Disable local Mermaid output on control node in Molecule

You're not allowed to place files into the control node during a Molecule scenario

Author: widhalmt

docs/logstash-pipelines.md

@@ -6,7 +6,7 @@ It can be quite difficult to stay on top of your pipeline configuration because
 
 This collection will leave some comments about how pipelines are interconnected within the `/etc/logstash/pipelines.yml` configuration file.
 
-If you set `logstash_mermaid` to `true` (which is the default), then you will also get a new file in `/etc/logstash/pipelines.mermaid`. You can paste it into a Mermaid editor in your documentation tool or in an [online Mermaid editor](https://mermaid.live/).
+If you set `logstash_mermaid` to `true` (which is the default), then you will also get a new file in `/etc/logstash/pipelines.mermaid`. You can paste it into a Mermaid editor in your documentation tool or in an [online Mermaid editor](https://mermaid.live/). The same content will be available on your control node in a temporary file. You can even add arbitrary code to reflect manually managed pipelines by using `logstash_mermaid_extra`.
 
 ## Git managed ##
 

docs/role-logstash.md

@@ -92,6 +92,7 @@ Aside from `logstash.yml` we can manage Logstashs pipelines.
 * *logstash_mermaid*: Print overview over Logstash pipelines in Mermaid syntax. (default: `true`)
 * *logstash_mermaid_logstash*: Place Mermaid syntax into `/etc/logstash/pipelines.mermaid` on Logstash hosts. (default: `true`)
 * *logstash_mermaid_local*: Place Mermaid syntax into temporary file on control node. (default: `true`)
+* *logstash_mermaid_extra*: You can add extra Mermaid syntax to the output by adding it to this variable. YAML-multiline is supported. (default: none)
 
 The following variables configure Log4j for Logstash. All default to `true` as this is the default after the installation.
 

molecule/elasticstack_default/converge.yml

@@ -19,6 +19,7 @@
     elasticstack_no_log: false
     logstash_pipeline_unsafe_shutdown: true
     logstash_redis_password: "{{ lookup('ansible.builtin.password', '/tmp/redispassword', chars=['ascii_letters'], length=15) }}"
+    logstash_mermaid_local: false # no permission to write into Docker control node
     redis_requirepass: "{{ logstash_redis_password }}"
     beats_filebeat_journald: true
     beats_filebeat_modules:

roles/logstash/templates/pipelines.mermaid.j2

@@ -26,3 +26,6 @@ p_{{ item.name }}{{ '[' }}{{ item.name }}{{ ']' }} --> {% if output.condition is
 {% endif %}
 {% endfor %}
 {% endif %}
+{% if logstash_mermaid_extra is defined %}
+{{ logstash_mermaid_extra }}
+{% endif %}