doc: describe usage of ansible-galaxy for installing required role dependencies

README.md

@@ -23,7 +23,7 @@ In order to create a bootable ISO image, you have to provide a RHEL ISO image (n
 
 ## General Ansible usage
 
-Most options already have sensible defaults in `ansible.cfg`. However, you can override these defaults using CLI options/flags if you want to.
+Most options already have sensible defaults in `ansible.cfg`. However, you can override these defaults using CLI options/flags if you want to. The flags can be combined if necessary, and most of them have long versions as well. Get more information using `ansible-playbook --help`.
 
 To simply run the playbook, just call the `site.yml` playbook like this:
 ```
@@ -39,30 +39,6 @@ If you want to limit the execution to a subset of all hosts that are listed in t
 	ansible-playbook site.yml --limit=<hostna*>
 ```
 
-If you do not have Vault password files in the directory above the role direcory, you have to give the Vault password before execution:
-```
-	ansible-playbook site.yml --ask-vault-pass
-```
-
-You can use your own inventory file by adding the `-i` or `--inventory=INVENTORY` option:
-```
-	ansible-playbook site.yml -i inventory.yml
-	ansible-playbook site.yml --inventory=inventory.yml
-```
-
-Tasks in this role have been tagged to enable users to only run subsets of tasks. This can be leveraged to decrease run times or run only certain tasks after small changes.
-To list all available tags, use:
-```
-	ansible-playbook site.yml --list-tags
-```
-You can then run only certain tagged tasks by using the `--tags` option:
-```
-	ansible-playbook site.yml -t tag1,tag2,...,tagN
-	ansible-playbook site.yml --tags=tag1,tag2,...,tagN
-```
-
-For more help with ansible-playbook, use the `--help` flag.
-
 ## git configuration
 
 Just run the `setup_gitconfig.sh` script that comes with the repo to correctly setup all necessary local Git configurations.

requirements.yml

+---
+# https://docs.ansible.com/ansible/latest/galaxy/user_guide.html#installing-multiple-roles-from-a-file
+- src: git+https://git.slub-dresden.de/digital-preservation/ansible_lza_install_common.git
+  scm: git
+- src: git+https://git.slub-dresden.de/digital-preservation/ansible_lza_server_hardening.git
+  scm: git
+- src: git+https://git.slub-dresden.de/digital-preservation/ansible_slub_osquery.git
+  scm: git
+#- src: git+
+#  scm: git