[processor/resourcedetection] Add support for hetzner cloud (#42477)

<!--Ex. Fixing a bug - Describe the bug and how this fixes the issue.
Ex. Adding a feature - Explain what this achieves.-->
#### Description

This PR adds support for resource detection in Hetzner Cloud.

I have not added the Hetzner cloud into semantic conventions, but I can
open a PR for it.

<!-- Issue number (e.g. #1234) or full URL to issue, if applicable. -->
#### Link to tracking issue

Fixes #42476

<!--Describe what testing was performed and which tests were added.-->
#### Testing

Added tests to cover most of the cases, and I personally tested on a
Hetzner server.

```
2025-09-03T17:31:23.666+0100	info	service@v0.134.0/service.go:211	Starting otelcontribcol...	{"resource": {"service.instance.id": "f054fbb3-ad03-4aef-8c7a-1e38550cfec7", "service.name": "otelcontribcol", "service.version": "0.134.0-dev"}, "Version": "0.134.0-dev", "NumCPU": 8}
2025-09-03T17:31:23.666+0100	info	extensions/extensions.go:41	Starting extensions...	{"resource": {"service.instance.id": "f054fbb3-ad03-4aef-8c7a-1e38550cfec7", "service.name": "otelcontribcol", "service.version": "0.134.0-dev"}}
2025-09-03T17:31:23.666+0100	info	internal/resourcedetection.go:137	began detecting resource information	{"resource": {"service.instance.id": "f054fbb3-ad03-4aef-8c7a-1e38550cfec7", "service.name": "otelcontribcol", "service.version": "0.134.0-dev"}, "otelcol.component.id": "resourcedetection", "otelcol.component.kind": "processor", "otelcol.pipeline.id": "metrics", "otelcol.signal": "metrics"}
2025-09-03T17:31:23.672+0100	info	internal/resourcedetection.go:188	detected resource information	{"resource": {"service.instance.id": "f054fbb3-ad03-4aef-8c7a-1e38550cfec7", "service.name": "otelcontribcol", "service.version": "0.134.0-dev"}, "otelcol.component.id": "resourcedetection", "otelcol.component.kind": "processor", "otelcol.pipeline.id": "metrics", "otelcol.signal": "metrics", "resource": {"cloud.availability_zone":"nbg1-dc3","cloud.provider":"hetzner","cloud.region":"eu-central","host.id":"30727666","host.name":"vm1"}}
2025-09-03T17:31:23.672+0100	info	service@v0.134.0/service.go:234	Everything is ready. Begin running and processing data.	{"resource": {"service.instance.id": "f054fbb3-ad03-4aef-8c7a-1e38550cfec7", "service.name": "otelcontribcol", "service.version": "0.134.0-dev"}}
2025-09-03T17:31:24.673+0100	info	Metrics	{"resource": {"service.instance.id": "f054fbb3-ad03-4aef-8c7a-1e38550cfec7", "service.name": "otelcontribcol", "service.version": "0.134.0-dev"}, "otelcol.component.id": "debug", "otelcol.component.kind": "exporter", "otelcol.signal": "metrics", "resource metrics": 3, "metrics": 5, "data points": 73}
2025-09-03T17:31:24.673+0100	info	ResourceMetrics #0
Resource SchemaURL: https://opentelemetry.io/schemas/1.9.0
Resource attributes:
     -> cloud.provider: Str(hetzner)
     -> host.id: Str(30727666)
     -> host.name: Str(vm1)
     -> cloud.region: Str(eu-central)
     -> cloud.availability_zone: Str(nbg1-dc3)
```

<!--Describe the documentation added.-->
#### Documentation

Updated the `README.md` with this new detector.

<!--Please delete paragraphs that you did not use before submitting.-->

---------

Signed-off-by: Paulo Dias <paulodias.gm@gmail.com>

Author: paulojmdias

.chloggen/feat_42476.yaml

@@ -0,0 +1,27 @@
+# Use this changelog template to create an entry for release notes.
+
+# One of 'breaking', 'deprecation', 'new_component', 'enhancement', 'bug_fix'
+change_type: "enhancement"
+
+# The name of the component, or a single word describing the area of concern, (e.g. filelogreceiver)
+component: "processor/resourcedetection"
+
+# A brief description of the change.  Surround your text with quotes ("") if it needs to start with a backtick (`).
+note: "Add support for hetzner cloud in resourcedetectionprocessor"
+
+# Mandatory: One or more tracking issues related to the change. You can use the PR number here if no issue exists.
+issues: [42476]
+
+# (Optional) One or more lines of additional information to render under the primary note.
+# These lines will be padded with 2 spaces and then inserted directly into the document.
+# Use pipe (|) for multiline entries.
+subtext:
+
+# If your change doesn't affect end users or the exported elements of any package,
+# you should instead start your pull request title with [chore] or use the "Skip Changelog" label.
+# Optional: The change log or logs in which this entry should be included.
+# e.g. '[user]' or '[user, api]'
+# Include 'user' if the change is relevant to end users.
+# Include 'api' if there is a change to a library API.
+# Default: '[user]'
+change_logs: [user]

.github/CODEOWNERS

@@ -205,6 +205,7 @@ processor/redactionprocessor/                                    @open-telemetry
 processor/remotetapprocessor/                                    @open-telemetry/collector-contrib-approvers @atoulme @jaronoff97
 processor/resourcedetectionprocessor/                            @open-telemetry/collector-contrib-approvers @Aneurysm9 @dashpole
 processor/resourcedetectionprocessor/internal/dynatrace/         @open-telemetry/collector-contrib-approvers @bacherfl @evan-bradley
+processor/resourcedetectionprocessor/internal/hetzner/           @open-telemetry/collector-contrib-approvers @Aneurysm9 @dashpole @paulojmdias
 processor/resourceprocessor/                                     @open-telemetry/collector-contrib-approvers @dmitryax
 processor/schemaprocessor/                                       @open-telemetry/collector-contrib-approvers @MovieStoreGuy @ankitpatel96 @dineshg13
 processor/spanprocessor/                                         @open-telemetry/collector-contrib-approvers @boostchicken

.github/ISSUE_TEMPLATE/beta_stability.yaml

@@ -207,6 +207,7 @@ body:
       - processor/resource
       - processor/resourcedetection
       - processor/resourcedetection/internal/dynatrace
+      - processor/resourcedetection/internal/hetzner
       - processor/schema
       - processor/span
       - processor/sumologic

.github/ISSUE_TEMPLATE/bug_report.yaml

@@ -210,6 +210,7 @@ body:
       - processor/resource
       - processor/resourcedetection
       - processor/resourcedetection/internal/dynatrace
+      - processor/resourcedetection/internal/hetzner
       - processor/schema
       - processor/span
       - processor/sumologic

.github/ISSUE_TEMPLATE/feature_request.yaml

@@ -204,6 +204,7 @@ body:
       - processor/resource
       - processor/resourcedetection
       - processor/resourcedetection/internal/dynatrace
+      - processor/resourcedetection/internal/hetzner
       - processor/schema
       - processor/span
       - processor/sumologic

.github/ISSUE_TEMPLATE/other.yaml

@@ -204,6 +204,7 @@ body:
       - processor/resource
       - processor/resourcedetection
       - processor/resourcedetection/internal/dynatrace
+      - processor/resourcedetection/internal/hetzner
       - processor/schema
       - processor/span
       - processor/sumologic

.github/ISSUE_TEMPLATE/unmaintained.yaml

@@ -209,6 +209,7 @@ body:
       - processor/resource
       - processor/resourcedetection
       - processor/resourcedetection/internal/dynatrace
+      - processor/resourcedetection/internal/hetzner
       - processor/schema
       - processor/span
       - processor/sumologic

.github/component_labels.txt

@@ -186,6 +186,7 @@ processor/redactionprocessor processor/redaction
 processor/remotetapprocessor processor/remotetap
 processor/resourcedetectionprocessor processor/resourcedetection
 processor/resourcedetectionprocessor/internal/dynatrace processor/resourcedetection/internal/dynatrace
+processor/resourcedetectionprocessor/internal/hetzner processor/resourcedetection/internal/hetzner
 processor/resourceprocessor processor/resource
 processor/schemaprocessor processor/schema
 processor/spanprocessor processor/span

connector/datadogconnector/go.mod

@@ -35,8 +35,8 @@ require (
 	go.opentelemetry.io/collector/processor/batchprocessor v0.134.0
 	go.opentelemetry.io/collector/receiver v1.40.0
 	go.opentelemetry.io/collector/receiver/otlpreceiver v0.134.0
-	go.opentelemetry.io/otel v1.37.0
-	go.opentelemetry.io/otel/metric v1.37.0
+	go.opentelemetry.io/otel v1.38.0
+	go.opentelemetry.io/otel/metric v1.38.0
 	go.uber.org/zap v1.27.0
 	google.golang.org/protobuf v1.36.8
 )
@@ -332,7 +332,7 @@ require (
 	go.opentelemetry.io/otel/sdk v1.37.0 // indirect
 	go.opentelemetry.io/otel/sdk/log v0.13.0 // indirect
 	go.opentelemetry.io/otel/sdk/metric v1.37.0 // indirect
-	go.opentelemetry.io/otel/trace v1.37.0 // indirect
+	go.opentelemetry.io/otel/trace v1.38.0 // indirect
 	go.opentelemetry.io/proto/otlp v1.7.0 // indirect
 	go.uber.org/atomic v1.11.0 // indirect
 	go.uber.org/dig v1.19.0 // indirect