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Kernel Update with Fast Boot via kexec

# <-- NOTE: This represents the command prompt of a root user

Identify the latest installed kernel

# kernel_release_default="$(
 grubby --default-kernel \

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How to Enable RSyslog Debugging for Systemd Service Manager

Ref:

• man rsyslogd
• https://www.rsyslog.com/how-to-use-debug-on-demand/

Create a drop-in configuration for the service

1. As root level user, use systemctl edit to create a configuration override.

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#cloud-config

---
timezone: "UTC"
write_files:
  - path: "/etc/pki/rpm-gpg/RPM-GPG-KEY-EPEL-7"
    permissions: "0644"
    owner: "root:root"
    content: |
      -----BEGIN PGP PUBLIC KEY BLOCK-----

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<?php

$responseCode = 500;
$responseCodeOk = 200;
$responseCodeFail = 503;
$url = 'https://www.deathe.org/';

$ch = curl_init();

curl_setopt_array(

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Generate a File Listing for Review

Fields

• Last Modified
• Size (bytes)
• Relative Path

Command

Replace {{search-path}} with the path to search.

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Identify PHP FastCGI Process Memory Usage

pmap -x $(ps ax \
  | grep php-cgi \
  | grep -v grep \
  | awk '{ print $1 }' \
  | awk -v RS='' '{ gsub("\n", " "); print; }'\
) | grep -E '^(Address|total)'

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How to Enable MySQL Query Logging at Runtime

From the mysql client run:

mysql> SET GLOBAL general_log=true;
mysql> SET GLOBAL general_log_file='general.log';

After this queries will be logged to the named file located in the MySQL data directory. e.g. /var/lib/mysql/general.log.

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Identify Unavailable IUS PHP Packages Between 5.6 and 7.1

For all installed packages prefixed with php56u, check for availability php71u package.

# yum list installed \
| grep -o '^php56u[^ ]*' \
| { \
  mapfile -t packages; \
 for package in "${packages[@]}"; do \

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The output of apachectl -S is really useful but it's not easy to parse in a script. To make it easier to find the configuration file for a given NameVirtualHost host the following BASH one liner returns lines of output that can be easily parsed.

# apachectl -S 2>&1 \
| sed -rn -e '/NameVirtualHost$/,$ { /NameVirtualHost$/d; $ d; p; }' \
| sed -rn -e 's/^.*(port ([0-9]+) namevhost|alias) ([^ ]*)( )?(\((.*):[0-9]+\)|$)/\2 \6\n\3/p' \
| sed -r -e '/^$/d' -e 's/(.*\.conf$)/\n\1/g' \
| awk -vRS='' '$1=$1' \
| sort -n \
| uniq

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Requesting a Wildcard Certificate with Certbot on CentOS

To request a Let's Encrypt wildcard certificate there are the following prerequisites:

• The client must support ACME v2 (i.e Certbot >= 0.22.0)
• The DNS-01 challenge type must be used.
• The --server option or configuration directive must be changed to the appropriate v2 endpoint.

Installation

Install certbot-auto