Modify `promtail` config for `systemd`.

cookbooks/promtail/templates/etc/promtail/base.yaml

@@ -249,11 +249,36 @@ scrape_configs:
 
     pipeline_stages:
     - match:
-        selector: '{job="systemd"}'
+        selector: '{job="systemd"} !~ "temperature"'
         stages:
         - drop:
             expression: (CMD|UFW|session|TTY)
 
+    - match:
+        selector: '{job="systemd"} |~ "temperature"'
+
+        stages:
+        - regex:
+            expression: '^(?P<message>.+)$'
+
+        - template:
+            source: level
+            template: '{{ .message }}'
+
+        - template:
+            source: level
+            template: '{{ regexReplaceAllLiteral ".*normal.*" .Value "notice" }}'
+
+        - template:
+            source: level
+            template: '{{ regexReplaceAllLiteral ".*temperature.*" .Value "error" }}'
+
+        - labels:
+            level:
+
+        - output:
+            source: message
+
     relabel_configs:
       - source_labels: ['__journal__systemd_unit']
         target_label: 'unit'