Merge pull request #22890 from thaJeztah/docs/slashes

fix docs not building if branch-name contains slashes
(cherry picked from commit 07f79621ea3aef5220d6c275fcab03bb4ed6ce22)

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

docs/Makefile

@@ -24,9 +24,8 @@ HUGO_BASE_URL=$(shell test -z "$(DOCKER_IP)" && echo localhost || echo "$(DOCKER
 HUGO_BIND_IP=0.0.0.0
 
 GIT_BRANCH := $(shell git rev-parse --abbrev-ref HEAD 2>/dev/null)
-DOCKER_IMAGE := docker$(if $(GIT_BRANCH),:$(GIT_BRANCH))
-DOCKER_DOCS_IMAGE := docs-base$(if $(GIT_BRANCH),:$(GIT_BRANCH))
-
+GIT_BRANCH_CLEAN := $(shell echo $(GIT_BRANCH) | sed -e "s/[^[:alnum:]]/-/g")
+DOCKER_DOCS_IMAGE := docker-docs$(if $(GIT_BRANCH_CLEAN),:$(GIT_BRANCH_CLEAN))
 
 DOCKER_RUN_DOCS := docker run --rm -it $(DOCS_MOUNT) -e AWS_S3_BUCKET -e NOCACHE