test: add checklist for howto update the docker iamge

Signed-off-by: Joachim Wiberg <troglobit@gmail.com>

README.md

@@ -1,7 +1,6 @@
 <img align="right" src="doc/text3134.png" alt="Infix Linux Networking Made Easy">
 
 * [Introduction](#introduction)
-* [NETCONF Mode](#netconf-mode)
   * [NETCONF Mode](#netconf-mode)
   * [Classic Mode](#classic-mode)
   * [Hybrid Mode](#hybrid-mode)
@@ -9,6 +8,8 @@
 * [Qemu](#qemu)
 * [GNS3](#gns3)
 * [Building](#building)
+* [Testing](doc/testing.md)
+* [Docker Image](test/docker/README.md)
 * [Origin & Licensing](origin--licensing)
 
 

test/docker/README.md

@@ -0,0 +1,30 @@
+Checklist for Updating Docker Image
+===================================
+
+This directory holds the Dockerfile and any extras needed to build and
+update the infix-test container image used for the test system.
+
+The following is a checklist/reminder to maintainers for how to update
+the image, e.g., with missing Alpine packages.
+
+ 1. Update the Dockerfile
+ 2. Build the new image version, for latest version, see released images
+    here: <https://github.com/kernelkit/infix/pkgs/container/infix-test>
+	in this example we use version 0.4:
+
+        docker build -t ghcr.io/kernelkit/infix-test:0.4 .
+
+ 3. Update the `test/env` file to use the new version
+ 4. Verify your new image works properly
+ 5. Send PR to co-maintainer for review
+
+The co-maintainer should then verify themselves before approving the PR.
+A crucial step to remember is to:
+
+ 1. Push the new image version to <https://ghcr.io>.  For instructions on
+    how to do this, see [the GitHub Container Registry docs](https://docs.github.com/en/packages/working-with-a-github-packages-registry/working-with-the-container-registry)
+ 2. Merge the PR to the `main` branch.
+
+> **Note:** the co-maintainer may delegate the chore of uploading the
+> new image to the one who prepared the PR (you), provided of course
+> they have the access rights to do so.