Generar un certificado SSL wildcard con Let’s Encrypt

En un servidor de preproducción habitualmente uso un dominio propio para poder tener cada proyecto con un subdominio. Por ejemplo:

  • comercioelectronico1.example.com
  • webapp5.example.com

En estos proyectos quiero tener un certificado SSL válido para cada proyecto.

La primera opción que se me ocurre es crear un certificado SSL para cada proyecto cada vez que lo necesite. Pero hay una solución mejor: crear un certificado wildcard, válido para todos los subdominios dentro de un dominio, y olvidarme de crear más certificados para esos subdominios. Let’s Encrypt, la popular autoridad de certificación, nos proporciona esta funcionalidad.

How to setup a master-master replication system between two MySQL servers

In this post, I will go to explain how to set up a master-master replication system between two MySQL to replicate an existing database.

The MySQL master-master configuration is a master-slave configuration in both directions and allows us to get a high availability configuration because you have the same data in both servers and if one goes down you can still work with the live server.

Problem updating Grafana in a Debian 9

Updating a Debian 9 I get this error with the “grafana” update:

$ apt update
...
Ign:7  stretch InRelease
Err:9  stretch Release
404 Not Found
Reading package lists... Done
E: The repository 'https://packagecloud.io/grafana/stable/debian stretch Release' does no longer have a Release file.
N: Updating from such a repository can't be done securely, and is therefore disabled by default.
N: See apt-secure(8) manpage for repository creation and user configuration details.
...

Failed to fetch http://ftp.debian.org/debian/dists/jessie-updates/main/ 404 Not Found

Executing apt update in a Debian 8 I get the error

W: Failed to fetch http://ftp.debian.org/debian/dists/wheezy-backports/main/binary-amd64/Packages 404 Not Found [IP: 2001:67c:2564:a119::148:12 80]
W: Failed to fetch http://ftp.debian.org/debian/dists/jessie-updates/main/source/Sources 404 Not Found [IP: 2001:41d0:202:100:213:32:5:7 80]
W: Failed to fetch http://ftp.debian.org/debian/dists/jessie-updates/main/binary-amd64/Packages 404 Not Found [IP: 2001:41d0:202:100:213:32:5:7 80]
W: Failed to fetch http://ftp.debian.org/debian/dists/jessie-backports/main/source/Sources 404 Not Found [IP: 2001:41d0:202:100:213:32:5:7 80]
W: Failed to fetch http://ftp.debian.org/debian/dists/jessie-backports/main/binary-amd64/Packages 404 Not Found [IP: 2001:41d0:202:100:213:32:5:7 80]
E: Some index files failed to download. They have been ignored, or old ones used instead.