# Postgres connection error on 'bundle exec rails c'
**URL:** https://meta.discourse.org/t/postgres-connection-error-on-bundle-exec-rails-c/222153
**Category:** Self-hosting
**Created:** [March 28, 2022, 12:24pm UTC](https://meta.discourse.org/t/postgres-connection-error-on-bundle-exec-rails-c/222153 "2022-03-28T12:24:00Z")
**Posts on this page:** 8
**Page:** 1
### Author:  [@helmi](https://meta.discourse.org/u/helmi)
#### Post date: [March 28, 2022, 12:24pm UTC](https://meta.discourse.org/t/postgres-connection-error-on-bundle-exec-rails-c/222153/1 "2022-03-28T12:24:00Z")
I’m trying to change some forum settings through the console. I didn’t do that a lot yet so I searched for similar questions on the forum.
Unfortunately when executing ‘bundle exec rails c’ i get an error trace that ends with this line
`/var/www/discourse/vendor/bundle/ruby/2.7.0/gems/activerecord-6.1.4.7/lib/active_record/connection_adapters/postgresql_adapter.rb:81:in `rescue in new_client': connection to server on socket "/var/run/postgresql/.s.PGSQL.5432" failed: FATAL: Peer authentication failed for user "discourse" (ActiveRecord::NoDatabaseError)`
Any idea what’s going on there? Forum itself runs fine - just updated to the latest version the other day.
---
### Author:  [@JammyDodger](https://meta.discourse.org/u/JammyDodger)
#### Post date: [March 28, 2022, 12:43pm UTC](https://meta.discourse.org/t/postgres-connection-error-on-bundle-exec-rails-c/222153/2 "2022-03-28T12:43:56Z")
I get to the rails console from the server by using:
```plaintext
cd /var/discourse
./launcher enter app
rails c
```
There’s an example of changing a site setting in this topic, [Enable setting to allow admins to permanently delete data](https://meta.discourse.org/t/enable-the-hidden-can-permanently-delete-site-setting/206678) (this one is a hidden one, but the method is the same)
---
### Author:  [@helmi](https://meta.discourse.org/u/helmi)
#### Post date: [March 28, 2022, 12:53pm UTC](https://meta.discourse.org/t/postgres-connection-error-on-bundle-exec-rails-c/222153/3 "2022-03-28T12:53:36Z")
Thanks, I guess I mixed up both - I was doing bundle exec from within the app.
Still struggling though. I’m looking to change the IP regex for the [prometheus exporter plugin](https://meta.discourse.org/t/prometheus-exporter-plugin-for-discourse/72666).
Not sure which syntax is good to use. I tried
`SiteSetting.prometheus_trusted_ip_allowlist_regex=1.2.3.4` with escaping backslashes and quotes around it but nothing worked. 1.2.3.4 being a placeholder of my real IP.
---
### Author:  [@helmi](https://meta.discourse.org/u/helmi)
#### Post date: [March 28, 2022, 1:15pm UTC](https://meta.discourse.org/t/postgres-connection-error-on-bundle-exec-rails-c/222153/4 "2022-03-28T13:15:02Z")
Actually I just noticed it’s probably not a syntax issue
```plaintext
SiteSetting.prometheus_trusted_ip_allowlist_regex="123.145.167.189"
NoMethodError: undefined method `prometheus_trusted_ip_allowlist_regex=' for #
```
Maybe @sam can help with that. Or I’m really just making a mistake here. 🤔
---
### Author:  [@Falco](https://meta.discourse.org/u/Falco)
#### Post date: [March 28, 2022, 2:06pm UTC](https://meta.discourse.org/t/postgres-connection-error-on-bundle-exec-rails-c/222153/5 "2022-03-28T14:06:53Z")
You must set `DISCOURSE_PROMETHEUS_TRUSTED_IP_ALLOWLIST_REGEX` and a ENV variable on your app.yml file.
---
### Author:  [@helmi](https://meta.discourse.org/u/helmi)
#### Post date: [March 28, 2022, 2:14pm UTC](https://meta.discourse.org/t/postgres-connection-error-on-bundle-exec-rails-c/222153/6 "2022-03-28T14:14:14Z")
Correct me if I’m wrong but I thought I could set it on runtime first. So I need to set it on app.yml first to then be able to modify it on runtime?
The forum is quite busy so I was hoping to be able to set it on runtime first before setting it permanently in the ENV.
Any hints about the syntax? Can this just be
```plaintext
DISCOURSE_PROMETHEUS_TRUSTED_IP_ALLOWLIST_REGEX: 123.145.167.189
```
---
### Author:  [@Falco](https://meta.discourse.org/u/Falco)
#### Post date: [March 28, 2022, 2:24pm UTC](https://meta.discourse.org/t/postgres-connection-error-on-bundle-exec-rails-c/222153/7 "2022-03-28T14:24:08Z")
> [@helmi](#):
>
> I thought I could set it on runtime first. So I need to set it on app.yml first to then be able to modify it on runtime?
No runtime changes, only via the ENV.
> [@helmi](#):
>
> Any hints about the syntax
It’s a Ruby Regex object, see [https://rubular.com/](https://rubular.com/)
> [@helmi](#):
>
> Can this just be
>
> ```plaintext
> DISCOURSE_PROMETHEUS_TRUSTED_IP_ALLOWLIST_REGEX: 123.145.167.189
>
> ```
Yes, that works.
---
### Author:  [@sam](https://meta.discourse.org/u/sam)
#### Post date: [September 21, 2022, 12:54am UTC](https://meta.discourse.org/t/postgres-connection-error-on-bundle-exec-rails-c/222153/8 "2022-09-21T00:54:01Z")