[receiver/sshcheck] Include SSH endpoint resource attribute

[DewaldDeJager]

Description: The metadata.yml for the SSH check receiver currently documents a resource attribute containing the SSH endpoint but this is not emitted. This PR updates the receiver to include this resource attribute.

Link to tracking Issue: #24441

Testing:

Example collector config:

receivers:
  sshcheck:
    endpoint: 13.245.150.131:22
    username: ec2-user
    key_file: /Users/dewald.dejager/.ssh/sandbox.pem
    collection_interval: 15s
    known_hosts: /Users/dewald.dejager/.ssh/known_hosts
    ignore_host_key: false
    resource_attributes:
      "ssh.endpoint":
        enabled: true

exporters:
  logging:
    verbosity: detailed
  prometheus:
    endpoint: 0.0.0.0:8081
    resource_to_telemetry_conversion:
      enabled: true

service:
  pipelines:
    metrics:
      receivers: [sshcheck]
      exporters: [logging, prometheus]

The log output looks like this:

2023-07-30T16:52:38.724+0200    info    MetricsExporter {"kind": "exporter", "data_type": "metrics", "name": "logging", "resource metrics": 1, "metrics": 2, "data points": 2}
2023-07-30T16:52:38.724+0200    info    ResourceMetrics #0
Resource SchemaURL: 
Resource attributes:
     -> ssh.endpoint: Str(13.245.150.131:22)
ScopeMetrics #0
ScopeMetrics SchemaURL: 
InstrumentationScope otelcol/sshcheckreceiver 0.82.0-dev
Metric #0
Descriptor:
     -> Name: sshcheck.duration
     -> Description: Measures the duration of SSH connection.
     -> Unit: ms
     -> DataType: Gauge
NumberDataPoints #0
StartTimestamp: 2023-07-30 14:52:22.381672 +0000 UTC
Timestamp: 2023-07-30 14:52:38.404003 +0000 UTC
Value: 319
Metric #1
Descriptor:
     -> Name: sshcheck.status
     -> Description: 1 if the SSH client successfully connected, otherwise 0.
     -> Unit: 1
     -> DataType: Sum
     -> IsMonotonic: false
     -> AggregationTemporality: Cumulative
NumberDataPoints #0
StartTimestamp: 2023-07-30 14:52:22.381672 +0000 UTC
Timestamp: 2023-07-30 14:52:38.404003 +0000 UTC
Value: 1

And the Prometheus metrics look like this:

# HELP sshcheck_duration Measures the duration of SSH connection.
# TYPE sshcheck_duration gauge
sshcheck_duration{ssh_endpoint="13.245.150.131:22"} 311
# HELP sshcheck_status 1 if the SSH client successfully connected, otherwise 0.
# TYPE sshcheck_status gauge
sshcheck_status{ssh_endpoint="13.245.150.131:22"} 1

[DewaldDeJager]

The failing test is unrelated to the changes in this PR. Looks like a K8s scheduling/resourcing issue. Please would you trigger a re-run of the failing check?

[atoulme]

Done.

[DewaldDeJager]

One of the lint matrix checks is failing because of a timeout. I don't think it's related to these changes. Please could you re-run that check?