Final debug helper images must be for target platform (#78)

* enable mirror.gcr.io registry mirror in the hope that it avoid rate limits

Author: briandealwis

go/helper-image/Dockerfile

@@ -23,7 +23,7 @@ RUN cd delve-source && CGO_ENABLED=0 GOOS=$TARGETOS GOARCH=$TARGETARCH go build
 
 # Now populate the duct-tape image with the language runtime debugging support files
 # The debian image is about 95MB bigger
-FROM --platform=$BUILDPLATFORM busybox
+FROM busybox
 # The install script copies all files in /duct-tape to /dbg
 COPY install.sh /
 CMD ["/bin/sh", "/install.sh"]

hack/enable-docker-buildkit.sh

@@ -6,11 +6,15 @@ if [ -f /etc/docker/daemon.json ]; then
     echo "/etc/docker/daemon.json was:"
     sed 's/^/> /' /etc/docker/daemon.json
     echo "/etc/docker/daemon.json now:"
-    jq '.+{"experimental":true}' /etc/docker/daemon.json | sudo tee /etc/docker/daemon.json
+    jq '.+{"experimental":true}' /etc/docker/daemon.json \
+    | jq '."registry-mirrors" += ["https://mirror.gcr.io"]' \
+    | sudo tee /etc/docker/daemon.json
 else
     sudo mkdir -vp /etc/docker
     echo "/etc/docker/daemon.json now:"
-    echo '{"experimental":true}' | sudo tee /etc/docker/daemon.json
+    echo '{"experimental":true}' \
+    | jq '."registry-mirrors" += ["https://mirror.gcr.io"]' \
+    | sudo tee /etc/docker/daemon.json
 fi
 
 if [ -f $HOME/.docker/config.json ]; then

netcore/helper-image/Dockerfile

@@ -5,7 +5,7 @@ RUN apt-get update \
 
 # Now populate the duct-tape image with the language runtime debugging support files
 # The debian image is about 95MB bigger
-FROM --platform=$BUILDPLATFORM busybox
+FROM busybox
 ARG BUILDPLATFORM
 
 # The install script copies all files in /duct-tape to /dbg

nodejs/helper-image/Dockerfile

@@ -10,7 +10,7 @@ RUN GOPATH="" CGO_ENABLED=0 GOOS=$TARGETOS GOARCH=$TARGETARCH go build -o node -
 
 # Now populate the duct-tape image with the language runtime debugging support files
 # The debian image is about 95MB bigger
-FROM --platform=$BUILDPLATFORM busybox
+FROM busybox
 # The install script copies all files in /duct-tape to /dbg
 COPY install.sh /
 CMD ["/bin/sh", "/install.sh"]

python/helper-image/Dockerfile

@@ -76,7 +76,7 @@ RUN GOPATH="" CGO_ENABLED=0 go build -o launcher -ldflags '-s -w -extldflags "-s
 
 # Now populate the duct-tape image with the language runtime debugging support files
 # The debian image is about 95MB bigger
-FROM --platform=$BUILDPLATFORM busybox
+FROM busybox
 ARG BUILDPLATFORM
 
 # The install script copies all files in /duct-tape to /dbg