add docs and a portable shell script buildx.sh for pushing the multi-platform Docker image

ziti-tunnel/docker/BUILD.md

@@ -1,4 +1,4 @@
-The Dockerfile and scripts in this directory build a ziti-tunnel Docker image.
+The Dockerfile and scripts in this directory build a `ziti-tunnel` (Go tunneler) Docker image. This procedure is highly similar to that of the `ziti-edge-tunnel` (C tunneler) Docker image [documented here](https://github.com/openziti/ziti-tunnel-sdk-c/blob/main/docker/BUILD.md).
 
 Ziti binaries are downloaded from https://netfoundry.artifactory.io/netfoundry/ziti-release
 by default. The following build arguments are supported:
@@ -47,7 +47,7 @@ the image to a public registry.
 
 3. Create a Builder Instance
 
-       $ docker buildx create --use
+        $ docker buildx create --use --name=ziti-builder
 
 ## Building
 
@@ -66,10 +66,10 @@ Notes:
 
   Unfortunately `buildx` doesn't currently support building images directly into
   the local docker cache. Although the `--load` and `--output=type=docker` options
-  exist, the underlying capability will be implemented in a future docker release
-  (see https://github.com/docker/buildx/issues/59). In the meantime, you'll need
-  to push your image builds (with the `--push` build option) and then pull them to
-  run the image locally when building with `buildx`.
+  exist, the underlying capability to load a multi-platform image (OCI) will be
+  implemented in a future Docker release (see https://github.com/docker/buildx/issues/59).
+  In the meantime, you'll need to push your image builds (with the `--push` build option)
+  and then pull them to run the image locally when building with `buildx`.
 
 - The armv8 image uses armv7 (32-bit) ziti executables. The 32-bit compatibility
   libraries are installed in the image, but your Arm CPU must support 32-bit emulation.
@@ -81,14 +81,32 @@ Notes:
 - <https://community.arm.com/developer/tools-software/tools/b/tools-software-ides-blog/posts/getting-started-with-docker-for-arm-on-linux>
 - <https://medium.com/@drpdishant/installing-docker-on-fedora-31-a073db823bb8>
 
-
 # Building for Development
 
 This build method produces an image for the CPU that is running the build host
 (typically amd64), and places the resulting image into your local Docker image
 cache.
 
-    $ ziti_version="0.15.3" \
+    $ git fetch --tags && git tag -l | sort -Vr | head -1
+    v0.19.10
+    $ ziti_version="0.19.10" \
     $ docker build \
         --build-arg ZITI_VERSION="${ziti_version}" \
-        -t "netfoundry/ziti-tunnel:${ziti_version}" .
+        -t "netfoundry/ziti-tunnel:${ziti_version}" .
+
+## Shell Script for Linux
+
+        $ ./buildx.sh -h
+        Usage: VARIABLES ./buildx.sh [OPTION]...
+
+        Build multi-platform Docker container image on Linux.
+
+        VARIABLES
+            ZITI_VERSION      e.g. "0.16.1" corresponding to Git tag "v0.16.1"
+
+        OPTIONS
+            -r REPO           container image repository e.g. netfoundry/ziti-edge-tunnel
+            -c                don't check out v${ZITI_VERSION} (use Git working copy)
+
+        EXAMPLES
+            ZITI_VERSION=0.16.1 ./buildx.sh -r netfoundry/ziti-tunnel

ziti-tunnel/docker/Dockerfile

@@ -2,7 +2,7 @@ FROM debian:stable-slim as fetch-ziti-artifacts
 # This build stage grabs artifacts that are copied into the final image.
 # It uses the same base as the final image to maximize docker cache hits.
 
-ARG ZITI_VERSION="0.18.2"
+ARG ZITI_VERSION
 
 ARG ARTIFACTORY_TOKEN
 ARG ARTIFACTORY_BASE_URL="https://netfoundry.jfrog.io/netfoundry"

ziti-tunnel/docker/buildx.sh

@@ -0,0 +1,79 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+_usage(){
+    cat >&2 <<-EOF
+Usage: VARIABLES ./buildx.sh [OPTION]...
+
+Build multi-platform Docker container image on Linux.
+
+VARIABLES
+    ZITI_VERSION      e.g. "0.16.1" corresponding to Git tag "v0.16.1"
+
+OPTIONS
+    -r REPO           container image repository e.g. netfoundry/ziti-edge-tunnel
+    -c                don't check out v\${ZITI_VERSION} (use Git working copy)
+
+
+EXAMPLES
+    ZITI_VERSION=0.16.1 ./buildx.sh -c
+
+REFERENCE
+    https://github.com/openziti/ziti-tunnel-sdk-c/blob/main/docker/BUILD.md
+EOF
+    [[ $# -eq 1 ]] && {
+        return $1
+    } || {
+        return 0
+    }
+}
+
+BASENAME=$(basename $0) || exit $?
+DIRNAME=$(dirname $0) || exit $?
+
+while getopts :r:c OPT;do
+    case $OPT in
+        r)  CONTAINER_REPO=$OPTARG 
+            ;;
+        c) 	FLAGS+=$OPT     # don't checkout vZITI_VERSION
+            ;;
+        h) _usage; exit 0   # not an error
+            ;;
+        *|\?) _usage 1      # error
+            ;;
+    esac
+done
+shift "$((OPTIND-1))"
+
+# default to latest
+: ${ZITI_VERSION:=$(git fetch --quiet --tags && git tag -l|sort -Vr|head -1|sed -E 's/^v(.*)/\1/')}
+
+# required opts
+[[ ! -z ${CONTAINER_REPO:+true} ]] || {
+    echo "ERROR: missing -r REPO option to define container image repository name for image push" >&2
+    _usage; exit 1
+}
+
+if [[ ${FLAGS:-} =~ c ]]; then
+    echo "WARN: not checking out Git tag v${ZITI_VERSION}"
+else
+    git diff --exit-code # bail if unstaged differences
+    git fetch --tags
+    git co v${ZITI_VERSION}
+fi
+
+docker run --rm --privileged docker/binfmt:a7996909642ee92942dcd6cff44b9b95f08dad64
+egrep -q enabled /proc/sys/fs/binfmt_misc/qemu-arm
+docker run --rm arm64v8/alpine uname -a|egrep -q 'aarch64 Linux'
+docker run --rm arm32v7/alpine uname -a|egrep -q 'armv7l Linux'
+
+docker buildx create --use --name=ziti-builder 2>/dev/null || docker buildx use --default ziti-builder
+
+docker buildx build $DIRNAME \
+    --platform linux/amd64,linux/arm/v7,linux/arm64 \
+    --build-arg ZITI_VERSION=${ZITI_VERSION} \
+    --tag ${CONTAINER_REPO}:${ZITI_VERSION} \
+    --tag ${CONTAINER_REPO}:latest \
+    --push
+
+docker buildx stop ziti-builder