Enable the Fluentd Plugin Systemd

Adds configurations and changes tasks to enable the
systemd plugin. Additionaly, the plugin is set to
read logs from the /var/log/journal directory

Implements: enable-fluent-plugin-systemd
Signed-off-by: Juan Pablo Suazo <jsuazo@whitestack.com>
Change-Id: Ic714a341befa5f906d9c0f78fa86f4c934df87cd

ansible/group_vars/all.yml

@@ -803,6 +803,7 @@ enable_cyborg: "no"
 enable_designate: "no"
 enable_etcd: "no"
 enable_fluentd: "yes"
+enable_fluentd_systemd: "{{ (enable_fluentd | bool) and (enable_central_logging | bool) }}"
 enable_freezer: "no"
 enable_gnocchi: "no"
 enable_gnocchi_statsd: "no"

ansible/roles/common/defaults/main.yml

@@ -120,6 +120,7 @@ fluentd_default_volumes:
   - "{{ '/etc/timezone:/etc/timezone:ro' if ansible_facts.os_family == 'Debian' else '' }}"
   - "kolla_logs:/var/log/kolla/"
   - "fluentd_data:/var/lib/fluentd/data/"
+  - "/var/log/journal:/var/log/journal:ro"
 kolla_toolbox_extra_volumes: "{{ default_extra_volumes }}"
 cron_extra_volumes: "{{ default_extra_volumes }}"
 fluentd_extra_volumes: "{{ default_extra_volumes }}"

ansible/roles/common/tasks/config.yml

@@ -114,6 +114,8 @@
         enabled: true
       - name: "conf/input/11-letsencrypt.conf.j2"
         enabled: "{{ enable_letsencrypt | bool }}"
+      - name: "conf/input/12-systemd.conf.j2"
+        enabled: "{{ enable_fluentd_systemd | bool }}"
     customised_input_files: "{{ find_custom_fluentd_inputs.files | map(attribute='path') | list }}"
     # Filters
     fluentd_filter_files: "{{ default_filter_files | customise_fluentd(customised_filter_files) }}"

ansible/roles/common/templates/conf/input/12-systemd.conf.j2

+<source>
+  @type systemd
+  tag journal
+  path /var/log/journal
+  <entry>
+    fields_strip_underscores true
+    fields_lowercase true
+  </entry>
+</source>

ansible/roles/common/templates/fluentd.json.j2

@@ -26,6 +26,13 @@
             "recurse": true
         },
 {% endfor %}
+{% if enable_fluentd_systemd | bool %}
+        {
+            "path": "/var/log/journal",
+            "owner": "{{ fluentd_user }}:{{ fluentd_user }}",
+            "recurse": true
+        },
+{% endif %}
         {
             "path": "/var/lib/fluentd/data",
             "owner": "{{ fluentd_user }}:{{ fluentd_user }}",

doc/source/reference/logging-and-monitoring/central-logging-guide.rst

@@ -232,3 +232,13 @@ network equipment. This can be done by configuring custom fluentd inputs.
 Configuration of custom fluentd inputs is possible by placing input
 configuration files in ``/etc/kolla/config/fluentd/input/*.conf`` on the
 control host.
+
+Systemd Logs
+------------
+
+By default, when enabling central logging, we also enable reading ``systemd``
+logs from the ``/var/log/journal`` file.
+
+To disable this behavior when central logging is enabled, set the value of
+the variable ``enable_fluentd_systemd`` to ``false`` in the configuration
+file ``/etc/kolla/globals.yml``.

etc/kolla/globals.yml

@@ -345,6 +345,7 @@ workaround_ansible_issue_8743: yes
 #enable_destroy_images: "no"
 #enable_etcd: "no"
 #enable_fluentd: "yes"
+#enable_fluentd_systemd: "{{ (enable_fluentd | bool) and (enable_central_logging | bool) }}"
 #enable_freezer: "no"
 #enable_gnocchi: "no"
 #enable_gnocchi_statsd: "no"

releasenotes/notes/feature_enable-fluent-plugin-systemd-9326efac3a64fbfd.yaml

+---
+features:
+  - |
+    Implements [Enable Fluentd Plugin Systemd].
+    Adds the needed changes and configurations in order to use the
+    fluentd plugin, systemd, to read logs from /var/log/journal by
+    default. This allows us to read and manipulate this logs for
+    monitoring purposes.
+
+    These logs will be sent to OpenSearch by default, to disable this
+    behavior, set the value of the variable ``enable_fluentd_systemd``
+    to ``false`` in the configuration file ``/etc/kolla/globals.yml``.
+
+    By default, when enabling central logging, we also enable the
+    ``systemd`` plugin. To disable this behavior when central logging
+    is enabled, set the value of the variable ``enable_fluentd_systemd``
+    to ``false`` in the configuration file ``/etc/kolla/globals.yml``.
+
+    fluent-plugin-systemd source:
+    https://github.com/fluent-plugin-systemd/fluent-plugin-systemd
+
+    `Blueprint enable-fluent-plugin-systemd
+    <https://blueprints.launchpad.net/kolla-ansible/+spec/enable-fluent-plugin-systemd>`__