migrate: docker image location on GHCR only (#4054)

doc: delete reference to registry.opensource.zalan.do/teapot/skipper

Please everyone migrate to ghcr.io/zalando/skipper

Signed-off-by: Sandor Szücs <sandor.szuecs@zalando.de>

Author: szuecs

VERSION

@@ -1 +1 @@
-v0.26
+v0.27

delivery.yaml

@@ -30,7 +30,6 @@ pipeline:
     cmd: |
       set -eo pipefail
 
-      IMAGE_REGISTRY="registry-write.opensource.zalan.do"
       MULTIARCH_REGISTRY="container-registry-test.zalando.net"
 
       if [[ $CDP_TARGET_BRANCH == master && ! $CDP_PULL_REQUEST_NUMBER ]]; then
@@ -43,10 +42,8 @@ pipeline:
         RELEASE_VERSION=${VERSION_PART}.${NEW_PATCH}
         export VERSION="${RELEASE_VERSION}"
 
-        IMAGE="${IMAGE_REGISTRY}/teapot/skipper:${RELEASE_VERSION}"
         MULTIARCH_IMAGE="${MULTIARCH_REGISTRY}/teapot/skipper:${RELEASE_VERSION}"
       else
-        IMAGE="${IMAGE_REGISTRY}/teapot/skipper-test:${CDP_BUILD_VERSION}"
         MULTIARCH_IMAGE="${MULTIARCH_REGISTRY}/teapot/skipper-test:${CDP_BUILD_VERSION}"
       fi
       export IMAGE MULTIARCH_IMAGE
@@ -67,8 +64,6 @@ pipeline:
       make docker.build.amd64 && git status && git diff && make docker.push.amd64 && make docker.push.multiarch
 
       if [[ $CDP_TARGET_BRANCH == master && ! $CDP_PULL_REQUEST_NUMBER ]]; then
-        echo "Created docker image registry.opensource.zalan.do/teapot/skipper:${RELEASE_VERSION}"
-
         cdp-promote-image "${MULTIARCH_IMAGE}"
         echo "Created multi-arch docker image container-registry.zalando.net/teapot/skipper:${RELEASE_VERSION}"
 
@@ -86,11 +81,6 @@ pipeline:
         echo -e '```' >>$tf
         echo -e "docker run -it ghcr.io/zalando/skipper:${RELEASE_VERSION} skipper --help" >>$tf
         echo -e '```' >>$tf
-        echo -e "\n### Docker image\n" >>$tf
-        echo -e "Docker image is available in Zalando's Open Source registry:\n" >>$tf
-        echo -e '```' >>$tf
-        echo -e "docker run -it registry.opensource.zalan.do/teapot/skipper:${RELEASE_VERSION} skipper --help" >>$tf
-        echo -e '```' >>$tf
         echo "################################"
         cat $tf
         echo "################################"