Caution
Grafana Alloy is the new name for our distribution of the OTel collector. Grafana Agent has been deprecated and is in Long-Term Support (LTS) through October 31, 2025. Grafana Agent will reach an End-of-Life (EOL) on November 1, 2025. Read more about why we recommend migrating to Grafana Alloy.
Important: This documentation is about an older version. It's relevant only to the release noted, many of the features and functions have been updated or replaced. Please view the current version.
loki.source.kubernetes
loki.source.kubernetes
tails logs from Kubernetes containers using the
Kubernetes API. It has the following benefits over loki.source.file
:
- It works without a privileged container.
- It works without a root user.
- It works without needing access to the filesystem of the Kubernetes node.
- It doesn’t require a DaemonSet to collect logs, so one agent could collect logs for the whole cluster.
NOTE: Because
loki.source.kubernetes
uses the Kubernetes API to tail logs, it uses more network traffic and CPU consumption of Kubelets thanloki.source.file
.
Multiple loki.source.kubernetes
components can be specified by giving them
different labels.
Usage
loki.source.kubernetes "LABEL" {
targets = TARGET_LIST
forward_to = RECEIVER_LIST
}
Arguments
The component starts a new reader for each of the given targets
and fans out
log entries to the list of receivers passed in forward_to
.
loki.source.kubernetes
supports the following arguments:
Name | Type | Description | Default | Required |
---|---|---|---|---|
targets | list(map(string)) | List of files to read from. | yes | |
forward_to | list(LogsReceiver) | List of receivers to send log entries to. | yes |
Each target in targets
must have the following labels:
__meta_kubernetes_namespace
or__pod_namespace__
to specify the namespace of the pod to tail.__meta_kubernetes_pod_name
or__pod_name__
to specify the name of the pod to tail.__meta_kubernetes_pod_container_name
or__pod_container_name__
to specify the container within the pod to tail.__meta_kubernetes_pod_uid
or__pod_uid__
to specify the UID of the pod to tail.
By default, all of these labels are present when the output
discovery.kubernetes
is used.
A log tailer is started for each unique target in targets
. Log tailers will
reconnect with exponential backoff to Kubernetes if the log stream returns
before the container has permanently terminated.
Blocks
The following blocks are supported inside the definition of
loki.source.kubernetes
:
Hierarchy | Block | Description | Required |
---|---|---|---|
client | client | Configures Kubernetes client used to tail logs. | no |
client > http_client_config | http_client_config | HTTP client configuration for Kubernetes requests. | no |
The >
symbol indicates deeper levels of nesting. For example, client > http_client_config
refers to an http_client_config
block defined
inside a client
block.
client block
The client
block configures the Kubernetes client used to tail logs from
containers. If the client
block isn’t provided, the default in-cluster
configuration with the service account of the running Grafana Agent pod is
used.
The following arguments are supported:
Name | Type | Description | Default | Required |
---|---|---|---|---|
api_server | string | URL of the Kubernetes API server. | no | |
kubeconfig_file | string | Path of the kubeconfig file to use for connecting to Kubernetes. | no |
http_client_config block
The http_client_config
block configures settings used to connect to the
Kubernetes API server.
Name | Type | Description | Default | Required |
---|---|---|---|---|
bearer_token | secret | Bearer token to authenticate with. | no | |
bearer_token_file | string | File containing a bearer token to authenticate with. | no | |
proxy_url | string | HTTP proxy to proxy requests through. | no | |
follow_redirects | bool | Whether redirects returned by the server should be followed. | true | no |
enable_http_2 | bool | Whether HTTP2 is supported for requests. | true | no |
bearer_token
, bearer_token_file
, basic_auth
, authorization
, and
oauth2
are mutually exclusive and only one can be provided inside of a
http_client_config
block.
Exported fields
loki.source.kubernetes
does not export any fields.
Component health
loki.source.kubernetes
is only reported as unhealthy if given an invalid
configuration.
Debug information
loki.source.kubernetes
exposes some target-level debug information per
target:
- The labels associated with the target.
- The full set of labels which were found during service discovery.
- The most recent time a log line was read and forwarded to the next components in the pipeline.
- The most recent error from tailing, if any.
Debug metrics
loki.source.kubernetes
does not expose any component-specific debug metrics.
Example
This example collects logs from all Kubernetes pods and forwards them to a
loki.write
component so they are can be written to Loki.
discovery.kubernetes "pods" {
role = "pod"
}
loki.source.kubernetes "pods" {
targets = discovery.kubernetes.pods.targets
forward_to = [loki.write.local.receiver]
}
loki.write "local" {
endpoint {
url = env("LOKI_URL")
}
}