Merge pull request #26 from openmeterio/generate-example

feat(examples): add generate example

examples/README.md

@@ -5,6 +5,7 @@ The following examples demonstrate how to ingest events from various sources int
 The examples use the custom Benthos distribution in this repository.
 
 - [Database](database/)
+- [Generate](generate/) random events
 - [HTTP server](http-server/) (forwarding events to OpenMeter)
 - [Kubernetes Pod execution time](kubernetes-pod-exec-time/)
 

examples/generate/README.md

@@ -0,0 +1,75 @@
+# Generate
+
+This example is based on [our earlier blog post](https://openmeter.io/blog/testing-stream-processing) about testing OpenMeter with Benthos.
+
+The input in this case generates random events (mimicking API calls).
+
+## Table of Contents <!-- omit from toc -->
+
+- [Prerequisites](#prerequisites)
+- [Launch the example](#launch-the-example)
+- [Checking events](#checking-events)
+- [Advanced configuration](#advanced-configuration)
+- [Production use](#production-use)
+
+## Prerequisites
+
+Go to the [GitHub Releases](https://github.com/openmeterio/benthos-openmeter/releases/latest) page and download the latest `benthos` binary for your platform.
+
+Check out this repository if you want to run the example locally:
+
+```shell
+git clone https://github.com/openmeterio/benthos-openmeter.git
+cd benthos-openmeter/examples/generate
+```
+
+Create a new `.env` file and add the details of your OpenMeter instance:
+
+```shell
+cp .env.dist .env
+# edit .env and fill in the details
+```
+
+> [!TIP]
+> Tweak other options in the `.env` file to change the behavior of the example.
+
+Create a meter in OpenMeter with the following details:
+
+- Event type: `api-calls`
+- Aggregation: `SUM`
+- Value property: `$.duration_ms`
+- Group by (optional):
+  - `method`: `$.method`
+  - `path`: `$.path`
+  - `region`: `$.region`
+  - `zone`: `$.zone`
+
+> [!TIP]
+> Read more about creating a meter in the general examples [README](../README.md#Create-a-meter).
+
+## Launch the example
+
+Launch the example:
+
+```shell
+export OPENMETER_TOKEN=<YOUR TOKEN>
+benthos -c config.yaml
+```
+
+> [!WARNING]
+> By default the example generates 1000 events per second.
+
+## Checking events
+
+Read more in the general examples [README](../README.md#Checking-events-in-OpenMeter).
+
+## Advanced configuration
+
+Check out the configuration files and the [Benthos documentation](https://www.benthos.dev/docs/about) for more details.
+
+## Production use
+
+We are actively working on improving the documentation and the examples.
+In the meantime, feel free to contact us [in email](https://us10.list-manage.com/contact-form?u=c7d6a96403a0e5e19032ee885&form_id=fe04a7fc4851f8547cfee56763850e95) or [on Discord](https://discord.gg/nYH3ZQ3Xzq).
+
+We are more than happy to help you set up OpenMeter in your production environment.

examples/generate/config.yaml

@@ -0,0 +1,57 @@
+input:
+  generate:
+    count: ${SEEDER_COUNT:0}
+    interval: "${SEEDER_INTERVAL:1s}"
+    batch_size: ${SEEDER_BATCH_SIZE:1}
+    mapping: |
+      let max_subjects = ${SEEDER_MAX_SUBJECTS:100}
+
+      let event_type = "api-calls"
+      let source = "api-gateway"
+      let methods = ["GET", "POST"]
+      let paths = ["/", "/about", "/contact", "/pricing", "/docs"]
+      let regions = ["us-east-1", "us-west-1", "us-east-2", "us-west-2"]
+      let zoneSuffixes = ["a", "b", "c", "d"]
+
+      let subject = "customer-%d".format(random_int(seed: timestamp_unix_nano()) % $max_subjects)
+      let time = (now().ts_sub_iso8601("P3D").ts_unix() + random_int(min: 60, max: 60 * 60 * 24 * 3)).ts_format()
+
+      let method = $methods.index(random_int(seed: timestamp_unix_nano()) % $methods.length())
+      let path = $paths.index(random_int(seed: timestamp_unix_nano()) % $paths.length())
+      let region = $regions.index(random_int(seed: timestamp_unix_nano()) % $regions.length())
+      let zone = "%s%s".format($region, $zoneSuffixes.index(random_int(seed: timestamp_unix_nano()) % $zoneSuffixes.length()))
+      let duration = random_int(seed: timestamp_unix_nano(), max: 1000)
+
+      root = {
+        "id": uuid_v4(),
+        "specversion": "1.0",
+        "type": $event_type,
+        "source": $source,
+        "subject": $subject,
+        "time": $time,
+        "data": {
+          "method": $method,
+          "path": $path,
+          "region": $region,
+          "zone": $zone,
+          "duration_ms": $duration,
+        },
+      }
+
+output:
+  switch:
+    cases:
+      - check: ""
+        continue: true
+        output:
+          openmeter:
+            url: "${OPENMETER_URL:https://openmeter.cloud}"
+            token: "${OPENMETER_TOKEN:}"
+            batching:
+              count: ${BATCH_SIZE:20}
+              period: ${BATCH_PERIOD:}
+
+      - check: '"${SEEDER_LOG:false}" == "true"'
+        output:
+          stdout:
+            codec: lines