Add discoverybundler, initial embedded bundle.d, and enabled properties

Makefile

@@ -149,6 +149,10 @@ migratecheckpoint:
 	GO111MODULE=on CGO_ENABLED=0 go build -trimpath -o ./bin/migratecheckpoint_$(GOOS)_$(GOARCH)$(EXTENSION) $(BUILD_INFO) ./cmd/migratecheckpoint
 	ln -sf migratecheckpoint_$(GOOS)_$(GOARCH)$(EXTENSION) ./bin/migratecheckpoint
 
+.PHONY: bundle.d
+bundle.d:
+	go generate -tags bundle.d ./...
+
 .PHONY: add-tag
 add-tag:
 	@[ "${TAG}" ] || ( echo ">> env var TAG is not set"; exit 1 )

go.mod

@@ -469,7 +469,7 @@ require (
 	gopkg.in/natefinch/lumberjack.v2 v2.0.0 // indirect
 	gopkg.in/square/go-jose.v2 v2.6.0 // indirect
 	gopkg.in/tomb.v1 v1.0.0-20141024135613-dd632973f1e7 // indirect
-	gopkg.in/yaml.v3 v3.0.1 // indirect
+	gopkg.in/yaml.v3 v3.0.1
 	k8s.io/api v0.26.1 // indirect
 	k8s.io/apimachinery v0.26.1 // indirect
 	k8s.io/client-go v0.26.1 // indirect

internal/confmapprovider/discovery/README.md

@@ -16,7 +16,7 @@ graph LR
     2 --> 2a1>otlp.yaml]
     2a1 --> 2b1[[otlp:<br>endpoint: 1.2.3.4:2345]]
     2 --> 2a2>logging.yaml]
-    2a2 --> 2b2[[logging:<br>loglevel: debug]]
+    2a2 --> 2b2[[logging:<br>verbosity: detailed]]
   end
   config.d --> 3[/extensions/]
   subgraph 3a[extensions]
@@ -35,17 +35,70 @@ graph LR
   config.d --> 5[/receivers/]
   subgraph 5a[receivers]
     5 --> 5a1>otlp.yaml]
-    5a1 --> 5b1[[otlp:<br>protocols:<br>grpc]]
+    5a1 --> 5b1[[otlp:<br>protocols:<br>grpc:]]
   end
 ```
 
-This component is currently exposed in the Collector via the `--configd` option with corresponding
-`--config-dir <config.d path>` and `SPLUNK_CONFIG_DIR` option and environment variable to load
-additional components and service configuration from the specified `config.d` directory (`/etc/otel/collector/config.d`
-by default).
+This component is currently supported in the Collector settings via the following commandline options:
 
-This component is also exposed in the Collector via the `--discovery [--dry-run]` option that also uses the
-`--config-dir <config.d path>` and `SPLUNK_CONFIG_DIR` option and environment variable that attempts to
-instantiate any `.discovery.yaml` receivers using corresponding `.discovery.yaml` observers in a "preflight"
-Collector service, using any successfully discovered entities in the final config, or writing it to stdout
-if `--dry-run` was specified.
+| option         | environment variable | default                        | description                                                                                                                             |
+|----------------|----------------------|--------------------------------|-----------------------------------------------------------------------------------------------------------------------------------------|
+| `--configd`    | none                 | disabled                       | Whether to enable `config.d` functionality for final Collector config content.                                                          |
+| `--config-dir` | `SPLUNK_CONFIG_DIR`  | `/etc/otel/collector/config.d` | The root `config.d` directory to walk for component directories and yaml mapping files.                                                 |
+| `--dry-run`    | none                 | disabled                       | Whether to report the final assembled config contents to stdout before immediately exiting. This can be used with or without `config.d` |
+
+To source only `config.d` content and not an additional or default configuration file, the `--config` option or
+`SPLUNK_CONFIG` environment variable must be set to `/dev/null` or an arbitrary empty file:
+
+```bash
+$ # run the Collector without a config file using components from a local ./config.d config directory,
+$ # printing the config to stdout before exiting instead of starting the Collector service:
+$ bin/otelcol --config /dev/null --configd --config-dir ./config.d --dry-run
+2023/02/24 19:54:23 settings.go:331: Set config to [/dev/null]
+2023/02/24 19:54:23 settings.go:384: Set ballast to 168 MiB
+2023/02/24 19:54:23 settings.go:400: Set memory limit to 460 MiB
+exporters:
+  logging:
+    verbosity: detailed
+  otlp:
+    endpoint: 1.2.3.4:2345
+extensions:
+  health_check:
+    path: /health
+  zpages:
+    endpoint: 0.0.0.0:1234
+processors:
+  batch: {}
+  resourcedetection:
+    detectors:
+    - system
+receivers:
+  otlp:
+    protocols:
+      grpc: null
+service:
+  pipelines:
+    metrics:
+      exporters:
+      - logging
+      receivers:
+      - otlp
+```
+
+## Discovery Mode
+
+This component also provides a `--discovery [--dry-run]` option compatible with `config.d` that attempts to instantiate
+any `.discovery.yaml` receivers using corresponding `.discovery.yaml` observers in a "preflight" Collector service.
+Discovery mode will:
+
+1. Load and attempt to start any observers in `config.d/extensions/<name>.discovery.yaml`.
+1. Load and attempt to start any receiver blocks in `config.d/receivers/<name>.discovery.yaml` in a
+[Discovery Receiver](../../receiver/discoveryreceiver/README.md) instance to receive discovery events from all
+successfully started observers.
+1. Wait 10s or the configured `SPLUNK_DISCOVERY_DURATION` environment variable [`time.Duration`](https://pkg.go.dev/time#ParseDuration).
+1. Embed any receiver instances' configs resulting in a `discovery.status` of `successful` inside a `receiver_creator/discovery` receiver's configuration to be passed to the final Collector service config (or outputted w/ `--dry-run`).
+1. Log any receiver resulting in a `discovery.status` of `partial` with the configured guidance for setting any relevant discovery properties.
+1. Stop all temporary components before continuing on to the actual Collector service (or exiting early with `--dry-run`).
+
+
+By default, the Discovery mode is provided with pre-made discovery config components in [`bundle.d`](./bundle/README.md).

internal/confmapprovider/discovery/bundle/README.md

@@ -0,0 +1,72 @@
+## bundle.d
+
+`bundle.d` refers to the [`embed.FS`](https://pkg.go.dev/embed#hdr-File_Systems) config directory made available by the
+[`bundle.BundledFS`](./bundle.go). It currently consists of all `./bundle.d/extensions/*.discovery.yaml` and
+`./bundle.d/receivers/*.discovery.yaml` files that are generated by the `discoverybundler` cmd as used by `go:generate`
+directives in [bundle_gen.go](./bundle_gen.go).
+
+To construct the latest bundle.d contents before building the collector run:
+
+```bash
+$ make bundle.d
+```
+
+### *.discovery.yaml.tmpl
+
+All discovery config component discovery.yaml files are generated from [`text/template`](https://pkg.go.dev/text/template)
+`discovery.yaml.tmpl` files using built-in validators and property guidance helpers:
+
+Example `redis.discovery.yaml.tmpl`:
+
+```yaml
+{{ receiver "redis" }}:
+  rule:
+    docker_observer: type == "container" and port == 6379
+    <...>
+  status:
+    <...>
+    statements:
+      partial:
+        - regexp: 'ERR AUTH.*'
+          first_only: true
+          log_record:
+            severity_text: info
+            body: >-
+              Please ensure your redis password is correctly specified with
+              `--set {{ configProperty "password" "<password>" }}` or
+              `{{ configPropertyEnvVar "password" "<username>" }}` environment variable.
+```
+
+After adding the required generate directive to `bundle_gen.go` and running `make bundle.d`:
+
+```go
+//go:generate discoverybundler -r -t bundle.d/receivers/redis.discovery.yaml.tmpl
+```
+
+There is now a corresponding `bundle.d/receiver/redis.discovery.yaml`:
+
+```yaml
+#####################################################################################
+# This file is generated by the Splunk Distribution of the OpenTelemetry Collector. #
+#####################################################################################
+redis:
+  rule:
+    docker_observer: type == "container" and port == 6379
+  <...>
+  status:
+  <...>
+    statements:
+      partial:
+        - regexp: 'ERR AUTH.*'
+          first_only: true
+          log_record:
+            severity_text: info
+            body: >-
+              Please ensure your redis password is correctly specified with
+              `--set splunk.discovery.receivers.redis.config.password="<password>"` or
+              `SPLUNK_DISCOVERY_RECEIVERS_redis_CONFIG_password="<username>"` environment variable.
+```
+
+When building the collector afterward, this redis receiver discovery config is now made available to discovery mode, and
+it can be disabled by `--set splunk.discovery.receivers.redis.enabled=false` or
+`SPLUNK_DISCOVERY_RECEIVERS_redis_ENABLED=false`.

internal/confmapprovider/discovery/bundle/bundle.d/extensions/docker-observer.discovery.yaml

@@ -0,0 +1,4 @@
+#####################################################################################
+# This file is generated by the Splunk Distribution of the OpenTelemetry Collector. #
+#####################################################################################
+docker_observer:

internal/confmapprovider/discovery/bundle/bundle.d/extensions/docker-observer.discovery.yaml.tmpl

@@ -0,0 +1 @@
+{{ extension "docker_observer" }}:

internal/confmapprovider/discovery/bundle/bundle.d/extensions/host-observer.discovery.yaml

@@ -0,0 +1,4 @@
+#####################################################################################
+# This file is generated by the Splunk Distribution of the OpenTelemetry Collector. #
+#####################################################################################
+host_observer:

internal/confmapprovider/discovery/bundle/bundle.d/extensions/host-observer.discovery.yaml.tmpl

@@ -0,0 +1 @@
+{{ extension "host_observer" }}:

internal/confmapprovider/discovery/bundle/bundle.d/extensions/k8s-observer.discovery.yaml

@@ -0,0 +1,5 @@
+#####################################################################################
+# This file is generated by the Splunk Distribution of the OpenTelemetry Collector. #
+#####################################################################################
+k8s_observer:
+  auth_type: serviceAccount

internal/confmapprovider/discovery/bundle/bundle.d/extensions/k8s-observer.discovery.yaml.tmpl

@@ -0,0 +1,2 @@
+{{ extension "k8s_observer" }}:
+  auth_type: serviceAccount

internal/confmapprovider/discovery/bundle/bundle.d/receivers/smartagent-postgresql.discovery.yaml

@@ -0,0 +1,49 @@
+#####################################################################################
+# This file is generated by the Splunk Distribution of the OpenTelemetry Collector. #
+#####################################################################################
+smartagent/postgresql:
+  rule:
+    docker_observer: type == "container" and port == 5432
+    host_observer: type == "hostport" and command contains "pg" and port == 5432
+  config:
+    default:
+      type: postgresql
+      connectionString: 'sslmode=disable user={{.username}} password={{.password}}'
+      params:
+        username: bundle.default
+        password: bundle.default
+      masterDBName: postgres
+  status:
+    metrics:
+      successful:
+        - strict: postgres_block_hit_ratio
+          first_only: true
+          log_record:
+            severity_text: info
+            body: postgresql SA receiver working!
+    statements:
+      failed:
+        - regexp: '.* connect: connection refused'
+          first_only: true
+          log_record:
+            severity_text: info
+            body: container appears to not be accepting postgres connections
+      partial:
+        - regexp: '.*pq: password authentication failed for user.*'
+          first_only: true
+          log_record:
+            severity_text: info
+            body: >-
+              Please ensure your user credentials are correctly specified with
+              `--set splunk.discovery.receivers.smartagent/postgresql.config.params::username="<username>"` and
+              `--set splunk.discovery.receivers.smartagent/postgresql.config.params::password="<password>"` or
+              `SPLUNK_DISCOVERY_RECEIVERS_smartagent_x2f_postgresql_CONFIG_params_x3a__x3a_username="<username>"` and
+              `SPLUNK_DISCOVERY_RECEIVERS_smartagent_x2f_postgresql_CONFIG_params_x3a__x3a_password="<password>"` environment variables.
+        - regexp: '.*pq: database ".*" does not exist.*'
+          first_only: true
+          log_record:
+            severity_text: info
+            body: >-
+              Please ensure your target database is correctly specified with
+              `--set splunk.discovery.receivers.smartagent/postgresql.config.masterDBName="<db>"` or
+              `SPLUNK_DISCOVERY_RECEIVERS_smartagent_x2f_postgresql_CONFIG_masterDBName="<db>"` environment variable.

internal/confmapprovider/discovery/bundle/bundle.d/receivers/smartagent-postgresql.discovery.yaml.tmpl

@@ -0,0 +1,46 @@
+{{ receiver "smartagent/postgresql" }}:
+  rule:
+    docker_observer: type == "container" and port == 5432
+    host_observer: type == "hostport" and command contains "pg" and port == 5432
+  config:
+    default:
+      type: postgresql
+      connectionString: 'sslmode=disable user={{ "{{.username}}" }} password={{ "{{.password}}" }}'
+      params:
+        username: bundle.default
+        password: bundle.default
+      masterDBName: postgres
+  status:
+    metrics:
+      successful:
+        - strict: postgres_block_hit_ratio
+          first_only: true
+          log_record:
+            severity_text: info
+            body: postgresql SA receiver working!
+    statements:
+      failed:
+        - regexp: '.* connect: connection refused'
+          first_only: true
+          log_record:
+            severity_text: info
+            body: container appears to not be accepting postgres connections
+      partial:
+        - regexp: '.*pq: password authentication failed for user.*'
+          first_only: true
+          log_record:
+            severity_text: info
+            body: >-
+              Please ensure your user credentials are correctly specified with
+              `--set {{ configProperty "params" "username" "<username>" }}` and
+              `--set {{ configProperty "params" "password" "<password>" }}` or
+              `{{ configPropertyEnvVar "params" "username" "<username>" }}` and
+              `{{ configPropertyEnvVar "params" "password" "<password>" }}` environment variables.
+        - regexp: '.*pq: database ".*" does not exist.*'
+          first_only: true
+          log_record:
+            severity_text: info
+            body: >-
+              Please ensure your target database is correctly specified with
+              `--set {{ configProperty "masterDBName" "<db>" }}` or
+              `{{ configPropertyEnvVar "masterDBName" "<db>" }}` environment variable.

internal/confmapprovider/discovery/bundle/bundle.go

@@ -0,0 +1,29 @@
+// Copyright  Splunk, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package bundle
+
+import (
+	"embed"
+)
+
+// BundledFS is the in-executable filesystem that contains all bundled discovery config.d components.
+//
+// If you are bootstrapping bundle_gen.go or the `discoverybundler` cmd without any rendered files in bundle.d,
+// comment out the below embed directives before installing to prevent "no matching files found"
+// build errors.
+//
+//go:embed bundle.d/extensions/*.discovery.yaml
+//go:embed bundle.d/receivers/*.discovery.yaml
+var BundledFS embed.FS

internal/confmapprovider/discovery/bundle/bundle_gen.go

@@ -0,0 +1,27 @@
+// Copyright  Splunk, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+//go:build bundle.d
+
+// These are the discovery config component generating statements.
+// In order to update run go generate -tags bundle.d ./...
+//go:generate go install github.com/signalfx/splunk-otel-collector/internal/confmapprovider/discovery/bundle/cmd/discoverybundler
+
+//go:generate discoverybundler -r -t bundle.d/receivers/smartagent-postgresql.discovery.yaml.tmpl
+
+//go:generate discoverybundler -r -t bundle.d/extensions/docker-observer.discovery.yaml.tmpl
+//go:generate discoverybundler -r -t bundle.d/extensions/host-observer.discovery.yaml.tmpl
+//go:generate discoverybundler -r -t bundle.d/extensions/k8s-observer.discovery.yaml.tmpl
+
+package bundle