tidy up of extra docs (#14)

slides/gcloud.md → docs/gcloud.md

@@ -1,15 +1,15 @@
+# Docker in Google Cloud Shell
 
 ## Web preview
 
+It's very easy to pull and run a container in Cloud Shell. e.g.
+
 ```sh
 mike_saunby@cloudshell:~ (docker-demo-2023)$ docker pull tiangolo/uwsgi-nginx-flask
 mike_saunby@cloudshell:~ (docker-demo-2023)$ docker run  -p 8080:80 docker.io/tiangolo/uwsgi-nginx-flask:latest
 ```
 
-
-## SSH to Cloud Shell
-
-<https://medium.com/@alex.burdenko/vs-code-happens-to-be-my-favorite-code-editor-and-ive-been-lucky-to-participate-so-many-diverse-952102856a7a>
+The web preview feature enables forwarding of port 8080 to you web browser.
 
 ## Docker command line
 

docs/ghrc-notes.md

@@ -0,0 +1,47 @@
+# Container registries
+
+Building a Docker image in a GitHub action is very simple, however generating an appropriately tagged image and authenticating and pushing to a container registry is more complicated.
+
+## Docker Hub - docker.io
+
+To push to Hocker Hub from an Action secret environment variables are used. e.g.
+
+```sh
+username: ${{ secrets.DOCKER_HUB_USERNAME }}
+password: ${{ secrets.DOCKER_HUB_ACCESS_TOKEN }}
+```
+
+And set a secret in the repository settings.
+
+![](Screenshot-github-secret.png)
+
+## GitHub Container Registry - ghcr.io
+
+The GitHub container registry avoids having to set secret variables as we can get the username and password using the built in GITHUB_TOKEN
+
+```
+username: ${{ github.actor }}
+password: ${{ secrets.GITHUB_TOKEN }}
+```
+
+To pull an image from any repository other than docker.io requires that the full name is used. e.g.
+
+```msaunby/building-docker-containers-in-github:latest``` and ```docker.io/msaunby/building-docker-containers-in-github:latest``` are equivalent.
+
+GitHub registry
+
+```ghcr.io/msaunby/building-docker-containers-in-github:latest```
+
+Google 
+
+```gcr.io```
+
+Azure
+
+```{myregistry}.azurecr.io```
+
+AWS
+
+```public.ecr.aws``` Private registries have more complicated names.
+
+