Refactor Docker setup to support multi-architecture builds and update base image to Alpine

Signed-off-by: Stephen Simpson <ssimpson89@users.noreply.github.com>

.github/workflows/docker-image-linux.yml

@@ -29,12 +29,33 @@ jobs:
           username: ${{ github.actor }}
           password: ${{ secrets.GITHUB_TOKEN }}
 
-      - name: Build and push
+      - name: Build and push amd64
         uses: docker/build-push-action@v6
         with:
           context: .
           file: ./Dockerfile
           push: true
-          platforms: linux/amd64,linux/arm64
+          platforms: linux/amd64
+          build-args: |
+            ARCH=x86_64
           tags: |
-            ${{ env.REGISTRY }}/${{ env.GITHUBUSER }}/${{ env.IMAGE_NAME }}:latest
+            ${{ env.REGISTRY }}/${{ env.GITHUBUSER }}/${{ env.IMAGE_NAME }}:amd64
+
+      - name: Build and push arm64
+        uses: docker/build-push-action@v6
+        with:
+          context: .
+          file: ./Dockerfile
+          push: true
+          platforms: linux/arm64
+          build-args: |
+            ARCH=aarch64
+          tags: |
+            ${{ env.REGISTRY }}/${{ env.GITHUBUSER }}/${{ env.IMAGE_NAME }}:arm64
+
+      - name: Create and push manifest
+        run: |
+          docker manifest create ${{ env.REGISTRY }}/${{ env.GITHUBUSER }}/${{ env.IMAGE_NAME }}:latest \
+            ${{ env.REGISTRY }}/${{ env.GITHUBUSER }}/${{ env.IMAGE_NAME }}:amd64 \
+            ${{ env.REGISTRY }}/${{ env.GITHUBUSER }}/${{ env.IMAGE_NAME }}:arm64
+          docker manifest push ${{ env.REGISTRY }}/${{ env.GITHUBUSER }}/${{ env.IMAGE_NAME }}:latest

Dockerfile

@@ -1,8 +1,14 @@
-FROM rockylinux/rockylinux:8.4
+FROM alpine:latest
 
-RUN curl -s https://packagecloud.io/install/repositories/ookla/speedtest-cli/script.rpm.sh | bash
+# Set architecture as a build argument with a default value
+ARG ARCH=x86_64
 
-RUN yum -y install speedtest
+RUN apk add --no-cache wget ca-certificates tar
+
+RUN wget -q https://install.speedtest.net/app/cli/ookla-speedtest-1.2.0-linux-${ARCH}.tgz && \
+    tar -xzf ookla-speedtest-1.2.0-linux-${ARCH}.tgz -C /usr/bin && \
+    rm ookla-speedtest-1.2.0-linux-${ARCH}.tgz && \
+    chmod +x /usr/bin/speedtest
 
 COPY entrypoint.sh /entrypoint.sh
 RUN chmod +x /entrypoint.sh

entrypoint.sh

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/bin/sh
 
 # Set terminal type
 export TERM=xterm-256color