Add and support receiver creator endpoint properties

.chloggen/receivercreatorconfigfromenv.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: receiver_creator
+
+# A brief description of the change.  Surround your text with quotes ("") if it needs to start with a backtick (`).
+note: Support `accept_endpoint_environments` for dynamic template evaluation from observer endpoint environments
+
+# Mandatory: One or more tracking issues related to the change. You can use the PR number here if no issue exists.
+issues: [17418]
+
+# (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/receivercreator/README.md

@@ -143,6 +143,86 @@ receivers:
 
 Similar to the per-endpoint type `resource_attributes` described above but for individual receiver instances. Duplicate attribute entries (including the empty string) in this receiver-specific mapping take precedence. These attribute values also support expansion from endpoint environment content. At this time their values must be strings.
 
+**accept_endpoint_properties**
+
+```yaml
+accept_endpoint_properties: true
+```
+
+Enabling this feature will allow observer endpoints to embed receiver configuration entries for both modifying existing entries and creating new ones during the evaluation of the containing endpoint. Endpoint properties will not extend to any other observed endpoint or instantiated receiver. The default value is `false`.
+
+Endpoint properties are key-value pairs of the form `<Prefix><Property Key>: <Property Value>`. The prefix is either the RFC 1123 compatible or reverse DNS variant:
+
+`receiver-creator.collector.opentelemetry.io/` or `io.opentelemetry.collector.receiver-creator.`
+
+The property key is of the form `<receiver type>(/<optional receiver name>)(.<optional field type>(.<optional mapping key>))`. For Kubernetes qualified names where only a lone prefix-separating `/` is allowed, `__` can be used to signify `/` for specifying name references. The optional field types are `config`, `resources_attributes`, and `rule`, which can be used in any combination in a full mapping value. The optional mapping key is the first-level mapping field name. The `::` field separator is supported in values, and where compatible with metadata carriers (generally container labels), the `::` field separator can also be used in the `config` field type's optional mapping key.
+
+Currently, endpoint properties are only parsed from `pod`, `port`, `k8s.node` endpoint types' `annotations` maps, as well as `container` endpoint types' `labels` maps.
+
+Examples:
+
+Redis receiver full mapping endpoint property via kubernetes pod annotation:
+
+Collector configuration segment:
+
+```yaml
+extensions:
+  k8s_observer:
+
+receivers:
+  receiver_creator:
+    accept_endpoint_properties: true
+    watch_observers: [k8s_observer]
+```
+
+Redis pod manifest:
+
+``` yaml
+apiVersion: v1
+kind: Pod
+metadata:
+  name: redis
+  annotations:
+    receiver-creator.collector.opentelemetry.io/redis: |
+      rule: type == "port" and port == 6379
+      config:
+        collection_interval: 5s
+      resource_attributes:
+        some_attribute: attribute_value
+spec:
+  containers:
+  - name: redis
+    image: redis
+    ports:
+    - containerPort: 6379
+```
+
+
+Simple prometheus receiver `config`, `resource_attributes`, and `rule` endpoint properties via docker container labels:
+
+Collector configuration segment:
+
+```yaml
+extensions:
+  docker_observer:
+
+receivers:
+  receiver_creator:
+    accept_endpoint_properties: true
+    watch_observers: [docker_observer]
+```
+
+docker run command:
+
+```bash
+docker run \
+  -l io.opentelemetry.collector.receiver-creator.prometheus_simple/bitnami.config.collection_interval=30s \
+  -l io.opentelemetry.collector.receiver-creator.prometheus_simple/bitnami.config.labels::a.label=label_value \
+  -l io.opentelemetry.collector.receiver-creator.prometheus_simple/bitnami.resource_attributes.some_attribute=attribute_value \
+  -l io.opentelemetry.collector.receiver-creator.prometheus_simple/bitnami.rule='type == "container" and port == 9090' \
+  bitnami/prometheus
+```
+
 ## Rule Expressions
 
 Each rule must start with `type == ("pod"|"port"|"hostport"|"container"|"k8s.node") &&` such that the rule matches

receiver/receivercreator/config.go

@@ -65,6 +65,7 @@ func newReceiverTemplate(name string, cfg userConfigMap) (receiverTemplate, erro
 			config:     cfg,
 			endpointID: observer.EndpointID("endpoint.id"),
 		},
+		ResourceAttributes: map[string]any{},
 	}, nil
 }
 
@@ -78,6 +79,9 @@ type Config struct {
 	// ResourceAttributes is a map of default resource attributes to add to each resource
 	// object received by this receiver from dynamically created receivers.
 	ResourceAttributes resourceAttributes `mapstructure:"resource_attributes"`
+	// AcceptEndpointProperties determines whether properties specified in observer.EndpointEnv
+	// should be used in determining receiver runtime configuration for a given endpoint.
+	AcceptEndpointProperties bool `mapstructure:"accept_endpoint_properties"`
 }
 
 func (cfg *Config) Unmarshal(componentParser *confmap.Conf) error {
@@ -135,3 +139,23 @@ func (cfg *Config) Unmarshal(componentParser *confmap.Conf) error {
 
 	return nil
 }
+
+func (rt receiverTemplate) copy() receiverTemplate {
+	cp := receiverTemplate{
+		receiverConfig: receiverConfig{
+			id: rt.id, endpointID: rt.endpointID,
+			config: map[string]any{},
+		},
+		Rule:               rt.Rule,
+		ResourceAttributes: map[string]any{},
+		rule:               rt.rule,
+	}
+
+	for k, v := range rt.config {
+		cp.config[k] = v
+	}
+	for k, v := range rt.ResourceAttributes {
+		cp.ResourceAttributes[k] = v
+	}
+	return cp
+}

receiver/receivercreator/config_test.go

@@ -78,6 +78,7 @@ func TestLoadConfig(t *testing.T) {
 		{
 			id: component.NewIDWithName(metadata.Type, "1"),
 			expected: &Config{
+				AcceptEndpointProperties: true,
 				receiverTemplates: map[string]receiverTemplate{
 					"examplereceiver/1": {
 						receiverConfig: receiverConfig{
@@ -161,8 +162,19 @@ func TestInvalidReceiverResourceAttributeValueType(t *testing.T) {
 }
 
 type nopWithEndpointConfig struct {
-	Endpoint string `mapstructure:"endpoint"`
-	IntField int    `mapstructure:"int_field"`
+	Endpoint   string  `mapstructure:"endpoint"`
+	IntField   int     `mapstructure:"int_field"`
+	FloatField float64 `mapstructure:"float_field"`
+	Nested     nested  `mapstructure:"nested"`
+}
+
+type nested struct {
+	BoolField    bool         `mapstructure:"bool_field"`
+	DoublyNested doublyNested `mapstructure:"doubly_nested"`
+}
+
+type doublyNested struct {
+	MapField map[string]any `mapstructure:"map_field"`
 }
 
 type nopWithEndpointFactory struct {

receiver/receivercreator/factory.go

@@ -53,7 +53,8 @@ func createDefaultConfig() component.Config {
 				conventions.AttributeK8SNodeUID:  "`uid`",
 			},
 		},
-		receiverTemplates: map[string]receiverTemplate{},
+		receiverTemplates:        map[string]receiverTemplate{},
+		AcceptEndpointProperties: false,
 	}
 }
 

receiver/receivercreator/go.mod

@@ -3,6 +3,7 @@ module github.com/open-telemetry/opentelemetry-collector-contrib/receiver/receiv
 go 1.20
 
 require (
+	github.com/alecthomas/participle/v2 v2.0.0
 	github.com/antonmedv/expr v1.15.3
 	github.com/open-telemetry/opentelemetry-collector-contrib/extension/observer v0.86.1-0.20231006161201-d364ad61c4d7
 	github.com/open-telemetry/opentelemetry-collector-contrib/internal/sharedcomponent v0.86.1-0.20231006161201-d364ad61c4d7
@@ -19,6 +20,8 @@ require (
 	go.opentelemetry.io/collector/semconv v0.86.1-0.20231006161201-d364ad61c4d7
 	go.uber.org/multierr v1.11.0
 	go.uber.org/zap v1.26.0
+	gopkg.in/yaml.v3 v3.0.1
+	k8s.io/apimachinery v0.27.4
 )
 
 require (
@@ -97,7 +100,7 @@ require (
 	google.golang.org/grpc v1.58.2 // indirect
 	google.golang.org/protobuf v1.31.0 // indirect
 	gopkg.in/yaml.v2 v2.4.0 // indirect
-	gopkg.in/yaml.v3 v3.0.1 // indirect
+	k8s.io/utils v0.0.0-20230209194617-a36077c30491 // indirect
 )
 
 replace github.com/open-telemetry/opentelemetry-collector-contrib/extension/observer => ../../extension/observer