GHW for building and publishing docker images (#1391)

* add ghw and scripts for docker image deployment

* debug

* add permissions for content

* fix path to the bin folder

* add tags

* rename env

* fix path to docker file

* make polkadot-parachain executable

* fix typo

* fix more typos

* test

* revert back  use of  working directory

* mke bin executable in the artifacts folder

* use cd instead of working directory

* change path to cash

* fix path to cash

* change cache key

* delete old flows

* addressed PR comments

* fix path

* reorg docker files

docker/dockerfiles/parachain-registrar.dockerfile

@@ -0,0 +1,27 @@
+FROM node:latest AS pjs
+
+# It would be great to depend on a more stable tag, but we need some
+# as-yet-unreleased features.
+RUN yarn global add @polkadot/api-cli@0.10.0-beta.14
+
+ENTRYPOINT [ "polkadot-js-api" ]
+CMD [ "--version" ]
+
+# To use the pjs build stage to access the blockchain from the host machine:
+#
+#   docker build -f docker/dockerfiles/parachain-registrar.dockerfile --target pjs -t parachain-registrar:pjs .
+#   alias pjs='docker run --rm --net cumulus_testing_net parachain-registrar:pjs --ws ws://172.28.1.1:9944'
+#
+# Then, as long as the chain is running, you can use the polkadot-js-api CLI like:
+#
+#   pjs query.sudo.key
+
+FROM pjs
+RUN apt-get update && apt-get install curl netcat -y && \
+    curl -sSo /wait-for-it.sh https://raw.githubusercontent.com/vishnubob/wait-for-it/master/wait-for-it.sh && \
+    chmod +x /wait-for-it.sh
+# the only thing left to do is to actually run the transaction.
+COPY ./docker/scripts/register_para.sh /usr/bin
+# unset the previous stage's entrypoint
+ENTRYPOINT []
+CMD [ "/usr/bin/register_para.sh" ]