Simplify otel-collector example

CHANGELOG.md

@@ -27,6 +27,7 @@ This project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.htm
 - `traceIDRatioSampler` (given by `TraceIDRatioBased(float64)`) now uses the rightmost bits for sampling decisions,
   fixing random sampling when using ID generators like `xray.IDGenerator`
   and increasing parity with other language implementations. (#3557)
+- Update example of `otel-collector`: simplify setup by using `docker-compose` and add metric exporter (#3560)
 
 ### Deprecated
 

example/otel-collector/Dockerfile

@@ -0,0 +1,13 @@
+FROM golang:1.18-alpine AS base
+
+COPY . /src
+
+WORKDIR /src/example/otel-collector
+
+RUN go build -o main .
+
+FROM alpine:latest
+
+COPY --from=base /src/example/otel-collector/main /app/main
+
+CMD ["/app/main"]

example/otel-collector/README.md

@@ -1,4 +1,4 @@
-# OpenTelemetry Collector Traces Example
+# OpenTelemetry Collector Traces, Metrics Example
 
 This example illustrates how to export trace and metric data from the
 OpenTelemetry-Go SDK to the OpenTelemetry Collector. From there, we bring the
@@ -13,116 +13,32 @@ App + SDK ---> OpenTelemetry Collector ---|
 
 # Prerequisites
 
-You will need access to a Kubernetes cluster for this demo. We use a local
-instance of [microk8s](https://microk8s.io/), but please feel free to pick
-your favorite. If you do decide to use microk8s, please ensure that dns
-and storage addons are enabled
+You need docker and docker-compose to run this example. If you don't have docker
+installed, you can follow the instructions [here](https://docs.docker.com/get-docker/).
 
-```bash
-microk8s enable dns storage
-```
-
-For simplicity, the demo application is not part of the k8s cluster, and will
-access the OpenTelemetry Collector through a NodePort on the cluster. Note that
-the NodePort opened by this demo is not secured.
-
-Ideally you'd want to either have your application running as part of the
-kubernetes cluster, or use a secured connection (NodePort/LoadBalancer with TLS
-or an ingress extension).
-
-If not using microk8s, ensure that cert-manager is installed by following [the
-instructions here](https://cert-manager.io/docs/installation/).
-
-# Deploying to Kubernetes
-
-All the necessary Kubernetes deployment files are available in this demo, in the
-[k8s](./k8s) folder. For your convenience, we assembled a [makefile](./Makefile)
-with deployment commands (see below). For those with subtly different systems,
-you are, of course, welcome to poke inside the Makefile and run the commands
-manually. If you use microk8s and alias `microk8s kubectl` to `kubectl`, the
-Makefile will not recognize the alias, and so the commands will have to be run
-manually.
-
-## Setting up the Prometheus operator
-
-If you're using microk8s like us, simply do
-
-```bash
-microk8s enable prometheus
-```
-
-and you're good to go. Move on to [Using the makefile](#using-the-makefile).
-
-Otherwise, obtain a copy of the Prometheus Operator stack from
-[prometheus-operator](https://github.com/prometheus-operator/kube-prometheus):
-
-```bash
-git clone https://github.com/prometheus-operator/kube-prometheus.git
-cd kube-prometheus
-kubectl create -f manifests/setup
-
-# wait for namespaces and CRDs to become available, then
-kubectl create -f manifests/
-```
-
-And to tear down the stack when you're finished:
-
-```bash
-kubectl delete --ignore-not-found=true -f manifests/ -f manifests/setup
-```
-
-## Using the makefile
-
-Next, we can deploy our Jaeger instance, Prometheus monitor, and Collector
-using the [makefile](./Makefile).
-
-```bash
-# Create the namespace
-make namespace-k8s
-
-# Deploy Jaeger operator
-make jaeger-operator-k8s
-
-# After the operator is deployed, create the Jaeger instance
-make jaeger-k8s
-
-# Then the Prometheus instance. Ensure you have enabled a Prometheus operator
-# before executing (see above).
-make prometheus-k8s
-
-# Finally, deploy the OpenTelemetry Collector
-make otel-collector-k8s
-```
-
-If you want to clean up after this, you can use the `make clean-k8s` to delete
-all the resources created above. Note that this will not remove the namespace.
-Because Kubernetes sometimes gets stuck when removing namespaces, please remove
-this namespace manually after all the resources inside have been deleted,
-for example with
+# Running the example
 
 ```bash
-kubectl delete namespaces observability
+docker-compose up -d
 ```
 
 # Configuring the OpenTelemetry Collector
 
 Although the above steps should deploy and configure everything, let's spend
-some time on the [configuration](./k8s/otel-collector.yaml) of the Collector.
+some time on the [configuration](./otel-collector-config.yaml) of the Collector.
 
 One important part here is that, in order to enable our application to send data
 to the OpenTelemetry Collector, we need to first configure the `otlp` receiver:
 
 ```yml
 ...
-  otel-collector-config: |
-    receivers:
-      # Make sure to add the otlp receiver.
-      # This will open up the receiver on port 4317.
-      otlp:
-        protocols:
-          grpc:
-            endpoint: "0.0.0.0:4317"
-    processors:
+receivers:
+  # Make sure to add the otlp receiver.
+  # This will open up the receiver on port 4317
+  otlp:
+    protocols:
+      grpc:
+        endpoint: "0.0.0.0:4317"
 ...
 ```
 
@@ -134,98 +50,28 @@ need to create the Jaeger and Prometheus exporters:
 
 ```yml
 ...
-    exporters:
-      jaeger:
-        endpoint: "jaeger-collector.observability.svc.cluster.local:14250"
-
-      prometheus:
-           endpoint: 0.0.0.0:8889
-           namespace: "testapp"
+exporters:
+  jaeger:
+    endpoint: "jaeger:14250"
+    tls:
+      insecure: true
+  prometheus:
+    endpoint: 0.0.0.0:8889
 ...
 ```
 
-## OpenTelemetry Collector service
-
-One more aspect in the OpenTelemetry Collector [configuration](./k8s/otel-collector.yaml) worth looking at is the NodePort service used for accessing it:
-
-```yaml
-apiVersion: v1
-kind: Service
-metadata:
-        ...
-spec:
-  ports:
-  - name: otlp # Default endpoint for otlp receiver.
-    port: 4317
-    protocol: TCP
-    targetPort: 4317
-    nodePort: 30080
-  - name: metrics # Endpoint for metrics from our app.
-    port: 8889
-    protocol: TCP
-    targetPort: 8889
-  selector:
-    component: otel-collector
-  type:
-    NodePort
-```
-
-This service will bind the `4317` port used to access the otlp receiver to port `30080` on your cluster's node. By doing so, it makes it possible for us to access the Collector by using the static address `<node-ip>:30080`. In case you are running a local cluster, this will be `localhost:30080`. Note that you can also change this to a LoadBalancer or have an ingress extension for accessing the service.
-
-# Running the code
-
-You can find the complete code for this example in the [main.go](./main.go)
-file. To run it, ensure you have a somewhat recent version of Go (preferably >=
-1.13) and do
-
-```bash
-go run main.go
-```
-
-The example simulates an application, hard at work, computing for ten seconds
-then finishing.
-
 # Viewing instrumentation data
 
 Now the exciting part! Let's check out the telemetry data generated by our
 sample application
 
 ## Jaeger UI
 
-First, we need to enable an ingress provider. If you've been using microk8s,
-do
-
-```bash
-microk8s enable ingress
-```
-
-Then find out where the Jaeger console is living:
-
-```bash
-kubectl get ingress --all-namespaces
-```
-
-For us, we get the output
-
-```
-NAMESPACE       NAME           CLASS    HOSTS   ADDRESS     PORTS   AGE
-observability   jaeger-query   <none>   *       127.0.0.1   80      5h40m
-```
-
-indicating that the Jaeger UI is available at
-[http://localhost:80](http://localhost:80). Navigate there in your favorite
+Jaeger UI is available at
+[http://localhost:16686](http://localhost:16686). Navigate there in your favorite
 web-browser to view the generated traces.
 
 ## Prometheus
 
-Unfortunately, the Prometheus operator doesn't provide a convenient
-out-of-the-box ingress route for us to use, so we'll use port-forwarding
-instead. Note: this is a quick-and-dirty solution for the sake of example.
-You *will* be attacked by shady people if you do this in production!
-
-```bash
-kubectl --namespace monitoring port-forward svc/prometheus-k8s 9090
-```
-
-Then navigate to [http://localhost:9090](http://localhost:9090) to view
+Navigate to [http://localhost:9090](http://localhost:9090) to view
 the Prometheus dashboard.

example/otel-collector/docker-compose.yaml

@@ -0,0 +1,42 @@
+version: "3.7"
+networks:
+  otel-collector-example:
+    name: otel-collector-example
+
+services:
+  go-app:
+    build:
+      context: ../..
+      dockerfile: $PWD/Dockerfile
+    networks:
+      - otel-collector-example
+  otel-collector:
+    image: otel/opentelemetry-collector:latest
+    networks:
+      - otel-collector-example
+    volumes:
+      - ./otel-collector-config.yaml:/etc/otel-collector-config.yaml
+    command: ["--config=/etc/otel-collector-config.yaml"]
+    expose:
+      - 4317 # Default endpoint for otlp receiver
+      - 8889 # Default endpoint for querying metrics
+  jaeger:
+    image: jaegertracing/all-in-one:latest
+    networks:
+      - otel-collector-example
+    expose:
+      - 14250 # Default endpoint for jaeger receiver
+      - 16686 # Default endpoint for jaeger query
+    ports:
+      - 16686:16686
+  prometheus: 
+    image: quay.io/prometheus/prometheus:latest
+    networks:
+      - otel-collector-example
+    volumes:
+      - ./prometheus-config.yaml:/etc/prometheus/prometheus.yml
+    expose:
+      - 9090 # Default endpoint for prometheus
+    ports:
+      - 9090:9090
+    command: ["--config.file=/etc/prometheus/prometheus.yml"]

example/otel-collector/go.mod

@@ -9,8 +9,11 @@ replace (
 
 require (
 	go.opentelemetry.io/otel v1.11.2
+	go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetricgrpc v0.34.0
 	go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracegrpc v1.11.2
+	go.opentelemetry.io/otel/metric v0.34.0
 	go.opentelemetry.io/otel/sdk v1.11.2
+	go.opentelemetry.io/otel/sdk/metric v0.34.0
 	go.opentelemetry.io/otel/trace v1.11.2
 	google.golang.org/grpc v1.51.0
 )
@@ -22,6 +25,7 @@ require (
 	github.com/golang/protobuf v1.5.2 // indirect
 	github.com/grpc-ecosystem/grpc-gateway/v2 v2.7.0 // indirect
 	go.opentelemetry.io/otel/exporters/otlp/internal/retry v1.11.2 // indirect
+	go.opentelemetry.io/otel/exporters/otlp/otlpmetric v0.34.0 // indirect
 	go.opentelemetry.io/otel/exporters/otlp/otlptrace v1.11.2 // indirect
 	go.opentelemetry.io/proto/otlp v0.19.0 // indirect
 	golang.org/x/net v0.0.0-20220722155237-a158d28d115b // indirect
@@ -38,3 +42,11 @@ replace go.opentelemetry.io/otel/exporters/otlp/otlptrace => ../../exporters/otl
 replace go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracegrpc => ../../exporters/otlp/otlptrace/otlptracegrpc
 
 replace go.opentelemetry.io/otel/exporters/otlp/internal/retry => ../../exporters/otlp/internal/retry
+
+replace go.opentelemetry.io/otel/metric => ../../metric
+
+replace go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetricgrpc => ../../exporters/otlp/otlpmetric/otlpmetricgrpc
+
+replace go.opentelemetry.io/otel/exporters/otlp/otlpmetric => ../../exporters/otlp/otlpmetric
+
+replace go.opentelemetry.io/otel/sdk/metric => ../../sdk/metric