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.podlogs
EXPERIMENTAL: This is an experimental component. Experimental components are subject to frequent breaking changes, and may be removed with no equivalent replacement.
loki.source.podlogs
discovers PodLogs
resources on Kubernetes and, using
the Kubernetes API, tails logs from Kubernetes containers of Pods specified by
the discovered them.
loki.source.podlogs
is similar to loki.source.kubernetes
, but uses custom
resources rather than being fed targets from another Flow component.
NOTE: Unlike
loki.source.kubernetes
, it is not possible to distribute responsibility of collecting logs across multiple agents. To avoid collecting duplicate logs, only one agent should be running aloki.source.podlogs
component.
NOTE: Because
loki.source.podlogs
uses the Kubernetes API to tail logs, it uses more network traffic and CPU consumption of Kubelets thanloki.source.file
.
Multiple loki.source.podlogs
components can be specified by giving them
different labels.
Usage
loki.source.podlogs "LABEL" {
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.podlogs
supports the following arguments:
Name | Type | Description | Default | Required |
---|---|---|---|---|
forward_to | list(LogsReceiver) | List of receivers to send log entries to. | yes |
loki.source.podlogs
searches for PodLogs
resources on Kubernetes. Each
PodLogs
resource describes a set of pods to tail logs from.
PodLogs custom resource
The PodLogs
resource describes a set of Pods to collect logs from.
NOTE:
loki.source.podlogs
looks forPodLogs
ofmonitoring.grafana.com/v1alpha2
, and is not compatible withPodLogs
from the Grafana Agent Operator, which are versionv1alpha1
.
Field | Type | Description |
---|---|---|
apiVersion | string | monitoring.grafana.com/v1alpha2 |
kind | string | PodLogs |
metadata | ObjectMeta | Metadata for the PodLogs. |
spec | PodLogsSpec | Definition of what Pods to collect logs from. |
PodLogsSpec
PodLogsSpec
describes a set of Pods to collect logs from.
Field | Type | Description |
---|---|---|
selector | LabelSelector | Label selector of Pods to collect logs from. |
namespaceSelector | LabelSelector | Label selector of Namespaces that Pods can be discovered in. |
relabelings | RelabelConfig | Relabel rules to apply to discovered Pods. |
If selector
is left as the default value, all Pods are discovered. If
namespaceSelector
is left as the default value, all Namespaces are used for
Pod discovery.
The relabelings
field can be used to modify labels from discovered Pods. The
following meta labels are available for relabeling:
__meta_kubernetes_namespace
: The namespace of the Pod.__meta_kubernetes_pod_name
: The name of the Pod.__meta_kubernetes_pod_ip
: The pod IP of the Pod.__meta_kubernetes_pod_label_<labelname>
: Each label from the Pod.__meta_kubernetes_pod_labelpresent_<labelname>
:true
for each label from the Pod.__meta_kubernetes_pod_annotation_<annotationname>
: Each annotation from the Pod.__meta_kubernetes_pod_annotationpresent_<annotationname>
:true
for each annotation from the Pod.__meta_kubernetes_pod_container_init
:true
if the container is anInitContainer
.__meta_kubernetes_pod_container_name
: Name of the container.__meta_kubernetes_pod_container_image
: The image the container is using.__meta_kubernetes_pod_ready
: Set totrue
orfalse
for the Pod’s ready state.__meta_kubernetes_pod_phase
: Set toPending
,Running
,Succeeded
,Failed
orUnknown
in the lifecycle.__meta_kubernetes_pod_node_name
: The name of the node the pod is scheduled onto.__meta_kubernetes_pod_host_ip
: The current host IP of the pod object.__meta_kubernetes_pod_uid
: The UID of the Pod.__meta_kubernetes_pod_controller_kind
: Object kind of the Pod’s controller.__meta_kubernetes_pod_controller_name
: Name of the Pod’s controller.
In addition to the meta labels, the following labels are exposed to tell
loki.source.podlogs
which container to tail:
__pod_namespace__
: The namespace of the Pod.__pod_name__
: The name of the Pod.__pod_container_name__
: The container name within the Pod.__pod_uid__
: The UID of the Pod.
Blocks
The following blocks are supported inside the definition of
loki.source.podlogs
:
Hierarchy | Block | Description | Required |
---|---|---|---|
client | client | Configures Kubernetes client used to tail logs. | no |
client > basic_auth | basic_auth | Configure basic_auth for authenticating to the endpoint. | no |
client > authorization | authorization | Configure generic authorization to the endpoint. | no |
client > oauth2 | oauth2 | Configure OAuth2 for authenticating to the endpoint. | no |
client > oauth2 > tls_config | tls_config | Configure TLS settings for connecting to the endpoint. | no |
client > tls_config | tls_config | Configure TLS settings for connecting to the endpoint. | no |
selector | selector | Label selector for which PodLogs to discover. | no |
selector > match_expression | match_expression | Label selector expression for which PodLogs to discover. | no |
namespace_selector | selector | Label selector for which namespaces to discover PodLogs in. | no |
namespace_selector > match_expression | match_expression | Label selector expression for which namespaces to discover PodLogs in. | no |
The >
symbol indicates deeper levels of nesting. For example, client > basic_auth
refers to a basic_auth
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 | |
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_http2 | bool | Whether HTTP2 is supported for requests. | true | no |
At most one of the following can be provided:
basic_auth block
Name | Type | Description | Default | Required |
---|---|---|---|---|
username | string | Basic auth username. | no | |
password | secret | Basic auth password. | no | |
password_file | string | File containing the basic auth password. | no |
password
and password_file
are mutually exclusive and only one can be
provided inside of a basic_auth
block.
authorization block
Name | Type | Description | Default | Required |
---|---|---|---|---|
type | string | Authorization type, for example, “Bearer”. | no | |
credentials | secret | Secret value. | no | |
credentials_file | string | File containing the secret value. | no |
credential
and credentials_file
are mutually exclusive and only one can be
provided inside of an authorization
block.
oauth2 block
Name | Type | Description | Default | Required |
---|---|---|---|---|
client_id | string | OAuth2 client ID. | no | |
client_secret | secret | OAuth2 client secret. | no | |
client_secret_file | string | File containing the OAuth2 client secret. | no | |
scopes | list(string) | List of scopes to authenticate with. | no | |
token_url | string | URL to fetch the token from. | no | |
endpoint_params | map(string) | Optional parameters to append to the token URL. | no | |
proxy_url | string | Optional proxy URL for OAuth2 requests. | no |
client_secret
and client_secret_file
are mutually exclusive and only one
can be provided inside of an oauth2
block.
The oauth2
block may also contain its own separate tls_config
sub-block.
tls_config block
Name | Type | Description | Default | Required |
---|---|---|---|---|
ca_pem | string | CA PEM-encoded text to validate the server with. | no | |
ca_file | string | CA certificate to validate the server with. | no | |
cert_pem | string | Certificate PEM-encoded text for client authentication. | no | |
cert_file | string | Certificate file for client authentication. | no | |
key_pem | secret | Key PEM-encoded text for client authentication. | no | |
key_file | string | Key file for client authentication. | no | |
server_name | string | ServerName extension to indicate the name of the server. | no | |
insecure_skip_verify | bool | Disables validation of the server certificate. | no | |
min_version | string | Minimum acceptable TLS version. | no |
The following pairs of arguments are mutually exclusive and cannot both be set simultaneously:
ca_pem
andca_file
cert_pem
andcert_file
key_pem
andkey_file
When configuring client authentication, both the client certificate (using
cert_pem
or cert_file
) and the client key (using key_pem
or key_file
)
must be provided.
When min_version
is not provided, the minimum acceptable TLS version is
inherited from Go’s default minimum version, TLS 1.2. If min_version
is
provided, it must be set to one of the following strings:
"TLS10"
(TLS 1.0)"TLS11"
(TLS 1.1)"TLS12"
(TLS 1.2)"TLS13"
(TLS 1.3)
selector block
The selector
block describes a Kubernetes label selector for PodLogs
or
Namespace discovery.
The following arguments are supported:
Name | Type | Description | Default | Required |
---|---|---|---|---|
match_labels | map(string) | Label keys and values used to discover resources. | {} | no |
When the match_labels
argument is empty, all resources will be matched.
match_expression block
The match_expression
block describes a Kubernetes label match expression for
PodLogs
or Namespace discovery.
The following arguments are supported:
Name | Type | Description | Default | Required |
---|---|---|---|---|
key | string | The label name to match against. | yes | |
operator | string | The operator to use when matching. | yes | |
values | list(string) | The values used when matching. | no |
The operator
argument must be one of the following strings:
"In"
"NotIn"
"Exists"
"DoesNotExist"
Both selector
and namespace_selector
can make use of multiple
match_expression
inner blocks which are treated as AND clauses.
Exported fields
loki.source.podlogs
does not export any fields.
Component health
loki.source.podlogs
is only reported as unhealthy if given an invalid
configuration.
Debug information
loki.source.podlogs
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.podlogs
does not expose any component-specific debug metrics.
Example
This example discovers all PodLogs
resources and forwards collected logs to a
loki.write
component so they are written to Loki.
loki.source.podlogs "default" {
forward_to = [loki.write.local.receiver]
}
loki.write "local" {
endpoint {
url = env("LOKI_URL")
}
}