Multiple config files merging rules

[RomanChernyshev]

Hi. Could you please help me. I found this brief information about using multiple configuration files, but I can't find any details about merging settings. How does it work? I am especially interested in the behavior of arrays. How are the "sink.inputs" arrays combined?

[RomanChernyshev]

https://vector.dev/highlights/2020-02-07-multi-config-files/

[pront]

Hi @RomanChernyshev, can you share an example of what config files you want to merge? I usually recommend a pre-processing tool outside of Vector to manage complex configurations that span multiple files and are not just blocks that are merged together.

[RomanChernyshev]

For example.
Here's vector1.toml.

[sinks.sink_logs_collector]
  type = "http"
  inputs = [ "transform_some_another_logs"]
  uri = "{{ collector_endpoint_url }}"
  healthcheck = true

[sinks.sink_logs_collector.framing]
  method = "newline_delimited"

[sinks.sink_logs_collector.batch]
  timeout_secs = 0.5
  max_events = 100

[sinks.sink_logs_collector.encoding]
  codec = "json"

Here's vector2.toml:

[sources.k3s_source_pods_logs]
  <source_settings>

[transforms.transform_k3s_pods_logs]
  <transform_settings>

[sinks.sink_logs_collector]
  inputs = [ "transform_k3s_pods_logs"]

So we have two different "sinks.sink_logs_collector.inputs" arrays.

[pront]

I ran a quick example:

part1:

[sources.s0]
type = "demo_logs"
format = "shuffle"
lines = ["test line"]
interval = 10

[sources.s1]
type = "demo_logs"
format = "apache_error"
interval = 5

[sinks.console]
  type = "console"
  inputs = [ "s0"]

[sinks.console.encoding]
  codec = "json"

part2:

[sinks.console]
  inputs = [ "s1"]

The resulting inputs should be the union of the two. We can see events from both sources in the following sample output:

{"host":"localhost","message":"[Wed Aug 27 11:25:53 2025] [BronzeGamer:info] [pid 9825:tid] [client 163.17.2.35:24717] There's a breach in the warp core, captain","service":"vector","source_type":"demo_logs","timestamp":"2025-08-27T15:25:53.570580Z"}
{"host":"localhost","message":"test line","service":"vector","source_type":"demo_logs","timestamp":"2025-08-27T15:25:59.567469Z"}