Update Docker Hub -> GitHub Container Registry

Since we cannot push anymore, I removed the push-target.

Makefile

@@ -2,7 +2,7 @@
 XSOCK?=/tmp/.X11-unix
 DUNSTRC=${HOME}/.config/dunst/dunstrc
 DOCKER_REPO?=dunst/dunst
-DOCKER_REPO_CI?=dunst/ci
+DOCKER_REPO_CI?=ghcr.io/dunst-project/docker-images
 DOCKER_TECHNIQUE?=build
 REPO=./dunst
 CFLAGS?=-Werror
@@ -19,7 +19,7 @@ endif
 
 # Structure of the makefile
 #
-# We have generic targets (run push pull build clean), wich
+# We have generic targets (run pull build clean), wich
 # depend on the image's specific target
 #
 # Every docker image flavor has a unique name. It is used as
@@ -37,20 +37,14 @@ IMG_CI?=$(shell find ci -name 'Dockerfile.*' | sed 's/ci\/Dockerfile\.\(.*\)/\1/
 # force make to execute the find call only once
 IMG_CI:=${IMG_CI}
 
-.PHONY: all ci push pull build clean
+.PHONY: all ci pull build clean
 all: ci
 ci: ci-run
 run: ci-run
-push: ci-push
 pull: ci-pull
 build: ci-build
 clean: ci-clean
 
-# Push all images to docker hub
-ci-push: ${IMG_CI:%=ci-push-%}
-ci-push-%: ci-build-%
-	$(DOCKER) push "${DOCKER_REPO_CI}:${@:ci-push-%=%}"
-
 # Pull all images from docker hub
 ci-pull: ${IMG_CI:%=ci-pull-%}
 ci-pull-%:

README.md

@@ -22,7 +22,7 @@ Use `make` for this and point the `REPO` variable to your repository. So a `make
 - **copy** the repo into the container (you local repo stays untouched)
 - execute the tests in the docker image
 
-If you do not want to build the images, but download the prebuilt ones from dockerhub, add the variable `DOCKER_TECHNIQUE=pull` to your make call.
+If you do not want to build the images, but download the prebuilt ones from Github Container Registry (ghcr.io), add the variable `DOCKER_TECHNIQUE=pull` to your make call.
 
 If you do not use docker but a replacement (with compatible CLI; e.g. [podman](https://github.com/containers/podman)), add the variable `DOCKER=podman` to your make call.
 
@@ -32,8 +32,7 @@ Example: `make REPO=../dunst.git ci-run-alpine`
 
 # Other make targets
 
-- `ci-pull`: Download all images from Docker Hub
-- `ci-push`: Push the local images to Docker Hub
+- `ci-pull`: Download all images from GitHub Package Registry
 - `ci-build`: Build all docker images locally
 - `ci-clean`: Remove all local docker images
 
@@ -53,5 +52,6 @@ CentOS is not supported, as [basic libraries are missing on CentOS](https://unix
 # Adding new images
 
 - Add your new `Dockerfile.<name>` in [`./ci/`](./ci) folder.
-- Edit the [build settings of the project](https://hub.docker.com/repository/docker/dunst/ci/builds/edit) to have a mapping from `Dockerfile.<name>` to `dunst-project/ci:<name>`.
-- In the [GitHub Action workflow](https://github.com/dunst-project/dunst/blob/master/.github/workflows/main.yml) of the main dunst project, add the new tag names in the matrix.
+- Add the new `<name>` in the GitHub Actions matrix:
+  - In the [GitHub Action workflow](.github/workflows/main.yml) of this project.
+  - In the [GitHub Action workflow](https://github.com/dunst-project/dunst/blob/master/.github/workflows/main.yml) of the main dunst project