create quickstart local image builder unless existing builder

quickstart/docker/README.md

@@ -21,25 +21,16 @@ First, decide what you are trying to do. Are you trying to:
 1. change to this directory from checkout root: `cd quickstart/docker`
 1. run the script `./createLocalImage.sh` which will create a `openziti/quickstart:latest` tag
    using the latest `ziti` [release from GitHub](https://github.com/openziti/ziti/releases/latest)
-   1. Optionally, you may provide an argument for the image tag. `./createLocalImage.sh <tagname>`
+   1. Optionally, you may provide an argument, e.g., `./createLocalImage.sh <tagname>`, to create a tag
+      other than `latest`.
 
 ## Build Docker Image with Specific ziti Version
 1. change to this directory from checkout root: `cd quickstart/docker`
 1. set `ZITI_VERSION_OVERRIDE` to desired version: `export ZITI_VERSION_OVERRIDE=v0.28.4`
 1. run the script `./createLocalImage.sh` which will create a `openziti/quickstart:latest` tag
    using the specified version of `ziti` [from GitHub](https://github.com/openziti/ziti/releases/tag/v0.28.4)
-   1. Optionally, you may provide an argument for the image tag. `./createLocalImage.sh <tagname>`
-
-## ERROR: existing instance for "ziti-builder"
-When running the `./createLocalImage.sh` script, you might get this error:
-```
-ERROR: existing instance for "ziti-builder" but no append mode, specify --node to make changes for existing instances
-```
-It's probably safest to just remove the buildx builder using:
-```
-docker buildx rm ziti-builder
-```
-
+   1. Optionally, you may provide an argument, e.g., `./createLocalImage.sh <tagname>`, to create a tag
+      other than `latest`.
 
 ## Build Docker Image For Publication
 To publish the latest `ziti` CLI, use [the GitHub Action](https://github.com/openziti/ziti/actions/workflows/push-quickstart.yml).

quickstart/docker/image/fetch-ziti-bins.sh

@@ -7,7 +7,7 @@ dest="${1}"
 if [ -d /docker.build.context/ziti-bin ]; then
   mv /docker.build.context/ziti-bin/ "${dest}"
 else
-   source /docker.build.context/ziti-cli-functions.sh
-   getZiti
-   mv "${ZITI_BIN_DIR}" "${dest}"
+  source /docker.build.context/ziti-cli-functions.sh
+  getZiti
+  mv "${ZITI_BIN_DIR}" "${dest}"
 fi

quickstart/docker/pushLatestDocker.sh

@@ -21,8 +21,6 @@ if [ -z "${IMAGE_TAG}" ]; then
   echo "image tag name was not provided, using default '${IMAGE_TAG}'"
 fi
 
-docker buildx create --use --name=ziti-builder
-
 if [ "local" == "${1}" ]; then
   echo "LOADING LOCALLY instead of pushing to dockerhub"
   _BUILDX_PLATFORM=""
@@ -31,8 +29,13 @@ else
   _BUILDX_PLATFORM="--platform linux/amd64,linux/arm64"
   _BUILDX_ACTION="--push"
 fi
-docker buildx build ${_BUILDX_PLATFORM} "${SCRIPT_DIR}/image" \
+
+docker buildx create \
+  --use --name=ziti-builder --driver docker-container 2>/dev/null \
+  || docker buildx use --default ziti-builder
+
+eval docker buildx build "${_BUILDX_PLATFORM}" "${SCRIPT_DIR}/image" \
   --build-arg ZITI_VERSION_OVERRIDE="v${ZITI_VERSION}" \
   --tag "openziti/quickstart:${ZITI_VERSION}" \
   --tag "openziti/quickstart:${IMAGE_TAG}" \
-  ${_BUILDX_ACTION}
+  "${_BUILDX_ACTION}"