Change Dockerfile to use public AL ECR (#115)

Move away from busybox and towards AmazonLinux for compliance reasons.
This does increase image size from ~100MB to ~189MB. In future, we want
to move to `scratch`, which brings in no extras, which will reduce to
~50MB, but for now, this should suffice.

Tested with EKS cluster and confirmed metrics are produced.

By submitting this pull request, I confirm that you can use, modify,
copy, and redistribute this contribution, under the terms of your
choice.

Author: thpierce

.github/actions/artifacts_build/action.yml

@@ -65,14 +65,23 @@ runs:
     - name: Set up Docker Buildx
       uses: docker/setup-buildx-action@v3
 
-    - name: Login to AWS ECR
+    - name: Login to private AWS ECR
       if: ${{ inputs.push_image == true || inputs.push_image == 'true' }}
       uses: docker/login-action@v3
       with:
         registry: ${{ inputs.image_registry }}
       env:
         AWS_REGION: ${{ inputs.aws-region }}
 
+    # Per https://docs.aws.amazon.com/AmazonECR/latest/public/docker-pull-ecr-image.html, it is possible to
+    # make unauthorized calls to get public ECR images (needed to build the ADOT Python docker image), but
+    # it can fail if you previously authenticated to a public repo. Adding this step to log out, so we
+    # ensure we can make unauthenticated call. This is important for making the pr_build workflow run on
+    # PRs created from forked repos.
+    - name: Logout of public AWS ECR
+      shell: bash
+      run: docker logout public.ecr.aws
+
     - name: Build and push image according to input
       uses: docker/build-push-action@v5
       with:

Dockerfile

@@ -17,7 +17,7 @@ ADD aws-opentelemetry-distro/ ./aws-opentelemetry-distro/
 
 RUN mkdir workspace && pip install --target workspace ./aws-opentelemetry-distro
 
-FROM busybox
+FROM public.ecr.aws/amazonlinux/amazonlinux:minimal
 
 COPY --from=build /operator-build/workspace /autoinstrumentation