--- title: "loki.source.gcplog | Grafana Agent documentation" description: "Learn about loki.source.gcplog" --- # loki.source.gcplog `loki.source.gcplog` retrieves logs from cloud resources such as GCS buckets, load balancers, or Kubernetes clusters running on GCP by making use of Pub/Sub [subscriptions](https://cloud.google.com/pubsub/docs/subscriber). The component uses either the ‘push’ or ‘pull’ strategy to retrieve log entries and forward them to the list of receivers in `forward_to`. Multiple `loki.source.gcplog` components can be specified by giving them different labels. ## Usage Alloy ![Copy code to clipboard](/media/images/icons/icon-copy-small-2.svg) Copy ```alloy loki.source.gcplog "LABEL" { pull { project_id = "PROJECT_ID" subscription = "SUB_ID" } forward_to = RECEIVER_LIST } ``` ## Arguments `loki.source.gcplog` supports the following arguments: Expand table | Name | Type | Description | Default | Required | |-----------------|----------------------|-------------------------------------------|---------|----------| | `forward_to` | `list(LogsReceiver)` | List of receivers to send log entries to. | | yes | | `relabel_rules` | `RelabelRules` | Relabeling rules to apply on log entries. | “{}” | no | ## Blocks The following blocks are supported inside the definition of `loki.source.gcplog`: Expand table | Hierarchy | Name | Description | Required | |----------------|---------------------|-------------------------------------------------------------------------------|----------| | pull | [pull](#pull-block) | Configures a target to pull logs from a GCP Pub/Sub subscription. | no | | push | [push](#push-block) | Configures a server to receive logs as GCP Pub/Sub push requests. | no | | push > http | [http](#http) | Configures the HTTP server that receives requests when using the `push` mode. | no | | push > grpc | [grpc](#grpc) | Configures the gRPC server that receives requests when using the `push` mode. | no | The `pull` and `push` inner blocks are mutually exclusive; a component must contain exactly one of the two in its definition. The `http` and `grpc` block are just used when the `push` block is configured. ### pull block The `pull` block defines which GCP project ID and subscription to read log entries from. The following arguments can be used to configure the `pull` block. Any omitted fields take their default values. Expand table | Name | Type | Description | Default | Required | |--------------------------|---------------|---------------------------------------------------------------------------|---------|----------| | `project_id` | `string` | The GCP project id the subscription belongs to. | | yes | | `subscription` | `string` | The subscription to pull logs from. | | yes | | `labels` | `map(string)` | Additional labels to associate with incoming logs. | `"{}"` | no | | `use_incoming_timestamp` | `bool` | Whether to use the incoming log timestamp. | `false` | no | | `use_full_line` | `bool` | Send the full line from Cloud Logging even if `textPayload` is available. | `false` | no | To make use of the `pull` strategy, the GCP project must have been [configured](/docs/loki/next/clients/promtail/gcplog-cloud/) to forward its cloud resource logs onto a Pub/Sub topic for `loki.source.gcplog` to consume. Typically, the host system also needs to have its GCP [credentials](https://cloud.google.com/docs/authentication/application-default-credentials) configured. One way to do it is to point the `GOOGLE_APPLICATION_CREDENTIALS` environment variable to the location of a credential configuration JSON file or a service account key. ### push block The `push` block defines the configuration of the server that receives push requests from GCP’s Pub/Sub servers. The following arguments can be used to configure the `push` block. Any omitted fields take their default values. Expand table | Name | Type | Description | Default | Required | |-----------------------------|---------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------|---------|----------| | `graceful_shutdown_timeout` | `duration` | Timeout for servers graceful shutdown. If configured, should be greater than zero. | “30s” | no | | `push_timeout` | `duration` | Sets a maximum processing time for each incoming GCP log entry. | `"0s"` | no | | `labels` | `map(string)` | Additional labels to associate with incoming entries. | `"{}"` | no | | `use_incoming_timestamp` | `bool` | Whether to use the incoming entry timestamp. | `false` | no | | `use_full_line` | `bool` | Send the full line from Cloud Logging even if `textPayload` is available. By default, if `textPayload` is present in the line, then it’s used as log line | `false` | no | The server listens for POST requests from GCP’s Push subscriptions on `HOST:PORT/gcp/api/v1/push`. By default, for both strategies the component assigns the log entry timestamp as the time it was processed, except if `use_incoming_timestamp` is set to true. The `labels` map is applied to every entry that passes through the component. ### 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. Expand table | 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 | ### grpc The `grpc` block configures the gRPC server. You can use the following arguments to configure the `grpc` block. Any omitted fields take their default values. Expand table | 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. It defaults to accepting all incoming connections. | `""` | no | | `listen_port` | `int` | Port number on which the server listens for new connections. Defaults to a random free port. | `0` | no | | `max_connection_age_grace` | `duration` | An additive period after `max_connection_age` after which the connection is forcibly closed. | `"infinity"` | no | | `max_connection_age` | `duration` | The duration for the maximum time a connection may exist before it is closed. | `"infinity"` | no | | `max_connection_idle` | `duration` | The duration after which an idle connection is closed. | `"infinity"` | no | | `server_max_concurrent_streams` | `int` | Limit on the number of concurrent streams for gRPC calls (0 = unlimited). | `100` | no | | `server_max_recv_msg_size` | `int` | Limit on the size of a gRPC message this server can receive (bytes). | `4MB` | no | | `server_max_send_msg_size` | `int` | Limit on the size of a gRPC message this server can send (bytes). | `4MB` | no | ## Exported fields `loki.source.gcplog` does not export any fields. ## Component health `loki.source.gcplog` is only reported as unhealthy if given an invalid configuration. ## Debug information `loki.source.gcplog` exposes some debug information per gcplog listener: - The configured strategy. - Their label set. - When using a `push` strategy, the listen address. ## Debug metrics When using the `pull` strategy, the component exposes the following debug metrics: - `loki_source_gcplog_pull_entries_total` (counter): Number of entries received by the gcplog target. - `loki_source_gcplog_pull_parsing_errors_total` (counter): Total number of parsing errors while receiving gcplog messages. - `loki_source_gcplog_pull_last_success_scrape` (gauge): Timestamp of target’s last successful poll. When using the `push` strategy, the component exposes the following debug metrics: - `loki_source_gcplog_push_entries_total` (counter): Number of entries received by the gcplog target. - `loki_source_gcplog_push_entries_total` (counter): Number of parsing errors while receiving gcplog messages. ## Example This example listens for GCP Pub/Sub PushRequests on `0.0.0.0:8080` and forwards them to a `loki.write` component. Alloy ![Copy code to clipboard](/media/images/icons/icon-copy-small-2.svg) Copy ```alloy loki.source.gcplog "local" { push {} forward_to = [loki.write.local.receiver] } loki.write "local" { endpoint { url = "loki:3100/api/v1/push" } } ``` On the other hand, if we need the server to listen on `0.0.0.0:4040`, and forwards them to a `loki.write` component. Alloy ![Copy code to clipboard](/media/images/icons/icon-copy-small-2.svg) Copy ```alloy loki.source.gcplog "local" { push { http { listen_port = 4040 } } forward_to = [loki.write.local.receiver] } loki.write "local" { endpoint { url = "loki:3100/api/v1/push" } } ``` ## Compatible components `loki.source.gcplog` can accept arguments from the following components: - Components that export [Loki `LogsReceiver`](../../compatibility/#loki-logsreceiver-exporters) > 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.