Change rule expression to match endpoint types for receiver creator (#2661)

Change the rule expression in receiver creator for matching endpoints types port, hostport and pod from type.port, type.hostport and type.pod respectively, to type == "port", type == "hostport" and type == "pod".

Testing: Fixed unit tests failing due to change

Documentation: Updated documentation to reflect change.

Author: bjsignalfx

extension/observer/endpoints.go

@@ -38,13 +38,6 @@ const (
 )
 
 var (
-	// EndpointTypes is a map of all known endpoint types.
-	EndpointTypes = map[EndpointType]bool{
-		PortType:     true,
-		PodType:      true,
-		HostPortType: true,
-	}
-
 	_ EndpointDetails = (*Pod)(nil)
 	_ EndpointDetails = (*Port)(nil)
 	_ EndpointDetails = (*HostPort)(nil)
@@ -71,17 +64,11 @@ func (e *Endpoint) Env() (EndpointEnv, error) {
 	if e.Details == nil {
 		return nil, errors.New("endpoint is missing details")
 	}
+
 	env := e.Details.Env()
 	env["endpoint"] = e.Target
+	env["type"] = string(e.Details.Type())
 
-	// Populate type field for evaluating rules with `type.port && ...`.
-	// Use string instead of EndpointType for rule evaluation.
-	types := map[string]bool{}
-	for endpointType := range EndpointTypes {
-		types[string(endpointType)] = false
-	}
-	types[string(e.Details.Type())] = true
-	env["type"] = types
 	return env, nil
 }
 

extension/observer/endpoints_test.go

@@ -44,11 +44,7 @@ func TestEndpointEnv(t *testing.T) {
 				},
 			},
 			want: EndpointEnv{
-				"type": map[string]bool{
-					"pod":      true,
-					"hostport": false,
-					"port":     false,
-				},
+				"type":     "pod",
 				"endpoint": "192.68.73.2",
 				"name":     "pod_name",
 				"labels": map[string]string{
@@ -85,11 +81,7 @@ func TestEndpointEnv(t *testing.T) {
 				},
 			},
 			want: EndpointEnv{
-				"type": map[string]bool{
-					"pod":      false,
-					"hostport": false,
-					"port":     true,
-				},
+				"type":     "port",
 				"endpoint": "192.68.73.2",
 				"name":     "port_name",
 				"port":     uint16(2379),
@@ -122,11 +114,7 @@ func TestEndpointEnv(t *testing.T) {
 				},
 			},
 			want: EndpointEnv{
-				"type": map[string]bool{
-					"hostport": true,
-					"pod":      false,
-					"port":     false,
-				},
+				"type":         "hostport",
 				"endpoint":     "127.0.0.1",
 				"process_name": "process_name",
 				"command":      "./cmd --config config.yaml",

extension/observer/hostobserver/README.md

@@ -22,7 +22,7 @@ Endpoint variables exposed by this observer are as follows.
 
 | Variable  | Description                                                                                |
 |-----------|--------------------------------------------------------------------------------------------|
-| type.port | `true`                                                                                     |
+| type      | `"port"`                                                                                     |
 | name      | name of the process associated to the port                                                 |
 | port      | port number                                                                                |
 | command   | full command used to invoke this process, including the executable itself at the beginning |

receiver/receivercreator/README.md

@@ -62,39 +62,39 @@ This setting controls what resource attributes are set on metrics emitted from t
 
 Note that the backticks below are not typos--they indicate the value is set dynamically.
 
-`type.pod`
+`type == "pod"`
 
 | Resource Attribute | Default       |
 |--------------------|---------------|
 | k8s.pod.name       | \`name\`      |
 | k8s.pod.uid        | \`uid\`       |
 | k8s.namespace.name | \`namespace\` |
 
-`type.port`
+`type == "port"`
 
 | Resource Attribute | Default           |
 |--------------------|-------------------|
 | k8s.pod.name       | \`pod.name\`      |
 | k8s.pod.uid        | \`pod.uid\`       |
 | k8s.namespace.name | \`pod.namespace\` |
 
-`type.hostport`
+`type == "hostport"`
 
 None
 
 See `redis/2` in [examples](#examples).
 
 ## Rule Expressions
 
-Each rule must start with `type.(pod|port|hostport) &&` such that the rule matches
+Each rule must start with `type == ("pod"|"port"|"hostport") &&` such that the rule matches
 only one endpoint type. Depending on the type of endpoint the rule is
 targeting it will have different variables available.
 
 ### Pod
 
 | Variable    | Description                       |
 |-------------|-----------------------------------|
-| type.pod    | `true`                            |
+| type        | `"pod"`                            |
 | name        | name of the pod                   |
 | namespace   | namespace of the pod              |
 | uid         | unique id of the pod              |
@@ -105,7 +105,7 @@ targeting it will have different variables available.
 
 | Variable        | Description                             |
 |-----------------|-----------------------------------------|
-| type.port       | `true`                                  |
+| type            | `"port"`                                  |
 | name            | container port name                     |
 | port            | port number                             |
 | protocol        | The transport protocol ("TCP" or "UDP") |
@@ -119,7 +119,7 @@ targeting it will have different variables available.
 
 | Variable      | Description                                      |
 |---------------|--------------------------------------------------|
-| type.hostport | `true`                                           |
+| type          | `"hostport"`                                           |
 | process_name  | Name of the process                              |
 | command       | Command line with the used to invoke the process |
 | is_ipv6       | true if endpoint is IPv6, otherwise false        |
@@ -141,14 +141,14 @@ receivers:
     receivers:
       prometheus_simple:
         # Configure prometheus scraping if standard prometheus annotations are set on the pod.
-        rule: type.pod && annotations["prometheus.io/scrape"] == "true"
+        rule: type == "pod" && annotations["prometheus.io/scrape"] == "true"
         config:
           metrics_path: '`"prometheus.io/path" in annotations ? annotations["prometheus.io/path"] : "/metrics"`'
           endpoint: '`endpoint`:`"prometheus.io/port" in annotations ? annotations["prometheus.io/port"] : 9090`'
 
       redis/1:
         # If this rule matches an instance of this receiver will be started.
-        rule: type.port && port == 6379
+        rule: type == "port" && port == 6379
         config:
           # Static receiver-specific config.
           password: secret
@@ -157,7 +157,7 @@ receivers:
 
       redis/2:
         # Set a resource attribute based on endpoint value.
-        rule: type.port && port == 6379
+        rule: type == "port" && port == 6379
         resource_attributes:
           # Dynamic value.
           app: `pod.labels["app"]`
@@ -169,7 +169,7 @@ receivers:
     receivers:
       redis/on_host:
         # If this rule matches an instance of this receiver will be started.
-        rule: type.port && port == 6379 && is_ipv6 == true
+        rule: type == "port" && port == 6379 && is_ipv6 == true
         config:
           service_name: redis_on_host
 

receiver/receivercreator/config_test.go

@@ -84,9 +84,11 @@ func TestLoadConfig(t *testing.T) {
 	r1 := cfg.Receivers["receiver_creator/1"].(*Config)
 
 	assert.NotNil(t, r1)
-	assert.Len(t, r1.receiverTemplates, 1)
+	assert.Len(t, r1.receiverTemplates, 2)
+	assert.Contains(t, r1.receiverTemplates, "examplereceiver/1")
+	assert.Equal(t, `type == "port"`, r1.receiverTemplates["examplereceiver/1"].Rule)
 	assert.Contains(t, r1.receiverTemplates, "nop/1")
-	assert.Equal(t, `type.port`, r1.receiverTemplates["nop/1"].Rule)
+	assert.Equal(t, `type == "port"`, r1.receiverTemplates["nop/1"].Rule)
 	assert.Equal(t, userConfigMap{
 		endpointConfigKey: "localhost:12345",
 	}, r1.receiverTemplates["nop/1"].config)

receiver/receivercreator/fixtures_test.go

@@ -48,6 +48,17 @@ var portEndpoint = observer.Endpoint{
 	},
 }
 
+var hostportEndpoint = observer.Endpoint{
+	ID:     "port-1",
+	Target: "localhost:1234",
+	Details: &observer.HostPort{
+		ProcessName: "splunk",
+		Command:     "./splunk",
+		Port:        1234,
+		Transport:   observer.ProtocolTCP,
+	},
+}
+
 var unsupportedEndpoint = observer.Endpoint{
 	ID:      "endpoint-1",
 	Target:  "localhost:1234",

receiver/receivercreator/observerhandler_test.go

@@ -52,7 +52,7 @@ func TestOnAdd(t *testing.T) {
 	rcvrCfg := receiverConfig{typeStr: configmodels.Type("name"), config: userConfigMap{"foo": "bar"}, fullName: "name/1"}
 	cfg := createDefaultConfig().(*Config)
 	cfg.receiverTemplates = map[string]receiverTemplate{
-		"name/1": {rcvrCfg, "", newRuleOrPanic(`type.port`)},
+		"name/1": {rcvrCfg, "", newRuleOrPanic(`type == "port"`)},
 	}
 	handler := &observerHandler{
 		config:                cfg,
@@ -104,7 +104,7 @@ func TestOnChange(t *testing.T) {
 	newRcvr := &nopWithEndpointReceiver{}
 	cfg := createDefaultConfig().(*Config)
 	cfg.receiverTemplates = map[string]receiverTemplate{
-		"name/1": {rcvrCfg, "", newRuleOrPanic(`type.port`)},
+		"name/1": {rcvrCfg, "", newRuleOrPanic(`type == "port"`)},
 	}
 	handler := &observerHandler{
 		config:                cfg,
@@ -136,8 +136,8 @@ func TestDynamicConfig(t *testing.T) {
 	cfg.receiverTemplates = map[string]receiverTemplate{
 		"name/1": {
 			receiverConfig: receiverConfig{typeStr: configmodels.Type("name"), config: userConfigMap{"endpoint": "`endpoint`:6379"}, fullName: "name/1"},
-			Rule:           "type.pod",
-			rule:           newRuleOrPanic("type.pod"),
+			Rule:           `type == "pod"`,
+			rule:           newRuleOrPanic("type == \"pod\""),
 		},
 	}
 	handler := &observerHandler{

receiver/receivercreator/rules.go

@@ -30,7 +30,7 @@ type rule struct {
 }
 
 // ruleRe is used to verify the rule starts type check.
-var ruleRe = regexp.MustCompile(`^type\.(pod|port)`)
+var ruleRe = regexp.MustCompile(`^type\s*==\s*("pod"|"port"|"hostport")`)
 
 // newRule creates a new rule instance.
 func newRule(ruleStr string) (rule, error) {

receiver/receivercreator/rules_test.go

@@ -44,9 +44,10 @@ func Test_ruleEval(t *testing.T) {
 	}{
 		// Doesn't work yet. See comment in newRule.
 		// {"unknown variable", args{`type == "port" && unknown_var == 1`, portEndpoint}, false, true},
-		{"basic port", args{`type.port && name == "http" && pod.labels["app"] == "redis"`, portEndpoint}, true, false},
-		{"basic pod", args{`type.pod && labels["region"] == "west-1"`, podEndpoint}, true, false},
-		{"annotations", args{`type.pod && annotations["scrape"] == "true"`, podEndpoint}, true, false},
+		{"basic port", args{`type == "port" && name == "http" && pod.labels["app"] == "redis"`, portEndpoint}, true, false},
+		{"basic hostport", args{`type == "hostport" && port == 1234 && process_name == "splunk"`, hostportEndpoint}, true, false},
+		{"basic pod", args{`type == "pod" && labels["region"] == "west-1"`, podEndpoint}, true, false},
+		{"annotations", args{`type == "pod" && annotations["scrape"] == "true"`, podEndpoint}, true, false},
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
@@ -81,7 +82,9 @@ func Test_newRule(t *testing.T) {
 		{"empty rule", args{""}, true},
 		{"does not start with type", args{"port == 1234"}, true},
 		{"invalid syntax", args{"port =="}, true},
-		{"valid", args{`type.port && port_name == "http"`}, false},
+		{"valid port", args{`type == "port" && port_name == "http"`}, false},
+		{"valid pod", args{`type=="pod" && port_name == "http"`}, false},
+		{"valid hostport", args{`type ==    "hostport" && port_name == "http"`}, false},
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {

receiver/receivercreator/testdata/config.yaml

@@ -3,8 +3,10 @@ receivers:
   receiver_creator/1:
     watch_observers: [mock_observer]
     receivers:
+      examplereceiver/1:
+        rule: type == "port"
       nop/1:
-        rule: type.port
+        rule: type == "port"
         config:
           endpoint: localhost:12345