项目作者: open-telemetry

项目描述 :
Kubernetes Operator for OpenTelemetry Collector
高级语言: Go
项目地址: git://github.com/open-telemetry/opentelemetry-operator.git
创建时间: 2019-12-18T21:39:22Z
项目社区:https://github.com/open-telemetry/opentelemetry-operator

开源协议:Apache License 2.0

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Continuous Integration Go Report Card GoDoc

OpenTelemetry Operator for Kubernetes

The OpenTelemetry Operator is an implementation of a Kubernetes Operator.

The operator manages:

Documentation

Helm Charts

You can install Opentelemetry Operator via Helm Chart from the opentelemetry-helm-charts repository. More information is available in here.

Getting started

To install the operator in an existing cluster, make sure you have cert-manager installed and run:

  1. kubectl apply -f https://github.com/open-telemetry/opentelemetry-operator/releases/latest/download/opentelemetry-operator.yaml

Once the opentelemetry-operator deployment is ready, create an OpenTelemetry Collector (otelcol) instance, like:

  1. kubectl apply -f - <<EOF
  2. apiVersion: opentelemetry.io/v1beta1
  3. kind: OpenTelemetryCollector
  4. metadata:
  5. name: simplest
  6. spec:
  7. config:
  8. receivers:
  9. otlp:
  10. protocols:
  11. grpc:
  12. endpoint: 0.0.0.0:4317
  13. http:
  14. endpoint: 0.0.0.0:4318
  15. processors:
  16. memory_limiter:
  17. check_interval: 1s
  18. limit_percentage: 75
  19. spike_limit_percentage: 15
  20. batch:
  21. send_batch_size: 10000
  22. timeout: 10s
  23. exporters:
  24. debug: {}
  25. service:
  26. pipelines:
  27. traces:
  28. receivers: [otlp]
  29. processors: [memory_limiter, batch]
  30. exporters: [debug]
  31. EOF

WARNING: Until the OpenTelemetry Collector format is stable, changes may be required in the above example to remain
compatible with the latest version of the OpenTelemetry Collector image being referenced.

This will create an OpenTelemetry Collector instance named simplest, exposing a jaeger-grpc port to consume spans from your instrumented applications and exporting those spans via debug, which writes the spans to the console (stdout) of the OpenTelemetry Collector instance that receives the span.

The config node holds the YAML that should be passed down as-is to the underlying OpenTelemetry Collector instances. Refer to the OpenTelemetry Collector documentation for a reference of the possible entries.

🚨 NOTE: At this point, the Operator does not validate the whole contents of the configuration file: if the configuration is invalid, the instance might still be created but the underlying OpenTelemetry Collector might crash.

🚨 Note: For private GKE clusters, you will need to either add a firewall rule that allows master nodes access to port 9443/tcp on worker nodes, or change the existing rule that allows access to port 80/tcp, 443/tcp and 10254/tcp to also allow access to port 9443/tcp. More information can be found in the Official GCP Documentation. See the GKE documentation on adding rules and the Kubernetes issue for more detail.

The Operator does examine the configuration file for a few purposes:

  • To discover configured receivers and their ports. If it finds receivers with ports, it creates a pair of kubernetes services, one headless, exposing those ports within the cluster. If the port is using environment variable expansion or cannot be parsed, an error will be returned. The headless service contains a service.beta.openshift.io/serving-cert-secret-name annotation that will cause OpenShift to create a secret containing a certificate and key. This secret can be mounted as a volume and the certificate and key used in those receivers’ TLS configurations.

  • To check if Collector observability is enabled (controlled by spec.observability.metrics.enableMetrics). In this case, a Service and ServiceMonitor/PodMonitor are created for the Collector instance. As a consequence, if the metrics service address contains an invalid port or uses environment variable expansion for the port, an error will be returned. A workaround for the environment variable case is to set enableMetrics to false and manually create the previously mentioned objects with the correct port if you need them.

Upgrades

As noted above, the OpenTelemetry Collector format is continuing to evolve. However, a best-effort attempt is made to upgrade all managed OpenTelemetryCollector resources.

In certain scenarios, it may be desirable to prevent the operator from upgrading certain OpenTelemetryCollector resources. For example, when a resource is configured with a custom .Spec.Image, end users may wish to manage configuration themselves as opposed to having the operator upgrade it. This can be configured on a resource by resource basis with the exposed property .Spec.UpgradeStrategy.

By configuring a resource’s .Spec.UpgradeStrategy to none, the operator will skip the given instance during the upgrade routine.

The default and only other acceptable value for .Spec.UpgradeStrategy is automatic.

Deployment modes

The CustomResource for the OpenTelemetryCollector exposes a property named .Spec.Mode, which can be used to specify whether the Collector should run as a DaemonSet, Sidecar, StatefulSet or Deployment (default).

See below for examples of each deployment mode:

Sidecar injection

A sidecar with the OpenTelemetry Collector can be injected into pod-based workloads by setting the pod annotation sidecar.opentelemetry.io/inject to either "true", or to the name of a concrete OpenTelemetryCollector, like in the following example:

  1. kubectl apply -f - <<EOF
  2. apiVersion: opentelemetry.io/v1beta1
  3. kind: OpenTelemetryCollector
  4. metadata:
  5. name: sidecar-for-my-app
  6. spec:
  7. mode: sidecar
  8. config:
  9. receivers:
  10. jaeger:
  11. protocols:
  12. thrift_compact: {}
  13. processors:
  14. exporters:
  15. debug: {}
  16. service:
  17. pipelines:
  18. traces:
  19. receivers: [jaeger]
  20. exporters: [debug]
  21. EOF
  22. kubectl apply -f - <<EOF
  23. apiVersion: v1
  24. kind: Pod
  25. metadata:
  26. name: myapp
  27. annotations:
  28. sidecar.opentelemetry.io/inject: "true"
  29. spec:
  30. containers:
  31. - name: myapp
  32. image: jaegertracing/vertx-create-span:operator-e2e-tests
  33. ports:
  34. - containerPort: 8080
  35. protocol: TCP
  36. EOF

When there are multiple OpenTelemetryCollector resources with a mode set to Sidecar in the same namespace, a concrete name should be used. When there’s only one Sidecar instance in the same namespace, this instance is used when the annotation is set to "true".

The annotation value can come either from the namespace, or from the pod. The most specific annotation wins, in this order:

  • the pod annotation is used when it’s set to a concrete instance name or to "false"
  • namespace annotation is used when the pod annotation is either absent or set to "true", and the namespace is set to a concrete instance or to "false"

The possible values for the annotation can be:

  • “true” - inject OpenTelemetryCollector resource from the namespace.
  • “sidecar-for-my-app” - name of OpenTelemetryCollector CR instance in the current namespace.
  • “my-other-namespace/my-instrumentation” - name and namespace of OpenTelemetryCollector CR instance in another namespace.
  • “false” - do not inject

When using a pod-based workload, such as Deployment or StatefulSet, make sure to add the annotation to the PodTemplate part. Like:

  1. kubectl apply -f - <<EOF
  2. apiVersion: apps/v1
  3. kind: Deployment
  4. metadata:
  5. name: my-app
  6. labels:
  7. app: my-app
  8. annotations:
  9. sidecar.opentelemetry.io/inject: "true" # WRONG
  10. spec:
  11. selector:
  12. matchLabels:
  13. app: my-app
  14. replicas: 1
  15. template:
  16. metadata:
  17. labels:
  18. app: my-app
  19. annotations:
  20. sidecar.opentelemetry.io/inject: "true" # CORRECT
  21. spec:
  22. containers:
  23. - name: myapp
  24. image: jaegertracing/vertx-create-span:operator-e2e-tests
  25. ports:
  26. - containerPort: 8080
  27. protocol: TCP
  28. EOF

When using sidecar mode the OpenTelemetry collector container will have the environment variable OTEL_RESOURCE_ATTRIBUTESset with Kubernetes resource attributes, ready to be consumed by the resourcedetection processor.

Using imagePullSecrets

The OpenTelemetry Collector defines a ServiceAccount field which could be set to run collector instances with a specific Service and their properties (e.g. imagePullSecrets). Therefore, if you have a constraint to run your collector with a private container registry, you should follow the procedure below:

  • Create Service Account.
  1. kubectl create serviceaccount <service-account-name>
  • Create an imagePullSecret.
  1. kubectl create secret docker-registry <secret-name> --docker-server=<registry name> \
  2. --docker-username=DUMMY_USERNAME --docker-password=DUMMY_DOCKER_PASSWORD \
  3. --docker-email=DUMMY_DOCKER_EMAIL
  • Add image pull secret to service account
  1. kubectl patch serviceaccount <service-account-name> -p '{"imagePullSecrets": [{"name": "<secret-name>"}]}'

OpenTelemetry auto-instrumentation injection

The operator can inject and configure OpenTelemetry auto-instrumentation libraries. Currently Apache HTTPD, DotNet, Go, Java, Nginx, NodeJS and Python are supported.

To use auto-instrumentation, configure an Instrumentation resource with the configuration for the SDK and instrumentation.

  1. kubectl apply -f - <<EOF
  2. apiVersion: opentelemetry.io/v1alpha1
  3. kind: Instrumentation
  4. metadata:
  5. name: my-instrumentation
  6. spec:
  7. exporter:
  8. endpoint: http://otel-collector:4317
  9. propagators:
  10. - tracecontext
  11. - baggage
  12. - b3
  13. sampler:
  14. type: parentbased_traceidratio
  15. argument: "0.25"
  16. python:
  17. env:
  18. # Required if endpoint is set to 4317.
  19. # Python autoinstrumentation uses http/proto by default
  20. # so data must be sent to 4318 instead of 4317.
  21. - name: OTEL_EXPORTER_OTLP_ENDPOINT
  22. value: http://otel-collector:4318
  23. dotnet:
  24. env:
  25. # Required if endpoint is set to 4317.
  26. # Dotnet autoinstrumentation uses http/proto by default
  27. # See https://github.com/open-telemetry/opentelemetry-dotnet-instrumentation/blob/888e2cd216c77d12e56b54ee91dafbc4e7452a52/docs/config.md#otlp
  28. - name: OTEL_EXPORTER_OTLP_ENDPOINT
  29. value: http://otel-collector:4318
  30. go:
  31. env:
  32. # Required if endpoint is set to 4317.
  33. # Go autoinstrumentation uses http/proto by default
  34. # so data must be sent to 4318 instead of 4317.
  35. - name: OTEL_EXPORTER_OTLP_ENDPOINT
  36. value: http://otel-collector:4318
  37. EOF

The values for propagators are added to the OTEL_PROPAGATORS environment variable.
Valid values for propagators are defined by the OpenTelemetry Specification for OTEL_PROPAGATORS.

The value for sampler.type is added to the OTEL_TRACES_SAMPLER environment variable.
Valid values for sampler.type are defined by the OpenTelemetry Specification for OTEL_TRACES_SAMPLER.
The value for sampler.argument is added to the OTEL_TRACES_SAMPLER_ARG environment variable. Valid values for sampler.argument will depend on the chosen sampler. See the OpenTelemetry Specification for OTEL_TRACES_SAMPLER_ARG for more details.

The instrumentation will automatically inject OTEL_NODE_IP and OTEL_POD_IP environment variables should you need to reference either value in an endpoint.

The above CR can be queried by kubectl get otelinst.

Then add an annotation to a pod to enable injection. The annotation can be added to a namespace, so that all pods within
that namespace will get instrumentation, or by adding the annotation to individual PodSpec objects, available as part of
Deployment, Statefulset, and other resources.

Java:

  1. instrumentation.opentelemetry.io/inject-java: "true"

NodeJS:

  1. instrumentation.opentelemetry.io/inject-nodejs: "true"

Python:
Python auto-instrumentation also honors an annotation that will permit it to run it on images with a different C library than glibc.

  1. instrumentation.opentelemetry.io/inject-python: "true"
  2. instrumentation.opentelemetry.io/otel-python-platform: "glibc" # for Linux glibc based images, this is the default value and can be omitted
  3. instrumentation.opentelemetry.io/otel-python-platform: "musl" # for Linux musl based images

.NET:
.NET auto-instrumentation also honors an annotation that will be used to set the .NET Runtime Identifiers(RIDs).
Currently, only two RIDs are supported: linux-x64 and linux-musl-x64.
By default linux-x64 is used.

  1. instrumentation.opentelemetry.io/inject-dotnet: "true"
  2. instrumentation.opentelemetry.io/otel-dotnet-auto-runtime: "linux-x64" # for Linux glibc based images, this is default value and can be omitted
  3. instrumentation.opentelemetry.io/otel-dotnet-auto-runtime: "linux-musl-x64" # for Linux musl based images

Go:

Go auto-instrumentation also honors an annotation that will be used to set the OTEL_GO_AUTO_TARGET_EXE env var.
This env var can also be set via the Instrumentation resource, with the annotation taking precedence.
Since Go auto-instrumentation requires OTEL_GO_AUTO_TARGET_EXE to be set, you must supply a valid
executable path via the annotation or the Instrumentation resource. Failure to set this value causes instrumentation injection to abort, leaving the original pod unchanged.

  1. instrumentation.opentelemetry.io/inject-go: "true"
  2. instrumentation.opentelemetry.io/otel-go-auto-target-exe: "/path/to/container/executable"

Go auto-instrumentation also requires elevated permissions. The below permissions are set automatically and are required.

  1. securityContext:
  2. privileged: true
  3. runAsUser: 0

Apache HTTPD:

  1. instrumentation.opentelemetry.io/inject-apache-httpd: "true"

Nginx:

  1. instrumentation.opentelemetry.io/inject-nginx: "true"

OpenTelemetry SDK environment variables only:

  1. instrumentation.opentelemetry.io/inject-sdk: "true"

The possible values for the annotation can be

  • "true" - inject and Instrumentation resource from the namespace.
  • "my-instrumentation" - name of Instrumentation CR instance in the current namespace.
  • "my-other-namespace/my-instrumentation" - name and namespace of Instrumentation CR instance in another namespace.
  • "false" - do not inject

Note: For DotNet auto-instrumentation, by default, operator sets the OTEL_DOTNET_AUTO_TRACES_ENABLED_INSTRUMENTATIONS environment variable which specifies the list of traces source instrumentations you want to enable. The value that is set by default by the operator is all available instrumentations supported by the openTelemery-dotnet-instrumentation release consumed in the image, i.e. AspNet,HttpClient,SqlClient. This value can be overriden by configuring the environment variable explicitly.

Multi-container pods with single instrumentation

If nothing else is specified, instrumentation is performed on the first container available in the pod spec.
In some cases (for example in the case of the injection of an Istio sidecar) it becomes necessary to specify on which container(s) this injection must be performed.

For this, it is possible to fine-tune the pod(s) on which the injection will be carried out.

For this, we will use the instrumentation.opentelemetry.io/container-names annotation for which we will indicate one or more container names (.spec.containers.name) on which the injection must be made:

  1. apiVersion: apps/v1
  2. kind: Deployment
  3. metadata:
  4. name: my-deployment-with-multiple-containers
  5. spec:
  6. selector:
  7. matchLabels:
  8. app: my-pod-with-multiple-containers
  9. replicas: 1
  10. template:
  11. metadata:
  12. labels:
  13. app: my-pod-with-multiple-containers
  14. annotations:
  15. instrumentation.opentelemetry.io/inject-java: "true"
  16. instrumentation.opentelemetry.io/container-names: "myapp,myapp2"
  17. spec:
  18. containers:
  19. - name: myapp
  20. image: myImage1
  21. - name: myapp2
  22. image: myImage2
  23. - name: myapp3
  24. image: myImage3

In the above case, myapp and myapp2 containers will be instrumented, myapp3 will not.

🚨 NOTE: Go auto-instrumentation does not support multicontainer pods. When injecting Go auto-instrumentation the first pod should be the only pod you want instrumented.

Multi-container pods with multiple instrumentations

Works only when enable-multi-instrumentation flag is true.

Annotations defining which language instrumentation will be injected are required. When feature is enabled, specific for Instrumentation language containers annotations are used:

Java:

  1. instrumentation.opentelemetry.io/java-container-names: "java1,java2"

NodeJS:

  1. instrumentation.opentelemetry.io/nodejs-container-names: "nodejs1,nodejs2"

Python:

  1. instrumentation.opentelemetry.io/python-container-names: "python1,python3"

DotNet:

  1. instrumentation.opentelemetry.io/dotnet-container-names: "dotnet1,dotnet2"

Go:

  1. instrumentation.opentelemetry.io/go-container-names: "go1"

ApacheHttpD:

  1. instrumentation.opentelemetry.io/apache-httpd-container-names: "apache1,apache2"

NGINX:

  1. instrumentation.opentelemetry.io/inject-nginx-container-names: "nginx1,nginx2"

SDK:

  1. instrumentation.opentelemetry.io/sdk-container-names: "app1,app2"

If language instrumentation specific container names are not specified, instrumentation is performed on the first container available in the pod spec (only if single instrumentation injection is configured).

In some cases containers in the pod are using different technologies. It becomes necessary to specify language instrumentation for container(s) on which this injection must be performed.

For this, we will use language instrumentation specific container names annotation for which we will indicate one or more container names (.spec.containers.name) on which the injection must be made:

  1. apiVersion: apps/v1
  2. kind: Deployment
  3. metadata:
  4. name: my-deployment-with-multi-containers-multi-instrumentations
  5. spec:
  6. selector:
  7. matchLabels:
  8. app: my-pod-with-multi-containers-multi-instrumentations
  9. replicas: 1
  10. template:
  11. metadata:
  12. labels:
  13. app: my-pod-with-multi-containers-multi-instrumentations
  14. annotations:
  15. instrumentation.opentelemetry.io/inject-java: "true"
  16. instrumentation.opentelemetry.io/java-container-names: "myapp,myapp2"
  17. instrumentation.opentelemetry.io/inject-python: "true"
  18. instrumentation.opentelemetry.io/python-container-names: "myapp3"
  19. spec:
  20. containers:
  21. - name: myapp
  22. image: myImage1
  23. - name: myapp2
  24. image: myImage2
  25. - name: myapp3
  26. image: myImage3

In the above case, myapp and myapp2 containers will be instrumented using Java and myapp3 using Python instrumentation.

NOTE: Go auto-instrumentation does not support multicontainer pods. When injecting Go auto-instrumentation the first container should be the only you want to instrument.

NOTE: This type of instrumentation does not allow to instrument a container with multiple language instrumentations.

NOTE: instrumentation.opentelemetry.io/container-names annotation is not used for this feature.

Use customized or vendor instrumentation

By default, the operator uses upstream auto-instrumentation libraries. Custom auto-instrumentation can be configured by
overriding the image fields in a CR.

  1. apiVersion: opentelemetry.io/v1alpha1
  2. kind: Instrumentation
  3. metadata:
  4. name: my-instrumentation
  5. spec:
  6. java:
  7. image: your-customized-auto-instrumentation-image:java
  8. nodejs:
  9. image: your-customized-auto-instrumentation-image:nodejs
  10. python:
  11. image: your-customized-auto-instrumentation-image:python
  12. dotnet:
  13. image: your-customized-auto-instrumentation-image:dotnet
  14. go:
  15. image: your-customized-auto-instrumentation-image:go
  16. apacheHttpd:
  17. image: your-customized-auto-instrumentation-image:apache-httpd
  18. nginx:
  19. image: your-customized-auto-instrumentation-image:nginx

The Dockerfiles for auto-instrumentation can be found in autoinstrumentation directory.
Follow the instructions in the Dockerfiles on how to build a custom container image.

Using Apache HTTPD autoinstrumentation

For Apache HTTPD autoinstrumentation, by default, instrumentation assumes httpd version 2.4 and httpd configuration directory /usr/local/apache2/conf as it is in the official Apache HTTPD image (f.e. docker.io/httpd:latest). If you need to use version 2.2, or your HTTPD configuration directory is different, and or you need to adjust agent attributes, customize the instrumentation specification per following example:

  1. apiVersion: opentelemetry.io/v1alpha1
  2. kind: Instrumentation
  3. metadata:
  4. name: my-instrumentation
  5. spec:
  6. apacheHttpd:
  7. image: your-customized-auto-instrumentation-image:apache-httpd
  8. version: "2.2"
  9. configPath: /your-custom-config-path
  10. attrs:
  11. - name: ApacheModuleOtelMaxQueueSize
  12. value: "4096"
  13. - name: ...
  14. value: ...

List of all available attributes can be found at otel-webserver-module

Using Nginx autoinstrumentation

For Nginx autoinstrumentation, Nginx versions 1.22.0, 1.23.0, and 1.23.1 are supported at this time. The Nginx configuration file is expected to be /etc/nginx/nginx.conf by default, if it’s different, see following example on how to change it. Instrumentation at this time also expects, that conf.d directory is present in the directory, where configuration file resides and that there is a include <config-file-dir-path>/conf.d/*.conf; directive in the http { ... } section of Nginx configuration file (like it is in the default configuration file of Nginx). You can also adjust OpenTelemetry SDK attributes. Example:

  1. apiVersion: opentelemetry.io/v1alpha1
  2. kind: Instrumentation
  3. metadata:
  4. name: my-instrumentation
  5. spec:
  6. nginx:
  7. image: your-customized-auto-instrumentation-image:nginx # if custom instrumentation image is needed
  8. configFile: /my/custom-dir/custom-nginx.conf
  9. attrs:
  10. - name: NginxModuleOtelMaxQueueSize
  11. value: "4096"
  12. - name: ...
  13. value: ...

List of all available attributes can be found at otel-webserver-module

Inject OpenTelemetry SDK environment variables only

You can configure the OpenTelemetry SDK for applications which can’t currently be autoinstrumented by using inject-sdk in place of inject-python or inject-java, for example. This will inject environment variables like OTEL_RESOURCE_ATTRIBUTES, OTEL_TRACES_SAMPLER, and OTEL_EXPORTER_OTLP_ENDPOINT, that you can configure in the Instrumentation, but will not actually provide the SDK.

  1. instrumentation.opentelemetry.io/inject-sdk: "true"

Controlling Instrumentation Capabilities

The operator allows specifying, via the flags, which languages the Instrumentation resource may instrument.
If a language is enabled by default its gate only needs to be supplied when disabling the gate.
Language support can be disabled by passing the flag with a value of false.

Language Gate Default Value
Java enable-java-instrumentation true
NodeJS enable-nodejs-instrumentation true
Python enable-python-instrumentation true
DotNet enable-dotnet-instrumentation true
ApacheHttpD enable-apache-httpd-instrumentation true
Go enable-go-instrumentation false
Nginx enable-nginx-instrumentation false

OpenTelemetry Operator allows to instrument multiple containers using multiple language specific instrumentations.
These features can be enabled using the enable-multi-instrumentation flag. By default flag is false.

For more information about multi-instrumentation feature capabilities please see Multi-container pods with multiple instrumentations.

Target Allocator

The OpenTelemetry Operator comes with an optional component, the Target Allocator (TA). When creating an OpenTelemetryCollector Custom Resource (CR) and setting the TA as enabled, the Operator will create a new deployment and service to serve specific http_sd_config directives for each Collector pod as part of that CR. It will also rewrite the Prometheus receiver configuration in the CR, so that it uses the deployed target allocator. The following example shows how to get started with the Target Allocator:

  1. kubectl apply -f - <<EOF
  2. apiVersion: opentelemetry.io/v1beta1
  3. kind: OpenTelemetryCollector
  4. metadata:
  5. name: collector-with-ta
  6. spec:
  7. mode: statefulset
  8. targetAllocator:
  9. enabled: true
  10. config:
  11. receivers:
  12. prometheus:
  13. config:
  14. scrape_configs:
  15. - job_name: 'otel-collector'
  16. scrape_interval: 10s
  17. static_configs:
  18. - targets: [ '0.0.0.0:8888' ]
  19. metric_relabel_configs:
  20. - action: labeldrop
  21. regex: (id|name)
  22. - action: labelmap
  23. regex: label_(.+)
  24. replacement: $$1
  25. exporters:
  26. debug: {}
  27. service:
  28. pipelines:
  29. metrics:
  30. receivers: [prometheus]
  31. exporters: [debug]
  32. EOF

The usage of $$ in the replacement keys in the example above is based on the information provided in the Prometheus receiver README documentation, which states:
Note: Since the collector configuration supports env variable substitution $ characters in your prometheus configuration are interpreted as environment variables. If you want to use $ characters in your prometheus configuration, you must escape them using $$.

Behind the scenes, the OpenTelemetry Operator will convert the Collector’s configuration after the reconciliation into the following:

  1. receivers:
  2. prometheus:
  3. target_allocator:
  4. endpoint: http://collector-with-ta-targetallocator:80
  5. interval: 30s
  6. collector_id: $POD_NAME
  7. exporters:
  8. debug:
  9. service:
  10. pipelines:
  11. metrics:
  12. receivers: [prometheus]
  13. exporters: [debug]

The OpenTelemetry Operator will also convert the Target Allocator’s Prometheus configuration after the reconciliation into the following:

  1. config:
  2. scrape_configs:
  3. - job_name: otel-collector
  4. scrape_interval: 10s
  5. static_configs:
  6. - targets: ["0.0.0.0:8888"]
  7. metric_relabel_configs:
  8. - action: labeldrop
  9. regex: (id|name)
  10. - action: labelmap
  11. regex: label_(.+)
  12. replacement: $1

Note that in this case, the Operator replaces “$$” with a single “$” in the replacement keys. This is because the collector supports environment variable substitution, whereas the TA (Target Allocator) does not. Therefore, to ensure compatibility, the TA configuration should only contain a single “$” symbol.

More info on the TargetAllocator can be found here.

Using Prometheus Custom Resources for service discovery

The target allocator can use Custom Resources from the prometheus-operator ecosystem, like ServiceMonitors and PodMonitors, for service discovery, performing
a function analogous to that of prometheus-operator itself. This is enabled via the prometheusCR section in the Collector CR.

See below for a minimal example:

  1. kubectl apply -f - <<EOF
  2. apiVersion: opentelemetry.io/v1beta1
  3. kind: OpenTelemetryCollector
  4. metadata:
  5. name: collector-with-ta-prometheus-cr
  6. spec:
  7. mode: statefulset
  8. targetAllocator:
  9. enabled: true
  10. serviceAccount: everything-prometheus-operator-needs
  11. prometheusCR:
  12. enabled: true
  13. serviceMonitorSelector: {}
  14. podMonitorSelector: {}
  15. config:
  16. receivers:
  17. prometheus:
  18. config: {}
  19. exporters:
  20. debug: {}
  21. service:
  22. pipelines:
  23. metrics:
  24. receivers: [prometheus]
  25. exporters: [debug]
  26. EOF

Configure resource attributes

Configure resource attributes with annotations

This example shows a pod configuration with OpenTelemetry annotations using the resource.opentelemetry.io/ prefix.
These annotations can be used to add resource attributes to data produced by OpenTelemetry instrumentation.

  1. apiVersion: v1
  2. kind: Pod
  3. metadata:
  4. name: example-pod
  5. annotations:
  6. # this is just an example, you can create any resource attributes you need
  7. resource.opentelemetry.io/service.name: "my-service"
  8. resource.opentelemetry.io/service.version: "1.0.0"
  9. resource.opentelemetry.io/deployment.environment.name: "production"
  10. spec:
  11. containers:
  12. - name: main-container
  13. image: your-image:tag

Configure resource attributes with labels

You can also use common labels to set resource attributes.

The following labels are supported:

  • app.kubernetes.io/name becomes service.name
  • app.kubernetes.io/version becomes service.version
  • app.kubernetes.io/part-of becomes service.namespace
  1. apiVersion: v1
  2. kind: Pod
  3. metadata:
  4. name: example-pod
  5. labels:
  6. app.kubernetes.io/name: "my-service"
  7. app.kubernetes.io/version: "1.0.0"
  8. app.kubernetes.io/part-of: "shop"
  9. spec:
  10. containers:
  11. - name: main-container
  12. image: your-image:tag

This requires an explicit opt-in as follows:

  1. apiVersion: opentelemetry.io/v1alpha1
  2. kind: Instrumentation
  3. metadata:
  4. name: my-instrumentation
  5. spec:
  6. defaults:
  7. useLabelsForResourceAttributes: true

Priority for setting resource attributes

The priority for setting resource attributes is as follows (first found wins):

  1. Resource attributes set via OTEL_RESOURCE_ATTRIBUTES and OTEL_SERVICE_NAME environment variables
  2. Resource attributes set via annotations (with the resource.opentelemetry.io/ prefix)
  3. Resource attributes set via labels (e.g. app.kubernetes.io/name)
    if the Instrumentation CR has defaults.useLabelsForResourceAttributes=true (see above)
  4. Resource attributes calculated from the pod’s metadata (e.g. k8s.pod.name)
  5. Resource attributes set via the Instrumentation CR (in the spec.resource.resourceAttributes section)

This priority is applied for each resource attribute separately, so it is possible to set some attributes via
annotations and others via labels.

How resource attributes are calculated from the pod’s metadata

The following resource attributes are calculated from the pod’s metadata.

How service.name is calculated

Choose the first value found:

  • pod.annotation[resource.opentelemetry.io/service.name]
  • if (config[useLabelsForResourceAttributes]) pod.label[app.kubernetes.io/name]
  • k8s.deployment.name
  • k8s.replicaset.name
  • k8s.statefulset.name
  • k8s.daemonset.name
  • k8s.cronjob.name
  • k8s.job.name
  • k8s.pod.name
  • k8s.container.name

How service.version is calculated

Choose the first value found:

  • pod.annotation[resource.opentelemetry.io/service.version]
  • if (cfg[useLabelsForResourceAttributes]) pod.label[app.kubernetes.io/version]
  • if (contains(container docker image tag, '/') == false) container docker image tag

How service.instance.id is calculated

Choose the first value found:

  • pod.annotation[resource.opentelemetry.io/service.instance.id]
  • concat([k8s.namespace.name, k8s.pod.name, k8s.container.name], '.')

Contributing and Developing

Please see CONTRIBUTING.md.

In addition to the core responsibilities the operator project requires approvers and maintainers to be responsible for releasing the project. See RELEASE.md for more information and release schedule.

Triagers (@open-telemetry/operator-triagers):

Approvers (@open-telemetry/operator-approvers):

Emeritus Approvers:

Maintainers (@open-telemetry/operator-maintainers):

Emeritus Maintainers

Learn more about roles in the community repository.

Thanks to all the people who already contributed!

Contributors

License

Apache 2.0 License.