NGINX web server discovery

NGINX is an open source web server with a load balancer. Discovery identifies the web server and information related to the load balancer.

Discovery identifies NGINX server software using the following process:

1. The NGINX Process Classifier detects a running process that matches the following criteria during the exploration of a Linux server:
   • Name starts with nginx
   • Name contains master
2. If there is a match:
   • A record is created in the NGINX Web Server [cmdb_ci_nginx_web_server] table.
   • A Runs on relationship is created in the CI Relationship [cmdb_rel_ci] table for a Linux server (Linux Server [cmdb_ci_linux_server]) and for an NGINX web server (NGINX Web Server [cmdb_ci_nginx_web_server]).
     The following two probes are triggered:

     • NGINX – Version: This probe contains a Bourne shell script. It determines the version of NGINX and populates the NGINX Web Server [cmdb_ci_nginx_web_server] table.
     • NGINX – Get Configuration: This probe contains a Bourne shell script and an argument that determines the path of the NGINX configuration file. The probe identifies configuration parameters based on keywords within the configuration file and returns them as a single payload result.
     The sensor on the ServiceNow instance parses the payload result and populates the CMDB.

You must have the following requirements to discover an NGINX webserver:

• NGINX is installed and running on the server.
• The MID Server has access to the NGINX configuration file, which is /etc/nginx/nginx.conf by default.

Requirements

For NGINIX servers:

• Ensure that the NGINX software is installed and running on the server.
• Grant the MID Server has access to the NGINX configuration file, which is /etc/nginx/nginx.conf by default.
• Enable secure shell (SSH) commands to identify the following associated elements:
  • NGINX Version
  • NGINX Get Configuration

The following probes require execute privileges to run commands:

Table 1. Commands

Probe	Commands
Nginx – Version	nginx
Nginx – Get Configuration	echo, sed, httpd, cut, grep, egrep (within the Bourne shell script)

Note:

The Nginx pattern performs top-down discovery on both Windows and Linux servers. For information on prerequisites for top-down discovery for NGINX web servers, see Prerequisites for performing top-down discovery using Service Mapping.

Probes and Sensors

Discovery identifies NGINX server software using the following process:

1. The Nginx Process Classifier detects a running process that matches the following criteria during the exploration of a UNIX server:
   • The name of the process starts with nginx.
   • The name of the process contains master.
2. If there is a match:
   • A record is created in the Web Server [cmdb_ci_web_server] table.
   • A Runs on relationship is created in the CI Relationship [cmdb_rel_ci] table for the Linux Server [cmdb_ci_linux_server] table and the Web Server [cmdb_ci_web_server] table.
3. The following two probes are triggered:
   • Nginx – Version: this probe contains a Bourne shell script. It determines the version of NGINX and populates the Web Server [cmdb_ci_web_server] table.
   • Nginx – Get Configuration: this probe contains a Bourne shell script and an argument that determines the path of the NGINX configuration file. The probe identifies configuration parameters based on keywords within the configuration file and returns them as a single payload result.
4. The sensor on the ServiceNow instance processes the payload and populates the CMDB.

Data Collected

Discovery creates or updates CMDB records when it detects a running NGINX process. The following data is collected.

Table 2. Data Collected by Discovery for NGINX

Table Name	Field and Label Name	Probe
Name	cmdb_ci_lb_appl [name]	Nginx– Get Configuration
IP Address	cmdb_ci_lb_appl [ip_address]	Nginx– Get Configuration
Last Discovered	cmdb_ci_lb_appl [last_discovered]	Nginx– Get Configuration
Version	cmdb_ci_lb_appl [version]	Nginx– Version
Name	cmdb_ci_lb_pool_member [name]	Nginx– Get Configuration
Last Discovered	cmdb_ci_lb_pool_member [last_discovered]	Nginx– Get Configuration
IP Address	cmdb_ci_lb_pool_member [ip_address]	Nginx– Get Configuration
Load Balancer	cmdb_ci_lb_pool_member [load_balancer]	Nginx– Get Configuration
Fully Qualified Domain Name	cmdb_ci_lb_pool_member [fqdn]	Nginx– Get Configuration
Port	cmdb_ci_lb_pool_member [port]	Nginx– Get Configuration
Last Discovered	cmdb_ci_lb_service [last_discovered]	Nginx– Get Configuration
IP Address	cmdb_ci_lb_service [ip_address]	Nginx– Get Configuration
Name	cmdb_ci_lb_service [name]	Nginx– Get Configuration
Load Balancer	cmdb_ci_lb_service [load_balancer]	Nginx– Get Configuration
Input URL	cmdb_ci_lb_service [input_url]	NGINX – Get Configuration

Relationships

In the table [cmdb_rel_ci] the following relationships are populated:

• The records in the cmdb_ci_lb_appl table run on the cmdb_ci_web_server table records.
• The records in the cmdb_ci_lb_service table use the cmdb_ci_lb_pool table records.
• The records in the cmdb_ci_pool table are used by the cmdb_ci_service table records.
• The records in the cmdb_ci_pool table are members of the cmdb_ci_pool_member table.
• The records in the cmdb_ci_pool_member table are members of cmdb_ci_pool table.