Welcome to CMT Documentation
Current release : 3.2 - 2023/09/13
Overwiew - CMT is a simple monitoring agent
CMT is a small footprint agent, with a single file configuration, available for most standard Linux OS. Once deployed on a system, it collects various data and monitors local/remote services.
Send to ElasticSearch/InfluxDB/Graylog
Collected data is sent to Metrology servers like ElasticSearch, InfluxDB V1/V2 or Graylog. These data points may carry alert information or warning levels for central alerting or display (Kibana for example).
Alerts and Pager to Teams and PagerDuty
If various conditions are met (or not met), CMT can also send direct alerts / pagers notifications to Teams channel.
Use as CLI
For sysadmin, CMT can be used as command line tool on each server during various sysadmin or software configuration tasks. One single run provides an immediate health check of all the configured check items.
$ cmt -s
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CMT - (c) cavaliba.com - Version 3.2 - 2023/09/13
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cmt_group : cavaliba
cmt_node : vmxu3
config file : /opt/cmt/conf.yml
OK boottime boot : 0 days since last reboot - 4:22:08 sec.
OK load load 1/5/15 min : 0.19 0.12 0.1 (2 cpus)
OK certificate 56 day(s) left for SSL certificate google.com on google.com:443
OK certificate 56 day(s) left for SSL certificate google.com on 142.250.201.174:443
OK certificate 307 day(s) left for SSL certificate duckduckgo.com on duckduckgo.com:443
CRITICAL certificate no ssl connection to duckduckgo.com:80
OK certificate 143 day(s) left for SSL certificate yahoo.com on yahoo.com:443
OK cpu cpu usage : 2.0 %
OK disk disk / - used: 44.6 % - used: 28.5 GB - free: 35.4 GB - total: 67.4 GB
OK disk disk /boot - used: 44.6 % - used: 28.5 GB - free: 35.4 GB - total: 67.4 GB
OK folder test_permission /opt/cmt/testdata/permission.txt OK - 1 files, 0 dirs, 0 bytes - targets 1/1
CRITICAL folder folder /opt/cmt/testdata/permission.txt : incorrect permission for /opt/cmt/testdata/permission.txt: found -rw-rw-r-- , expected -rw-rw-rw-
OK folder test_permissions /opt/cmt/testdata/permissions OK - 4 files, 0 dirs, 16 bytes - targets 3/3
OK folder test_extension /opt/cmt/testdata OK - 2 files, 6 dirs, 0 bytes - targets 0/0
OK folder test_regexp /opt/cmt/testdata OK - 2 files, 6 dirs, 0 bytes - targets 0/0
OK folder test_regexp_ext /opt/cmt/testdata OK - 1 files, 6 dirs, 0 bytes - targets 0/0
WARNING folder test_wrong_target /opt/cmt/testdata : unknown target is_blabla
OK folder test_hasfile /opt/cmt/testdata OK - 7 files, 6 dirs, 11004 bytes - targets 1/1
OK folder test_age_min /opt/cmt/testdata OK - 7 files, 6 dirs, 11004 bytes - targets 1/1
CRITICAL folder test_age_max /opt/cmt/testdata : some files are too old (25324485 sec)
OK folder test_files_min /opt/cmt/testdata OK - 7 files, 6 dirs, 11004 bytes - targets 1/1
OK folder test_files_max /opt/cmt/testdata OK - 7 files, 6 dirs, 11004 bytes - targets 1/1
CRITICAL folder test_size_min /opt/cmt/testdata : too small (11004)
CRITICAL folder test_size_max /opt/cmt/testdata : too big (11004)
OK folder test_has_recent /opt/cmt/testdata OK - 7 files, 6 dirs, 11004 bytes - targets 1/1
OK folder test_has_old /opt/cmt/testdata OK - 7 files, 6 dirs, 11004 bytes - targets 1/1
OK folder test_missing /opt/cmt/testdata/file.txt OK - 1 files, 0 dirs, 0 bytes - targets 0/0
OK folder test_nostore /opt/cmt/testdata/file.txt OK - 1 files, 0 dirs, 0 bytes [0.0 B] - targets 0/0
SKIPPED folder folder_root must run as root
OK folder folder_list /opt/cmt OK - 7 files, 1 dirs, 27593 bytes - targets 0/0
OK memory mem used 50.2 % - used 1.7 GB - avail 2.1 GB - total 4.1 GB
OK mount mount / found
ERROR mount mount /mnt not found
OK ping ping 192.168.0.1 ok
OK ping ping localhost ok
OK ping ping www.google.com ok
CRITICAL ping ping www.test.com not responding
CRITICAL ping ping www.averybadnammme_indeed.com not responding
CRITICAL process process redis missing (redis, None)
CRITICAL process process apache missing (httpd, None)
OK process process cron found (cron, None) - memory rss 3.0 MB - cpu 0.0 sec.
OK process process ssh found (sshd, None) - memory rss 5.3 MB - cpu 0.01 sec.
CRITICAL process process ntp missing (ntpd, None)
OK process process mysql found (mysqld, None) - memory rss 96.0 MB - cpu 7.93 sec.
CRITICAL process process php-fpm missing (php-fpm, None)
OK socket socket local redis localhost tcp/6379 - alive: yes - count: 0
OK socket socket remote www_google www.google.com tcp/443 - alive: yes - count: 0
OK swap swap used: 0.2 % / 4.5 MB - total 2.1 GB
OK url url www.cavaliba.com - https://www.cavaliba.com/ [Host: ] - http=200 - 127 ms ; pattern OK
OK url url header_check - https://www.cavaliba.com/ [Host: ] - http=200 - 64 ms ; pattern OK
CRITICAL url url www_non_existing - http://www.nonexisting/ [Host: ] - timeout/no response to query
OK url url google - https://www.google.com/ [Host: ] - http=200 - 102 ms ; pattern OK
OK url url yahoo - https://www.yahoo.com/ [Host: ] - http=200 - 751 ms ; pattern OK
SKIPPED send test_token1 must be run as single check w/ stdin piped command
OK mysql mydbmaster - cx=1 cx/s=0 r/s=0 w/s=0 q/s=0 mem=275195600
CRITICAL mysql mysql - can't connect with conf /opt/cmt/mysql_slave.cnf
OK sendfile /opt/cmt/demo.json - 3 lines/events
OK mysqldata user - 3 lines collected
2022/01/23 - 16:54:44 : SEVERITY=CRITICAL - 44/60 OK (73 %) - 16 NOK : 14 criticial - 1 error - 1 warning - 0 notice.
Data model / data storage
CMT provides a clean and well organized data model to enable an efficient metrology storage and further processing of collected data. You can then build various dashborad for data analysis and correlation, for reporting, finer alerting, etc.
Deploy easily
CMT is provided as a standalone binary for most recent linux distributions. Download and get running. Optionnaly yon can download and run directly the python3 code with a few mandatory librairies (yaml, requests, psutils, ...)
Modular
Ultimately, due to its simple configuration and modular design, it is very easy to add new checks or new modules, thus enabling a single tool to cover technical and functionnal monitoring and alerting needs.
Command and shortcuts
cmt --help- (...)
CMT remote management
CMT optionally supports additional configuration items from a remote URL, downloaded at runtime. It enables various modification from a central server (enable or disable some modules and check, require additional checks, ...).
No assumption is made on the remote server providing additional configuration. It can be as simple as text files from a shared Web server. It can also be an API to your existing systems which have to respond for a given CMT node, with a slice of configuration to be merged in the node's local configuration.
Modules and Checks
Think of module has class of check for a specific family of items, like URL, folder, process, disk... Modules are internally implemented as small python file in the checks/ folder.
Checks are instance of module execution. Each check create one metrology message or event. A check can carry several datapoint (checkitems). Each checks carries optionnal alert,warning, notice information and a message formatted for human reading.
Each Check depending on his Module capacbilities can set information such as alert, warning, notice that will be sent back to metrology servers and possibly direct Pagers services.
Pager notifications are sent only once per CMT exectuion at most. It is intended for (very) standalone usage of CMT, whereas advanced usage with many nodes will benefit from Pager notification fired from central systms where decisions can be made from many/all monitoring sources.
CMT provides various configuration to ease configuring alert levels, frequency, rate-limit, max level, threshold, and other stop switches to garantee a clean thread of monitoring data to Metrology servers and Pagers.
CMT automated run from crontab
CMT is intended to run from crontab, every minute. It has a built-in max-duration security to prevent unfinished executing to overcrowd a server.
Deployment layout
/usr/local/bin/cmt # binary standalone
/opt/cmt # Home dir
cmt # cmt binary agent if prefered over /usr/local/bin
mysql.cnf # credentials for mysql checks if needed
conf.yml # configuration what to measure / where to send
conf.d/ # additional configuration (eg. ansible additive deployment)
persist.json # optional data persistance across run (crontab mode mostly)
Why another monitoring tool ?
The initial requirements were :
- small footprint agent, easy to deploy (drop anywhere ...)
- usable both with CRON and as interactive/CLI directly on each system
- clean metric data structure (multi-tenant, multi-customers, multi nodes)
- simple configuration file (one for all)
- data agnostic: technical, business, ...
- push rather than pull : push data to metrology servers
- data is sent to very standard ElasticSearch / INfluxDB DataStore, private or in the cloud
- modular design for easy extension / additional checks or modules
- minimal learning curve : drop the binary, edit the conf, run as cron/CLI, send to Elasticsearch, create Dashboard.
- ansible aware for mass deployement and standardization
- open source and hopefully well documented enough
None of the reviewed tools covered this exact set of requirements, some being too specific on technical metrics, others requiring a steep learning curve (eg. to extend), other used specific datastore and needed very specific protocol to be allowed (network/firewalls) between agents and datastore ...
Enjoy
CMT is released under BSD-3clause licence, free to use, free to extend. Experiment, Adopt, Enjoy, Contribute.