tooling(delete-rem-tags): pass git commit info

Passes git author information via environment variables into the docker
container, in order to ensure commits done by the script have correct
author information.

Makefile

@@ -30,9 +30,9 @@
 ## set to the folder of the current .tex file. When called directly, we
 ## need to first change-dir to this folder.
 ifneq ($(DOCKER), false)
-DOCKER_IMAGE      = alpine-pandoc-hugo
-DOCKER_COMMAND    = docker run --rm -i
-DOCKER_USER       = -u "$(shell id -u):$(shell id -g)"
+DOCKER_IMAGE   = alpine-pandoc-hugo
+DOCKER_COMMAND = docker run --rm -i
+DOCKER_USER    = -u "$(shell id -u):$(shell id -g)"
 # GIT_DIR ensures that git works with the repository
 # no matter the owning user of the directory.
 # see https://github.com/Compilerbau/CB-Lecture-Bachelor/pull/16 for the discussion
@@ -42,14 +42,15 @@ DOCKER_USER       = -u "$(shell id -u):$(shell id -g)"
 # for a general overview of the issue.
 #
 # ***Important***: keep the location of GIT_DIR in sync with the mountpoint of the repository inside the container.
-DOCKER_VOLUME     = -v "$(shell pwd):/data" -w "/data" --env GIT_DIR=/data/.git
-DOCKER_TEX_VOLUME = -v "$(dir $(realpath $<)):/data" -w "/data" --env GIT_DIR=/data/.git
-
-PANDOC        = $(DOCKER_COMMAND) $(DOCKER_VOLUME)     $(DOCKER_USER) --entrypoint="pandoc"                $(DOCKER_IMAGE)
-HUGO          = $(DOCKER_COMMAND) $(DOCKER_VOLUME)     $(DOCKER_USER) --entrypoint="hugo"                  $(DOCKER_IMAGE)
-DOT           = $(DOCKER_COMMAND) $(DOCKER_VOLUME)     $(DOCKER_USER) --entrypoint="dot"                   $(DOCKER_IMAGE)
-LATEX         = $(DOCKER_COMMAND) $(DOCKER_TEX_VOLUME) $(DOCKER_USER) --entrypoint="latex"                 $(DOCKER_IMAGE)
-DELETE_SCRIPT = $(DOCKER_COMMAND) $(DOCKER_VOLUME)     $(DOCKER_USER) --entrypoint="/opt/delete-script.rb" $(DOCKER_IMAGE)
+DOCKER_VOLUME          = -v "$(shell pwd):/data" -w "/data" --env GIT_DIR=/data/.git
+DOCKER_TEX_VOLUME      = -v "$(dir $(realpath $<)):/data" -w "/data" --env GIT_DIR=/data/.git
+DOCKER_GIT_COMMIT_INFO = --env GIT_AUTHOR_NAME="$(shell git config user.name)" --env GIT_AUTHOR_EMAIL="$(shell git config user.email)"
+
+PANDOC        = $(DOCKER_COMMAND) $(DOCKER_VOLUME)     $(DOCKER_USER) --entrypoint="pandoc"                                          $(DOCKER_IMAGE)
+HUGO          = $(DOCKER_COMMAND) $(DOCKER_VOLUME)     $(DOCKER_USER) --entrypoint="hugo"                                            $(DOCKER_IMAGE)
+DOT           = $(DOCKER_COMMAND) $(DOCKER_VOLUME)     $(DOCKER_USER) --entrypoint="dot"                                             $(DOCKER_IMAGE)
+LATEX         = $(DOCKER_COMMAND) $(DOCKER_TEX_VOLUME) $(DOCKER_USER) --entrypoint="latex"                                           $(DOCKER_IMAGE)
+DELETE_SCRIPT = $(DOCKER_COMMAND) $(DOCKER_VOLUME)     $(DOCKER_USER) --entrypoint="/opt/delete-script.rb" $(DOCKER_GIT_COMMIT_INFO) $(DOCKER_IMAGE)
 else
 PANDOC        = pandoc
 HUGO          = hugo