Verify Apache HTTP Server "httpd" Environment

Linux Apps Tutorials - Herong's Tutorial Examples

∟Running Apache HTTP Server (httpd) on Linux Systems

∟Verify Apache HTTP Server "httpd" Environment

This section provides a tutorial example on how to verify key areas of the Apache HTTP Server 'httpd' environment on Linux systems.

In order to manage Apache HTTP Server, httpd, you need to remember a number of key areas of its running environment:

1. Software package - httpd: The latest version is 2.4.37.

herong$ dnf info httpd

Installed Packages
Name         : httpd
Version      : 2.4.37
Release      : 16.module_el8.1.0+256+ae790463
Architecture : x86_64
Size         : 5.4 M
Source       : httpd-2.4.37-16.module_el8.1.0+256+ae790463.src.rpm
Repository   : @System
From repo    : AppStream
Summary      : Apache HTTP Server
URL          : https://httpd.apache.org/
License      : ASL 2.0
Description  : The Apache HTTP Server is a powerful, efficient, and
             : extensible web server.

2. System service - httpd: It should be "active" and "running".

herong$ sudo systemctl status httpd

- httpd.service - The Apache HTTP Server
   Loaded: loaded (/usr/lib/systemd/system/httpd.service; disabled; ...)
   Active: active (running) since Sun 2022-05-22
  ...

3. Background processes - httpd: You should see one root process and several child processes waiting to handle client requests.

herong$ ps -elf | grep httpd
F S UID          PID    PPID  ... CMD
4 S root       36626       1  ... /usr/sbin/httpd -DFOREGROUND
5 S apache     36627   36626  ... /usr/sbin/httpd -DFOREGROUND
5 S apache     36628   36626  ... /usr/sbin/httpd -DFOREGROUND
5 S apache     36629   36626  ... /usr/sbin/httpd -DFOREGROUND
5 S apache     36630   36626  ... /usr/sbin/httpd -DFOREGROUND

4. Network service and port - http 80/tcp: This is the default. You can change it in the configuration file.

herong$ nmap localhost

PORT    STATE SERVICE
...
80/tcp  open  http
...

5. Log file - /var/log/httpd/access_log: This is the default. You can change it in the configuration file.

herong$ sudo tail /var/log/httpd/access_log

... "GET / HTTP/1.1" 403 4006 "-" "curl/7.61.1"
... "GET / HTTP/1.1" 403 4288 "-" "Mozilla/5.0 (X11; Linux x86_64; ...
... "GET /noindex/common/css/bootstrap.min.css HTTP/1.1" 200 99548 ...
... "GET /noindex/common/css/styles.css HTTP/1.1" 200 71634 ...
... "GET /noindex/common/images/pb-centos.png HTTP/1.1" 200 13122 ...
... "GET /noindex/common/images/pb-apache.png HTTP/1.1" 200 103267 ...
... "GET /noindex/common/images/centos-header.png HTTP/1.1" 200 28888 ...

6. Web page file root location - /var/www/html/: This is the default. You can change it in the configuration file.

herong$ ls -la /var/www/html/

drwxr-xr-x. 2 root root  6 Apr 1 2022 .
drwxr-xr-x. 4 root root 33 Apr 1 2022 ..

7. Configuration files - /etc/httpd/: This is the default. You can change it in the configuration file.

herong$ ls -l /etc/httpd/

drwxr-xr-x. 2 root root  37 conf
drwxr-xr-x. 2 root root  82 conf.d
drwxr-xr-x. 2 root root 226 conf.modules.d
lrwxrwxrwx. 1 root root  19 logs -> ../../var/log/httpd
lrwxrwxrwx. 1 root root  29 modules -> ../../usr/lib64/httpd/modules
lrwxrwxrwx. 1 root root  10 run -> /run/httpd
lrwxrwxrwx. 1 root root  19 state -> ../../var/lib/httpd

9. Program files - /usr/sbin/httpd and /usr/lib64/httpd/:

herong$ sudo ls -l /usr/sbin/httpd
-rwxr-xr-x. 1 root root 579840 Nov 12 2021 /usr/sbin/httpd

herong$ sudo ls -l /usr/lib64/httpd/
drwxr-xr-x. 2 root root 4096 Apr 1 2022 modules

herong$ sudo ls -l /usr/lib64/httpd/modules/
-rwxr-xr-x. 1 root root  12088 Nov 12 2021 mod_access_compat.so
-rwxr-xr-x. 1 root root  12024 Nov 12 2021 mod_actions.so
-rwxr-xr-x. 1 root root  20344 Nov 12 2021 mod_alias.so
-rwxr-xr-x. 1 root root  12008 Nov 12 2021 mod_allowmethods.so
...

10. System user - apache: It runs "httpd" background processes.

herong$ sudo grep apache /etc/passwd
apache:x:48:48:Apache:/usr/share/httpd:/sbin/nologin

herong$ sudo ls -l /usr/share/httpd
drwxr-xr-x. 3 root root 4096 Apr 1 2022 error
drwxr-xr-x. 3 root root 8192 Apr 1 2022 icons
drwxr-xr-x. 2 root root   24 Apr 1 2022 noindex

herong$ ps -elf | grep apache
F S UID          PID    PPID  ... CMD
5 S apache     36627   36626  ... /usr/sbin/httpd -DFOREGROUND
5 S apache     36628   36626  ... /usr/sbin/httpd -DFOREGROUND
5 S apache     36629   36626  ... /usr/sbin/httpd -DFOREGROUND
5 S apache     36630   36626  ... /usr/sbin/httpd -DFOREGROUND