Docs » Configure application receivers » Configure application receivers for hosts and servers » HTTP

HTTP 🔗

Description 🔗

The Splunk Distribution of OpenTelemetry Collector provides this integration as the http monitor by using the SignalFx Smart Agent Receiver.

Use this integration to generate metrics based on whether the HTTP response from the configured URL matches expectations. For example, correct body, status code, and so on.

If applicable, TLS information is automatically fetched from the base URL or redirection, depending on whether the useHTTPS parameter is configured.

Benefits 🔗

After you configure the integration, you can access these features:

  • View metrics using the built-in dashboard. For information about dashboards, see View dashboards in Observability Cloud.

  • View a data-driven visualization of the physical servers, virtual machines, AWS instances, and other resources in your environment that are visible to Infrastructure Monitoring. For information about navigators, see Splunk Infrastructure Monitoring navigators.

  • Access Metric Finder and search for metrics sent by the monitor. For information about Metric Finder, see Use the Metric Finder.

Installation 🔗

Follow these steps to deploy this integration:

  1. Deploy the Splunk Distribution of OpenTelemetry Collector to your host or container platform:

  2. Configure the monitor, as described in the Configuration section.

  3. Restart the Splunk Distribution of OpenTelemetry Collector.

Configuration 🔗

This monitor type is available in the Smart Agent Receiver, which is part of the Splunk Distribution of OpenTelemetry Collector. You can use existing Smart Agent monitors as OpenTelemetry Collector metric receivers with the Smart Agent Receiver.

This monitor type requires a properly configured environment on your system in which you’ve installed a functional Smart Agent release bundle. The Collector provides this bundle in the installation paths for x86_64/amd64.

To activate this monitor type in the Collector, add the following lines to your configuration (YAML) file:

receivers:
  smartagent/http:
    type: http
    ... # Additional config

To complete the integration, include the monitor in a metrics pipeline. Add the monitor item to the service/pipelines/metrics/receivers section of your configuration file. For example:

service:
  pipelines:
    metrics:
      receivers: [smartagent/http]

Configuration options 🔗

The following table shows the configuration options for this monitor:

Option Required Type Description
host no string The host or IP address to monitor.
port no integer The port of the HTTP server to monitor. The default value is 0.
path no string The HTTP path to use in the test request.
httpTimeout no int64 The HTTP timeout duration for both read and writes. This should be a duration string that is accepted by the ParseDuration type. The default value is 10s.
username no string The basic auth username to use on each request, if any.
password no string The basic auth password to use on each request, if any.
useHTTPS no bool If true, the Collector connects to the server using HTTPS instead of plain HTTP. The default value is false.
httpHeaders no map of strings A map of HTTP header names to values. Comma-separated multiple values for the same message-header are supported.
skipVerify no bool If useHTTPS is true and this option is also true, the exporter's TLS cert is not verified. The default value is false.
sniServerName no string If useHTTPS is true and skipVerify is true, the sniServerName is used to verify the host name on the returned certificates. It is also included in the client's handshake to support virtual hosting unless it is an IP address.
caCertPath no string The path to the CA certificate that has signed the TLS cert. This option is unnecessary if skipVerify is set to false.
clientCertPath no string The path to the client TLS cert to use for TLS required connections.
clientKeyPath no string The path to the client TLS key to use for TLS required connections.
requestBody no string Optional HTTP request body as string, for example, {"foo":"bar"}.
noRedirects no bool Do not follow redirect. The default value is false.
method no string HTTP request method to use. The default value is GET.
urls no list of strings Provides a list of HTTP URLs to monitor. This option is deprecated. Use host/port/useHTTPS/path instead.
regex no string Optional regex to match on URL(s) response(s).
desiredCode no integer Desired code to match for URL(s) response(s). The default value is 200.
addRedirectURL no bool Adds the redirect_url dimension, which could differ from url when redirection is followed. The default value is false.

Setup 🔗

To create a webcheck from a URL, split the URL into different configuration options. All of these options determine the URL dimension value from its “normalized” URL, which is in the format of {scheme}://{host}:{port}{path}:

  • scheme is https if useHTTPS:true, or http if useHTTPS:false.

  • host is the host name of the site to check. This option is required.

  • port is the port to connect to. If not defined, port is 443 if useHTTPS:true or 80 if useHTTPS:false. The default value for http is 80. If the default value is used, port is removed from the configuration because it is implicit and makes the behavior similar to what curl does.

  • path contains the full query including the resource path and finally the GET method parameters with ? separator.

Configure the following options to change the behavior of the request done on this URL:

  • Configure the method option to define request types such as GET or POST. See https://golang.org/src/net/http/method.go for the full list of available methods.

  • Configure the username and password options for basic authentication.

  • Configure the httpHeaders option to define request headers. Use this option to override the host header.

  • Configure the requestBody option to provide a body to the request. The form of this body depends on the Content-Type header. For example, {"foo":"bar"} with Content-Type: application/json.

  • Configure the noRedirects:false option to stop the URL from following redirects. The default value is true.

See Configuration examples for different request behaviors.

The following configuration options change the resulting values:

  • The desiredCode option determines the http.code_matched value. Configure this option if you expect a different “normal” value. The default value is 200. For example, configure desiredCode:301 and noRedirects:false to check a redirect (and not the end redirected URL) keeping the value to 1 (success).

  • The regex option does the same with the http.regex_matched metric, where the value is 1 only if the provided regex matches the response body.

  • The addRedirectURL option does not have impact on metrics, but adds a new dimension redirect_url with a “dynamic” value. If the url dimension changes with the monitor configuration, the redirect_url value is impacted by any server change and is always the last URL redirected. This option is disabled by default because this could cause issues with heartbeat detectors, for example.

The following HTTP headers let the client and the server pass additional information with an HTTP request or response:

  • Cache-Control: no-cache to send the request to the origin server for validation before releasing a cached copy.

  • Host to change the request, that is, to bypass CDN or load balancer requesting directly the backend.

  • Content-Type to indicate the media type of the resource. For example, json, xml, or octet-stream.

Configuration examples 🔗

This section provides curl commands with their corresponding configuration.

If the server reports that the requested page has moved to a different location, run curl -L http://signalfx.com to make curl redo the request on the new URL. The http.status_code=200 status response code indicates that the request has succeeded because it does follow the redirect to Splunk.

monitors:
 - type: http
   host: signalfx.com

Run curl -I http://signalfx.com to include the HTTP response headers in the output instead of the GET request. The HTTP response headers can include information such as server name, cookies, date of the document, and HTTP version. In this example, noRedirects: is set to true. The http.status_code=301 status response code means the request does not follow the redirect to Splunk.

monitors:
 - type: http
   host: signalfx.com
   noRedirects: true
   method: HEAD

Run curl -L -H 'Host: foobar' -A 'customAgent' https://signalfx.com to include extra headers in the request when sending HTTP to a server. The -H option removes an internal header by giving a replacement without content on the right side of the colon. The -A option specifies the User-Agent string to send to the HTTP server. The http.cert_valid=0 status response code means that the host does not match the certificate.

monitors:
 - type: http
   host: signalfx.com
   useHTTPS: true
   httpHeaders:
     Host: foobar
     User-Agent: customAgent

Run curl -G -X GET -d 'foo=bar' -d 'leet=1337' http://signalfx.com/fakepage to make all data specified with -d, --data, --data-binary, or --data-urlencode to be used in an HTTP GET request instead of the POST request that otherwise would be used:

monitors:
 - type: http
   host: signalfx.com
   path: '/fakepage?foo=bar&leet=1337'
   method: GET
   httpHeaders:
     Content-Type: application/x-www-form-urlencoded

Run curl -X POST -d '{"foo":"bar"}' http://signalfx.com to specify a custom request method to use when communicating with the HTTP server. The specified request method, POST, is used instead of the default GET method.

monitors:
 - type: http
   host: signalfx.com
   method: POST
   requestBody: '{"foo":"bar"}'

Run curl --resolve signalfx.com:443:127.0.0.1 https://signalfx.com to provide a custom address for a specific host and port pair:

monitors:
 - type: http
   host: 127.0.0.1
   port: 443
   useHTTPS: true
   sniServerName: signalfx.com
   httpHeaders:
     Host: signalfx.com

Metrics 🔗

These are the metrics available for this integration:

Troubleshooting 🔗

If you are not able to see your data in Splunk Observability Cloud, try these tips:

To learn about even more support options, see Splunk Customer Success.