Update Dockerfile to support arm, arm64 and amd64 architecture

Dockerfile

@@ -1,13 +1,15 @@
 FROM alpine:3.17
 MAINTAINER Serhiy Mitrovtsiy <[email protected]>
 
+ARG TARGETPLATFORM
 ARG KUBE_VERSION="v1.29.2"
 
 COPY entrypoint.sh /entrypoint.sh
 
-RUN chmod +x /entrypoint.sh && \
+RUN if [ "$TARGETPLATFORM" = "linux/amd64" ]; then ARCHITECTURE=amd64; elif [ "$TARGETPLATFORM" = "linux/arm/v7" ]; then ARCHITECTURE=arm; elif [ "$TARGETPLATFORM" = "linux/arm64" ]; then ARCHITECTURE=arm64; else ARCHITECTURE=amd64; fi && \
+    chmod +x /entrypoint.sh && \
     apk add --no-cache --update openssl curl ca-certificates && \
-    curl -L https://storage.googleapis.com/kubernetes-release/release/$KUBE_VERSION/bin/linux/amd64/kubectl -o /usr/local/bin/kubectl && \
+    curl -L https://storage.googleapis.com/kubernetes-release/release/$KUBE_VERSION/bin/linux/$ARCHITECTURE/kubectl -o /usr/local/bin/kubectl && \
     chmod +x /usr/local/bin/kubectl && \
     rm -rf /var/cache/apk/*