make build able to handle arm64 architecture

Author: sabbott-cg

Dockerfile

@@ -1,3 +1,12 @@
+FROM debian:stable-slim as fetcher
+COPY build/fetch_binaries.sh /tmp/fetch_binaries.sh
+
+RUN apt-get update && apt-get install -y \
+  curl \
+  wget
+
+RUN /tmp/fetch_binaries.sh
+
 FROM alpine:3.9
 
 RUN set -ex \
@@ -57,19 +66,13 @@ RUN set -ex \
 RUN mv /usr/sbin/tcpdump /usr/bin/tcpdump
 
 # Installing ctop - top-like container monitor
-RUN wget https://github.com/bcicen/ctop/releases/download/v0.7.1/ctop-0.7.1-linux-amd64 -O /usr/local/bin/ctop && chmod +x /usr/local/bin/ctop
+COPY --from=fetcher /tmp/ctop /usr/local/bin/ctop
 
 # Installing calicoctl
-ARG CALICOCTL_VERSION=v3.13.3
-RUN wget https://github.com/projectcalico/calicoctl/releases/download/${CALICOCTL_VERSION}/calicoctl && chmod +x calicoctl && mv calicoctl /usr/local/bin
+COPY --from=fetcher /tmp/calicoctl /usr/local/bin/calicoctl
 
 # Installing termshark
-ENV TERMSHARK_VERSION 2.1.1
-RUN wget https://github.com/gcla/termshark/releases/download/v${TERMSHARK_VERSION}/termshark_${TERMSHARK_VERSION}_linux_x64.tar.gz -O /tmp/termshark_${TERMSHARK_VERSION}_linux_x64.tar.gz && \
-    tar -zxvf /tmp/termshark_${TERMSHARK_VERSION}_linux_x64.tar.gz && \
-    mv termshark_${TERMSHARK_VERSION}_linux_x64/termshark /usr/local/bin/termshark && \
-    chmod +x /usr/local/bin/termshark
-
+COPY --from=fetcher /tmp/termshark /usr/local/bin/termshark
 
 # Settings
 ADD motd /etc/motd

build/fetch_binaries.sh

@@ -0,0 +1,56 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+get_latest_release() {
+  curl --silent "https://api.github.com/repos/$1/releases/latest" | # Get latest release from GitHub api
+    grep '"tag_name":' |                                            # Get tag line
+    sed -E 's/.*"([^"]+)".*/\1/'                                    # Pluck JSON value
+}
+
+
+ARCH=$(uname -m)
+case $ARCH in
+    x86_64)
+        ARCH=amd64
+        ;;
+    aarch64)
+        ARCH=arm64
+        ;;
+esac
+
+get_ctop() {
+  VERSION=$(get_latest_release bcicen/ctop | sed -e 's/^v//')
+  LINK="https://github.com/bcicen/ctop/releases/download/v${VERSION}/ctop-${VERSION}-linux-${ARCH}"
+  wget "$LINK" -O /tmp/ctop && chmod +x /tmp/ctop
+}
+
+get_calicoctl() {
+  VERSION=$(get_latest_release projectcalico/calicoctl)
+  LINK="https://github.com/projectcalico/calicoctl/releases/download/${VERSION}/calicoctl-linux-${ARCH}"
+  wget "$LINK" -O /tmp/calicoctl && chmod +x /tmp/calicoctl
+}
+
+get_termshark() {
+  case "$ARCH" in
+    "arm"*)
+      echo "echo termshark does not yet support arm" > /tmp/termshark && chmod +x /tmp/termshark
+      ;;
+    *)
+      VERSION=$(get_latest_release gcla/termshark | sed -e 's/^v//')
+      if [ "$ARCH" == "amd64" ]; then
+        TERM_ARCH=x64
+      else
+        TERM_ARCH="$ARCH"
+      fi
+      LINK="https://github.com/gcla/termshark/releases/download/v${VERSION}/termshark_${VERSION}_linux_${TERM_ARCH}.tar.gz"
+      wget "$LINK" -O /tmp/termshark.tar.gz && \
+      tar -zxvf /tmp/termshark.tar.gz && \
+      mv "termshark_${VERSION}_linux_${TERM_ARCH}/termshark" /tmp/termshark && \
+      chmod +x /tmp/termshark
+      ;;
+  esac
+}
+
+get_ctop
+get_calicoctl
+get_termshark