[receiver/jmx] fix config parsing issue (open-telemetry#41952)

The scraper should support passing in a jmx_configs parameter instead of
a target_system. This was not working previously, and is fixed with the
change in this PR

---------

Signed-off-by: alex boten <[email protected]>
Co-authored-by: Roger Coll <[email protected]>

Author: codeboten

.chloggen/codeboten_jmxreceiver-config-parse-issues.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: jmxreceiver
+
+# A brief description of the change.  Surround your text with quotes ("") if it needs to start with a backtick (`).
+note: "support `jmx_configs` for jmx scraper usecase"
+
+# Mandatory: One or more tracking issues related to the change. You can use the PR number here if no issue exists.
+issues: [41952]
+
+# (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: []

receiver/jmxreceiver/config.go

@@ -295,9 +295,11 @@ func (c *Config) Validate() error {
 		missingFields = append(missingFields, "`endpoint`")
 	}
 	if c.TargetSystem == "" {
-		// jmx-scraper can specify jmx_configs instead
-		if c.validateJar(jmxScraperVersions, c.JARPath) == nil && c.JmxConfigs == "" {
-			missingFields = append(missingFields, "`target_system`", "`jmx_configs`")
+		// jmx-scraper can use jmx_configs instead
+		if c.validateJar(jmxScraperVersions, c.JARPath) == nil {
+			if c.JmxConfigs == "" {
+				missingFields = append(missingFields, "`target_system`", "`jmx_configs`")
+			}
 		} else {
 			missingFields = append(missingFields, "`target_system`")
 		}
@@ -337,9 +339,11 @@ func (c *Config) Validate() error {
 		}
 	}
 
-	for _, system := range strings.Split(c.TargetSystem, ",") {
-		if _, ok := validTargetSystems[strings.ToLower(system)]; !ok {
-			return fmt.Errorf("`target_system` list may only be a subset of %s", listKeys(validTargetSystems))
+	if c.TargetSystem != "" {
+		for _, system := range strings.Split(c.TargetSystem, ",") {
+			if _, ok := validTargetSystems[strings.ToLower(system)]; !ok {
+				return fmt.Errorf("`target_system` list may only be a subset of %s", listKeys(validTargetSystems))
+			}
 		}
 	}
 

receiver/jmxreceiver/config_test.go

@@ -72,6 +72,21 @@ func TestLoadConfig(t *testing.T) {
 				},
 			},
 		},
+		{
+			id: component.NewIDWithName(metadata.Type, "validscraperjmxconfigs"),
+			expected: &Config{
+				JARPath:            "testdata/fake_jmx_scraper.jar",
+				Endpoint:           "myendpoint:55555",
+				CollectionInterval: 10 * time.Second,
+				JmxConfigs:         "testdata/rules.yaml",
+				OTLPExporterConfig: otlpExporterConfig{
+					Endpoint: "0.0.0.0:0",
+					TimeoutSettings: exporterhelper.TimeoutConfig{
+						Timeout: 5 * time.Second,
+					},
+				},
+			},
+		},
 		{
 			id:          component.NewIDWithName(metadata.Type, "missingendpoint"),
 			expectedErr: "missing required field(s): `endpoint`",

receiver/jmxreceiver/testdata/config.yaml

@@ -24,6 +24,13 @@ jmx/all:
     one: two
   additional_jars:
     - testdata/fake_additional.jar
+jmx/validscraperjmxconfigs:
+  jar_path: testdata/fake_jmx_scraper.jar
+  endpoint: myendpoint:55555
+  otlp:
+    endpoint: 0.0.0.0:0
+    timeout: 5s
+  jmx_configs: testdata/rules.yaml
 jmx/missingendpoint:
   jar_path: testdata/fake_jmx.jar
   target_system: jvm