Centos: Making sure your web services auto start after reboot

Your server had to restart, either by design or after some bad event, and now your website doesn’t work – “connection failure”.  Looks like your important web services are not set to start automatically on boot up.  Here is what to do to get your httpd and mysqld services running on restart.

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Mysql: Export entire database via command line (and import it again)

Sometimes, when migrating servers or copying data to a development environment for example, one needs to take a copy of an entire mysql database. Here is how you do this via the command line on a redhat/centos server:

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Centos: Create new SSL certificate for https

  1. Generate a new certificate signing request (.csr) and key file (.key)

    openssl req -new -newkey rsa:2048 -nodes -keyout server.key -out server.csr

    where server is the name of your server

  2. Fill in the details but you can leave email, challenge password and optional company name blank. Please note: The following characters cannot be accepted: < > ~ ! @ # $ % ^ / \ ( ) ?.,&
  3. Chek the contents of the csr:  https://www.sslshopper.com/csr-decoder.html  or enter this in the SSH console:

    openssl req -in server.csr -noout -text

    (again where server.csr is the name of the newly genererated csr file)

  4. Submit csr to commercial ssl provider.
  5. Copy the new certificate information into the correct location for the host.  You may need to look at the virtual host settings or apache config file to see where an existing one is. * See below
  6. Do the same for the intermediate certificate file if there is one.
  7. Move (or copy) the key
  8. Change the apache (or virtual host) config file to point at the new certificates.
  9. Restart the webserver.  For Debian this is “service apache2 restart”.  For Centos this would be “service httpd restart” or “systemctl restart httpd” for newer Centos versions.
  10. Make sure the server restarts – any typos in the config will stop it from running – you will be notified.

Additional resources:

Country Codes: https://www.digicert.com/ssl-certificate-country-codes.htm

https://www.digicert.com/csr-creation-apache.htm

https://www.digicert.com/ssl-certificate-installation-apache.htm

https://access.redhat.com/solutions/43575

Check they are working correctly: https://www.sslshopper.com/ssl-checker.html

Centos: Checking and Renaming the Server Hostname

A quicky this, for personal reference more than anything else.

Checking the Hostname
From within the console, run hostname to check the current hostname.

Changing the Hostname
To change the hostname run

hostname  mynewhostname.com

check it has happened with hostname and then restart the network

systemctl restart network

(or simply network restart on older centos versions)

mySQL (mariaDb) Useful User Management Via Command Line

Here is a collection of useful and common mysql commands for managing database users using the command line, perhaps whilst logged in to the server via ssh. The following commands work for MySql and mariaDb. Don’t forget to include the semi-colon at the ends of each command. Continue reading mySQL (mariaDb) Useful User Management Via Command Line

Red Hat / Centos: Web services not starting up on a server reboot

Ok, so your webserver has crashed. You reboot it and…and…nothing. No website.  Your apache / httpd and mysqld services have not restarted along with the server.  Here is how to check if they should and make them do so if they aren’t.

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