Error opening config file postgres_exporter.yml in logs

[maikelpoot]

What did you do?
Install/Upgrade to 0.12.0

Tried to add --config.file='' and --config.file='false' to disable the config file feature but it keeps trying to read the config file.
Also a default of 'postgres_exporter.yml' doesn't really specify where this file should be located.

What did you expect to see?
No errors in the logs

What did you see instead? Under which circumstances?
Error in the logs

caller=main.go:86 level=error msg="Error loading config" err="Error opening config file \"postgres_exporter.yml\": open postgres_exporter.yml: no such file or directory"

Environment

• System information:

Linux 3.10.0-1160.88.1.el7.x86_64 x86_64

• postgres_exporter version:

# postgres_exporter --version
postgres_exporter, version 0.12.0 (branch: HEAD, revision: f9a1edbbc6d629663aa658378e1d989293e6e488)
  build user:       root@463311dfdfb6
  build date:       20230321-23:52:03
  go version:       go1.20.2
  platform:         linux/amd64
  tags:             netgo static_build

• postgres_exporter flags:

Contents of Defaults file:

### Managed by SaltStack
DATA_SOURCE_NAME=postgresql://postgres_exporter:********@127.0.0.1:5432/postgres?sslmode=disable
PG_EXPORTER_WEB_LISTEN_ADDRESS=:9187
PG_EXPORTER_DISABLE_DEFAULT_METRICS=false
PG_EXPORTER_DISABLE_SETTINGS_METRICS=false
PG_EXPORTER_EXTEND_QUERY_PATH=/usr/share/prometheus/queries.yaml
PG_EXPORTER_AUTO_DISOVER_DATABASES=true
PG_EXPORTER_EXCLUDE_DATABASES=template0,template1

POSTGRES_EXPORTER_OPTS="--extend.query-path=/usr/share/prometheus/queries.yaml --web.listen-address=:9187"
### EOF ###

• PostgreSQL version:

not relevant

• Logs:

[tuomotalvitie]

Personally, I was kind of hoping for postgres_exporter.yml.example file. I wonder if one can for example set dsn within.

The PostgreSQL server's data source name must be set via the DATA_SOURCE_NAME environment variable.

[hcastrofactored]

@maikelpoot did you figure it out? What should this file look like?

[sysadmind]

This log message has been changed to a warning. It is not actually an error. The next release will show this as a warning instead.

[mgalgs]

It still contains the word "error", which makes it seem like an error... If the config file isn't required I don't think there should be any message.

time=2025-03-27T23:06:31.557Z level=WARN source=main.go:85 msg="Error loading config" err="Error opening config file \"postgres_exporter.yml\": open postgres_exporter.yml: no such file or directory"

Actually looks pretty scary and made me chase this down...