[com.influxdata.telegraf] Add OpenTelemetry Output plugin (#66)

packages/com.influxdata.telegraf/PklProject

@@ -22,5 +22,5 @@ dependencies {
 }
 
 package {
-  version = "1.1.1"
+  version = "1.2.0"
 }

packages/com.influxdata.telegraf/Telegraf.pkl

@@ -52,6 +52,7 @@ import "plugins/inputs/SolrInput.pkl"
 import "plugins/outputs/FileOutput.pkl"
 import "plugins/outputs/DiscardOutput.pkl"
 import "plugins/outputs/PrometheusClientOutput.pkl"
+import "plugins/outputs/OpenTelemetryOutput.pkl"
 import "plugins/processors/StarlarkProcessor.pkl"
 
 import "plugins/Plugin.pkl"
@@ -87,7 +88,13 @@ open class Outputs {
   /// It is only meant to be used for testing purposes.
   discard: Listing<DiscardOutput>?
 
+  /// This plugin starts a [Prometheus](https://prometheus.io) Client.
+  ///
+  /// Tt exposes all metrics on `/metrics` (default) to be polled by a Prometheus server.
   prometheus_client: Listing<PrometheusClientOutput>?
+
+  /// This plugin sends metrics to [OpenTelemetry](https://opentelemetry.io) servers and agents via gRPC.
+  opentelemetry: Listing<OpenTelemetryOutput>?
 }
 
 open class Inputs {

packages/com.influxdata.telegraf/examples/opentelemetry-output.pkl

@@ -0,0 +1,42 @@
+//===----------------------------------------------------------------------===//
+// Copyright © 2024 Apple Inc. and the Pkl project authors. All rights reserved.
+//
+// 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
+//
+//     https://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.
+//===----------------------------------------------------------------------===//
+amends "../Telegraf.pkl"
+
+outputs {
+  opentelemetry {
+    new {
+      service_address = "localhost:4312"
+      timeout = 10.s
+      tls_ca = "/path/to/ca/cert"
+      tls_cert = "/path/to/cert"
+      tls_key = "/path/to/key"
+      tls_server_name = "tls-server.com"
+      compression = "gzip"
+      coralogix {
+        application = "myapp"
+        private_key = "my secret value"
+        subsystem = "my subsystem"
+      }
+      attributes {
+        ["service.name"] = "foo"
+        ["service.version"] = "1.0.0"
+      }
+      headers {
+        ["x-api-key"] = "my-api-key"
+      }
+    }
+  }
+}

packages/com.influxdata.telegraf/plugins/outputs/OpenTelemetryOutput.pkl

@@ -0,0 +1,80 @@
+//===----------------------------------------------------------------------===//
+// Copyright © 2024 Apple Inc. and the Pkl project authors. All rights reserved.
+//
+// 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
+//
+//     https://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.
+//===----------------------------------------------------------------------===//
+/// Sends metrics to [OpenTelemetry](https://opentelemetry.io) servers and agents via gRPC.
+///
+/// <https://github.com/influxdata/telegraf/tree/master/plugins/outputs/opentelemetry>
+@ModuleInfo { minPklVersion = "0.24.0" }
+open module com.influxdata.telegraf.plugins.outputs.OpenTelemetryOutput
+
+extends "Output.pkl"
+
+/// The endpoint to which the metrics will be sent.
+///
+/// Default: `"localhost:4317"`
+service_address: String?
+
+/// The timeout for the connection.
+///
+/// Default: `5.s`
+timeout: Duration?
+
+/// Optional TLS Config.
+/// All variables should specify full path to the file.
+/// Root certificates for verifying server certificates encoded in PEM format.
+tls_ca: String?
+
+/// Path to the TLS certificate for the client encoded in PEM format.
+/// May contain intermediate certificates.
+tls_cert: String?
+
+/// Path to the TLS private key for the client encoded in PEM format.
+tls_key: String?
+
+/// Send the specified TLS server name via SNI.
+tls_server_name: String?
+
+/// Insecure option to skip TLS server cert verification.
+///
+/// Warning: it is insecure to enable this option.
+/// If enabled, crypto/tls accepts any certificate presented by the server and any host name in that certificate.
+///
+/// Default: `false`
+insecure_skip_verify: Boolean?
+
+/// Send data to a [Coralogix](https://coralogix.com) server.
+coralogix: Coralogix?
+
+/// Set the compression method used to send data.
+///
+/// Default: `"none"`
+compression: ("none"|"gzip")?
+
+/// Additional OpenTelemetry resource attributes
+attributes: Mapping<String,String>?
+
+/// Additional gRPC request metadata headers
+headers: Mapping<String,String>?
+
+class Coralogix {
+  /// The private key, which can be found in Settings > Send Your Data.
+  private_key: String
+
+  /// The application name, which will be added to metric attributes.
+  application: String
+
+  /// The subsystem name, which will be added to metric attributes.
+  subsystem: String
+}

packages/com.influxdata.telegraf/tests/Telegraf.pkl-expected.pcf

@@ -1,4 +1,28 @@
 examples {
+  ["opentelemetry-output.toml"] {
+    """
+    [[outputs.opentelemetry]]
+    service_address = "localhost:4312"
+    timeout = "10s"
+    tls_ca = "/path/to/ca/cert"
+    tls_cert = "/path/to/cert"
+    tls_key = "/path/to/key"
+    tls_server_name = "tls-server.com"
+    compression = "gzip"
+
+    [outputs.opentelemetry.coralogix]
+    private_key = "my secret value"
+    application = "myapp"
+    subsystem = "my subsystem"
+
+    [outputs.opentelemetry.attributes]
+    "service.name" = "foo"
+    "service.version" = "1.0.0"
+
+    [outputs.opentelemetry.headers]
+    x-api-key = "my-api-key"
+    """
+  }
   ["simple.toml"] {
     """
     [[outputs.file]]