" \
+    && curl -fsSL "$SWIFT_BIN_URL" -o swift.tar.gz "$SWIFT_SIG_URL" -o swift.tar.gz.sig \
+    && gpg --batch --quiet --keyserver ha.pool.sks-keyservers.net --recv-keys "$SWIFT_SIGNING_KEY" \
+    && gpg --batch --verify swift.tar.gz.sig swift.tar.gz \
+    # - Unpack the toolchain, set libs permissions, and clean up.
+    && tar -xzf swift.tar.gz --directory / --strip-components=1 $SWIFT_VERSION-$SWIFT_PLATFORM/usr/lib/swift/linux \
+    && chmod -R o+r /usr/lib/swift \
+    && rm -rf "$GNUPGHOME" swift.tar.gz.sig swift.tar.gz \
+    && apt-get purge --auto-remove -y curl gnupg