CentOS System Log Files
Ship system log files from CentOS to Logstash
Configure Filebeat to ship logs from Centos Systems to Logstash and Elasticsearch.
Follow this step by step guide to get 'logs' from your system to Logit.io:
Step 2 - Enable the System Module
There are several built in filebeat modules you can use. To enable the system module run.
sudo filebeat modules list
sudo filebeat modules enable system
Additional module configuration can be done using the per module config files located in the modules.d folder, most commonly this would be to read logs from a non-default location
rpm /etc/filebeat/modules.d/
Step 3 - Locate Configuration File
/etc/filebeat/filebeat.yml
Step 4 - Configure output
We'll be shipping to Logstash so that we have the option to run filters before the data is indexed.
Comment out the elasticsearch output block.
## Comment out elasticsearch output
#output.elasticsearch:
# hosts: ["localhost:9200"]
Step 5 - Validate configuration
If you have issues starting in the next step, you can use these commands below to troubleshoot.
Let's check the configuration file is syntactically correct by running directly inside the terminal.
If the file is invalid, will print an error loading config file
error message with details on how to correct the problem.
deb/rpm
sudo -e -c /etc//.yml
macOS
cd <EXTRACTED_ARCHIVE>
sudo ./ -e -c .yml
Windows
cd <EXTRACTED_ARCHIVE>
.\.exe -e -c .yml
Step 6 - how to diagnose no data in Stack
If you don't see data appearing in your Stack after following the steps, visit the Help Centre guide for steps to diagnose no data appearing in your Stack or Chat to support now.
Step 7 - (Optional) Update Logstash Filters
All Logit.io stacks come pre-configured with popular Logstash filters. We would recommend that you add System specific filters if you don't already have them, to ensure enhanced dashboards and modules work correctly.
Edit your Logstash filters by choosing Stack > Settings > Logstash Filters
if [fileset][module] == "system" {
if [fileset][name] == "auth" {
grok {
match => { "message" => ["%{SYSLOGTIMESTAMP:[system][auth][timestamp]} %{SYSLOGHOST:[system][auth][hostname]} sshd(?:\[%{POSINT:[system][auth][pid]}\])?: %{DATA:[system][auth][ssh][event]} %{DATA:[system][auth][ssh][method]} for (invalid user )?%{DATA:[system][auth][user]} from %{IPORHOST:[system][auth][ssh][ip]} port %{NUMBER:[system][auth][ssh][port]} ssh2(: %{GREEDYDATA:[system][auth][ssh][signature]})?",
"%{SYSLOGTIMESTAMP:[system][auth][timestamp]} %{SYSLOGHOST:[system][auth][hostname]} sshd(?:\[%{POSINT:[system][auth][pid]}\])?: %{DATA:[system][auth][ssh][event]} user %{DATA:[system][auth][user]} from %{IPORHOST:[system][auth][ssh][ip]}",
"%{SYSLOGTIMESTAMP:[system][auth][timestamp]} %{SYSLOGHOST:[system][auth][hostname]} sshd(?:\[%{POSINT:[system][auth][pid]}\])?: Did not receive identification string from %{IPORHOST:[system][auth][ssh][dropped_ip]}",
"%{SYSLOGTIMESTAMP:[system][auth][timestamp]} %{SYSLOGHOST:[system][auth][hostname]} sudo(?:\[%{POSINT:[system][auth][pid]}\])?: \s*%{DATA:[system][auth][user]} :( %{DATA:[system][auth][sudo][error]} ;)? TTY=%{DATA:[system][auth][sudo][tty]} ; PWD=%{DATA:[system][auth][sudo][pwd]} ; USER=%{DATA:[system][auth][sudo][user]} ; COMMAND=%{GREEDYDATA:[system][auth][sudo][command]}",
"%{SYSLOGTIMESTAMP:[system][auth][timestamp]} %{SYSLOGHOST:[system][auth][hostname]} groupadd(?:\[%{POSINT:[system][auth][pid]}\])?: new group: name=%{DATA:system.auth.groupadd.name}, GID=%{NUMBER:system.auth.groupadd.gid}",
"%{SYSLOGTIMESTAMP:[system][auth][timestamp]} %{SYSLOGHOST:[system][auth][hostname]} useradd(?:\[%{POSINT:[system][auth][pid]}\])?: new user: name=%{DATA:[system][auth][user][add][name]}, UID=%{NUMBER:[system][auth][user][add][uid]}, GID=%{NUMBER:[system][auth][user][add][gid]}, home=%{DATA:[system][auth][user][add][home]}, shell=%{DATA:[system][auth][user][add][shell]}$",
"%{SYSLOGTIMESTAMP:[system][auth][timestamp]} %{SYSLOGHOST:[system][auth][hostname]} %{DATA:[system][auth][program]}(?:\[%{POSINT:[system][auth][pid]}\])?: %{GREEDYMULTILINE:[system][auth][message]}"] }
pattern_definitions => {
"GREEDYMULTILINE"=> "(.|\n)*"
}
remove_field => "message"
}
date {
match => [ "[system][auth][timestamp]", "MMM d HH:mm:ss", "MMM dd HH:mm:ss" ]
}
geoip {
source => "[system][auth][ssh][ip]"
target => "[system][auth][ssh][geoip]"
}
}
else if [fileset][name] == "syslog" {
grok {
match => { "message" => ["%{SYSLOGTIMESTAMP:[system][syslog][timestamp]} %{SYSLOGHOST:[system][syslog][hostname]} %{DATA:[system][syslog][program]}(?:\[%{POSINT:[system][syslog][pid]}\])?: %{GREEDYMULTILINE:[system][syslog][message]}"] }
pattern_definitions => { "GREEDYMULTILINE" => "(.|\n)*" }
remove_field => "message"
}
date {
match => [ "[system][syslog][timestamp]", "MMM d HH:mm:ss", "MMM dd HH:mm:ss" ]
}
}
}
Step 7 - Start filebeat
Start or restart to apply the configuration changes.
Step 8 - Check Logit.io for your logs
Now you should view your data:
If you don't see logs take a look at How to diagnose no data in Stack below for how to diagnose common issues.
Step 9 - CentOS Overview
CentOS is a Linux distribution & computing platform that is often compared with Red Hat Enterprise Linux (RHEL).
The main difference between the two is that CentOS lacks the high level of technical support that is supplied as part of the RHEL package.
CentOS is built off of the Red Hat Enterprise Linux’s open source code base, explaining their commonalities and relative compatibility.
Due to this similarity their library versions are identical. This means that binaries that work on RHEL will work on CentOS. If you're using their administration tools you might notice incompatibilities between the two distributions as minor patches are updated at different rates. Large patches & major releases for CentOS are released sporadically & infrequently compared to other Linux distributions (such as Ubuntu & Debian).
CentOS users are typically individuals & businesses that don’t require strong levels of support, certification & training to use this enterprise class Linux distribution successfully.
Our built in CentOS log file analyser is included in our log management platform and is built upon the open source tools Elasticsearch, Logstash & Kibana to ease the processing of large amounts of Linux server data for troubleshooting & root cause analysis.
Logit.io can be used to centralise your Linux log data & alerts on errors to monitor your operating system (OS). The platform can also be used to view logs within Kibana for detailed visualisations & reporting.
If you need any assistance with analysing your CentOS logs we're here to help. Feel free to reach out by contacting the Logit.io support team via live chat & we'll be happy to help you get started.