docker(): added collectd system metrics collector that writes to graphite, just for testing

docker/blocks/collectd/Dockerfile

+FROM    ubuntu:xenial
+
+ENV     DEBIAN_FRONTEND noninteractive
+
+RUN     apt-get -y update
+RUN     apt-get -y install collectd curl python-pip
+
+# add a fake mtab for host disk stats
+ADD     etc_mtab /etc/mtab
+
+ADD     collectd.conf.tpl /etc/collectd/collectd.conf.tpl
+
+RUN	pip install envtpl
+ADD     start_container /usr/bin/start_container
+RUN     chmod +x /usr/bin/start_container
+CMD     start_container

docker/blocks/collectd/README.md

+collectd-write-graphite
+=======================
+
+Basic collectd-based server monitoring. Sends stats to Graphite.
+
+Collectd metrics:
+
+* CPU used/free/idle/etc
+* Free disk (via mounting hosts '/' into container, eg: -v /:/hostfs:ro)
+* Disk performance
+* Load average
+* Memory used/free/etc
+* Uptime
+* Network interface
+* Swap
+
+Environment variables
+---------------------
+
+* `HOST_NAME`
+  - Will be sent to Graphite
+  - Required
+* `GRAPHITE_HOST`
+  - Graphite IP or hostname
+  - Required
+* `GRAPHITE_PORT`
+  - Graphite port
+  - Optional, defaults to 2003
+* `GRAPHITE_PREFIX`
+  - Graphite prefix
+  - Optional, defaults to collectd.
+* `REPORT_BY_CPU`
+  - Report per-CPU metrics if true, global sum of CPU metrics if false (details: [collectd.conf man page](https://collectd.org/documentation/manpages/collectd.conf.5.shtml#plugin_cpu))
+  - Optional, defaults to false.
+* `COLLECT_INTERVAL`
+  - Collection interval and thus resolution of metrics
+  - Optional, defaults to 10

docker/blocks/collectd/collectd.conf.tpl

+Hostname "{{ HOST_NAME }}"
+
+FQDNLookup false
+Interval {{ COLLECT_INTERVAL | default("10") }}
+Timeout 2
+ReadThreads 5
+
+LoadPlugin cpu
+LoadPlugin df
+LoadPlugin load
+LoadPlugin memory
+LoadPlugin disk
+LoadPlugin interface
+LoadPlugin uptime
+LoadPlugin swap
+LoadPlugin write_graphite
+
+<Plugin cpu>
+  ReportByCpu {{ REPORT_BY_CPU | default("false") }}
+</Plugin>
+
+<Plugin df>
+  # expose host's mounts into container using -v /:/host:ro  (location inside container does not matter much)
+  # ignore rootfs; else, the root file-system would appear twice, causing
+  # one of the updates to fail and spam the log
+  FSType rootfs
+  # ignore the usual virtual / temporary file-systems
+  FSType sysfs
+  FSType proc
+  FSType devtmpfs
+  FSType devpts
+  FSType tmpfs
+  FSType fusectl
+  FSType cgroup
+  FSType overlay
+  FSType debugfs
+  FSType pstore
+  FSType securityfs
+  FSType hugetlbfs
+  FSType squashfs
+  FSType mqueue
+  MountPoint "/etc/resolv.conf"
+  MountPoint "/etc/hostname"
+  MountPoint "/etc/hosts"
+  IgnoreSelected true
+  ReportByDevice false
+  ReportReserved true
+  ReportInodes true
+</Plugin>
+
+<Plugin "disk">
+  Disk "/^[hs]d[a-z]/"
+  IgnoreSelected false
+</Plugin>
+
+
+<Plugin interface>
+  Interface "lo"
+  Interface "/^veth.*/"
+  Interface "/^docker.*/"
+  IgnoreSelected true
+</Plugin>
+
+
+<Plugin "write_graphite">
+ <Carbon>
+   Host "{{ GRAPHITE_HOST }}"
+   Port "{{ GRAPHITE_PORT | default("2003") }}"
+   Prefix "{{ GRAPHITE_PREFIX | default("collectd.") }}"
+   EscapeCharacter "_"
+   SeparateInstances true
+   StoreRates true
+   AlwaysAppendDS false
+ </Carbon>
+</Plugin>
+

docker/blocks/collectd/etc_mtab

+hostfs /.dockerinit ext4 ro,relatime,user_xattr,barrier=1,data=ordered 0 0

docker/blocks/collectd/fig

+collectd:
+  build: blocks/collectd
+  environment:
+    HOST_NAME: myserver
+    GRAPHITE_HOST: graphite
+    GRAPHITE_PORT: 2003
+    GRAPHITE_PREFIX: collectd.
+    REPORT_BY_CPU: 'false'
+    COLLECT_INTERVAL: 10
+  links:
+    - graphite

docker/blocks/collectd/start_container

+#!/bin/bash
+
+envtpl /etc/collectd/collectd.conf.tpl
+
+collectd -f