loki.source.api
loki.source.api
receives log entries over HTTP and forwards them to other loki.*
components.
The HTTP API exposed is compatible with Loki push API and the logproto
format.
This means that other loki.write
components can be used as a client and send requests to loki.source.api
which enables using Alloy as a proxy for logs.
Usage
loki.source.api "LABEL" {
http {
listen_address = "LISTEN_ADDRESS"
listen_port = PORT
}
forward_to = RECEIVER_LIST
}
The component will start an HTTP server on the configured port and address with the following endpoints:
/loki/api/v1/push
- acceptingPOST
requests compatible with Loki push API, for example, from another Alloy’sloki.write
component./loki/api/v1/raw
- acceptingPOST
requests with newline-delimited log lines in body. This can be used to send NDJSON or plain text logs. This is compatible with the Promtail push API endpoint. Refer to the Promtail documentation for more information. When this endpoint is used, the incoming timestamps can’t be used and theuse_incoming_timestamp = true
setting will be ignored./ready
- acceptingGET
requests. Can be used to confirm the server is reachable and healthy./api/v1/push
- internally reroutes to/loki/api/v1/push
./api/v1/raw
- internally reroutes to/loki/api/v1/raw
.
Arguments
loki.source.api
supports the following arguments:
The relabel_rules
field can make use of the rules
export value from a loki.relabel
component to apply one or more relabeling rules to log entries before they’re forwarded to the list of receivers in forward_to
.
Blocks
The following blocks are supported inside the definition of loki.source.api
:
http
The http
block configures the HTTP server.
You can use the following arguments to configure the http
block. Any omitted fields take their default values.
Exported fields
loki.source.api
doesn’t export any fields.
Component health
loki.source.api
is only reported as unhealthy if given an invalid configuration.
Debug metrics
The following are some of the metrics that are exposed when this component is used. Note that the metrics include labels such as status_code
where relevant, which can be used to measure request success rates.
loki_source_api_request_duration_seconds
(histogram): Time (in seconds) spent serving HTTP requests.loki_source_api_request_message_bytes
(histogram): Size (in bytes) of messages received in the request.loki_source_api_response_message_bytes
(histogram): Size (in bytes) of messages sent in response.loki_source_api_tcp_connections
(gauge): Current number of accepted TCP connections.
Example
This example starts an HTTP server on 0.0.0.0
address and port 9999
.
The server receives log entries and forwards them to a loki.write
component while adding a forwarded="true"
label.
The loki.write
component will send the logs to the specified loki instance using basic auth credentials provided.
Technical details
loki.source.api
filters out all labels that start with __
, for example, __tenant_id__
.
If you need to be able to set the tenant ID, you must either make sure the X-Scope-OrgID
header is present or use the loki.process
component.
Compatible components
loki.source.api
can accept arguments from the following components:
- Components that export Loki
LogsReceiver
Note
Connecting some components may not be sensible or components may require further configuration to make the connection work correctly. Refer to the linked documentation for more details.