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Grafana Alloy

Reference

Components

remote

remote.http

Grafana Cloud

remote.http

remote.http exposes the response body of a URL to other components. The URL is polled for changes so that the most recent content is always available.

The most common use of remote.http is to load discovery targets from an HTTP server.

Multiple remote.http components can be specified by giving them different labels.

Usage

remote.http "LABEL" {
  url = "URL_TO_POLL"
}

Arguments

The following arguments are supported:

Name	Type	Description	Default	Required
`url`	`string`	URL to poll.		yes
`method`	`string`	Define HTTP method for the request	`"GET"`	no
`headers`	`map(string)`	Custom headers for the request.	`{}`	no
`body`	`string`	The request body.	`""`	no
`poll_frequency`	`duration`	Frequency to poll the URL.	`"1m"`	no
`poll_timeout`	`duration`	Timeout when polling the URL.	`"10s"`	no
`is_secret`	`bool`	Whether the response body should be treated as a secret.	false	no

When remote.http performs a poll operation, an HTTP GET request is made against the URL specified by the url argument. A poll is triggered by the following:

When the component first loads.
Every time the component’s arguments get re-evaluated.
At the frequency specified by the poll_frequency argument.

The poll is successful if the URL returns a 200 OK response code. All other response codes are treated as errors and mark the component as unhealthy. After a successful poll, the response body from the URL is exported.

Blocks

The following blocks are supported inside the definition of remote.http:

Hierarchy	Block	Description	Required
client	client	HTTP client settings when connecting to the endpoint.	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

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

client block

The client block configures settings used to connect to the HTTP server.

Name	Type	Description	Default	Required
`bearer_token_file`	`string`	File containing a bearer token to authenticate with.		no
`bearer_token`	`secret`	Bearer token to authenticate with.		no
`enable_http2`	`bool`	Whether HTTP2 is supported for requests.	`true`	no
`follow_redirects`	`bool`	Whether redirects returned by the server should be followed.	`true`	no
`proxy_url`	`string`	HTTP proxy to send requests through.		no
`no_proxy`	`string`	Comma-separated list of IP addresses, CIDR notations, and domain names to exclude from proxying.		no
`proxy_from_environment`	`bool`	Use the proxy URL indicated by environment variables.	`false`	no
`proxy_connect_header`	`map(list(secret))`	Specifies headers to send to proxies during CONNECT requests.		no

bearer_token, bearer_token_file, basic_auth, authorization, and oauth2 are mutually exclusive, and only one can be provided inside of a http_client_config block.

no_proxy can contain IPs, CIDR notations, and domain names. IP and domain names can contain port numbers. proxy_url must be configured if no_proxy is configured.

proxy_from_environment uses the environment variables HTTP_PROXY, HTTPS_PROXY and NO_PROXY (or the lowercase versions thereof). Requests use the proxy from the environment variable matching their scheme, unless excluded by NO_PROXY. proxy_url and no_proxy must not be configured if proxy_from_environment is configured.

proxy_connect_header should only be configured if proxy_url or proxy_from_environment are configured.

basic_auth block

The basic_auth block configures basic authentication to use when polling the configured URL.

Name	Type	Description	Required
`password_file`	`string`	File containing the basic auth password.	no
`password`	`secret`	Basic auth password.	no
`username`	`string`	Basic auth username.	no

password and password_file are mutually exclusive, and only one can be provided inside a basic_auth block.

authorization block

The authorization block configures custom authorization to use when polling the configured URL.

Name	Type	Description	Required
`credentials_file`	`string`	File containing the secret value.	no
`credentials`	`secret`	Secret value.	no
`type`	`string`	Authorization type, for example, “Bearer”.	no

credential and credentials_file are mutually exclusive, and only one can be provided inside an authorization block.

oauth2 block

The oauth2 block configures OAuth2 authorization to use when polling the configured URL.

Name	Type	Description	Default	Required
`client_id`	`string`	OAuth2 client ID.		no
`client_secret_file`	`string`	File containing the OAuth2 client secret.		no
`client_secret`	`secret`	OAuth2 client secret.		no
`endpoint_params`	`map(string)`	Optional parameters to append to the token URL.		no
`proxy_url`	`string`	HTTP proxy to send requests through.		no
`no_proxy`	`string`	Comma-separated list of IP addresses, CIDR notations, and domain names to exclude from proxying.		no
`proxy_from_environment`	`bool`	Use the proxy URL indicated by environment variables.	`false`	no
`proxy_connect_header`	`map(list(secret))`	Specifies headers to send to proxies during CONNECT requests.		no
`scopes`	`list(string)`	List of scopes to authenticate with.		no
`token_url`	`string`	URL to fetch the token from.		no

client_secret and client_secret_file are mutually exclusive, and only one can be provided inside an oauth2 block.

The oauth2 block may also contain a separate tls_config sub-block.

no_proxy can contain IPs, CIDR notations, and domain names. IP and domain names can contain port numbers. proxy_url must be configured if no_proxy is configured.

proxy_connect_header should only be configured if proxy_url or proxy_from_environment are configured.

tls_config block

The tls_config block configures TLS settings for connecting to HTTPS servers.

Name	Type	Description	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
`insecure_skip_verify`	`bool`	Disables validation of the server certificate.	no
`key_file`	`string`	Key file for client authentication.	no
`key_pem`	`secret`	Key PEM-encoded text for client authentication.	no
`min_version`	`string`	Minimum acceptable TLS version.	no
`server_name`	`string`	ServerName extension to indicate the name of the server.	no

The following pairs of arguments are mutually exclusive and can’t both be set simultaneously:

ca_pem and ca_file
cert_pem and cert_file
key_pem and key_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)

Exported fields

The following field is exported and can be referenced by other components:

Name	Type	Description	Default	Required
`content`	`string` or `secret`	The contents of the file.		no

If the is_secret argument was true, content is a secret type.

Component health

Instances of remote.http report as healthy if the most recent HTTP GET request of the specified URL succeeds.

Debug information

remote.http doesn’t expose any component-specific debug information.

Debug metrics

remote.http doesn’t expose any component-specific debug metrics.

Example

This example reads a JSON array of objects from an endpoint and uses them as a set of scrape targets:

remote.http "targets" {
  url = sys.env("MY_TARGETS_URL")
}

prometheus.scrape "default" {
  targets    = encoding.from_json(remote.http.targets.content)
  forward_to = [prometheus.remote_write.default.receiver]
}

prometheus.remote_write "default" {
  client {
    url = sys.env("PROMETHEUS_URL")
  }
}