This is documentation for the next version of Alloy. For the latest stable release, go to the latest version.
prometheus.receive_http
prometheus.receive_http
listens for HTTP requests containing Prometheus metric samples and forwards them to other components capable of receiving metrics.
The HTTP API exposed is compatible with Prometheus remote_write
API. This means that other prometheus.remote_write
components can be used as a client and send requests to prometheus.receive_http
which enables using Alloy as a proxy for Prometheus metrics.
Usage
prometheus.receive_http "LABEL" {
http {
listen_address = "LISTEN_ADDRESS"
listen_port = PORT
}
forward_to = RECEIVER_LIST
}
The component will start an HTTP server supporting the following endpoint:
POST /api/v1/metrics/write
- send metrics to the component, which in turn will be forwarded to the receivers as configured inforward_to
argument. The request format must match that of Prometheusremote_write
API. One way to send valid requests to this component is to use another Alloy with aprometheus.remote_write
component.
Arguments
prometheus.receive_http
supports the following arguments:
Name | Type | Description | Default | Required |
---|---|---|---|---|
forward_to | list(MetricsReceiver) | List of receivers to send metrics to. | yes |
Blocks
The following blocks are supported inside the definition of prometheus.receive_http
:
Hierarchy | Name | Description | Required |
---|---|---|---|
http | http | Configures the HTTP server that receives requests. | no |
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.
Name | Type | Description | Default | Required |
---|---|---|---|---|
conn_limit | int | Maximum number of simultaneous HTTP connections. Defaults to no limit. | 0 | no |
listen_address | string | Network address on which the server listens for new connections. Defaults to accepting all incoming connections. | "" | no |
listen_port | int | Port number on which the server listens for new connections. | 8080 | no |
server_idle_timeout | duration | Idle timeout for HTTP server. | "120s" | no |
server_read_timeout | duration | Read timeout for HTTP server. | "30s" | no |
server_write_timeout | duration | Write timeout for HTTP server. | "30s" | no |
Exported fields
prometheus.receive_http
does not export any fields.
Component health
prometheus.receive_http
is reported as unhealthy if it is 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.
prometheus_receive_http_request_duration_seconds
(histogram): Time (in seconds) spent serving HTTP requests.prometheus_receive_http_request_message_bytes
(histogram): Size (in bytes) of messages received in the request.prometheus_receive_http_response_message_bytes
(histogram): Size (in bytes) of messages sent in response.prometheus_receive_http_tcp_connections
(gauge): Current number of accepted TCP connections.prometheus_fanout_latency
(histogram): Write latency for sending metrics to other components.prometheus_forwarded_samples_total
(counter): Total number of samples sent to downstream components.
Example
Receiving metrics over HTTP
This example creates a prometheus.receive_http
component which starts an HTTP server listening on 0.0.0.0
and port 9999
. The server receives metrics and forwards them to a prometheus.remote_write
component which writes these metrics to the specified HTTP endpoint.
// Receives metrics over HTTP
prometheus.receive_http "api" {
http {
listen_address = "0.0.0.0"
listen_port = 9999
}
forward_to = [prometheus.remote_write.local.receiver]
}
// Send metrics to a locally running Mimir.
prometheus.remote_write "local" {
endpoint {
url = "http://mimir:9009/api/v1/push"
basic_auth {
username = "example-user"
password = "example-password"
}
}
}
Proxying metrics
In order to send metrics to the prometheus.receive_http
component defined in the previous example, another Alloy can run with the following configuration:
// Collects metrics of localhost:12345
prometheus.scrape "self" {
targets = [
{"__address__" = "localhost:12345", "job" = "alloy"},
]
forward_to = [prometheus.remote_write.local.receiver]
}
// Writes metrics to localhost:9999/api/v1/metrics/write - e.g. served by
// the prometheus.receive_http component from the example above.
prometheus.remote_write "local" {
endpoint {
url = "http://localhost:9999/api/v1/metrics/write"
}
}
Technical details
prometheus.receive_http
uses snappy for compression.
Compatible components
prometheus.receive_http
can accept arguments from the following components:
- Components that export Prometheus
MetricsReceiver
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.