Documentation Grafana Alloy Reference Components loki loki.source.heroku

loki.source.heroku

loki.source.heroku listens for Heroku messages over TCP connections and forwards them to other loki.* components.

The component starts a new Heroku listener for the given listener block and fans out incoming entries to the list of receivers in forward_to.

Before using loki.source.heroku, Heroku should be configured with the URL where Alloy is listening. Follow the steps in Heroku HTTPS Drain docs for using the Heroku CLI with a command like the following:

shell Copy

heroku drains:add [http|https]://HOSTNAME:PORT/heroku/api/v1/drain -a HEROKU_APP_NAME

You can specify multiple loki.source.heroku components by giving them different labels.

Usage

Alloy Copy

loki.source.heroku "<LABEL>" {
    http {
        listen_address = "<LISTEN_ADDRESS>"
        listen_port    = "<LISTEN_PORT>"
    }
    forward_to = <RECEIVER_LIST>
}

Arguments

You can use the following arguments with loki.source.heroku:

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

You can use the following blocks with loki.source.heroku:

The > symbol indicates deeper levels of nesting. For example, http > tls refers to a tls block defined inside an http block.

grpc

http

tls

The tls block configures TLS for the HTTP and gRPC servers.

Labels

The labels map is applied to every message that the component reads.

The following internal labels all prefixed with __ are available but are discarded if not relabeled:

• __heroku_drain_app
• __heroku_drain_host
• __heroku_drain_log_id
• __heroku_drain_proc

All URL query parameters are translated to __heroku_drain_param_<name>

If the X-Scope-OrgID header is set it’s translated to __tenant_id__

Exported fields

loki.source.heroku doesn’t export any fields.

Component health

loki.source.heroku is only reported as unhealthy if given an invalid configuration.

Debug information

loki.source.heroku exposes some debug information per Heroku listener:

• Whether the listener is currently running.
• The listen address.

Debug metrics

• loki_source_heroku_drain_entries_total (counter): Number of successful entries received by the Heroku target.
• loki_source_heroku_drain_parsing_errors_total (counter): Number of parsing errors while receiving Heroku messages.

Example

This example listens for Heroku messages over TCP in the specified port and forwards them to a loki.write component using the Heroku timestamp.

Alloy Copy

loki.source.heroku "local" {
    http {
        listen_address = "0.0.0.0"
        listen_port    = 4040
    }
    use_incoming_timestamp = true
    labels                 = {component = "loki.source.heroku"}
    forward_to             = [loki.write.local.receiver]
}

loki.write "local" {
    endpoint {
        url = "loki:3100/api/v1/push"
    }
}

When using the default http block settings, the server listen for new connection on port 8080.

Alloy Copy

loki.source.heroku "local" {
    use_incoming_timestamp = true
    labels                 = {component = "loki.source.heroku"}
    forward_to             = [loki.write.local.receiver]
}

loki.write "local" {
    endpoint {
        url = "loki:3100/api/v1/push"
    }
}

Compatible components

loki.source.heroku can accept arguments from the following components:

• Components that export Loki LogsReceiver