feat: multi-platform Docker images

# Why

More and more systems are running on the arm64 platform. For example,
AWS EC2 instances with Graviton2 processors or ARM-based MacBooks.
One of our customers is facing issues, because Newman does not run
on ARM-based systems. More specifically, the `postman/newman` Docker
image only supports the `linux/amd64` platform.

# What

This change enables the creation of `linux/amd64` and
`linux/arm64` Docker images.

The change also removes the Docker image definition for Ubuntu 14.04 and
Alpine 3.3. Both of these newman Docker images haven't been published in
two years and can therefore be removed.

docker/images/ubuntu/Dockerfile

@@ -1,7 +1,7 @@
 FROM ubuntu:18.04
 LABEL maintainer="Postman Labs <[email protected]>"
 
-ARG NODE_VERSION=10
+ARG NODE_VERSION=16
 ARG NEWMAN_VERSION
 
 # Bail out early if NODE_VERSION is not provided

npm/postpublish.sh

@@ -1,7 +1,7 @@
-#!/bin/bash
+#!/usr/bin/env bash
 
 # Bail out on the first error
-set -e;
+set -eo pipefail;
 
 LATEST="alpine";
 BLUE="\033[0;34m";
@@ -17,62 +17,67 @@ GIT_BRANCH=$(git rev-parse --abbrev-ref HEAD);
 MAJOR=$(echo ${VERSION} | grep -oE "^\d+");
 MINOR=$(echo ${VERSION} | grep -oE "^\d+\.\d+");
 
-function build_docker_image {
-    local TAG=$(basename $1);
+function validate_docker_image {
+    local OS="$(basename $1)"
+    local IMAGE_NAME="newman-test-$OS";
 
     echo "";
 
-    echo -e "$BLUE Building $DOCKER_REPO:$VERSION-$TAG $NO_COLOUR";
+    echo -e "$BLUE Building Docker image (OS: $OS) for local image validation test $NO_COLOUR";
 
     docker build \
-        --no-cache --force-rm --squash -t ${DOCKER_REPO}:${VERSION}-${TAG} \
-        --file="docker/images/$TAG/Dockerfile" --build-arg NEWMAN_VERSION=${VERSION} .;
+        --no-cache \
+        --force-rm \
+        -t $IMAGE_NAME \
+        --file="docker/images/$OS/Dockerfile" \
+        --build-arg NEWMAN_VERSION=${VERSION} \
+        .;
 
-    echo -e "$BLUE Running docker image test for $DOCKER_REPO:$VERSION-$TAG, latest $NO_COLOUR";
+    echo -e "$BLUE Running Docker image (OS: $OS) test $NO_COLOUR";
 
     # Test
-    docker run -v ${PWD}/examples:/etc/newman -t ${DOCKER_REPO}:${VERSION}-${TAG} run "sample-collection.json";
+    docker run -v ${PWD}/examples:/etc/newman --rm -t $IMAGE_NAME run "sample-collection.json";
+
+    echo -e "$BLUE Removing Docker image (OS: $OS) from local Docker $NO_COLOUR";
+    docker rmi $IMAGE_NAME
+}
+
+function build_docker_image {
+    local OS="$(basename $1)"
 
-    echo -e "$BLUE Pushing docker image for $DOCKER_REPO:$VERSION-$TAG $NO_COLOUR";
+    local TAGS=""
+
+    echo "";
 
-    # Tag
     if [[ ${GIT_BRANCH} == "master" ]]; then
-        if [[ ${TAG} == "ubuntu1404" || ${TAG} == "alpine33" ]]; then
-            docker tag ${DOCKER_REPO}:${VERSION}-${TAG} ${DOCKER_REPO}_${TAG}:latest;
-            docker push ${DOCKER_REPO}_${TAG}:latest;
-        else
-            docker tag ${DOCKER_REPO}:${VERSION}-${TAG} ${DOCKER_REPO}:${TAG};
-            docker push ${DOCKER_REPO}:${TAG};
-
-            if [[ ${TAG} == ${LATEST} ]]; then
-                docker tag ${DOCKER_REPO}:${VERSION}-${TAG} ${DOCKER_REPO}:latest;
-                docker tag ${DOCKER_REPO}:${VERSION}-${TAG} ${DOCKER_REPO}:${VERSION};
-                docker tag ${DOCKER_REPO}:${VERSION}-${TAG} ${DOCKER_REPO}:${MINOR};
-                docker tag ${DOCKER_REPO}:${VERSION}-${TAG} ${DOCKER_REPO}:${MAJOR};
-
-                docker push ${DOCKER_REPO}:latest;
-                docker push ${DOCKER_REPO}:${VERSION};
-                docker push ${DOCKER_REPO}:${MINOR};
-                docker push ${DOCKER_REPO}:${MAJOR};
-            fi
+        TAGS="$TAGS -t ${DOCKER_REPO}:${OS}"
+
+        if [[ ${OS} == ${LATEST} ]]; then
+            TAGS="$TAGS -t ${DOCKER_REPO}:latest";
+            TAGS="$TAGS -t ${DOCKER_REPO}:${VERSION}";
+            TAGS="$TAGS -t ${DOCKER_REPO}:${MINOR}";
+            TAGS="$TAGS -t ${DOCKER_REPO}:${MAJOR}";
         fi
     fi
 
-    if [[ ${TAG} == "ubuntu1404" || ${TAG} == "alpine33" ]]; then
-        docker tag ${DOCKER_REPO}:${VERSION}-${TAG} ${DOCKER_REPO}_${TAG}:${VERSION};
-        docker push ${DOCKER_REPO}_${TAG}:${VERSION};
-    else
-        # Push
-        docker tag ${DOCKER_REPO}:${VERSION}-${TAG} ${DOCKER_REPO}:${VERSION}-${TAG};
-        docker tag ${DOCKER_REPO}:${VERSION}-${TAG} ${DOCKER_REPO}:${MINOR}-${TAG};
-        docker tag ${DOCKER_REPO}:${VERSION}-${TAG} ${DOCKER_REPO}:${MAJOR}-${TAG};
-
-        docker push ${DOCKER_REPO}:${VERSION}-${TAG};
-        docker push ${DOCKER_REPO}:${MINOR}-${TAG};
-        docker push ${DOCKER_REPO}:${MAJOR}-${TAG};
-    fi
+    TAGS="$TAGS -t ${DOCKER_REPO}:${VERSION}-${OS}";
+    TAGS="$TAGS -t ${DOCKER_REPO}:${MINOR}-${OS}";
+    TAGS="$TAGS -t ${DOCKER_REPO}:${MAJOR}-${OS}";
+
+    echo -e "$BLUE Will now build and push multi-platform Docker image with tags $TAGS $NO_COLOUR";
+
+    docker buildx build \
+        --platform linux/amd64,linux/arm64 \
+        --no-cache \
+        --force-rm \
+        ${TAGS} \
+        --file="docker/images/$OS/Dockerfile" \
+        --build-arg NEWMAN_VERSION=${VERSION} \
+        --push \
+        .;
 }
 
 for image in ${IMAGES_BASE_PATH}/*; do
+    validate_docker_image ${image};
     build_docker_image ${image};
 done