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Description:

opentelemetryresourcedetectorkubernetes 0.3.0

opentelemetry-resourcedetector-kubernetes
An OpenTelemetry package to populates Resource attributes for Kubernetes pods.
Usage
from opentelemetry.sdk.resources import get_aggregated_resources
from opentelemetry_resourcedetector_kubernetes import KubernetesResourceDetector

...

resource = get_aggregated_resources([
KubernetesResourceDetector(),
SomeOtherResourceDetector()
])

... pass the returned `resource` to a TracerProvder, for example ...

The KubernetesResourceDetector is able to detect the basic identifying information
for a Pod, returning as Resource with these attributes populated:

container.runtime - always the string "kubernetes"
container.id - the unique ID of the container (a string of hexadecimal characters)
k8s.pod.uid - the UUID of the pod where your container and code is running

This resource detector is the base class for the others in this package, and so you
will always get these three attributes in your traces, using any of the more detailed
detectors below.
Detecting more attributes with The "Downward API"
The Kubernetes "Downward API" is a safe way to to pass Kubernetes metadata about your
pod to itself, as either:

environment variables,
implemented by KubernetesDownwardAPIEnvironmentResourceDetector, or
files in a volume mounted to your pod,
implemented by KubernetesDownwardAPIVolumeResourceDetector

For either of these methods to work, you will need to add the appropriate configuration
to your Kubernetes manifests, and you'll configure the detector accordingly.
The opentelemetry_resourcedetector_kubernetes classes using the Downward API will only
detect and populate attributes from the standard OpenTelemetry Kubernetes Resource Attribute
that you choose to provide by configuring them in your manifests. These detectors will
only report k8s.* and container.* OpenTelemetry attributes, and are not intended to
be a general-purpose collection mechanism for other types of attributes.
The Downward API only supports a
subset of all the possible attributes you could
provide. Depending on your needs, you can also provide hard-coded environment variables
following the same naming conventino in your Kubernetes manifest, or mix the environment
and volume approaches to paint a more complete picture.
KubernetesDownwardAPIEnvironmentResourceDetector
For an example of using environment variables, you can pass a Pod's namespace and name:
apiVersion: v1
kind: Pod
metadata:
namespace: cool-app
name: example-pod
spec:
containers:
- name: a-container
image: my-image:1.0.0
command: ["run-my-cool-app"]
env:
- name: OTEL_RD_K8S_NAMESPACE_NAME
valueFrom:
fieldRef:
fieldPath: metadata.namespace
- name: OTEL_RD_K8S_POD_NAME
valueFrom:
fieldRef:
fieldPath: metadata.name

Then, your running pod will see these environment variables populated:
OTEL_RD_K8S_NAMESPACE_NAME=cool-app
OTEL_RD_K8S_POD_NAME=example-pod

When configuring your telemetry, you'll establish a "contract" for the names of the
environment variables, indicating that they will be prefixed with OTEL_RD. The
prefix is up to you, but the default is OTEL_RD. From there, the resource detector
will look for each environment variables prefixed with OTEL_RD_, and if the rest of
its name matches a
standard OpenTelemetry Kubernetes Resource Attribute,
it will be used during resource detection.
from opentelemetry.sdk.resources import get_aggregated_resources
from opentelemetry_resourcedetector_kubernetes import KubernetesDownwardAPIEnvironmentResourceDetector

...

resource = get_aggregated_resources([
KubernetesDownwardAPIEnvironmentResourceDetector(prefix='OTEL_RD'),
SomeOtherResourceDetector()
])

... pass the returned `resource` to a TracerProvder, for example ...

In this example, the Resource for all traces would include the attributes:
container.runtime = "kubernetes"
k8s.pod.uid = "...the UUID of the pod..."
container.id = "...the id of the container..."

k8s.namespace.name = "cool-app"
k8s.pod.name = "example-pod"

KubernetesDownwardAPIVolumeResourceDetector
For an example of using a Downward API volume, you can pass a Pod's namespace and name:
apiVersion: v1
kind: Pod
metadata:
namespace: cool-app
name: example-pod
spec:
containers:
- name: a-container
image: my-image:1.0.0
command: ["run-my-cool-app"]
volumeMounts: # this is at the *Container* level
- name: otelrd
mountPath: /etc/otelrd
volumes: # this is at the *Pod* level
- name: otelrd
downwardAPI:
items:
- path: k8s.namespace.name
fieldRef:
fieldPath: metadata.namespace
- path: k8s.pod.name
fieldRef:
fieldPath: metadata.name

Then, your running pod will see these environment variables populated:
$ cat /etc/otelrd/k8s.namespace.name
cool-app
$ cat /etc/otelrd/k8s.pod.name
example-pod

When configuring your telemetry, you'll establish a "contract" by indicating the
directory into which you are mounting the Downward API metadata files (/etc/otelrd
by default). From there, the resource detector will look for files matching the names
of standard OpenTelemetry Kubernetes Resource Attributes.
from opentelemetry.sdk.resources import get_aggregated_resources
from opentelemetry_resourcedetector_kubernetes import KubernetesDownwardAPIEnvironmentResourceDetector

...

resource = get_aggregated_resources([
KubernetesDownwardAPIVolumeResourceDetector(directory='/etc/otelrd'),
SomeOtherResourceDetector()
])

... pass the returned `resource` to a TracerProvder, for example ...

In this example, the Resource for all traces would include the attributes:
container.runtime = "kubernetes"
k8s.pod.uid = "...the UUID of the pod..."
container.id = "...the id of the container..."

k8s.namespace.name = "cool-app"
k8s.pod.name = "example-pod"