Fix logging to file and importing into Graylog

fluentd/Dockerfile

@@ -3,6 +3,7 @@ USER root
 RUN apt-get update \
  && apt-get -y install --no-install-recommends wget \
  && rm -rf /var/lib/apt/lists/*
+RUN gem install fluent-plugin-rewrite-tag-filter
 RUN gem install gelf
 RUN cd /fluentd/plugins \
  && wget -q https://raw.githubusercontent.com/emsearcy/fluent-plugin-gelf/master/lib/fluent/plugin/out_gelf.rb

fluentd/fluent.conf

@@ -20,13 +20,25 @@
 </source>
 
 <match devel.*>
-  @type file
-  path /var/log/hostlogs/containers/${tag}
-  append true
-  <buffer tag>
-    timekey 5s
-    flush_mode immediate
-  </buffer>
+  @type copy
+  <store>
+    @type file
+    path /var/log/hostlogs/containers/${tag}
+    pos_file /var/log/hostlogs/httpd/access_log.pos
+    append true
+    <buffer tag>
+      timekey 5s
+      flush_mode immediate
+    </buffer>
+  </store>
+  <store>
+    @type rewrite_tag_filter
+    <rule>
+      key container_name
+      pattern /(.+)/
+      tag ${tag}.$1
+    </rule>
+  </store>
 </match>
 
 <match **>