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Gravitational Teleport is a nice tool for centralizing and securing accesses to hosts and services on your infrastructure. In the following how-to I’ll explain how to: Install Teleport Community Edition server under Centos 7 Install Teleport CE client under Centos 7 Configure your first access user Configure an access limited user Some hints for better… Continue reading Install And Configure Teleport On Centos 7 / RHEL 7
This article is the result of my struggles to properly use GeoIP v2 database within Perl. TL;DR The FASTEST way to use the database is by installing and utilizing the “MaxMind::DB::Reader::XS” perl module. And here is a tiny example: use MaxMind::DB::Reader::XS ; use Data::Dumper; my $geoip_country = MaxMind::DB::Reader::XS->new( file => ‘/usr/share/GeoIP/GeoIP2-Country.mmdb’ ); print Dumper… Continue reading How To Use GeoIP2 (mmdb) Database With Perl
Sometimes you don’t want to wait all hosts to complete a task, before going to the next one in Ansible. For example you have the the following scenario 1) Stop web server 2) Do some magic (takes different time on different hosts) 3) Start web server You don’t want your web servers to… Continue reading Ansible Don’t Wait All Hosts To Complete A Task
Recently I found the following script pretty handy for calculating the maximum amount of memory mysql could use, based on the current buffers configuration. This is the source: #!/bin/sh# you might want to add some user authentication here mysql -e “show variables; show status” | awk ‘ { VAR[$1]=$2 } END { MAX_CONN =… Continue reading Calculate Maximum MySQL Memory Usage
At certain point in time, you will want to rotate (delete) your old indexes in ElasticSearch. Most of the time people are using time based naming convention for their index names like: index_name-Year-Month-Day or index_name-Year.Month.Day. Tools like Filebeat/Logstash can also use such naming conventions. Before you go and write your own script that will do… Continue reading Rotating Indexes in ElasticSearch with Curator
Proxying Grafana with Nginx is easy, but there are some small thins that needs to be considered. If you have already tried this and received strange errors like: 192.168.1.1 – – [09/May/2019:10:26:58 +0300] “-” 000 0 “-” “-” “-“ or 499 errors in your nginx proxy logs or Grafana dashboard graphics not being loaded most… Continue reading Configure Nginx Reverse Proxy For Grafana Access
If you are using Nginx as reverse proxy, you may encounter some of the following behaviors Receiving Empty Lines In Nginx Log 192.168.1.1 – – [09/May/2019:10:26:58 +0300] “-” 000 0 “-” “-” “-” 192.168.1.1 – – [09/May/2019:10:09:55 +0300] “-” 000 0 “-” “-” “-” Receiving 499 Status Code While Proxying I was observing such behavior… Continue reading Nginx Proxying Long URL Addresses
If you try to run some of your playbooks over old Centos/Rhel 5 host, you might be ending with weird message like this: {“changed”: false, “module_stderr”: ” File \”<stdin>\”, line 39\n with open(module, ‘wb’) as f:\n ^\nSyntaxError: invalid syntax\n”, “module_stdout”: “”, “msg”: “MODULE FAILURE\nSee stdout/stderr for the exact error”, “rc”: 1} Without going into too… Continue reading How To Use Ansible For Centos 5 / RHEL 5
If you ever asked yourself the following questions, this might be the right place for you: How to check how much cpu is consuming each system user ? How to check how much cpu is consumed by each command ? Check when a command has been executed and how much cpu it did ? How… Continue reading Detailed CPU Usage Overview With psacct
What are ingest pipelines and why you need to know about them ? Ingest Pipelines are powerful tool that ElasticSearch gives you in order to pre-process your documents, during the Indexing process. In fact they are integrating pretty much of the Logstash functionality, by giving you the ability to configure grok filters or using different… Continue reading Working With Ingest Pipelines In ElasticSearch And Filebeat