Ubuntu 20.04 install "502 Bad Gateway"

[wysedata]

I’ve tried twice now, virgin installs, following the install instructions for Ubuntu 20.04 but I get the same result both times. I am certain I didn’t make any mistakes.

/var/log/nginx/error.log

2020/09/18 00:39:52 [crit] 19595#19595: *1 connect() to unix:/run/php7.4-fpm-librenms.sock failed (2: No such file or directory) while connecting to upstream, client: 192.168.1.5, server: librenms, request: “GET /install HTTP/1.1”, upstream: “fastcgi://unix:/run/php7.4-fpm-librenms.sock:”, host: “librenms”

root@librenms:/var/run/php# ls -l
total 4
srw-rw---- 1 www-data www-data 0 Sep 18 00:37 php7.4-fpm-librenms.sock
-rw-r–r-- 1 root root 5 Sep 18 00:37 php7.4-fpm.pid
srw-rw---- 1 www-data www-data 0 Sep 18 00:37 php7.4-fpm.sock
lrwxrwxrwx 1 root root 30 Sep 18 00:21 php-fpm.sock -> /etc/alternatives/php-fpm.sock

/etc/php/7.4/fpm/pool.d/librenms.conf
(commented lines removed for brevity)
[librenms]

user = librenms
group = librenms

listen = /run/php/php7.4-fpm-librenms.sock

listen.owner = www-data
listen.group = www-data

librenms@librenms:~$ ./validate.php

Component	Version
LibreNMS	1.67-33-gd559ffa9e
DB Schema	Not Connected (0)
PHP	7.4.3
Python	3.8.2
MySQL	?
RRDTool	1.7.2
SNMP	NET-SNMP 5.8

====================================

[OK] Composer Version: 1.10.13
[OK] Dependencies up-to-date.
Could not connect to database, check logs/librenms.log.

Database error is because I can’t get to the /install to populate the database. The database exists as does the mysql user.

I appreciate your help.

[Edwin]

Hi,

In the error, the socket file is different then what is in your php-fpm config:
connect() to unix:/run/php7.4-fpm-librenms.sock failed
is not the same as:
listen = /run/php/php7.4-fpm-librenms.sock
(note the extra /php/ directory)

[wysedata]

Thanks Edwin. That was it. The annoying thing is that I did notice that but after a 12 hour day I didn’t process what I was looking at correctly. In the nginx config file in the documentation is missing the /php/ folder. Check here: https://docs.librenms.org/Installation/Install-LibreNMS/

Who should I notify? If anyone does an install using these instructions verbatim will fall into the problem as me.

[kidd_wu]

I have the same issue on "upstream: “fastcgi://unix:/var/run/php-fpm/php-fpm.sock”, have anyone alread to resolve it?

*3 connect() to unix:/var/run/php-fpm/php-fpm.sock failed (2: No such file or directory) while connecting to upstream

[nzjc]

Hey @kidd_wu

I just had this issue (albeit using Debian 10).

The three steps I took were:

1. Edit this file: /etc/php/7.3/fpm/pool.d/librenms.conf
   [line 36] /run/php-fpm-librenms.sock

2. Edit this file: /etc/nginx/sites-enabled/librenms.vhost
   [line 14] fastcgi_pass unix:/run/php/php-fpm-librenms.sock

3. systemctl restart nginx

That solved it, no more 502.

[Phoenix_IV]

I have the same issue. I am however using Apache.

tail -f /var/log/apache2/error.log ;
Mon Oct 25 04:36:45.369330 2021] [proxy:error] [pid 2918:tid 139869300979456] (2)No such file or directory: AH02454: FCGI: **attempt to connect to Unix domain socket /run/php-fpm-librenms.sock () failed

/etc/apache2/sites-available/librenms.conf ;
<FilesMatch “.+.php$”>
SetHandler “proxy:unix:/run/php-fpm-librenms.sock|fcgi://localhost”

/etc/php/7.4/fpm/pool.d/librenms.conf ;
listen = /run/php/php-fpm-librenms.sock

; Set listen(2) backlog.
; Default Value: 511 (-1 on FreeBSD and OpenBSD)
;listen.backlog = 511

; Set permissions for unix socket, if one is used. In Linux, read/write
; permissions must be set in order to allow connections from a web server. Many
; BSD-derived systems allow connections regardless of permissions.
; Default Values: user and group are set as the running user
; mode is set to 0660
listen.owner = librenms
listen.group = librenms
;listen.mode = 0660

[Jellyfrog]

You didn’t input the same path in php and apache config