net/url: invalid userinfo

[matt-baker-agd-systems]

I'm using the docker image (0.24.2) and the default sql_exporter.yml . When running this, it fails with net/url: invalid userinfo which suggests that the URL has not been parsed correctly?

I originally tried my own DSN string, but that also failed — even with the password URL encoded.

Full logs

time=2026-07-03T09:19:46.508Z level=INFO source=tls_config.go:357 msg="TLS is disabled." http2=false address=[::]:9399
time=2026-07-03T09:20:01.196Z level=WARN source=exporter.go:336 msg="Invalid context log item, ignoring" item=""
time=2026-07-03T09:20:01.196Z level=ERROR source=promhttp.go:59 msg="Error gathering metrics" error="[from Gatherer #1] [,target=mssql_database] net/url: invalid userinfo"

[burningalchemist]

Hey @matt-baker-agd-systems, could you share (excluding the sensitive data of course) the URL string you're using? I'm mainly concerned on the format. Let me know, I'm happy to assist. 👍

[burningalchemist]

sql_exporter.yml

# Global defaults.
global:
  scrape_timeout: 10s
  scrape_timeout_offset: 500ms
  min_interval: 0s
  max_connections: 3
  max_idle_connections: 3
  max_connection_lifetime: 5m
  ping_interval: 30s

# The target to monitor and the collectors to execute on it.
# The password we are implying is 'p@ssw0rd[]!{}^@abc'
target:
  data_source_name: 'sqlserver://prom_user:p%40ssw0rd%5B%5D%21%7B%7D%5E%40abc@dbserver1.example.com:1433/dbname'
  # Collectors (referenced by name) to execute on the target.
  # Glob patterns are supported (see <https://pkg.go.dev/path/filepath#Match> for syntax).
  collectors: [mssql_*]

# Collector files specifies a list of globs. One collector definition is read from each matching file.
# Glob patterns are supported (see <https://pkg.go.dev/path/filepath#Match> for syntax).
collector_files:
  - "*.collector.yml"

compose.yaml

services:
  sql-exporter:
    image: burningalchemist/sql_exporter:latest
    container_name: sql-exporter
    ports:
      - 9399:9399
    volumes:
      - './sql_exporter.yml:/sql_exporter.yml'
      - './mssql_standard.collector.yml:/mssql_standard.collector.yml'

This results in:

 ✔ Container sql-exporter  Created                                                                                                 0.0s
Attaching to sql-exporter
sql-exporter  | time=2026-07-03T10:23:55.947Z level=WARN source=main.go:101 msg="Starting SQL exporter" versionInfo="(version=0.24.2, branch=HEAD, revision=e7aae50dc078ee428d92008e2f4f7bea92cd2ede)" buildContext="(go=go1.26.4, platform=linux/arm64, user=root@buildkitsandbox, date=20260702-09:16:06, tags=netgo)"
sql-exporter  | time=2026-07-03T10:23:55.948Z level=INFO source=tls_config.go:372 msg="Listening on" address=[::]:9399
sql-exporter  | time=2026-07-03T10:23:55.948Z level=INFO source=tls_config.go:375 msg="TLS is disabled." http2=false address=[::]:9399
sql-exporter  | time=2026-07-03T10:24:06.643Z level=ERROR source=promhttp.go:59 msg="Error gathering metrics" error="[from Gatherer #1] lookup dbserver1.example.com on 10.89.1.1:53: no such host"
sql-exporter  | time=2026-07-03T10:24:06.643Z level=ERROR source=promhttp.go:62 msg="No metrics gathered" error="[from Gatherer #1] lookup dbserver1.example.com on 10.89.1.1:53: no such host"

no such host is the expected result.

UPD: Just in case, if you're on Windows for instance, I'd check there are no hidden chars in the string all of a sudden, or some smart quotes like “ ” ‘ ’ that look like normal chars but are not. 🤔

[matt-baker-agd-systems]

Thanks. Do you have the mssql_standard.collector.yml please

[burningalchemist]

Sure, it's located here: https://github.com/burningalchemist/sql_exporter/tree/master/examples/mssql

[matt-baker-agd-systems]

That appears to work as intended and show the no such host error.

Now that I have a working baseline, I can go from there. It looks like just using the sql_exporter.yml verbatim with nothing else causes the error. I used that as my starting point so it was a failure from the start, regardless of the DSN format.

[matt-baker-agd-systems]

Thanks for your help. It's appreciated!

[burningalchemist]

Cool, no worries. Ping me if you have any issues.
I guess on my end it makes sense to add some extra validation and/or hints for better error handling.

User experience is not the strong point of the project to be fair, but I'm slowly moving towards v1.0 with proper documentation, and hopefully some user experience improvements.👍