[receiver/sshcheck] Change keyfile -> key_file in e.g. config and docs (

open-telemetry#28834)

`keyfile` was the key used in config and documented in sshcheck, but
`key_file` is the preferred key for these purposes.

**Link to tracking Issue:** open-telemetry#27035 

**Testing:** Update tests to ensure this key is used in default.

**Documentation:** Updated documentation to reflect the change in key.

.chloggen/sshcheckreceiver-fix-key_file-config-27035.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: 'bug_fix'
+
+# The name of the component, or a single word describing the area of concern, (e.g. filelogreceiver)
+component: sshcheckreceiver
+
+# A brief description of the change.  Surround your text with quotes ("") if it needs to start with a backtick (`).
+note: Use key_file instead of keyfile for the key in config. Aligns project practice, code, and docs.
+
+# Mandatory: One or more tracking issues related to the change. You can use the PR number here if no issue exists.
+issues: [27035]
+
+# (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]

receiver/sshcheckreceiver/README.md

@@ -24,9 +24,9 @@ If `ignore_host_key` is not set then host key validation requires the agent eith
 The following settings are required:
 - `endpoint`
 - `username`
-- `password` or `keyfile`
+- `password` or `key_file`
 
-Either `password` or `keyfile` must be set. But if both are set then password is treated as the `passphrase` and the key is assumed to be encrypted.
+Either `password` or `key_file` must be set. But if both are set then password is treated as the `passphrase` and the key is assumed to be encrypted.
 
 The following settings are optional:
 

receiver/sshcheckreceiver/config.go

@@ -20,7 +20,7 @@ var (
 	errMissingEndpoint           = errors.New(`"endpoint" not specified in config`)
 	errInvalidEndpoint           = errors.New(`"endpoint" is invalid`)
 	errMissingUsername           = errors.New(`"username" not specified in config`)
-	errMissingPasswordAndKeyFile = errors.New(`either "password" or "keyfile" is required`)
+	errMissingPasswordAndKeyFile = errors.New(`either "password" or "key_file" is required`)
 
 	errConfigNotSSHCheck  = errors.New("config was not a SSH check receiver config")
 	errWindowsUnsupported = errors.New(metadata.Type + " is unsupported on Windows.")

receiver/sshcheckreceiver/config_test.go

@@ -4,10 +4,13 @@
 package sshcheckreceiver // import "github.com/open-telemetry/opentelemetry-collector-contrib/receiver/sshcheckreceiver"
 
 import (
+	"path/filepath"
 	"testing"
+	"time"
 
 	"github.com/stretchr/testify/require"
 	"go.opentelemetry.io/collector/component/componenttest"
+	"go.opentelemetry.io/collector/confmap/confmaptest"
 	"go.opentelemetry.io/collector/receiver/scraperhelper"
 	"go.uber.org/multierr"
 
@@ -32,7 +35,7 @@ func TestValidate(t *testing.T) {
 		expectedErr error
 	}{
 		{
-			desc: "missing password and keyfile",
+			desc: "missing password and key_file",
 			cfg: &Config{
 				SSHClientSettings: configssh.SSHClientSettings{
 					Username: "otelu",
@@ -82,7 +85,7 @@ func TestValidate(t *testing.T) {
 			expectedErr: error(nil),
 		},
 		{
-			desc: "no error with keyfile",
+			desc: "no error with key_file",
 			cfg: &Config{
 				SSHClientSettings: configssh.SSHClientSettings{
 					Endpoint: "localhost:2222",
@@ -105,3 +108,36 @@ func TestValidate(t *testing.T) {
 		})
 	}
 }
+
+func TestLoadConfig(t *testing.T) {
+	// load test config
+	cm, err := confmaptest.LoadConf(filepath.Join("testdata", "config.yaml"))
+	require.NoError(t, err)
+	rcvrs, err := cm.Sub("receivers")
+	require.NoError(t, err)
+	sshconf, err := rcvrs.Sub("sshcheck")
+	require.NoError(t, err)
+	// unmarshal to receiver config
+	actualConfig, ok := NewFactory().CreateDefaultConfig().(*Config)
+	require.True(t, ok)
+	require.NoError(t, sshconf.Unmarshal(actualConfig))
+
+	// set expected config
+	expectedConfig, ok := NewFactory().CreateDefaultConfig().(*Config)
+	require.True(t, ok)
+
+	expectedConfig.ScraperControllerSettings = scraperhelper.ScraperControllerSettings{
+		InitialDelay:       time.Second,
+		CollectionInterval: 10 * time.Second,
+	}
+	expectedConfig.SSHClientSettings = configssh.SSHClientSettings{
+		Endpoint:      "notdefault:1313",
+		Username:      "notdefault_username",
+		Password:      "notdefault_password",
+		KeyFile:       "notdefault/path/keyfile",
+		KnownHosts:    "path/to/collector_known_hosts",
+		IgnoreHostKey: false,
+		Timeout:       10 * time.Second,
+	}
+	require.Equal(t, expectedConfig, actualConfig)
+}

receiver/sshcheckreceiver/testdata/config.yaml

@@ -1,10 +1,10 @@
 receivers:
   sshcheck:
     endpoint: notdefault:1313
-    username: notdefault_password
+    username: notdefault_username
     password: notdefault_password
-    keyfile: notdefault/path/keyfile
-    collection_interval: 13m
+    key_file: notdefault/path/keyfile
+    collection_interval: 10s
     known_hosts: path/to/collector_known_hosts
     ignore_host_key: false