I upgrade from Ubuntu 16.04 to 18.04 and now it say Could not connect to database when I validate. PHP validate as follows:
====================================
| Component | Version |
|---|---|
| LibreNMS | 1.48.1-4-g57aec11aa |
| DB Schema | Not Connected (0) |
| PHP | 7.0.32-0ubuntu0.16.04.1 |
| MySQL | ? |
| RRDTool | 1.7.0 |
| SNMP | NET-SNMP 5.7.3 |
====================================
[OK] Composer Version: 1.8.3
[OK] Dependencies up-to-date.
Could not connect to database, check logs/librenms.log.
Appreciate any help to restore database
Thanks @murrant .I didn’t change my Database configuration. I can see on the config.php that it stays intact. I upgrade my Ubuntu server from 16.04 to 18.04 and I remember there was prompt during the upgrade about the mariaDB which I chose the option to go with the newer version or something of that sort
I would check your my.cnf is correct and check mariadb is running, check database still accessible using librenms db connection details
e.g
mysql -u username -p
SHOW DATABASES;
Which my.cnf you referring to ? The /opt/librenms/config.php ?
MySQL and MariaDB packages after the upgrade shows the following:
ii libdbd-mysql-perl 4.046-1 amd64 Perl5 database interface to the MariaDB/MySQL database
ii libmysqlclient20:amd64 5.7.25-0ubuntu0.18.04.2 amd64 MySQL database client library
ii mariadb-client 1:10.1.34-0ubuntu0.18.04.1 all MariaDB database client (metapackage depending on the latest version)
rc mariadb-client-10.0 10.0.36-0ubuntu0.16.04.1 amd64 MariaDB database client binaries
ii mariadb-client-10.1 1:10.1.34-0ubuntu0.18.04.1 amd64 MariaDB database client binaries
ii mariadb-client-core-10.1 1:10.1.34-0ubuntu0.18.04.1 amd64 MariaDB database core client binaries
ii mariadb-common 1:10.1.34-0ubuntu0.18.04.1 all MariaDB common metapackage
ii mariadb-server 1:10.1.34-0ubuntu0.18.04.1 all MariaDB database server (metapackage depending on the latest version)
rc mariadb-server-10.0 10.0.36-0ubuntu0.16.04.1 amd64 MariaDB database server binaries
ii mariadb-server-10.1 1:10.1.34-0ubuntu0.18.04.1 amd64 MariaDB database server binaries
ii mariadb-server-core-10.1 1:10.1.34-0ubuntu0.18.04.1 amd64 MariaDB database core server files
ii mysql-common 5.8+1.0.4 all MySQL database common files, e.g. /etc/mysql/my.cnf
rc php7.0-mysql 7.0.32-0ubuntu0.16.04.1 amd64 MySQL module for PHP
ii python-mysqldb 1.3.10-1build1 amd64 Python interface to MySQL
MySQL status shows this:
mariadb.service - MariaDB 10.1.34 database server
I tried to use the credentials in /opt/librenms/config.php for “mysql -u username -p” and came up with this error
ERROR 1045 (28000): Access denied for user ‘username’@‘localhost’ (using password: YES)
Looks like you need to figure out what your database credentials are.
Both the check the config.php and .env have the same settings with DB name, username and password
Running mysql -u root -p -e ‘show databases’ with the librenms DB password shows this result
±-------------------+
| Database |
±-------------------+
| information_schema |
| librenms |
| mysql |
| performance_schema |
±-------------------+
Had this issue as well. What I did was the following:
Installed the following again:
apt install curl composer fping git graphviz imagemagick mariadb-client mariadb-server mtr-tiny nginx-full nmap php7.2-cli php7.2-curl php7.2-fpm php7.2-gd php7.2-json php7.2-mbstring php7.2-mysql php7.2-snmp php7.2-xml php7.2-zip python-memcache python-mysqldb rrdtool snmp snmpd whois
After this I changed the time.zone in php files:
vi /etc/php/7.2/fpm/php.ini
vi /etc/php/7.2/cli/php.ini
systemctl restart php7.2-fpm
and changed the Php version in librenms.conf. I changed it in nginx folder
This solved my problem.
Don’t long in with root, log in with the credentials in the files (.env & config.php). You said that failed earlier. You need to check to see if they actually work.
Thanks @Bob_Puts. That step fixes it for me, however Ive got it on Apache. So for me the steps are as follows:
Upgrade to Ubuntu 18.04.2 LTS - do-release-upgrade
Install the package again:
apt install curl apache2 composer fping git graphviz imagemagick libapache2-mod-php7.2 mariadb-client mariadb-server mtr-tiny nmap php7.2-cli php7.2-curl php7.2-gd php7.2-json php7.2-mbstring php7.2-mysql php7.2-snmp php7.2-xml php7.2-zip python-memcache python-mysqldb rrdtool snmp snmpd whois
Change time zone in php files in :
/etc/php/7.2/cli/php.ini
/etc/php/7.2/apache2/php.ini
Reboot my server
Of couse I have to run ./validate php and fix certain things that needs to be fixed which is self explanatory on the result 
