http_endpoint: add program option to the configuration user interface (…

…elastic#12016)

packages/http_endpoint/_dev/test/system/test-http-cel-config.yml

@@ -0,0 +1,38 @@
+service: test-webhook-http
+service_notify_signal: SIGHUP
+input: http_endpoint
+vars:
+  data_stream.dataset: http_endpoint.http_endpoint
+  preserve_original_event: true
+  listen_address: 0.0.0.0
+  url: /json
+  program: |-
+    // Make it possible to differentiate a program's execution
+    // from a non-CEL handler. We don't make most of the mito
+    // libs available in http_endpoint, so just double up by
+    // making an array of parts of the message.
+    // We don't have the containers library, so flatten using
+    // an index into the array produced by the map; the array
+    // we actually want is the array in the map body.
+    obj.map(k, [
+      {"message": k},      // event 0
+      {"message": obj[k]}, // event 1
+    ])[0]
+  # Replace 'json' with '.' when kibana.version is ^8.15.0.
+  prefix: 'json'
+  listen_port: 9515
+  basic_auth: true
+  username: abc123
+  password: abc123
+  enable_request_tracer: true
+  # Remove processors when kibana.version is ^8.15.0.
+  processors: |
+    - rename:
+        fields:
+          - from: json.message
+            to: message
+    - drop_fields:
+        fields:
+          - json
+assert:
+  hit_count: 2

packages/http_endpoint/agent/input/http.yml.hbs

@@ -48,6 +48,9 @@ response_body: '{{response_body}}'
 {{#if url}}
 url: {{url}}
 {{/if}}
+{{#if program}}
+program: {{escape_string program}}
+{{/if}}
 {{#if include_headers}}
 include_headers:
 {{#each include_headers as |header|}}

packages/http_endpoint/changelog.yml

@@ -1,3 +1,8 @@
+- version: "2.3.0"
+  changes:
+    - description: Make CEL program configuration available.
+      type: enhancement
+      link: https://github.com/elastic/integrations/pull/12016
 - version: "2.2.1"
   changes:
     - description: Pass `preserve_original_event` state to input.

packages/http_endpoint/manifest.yml

@@ -3,7 +3,7 @@ name: http_endpoint
 title: Custom HTTP Endpoint Logs
 description: Collect JSON data from listening HTTP port with Elastic Agent.
 type: input
-version: "2.2.1"
+version: "2.3.0"
 conditions:
   kibana:
     version: "^8.14.0"
@@ -54,6 +54,15 @@ policy_templates:
         description: This options specific which URL path to accept requests on. Defaults to /.
         required: false
         show_user: true
+      - name: program
+        type: textarea
+        title: The CEL program to be run for each request.
+        description: |
+          Program is the CEL program that is executed each HTTP request to transform the request body data.
+          More information can be found in the [documentation](https://www.elastic.co/guide/en/beats/filebeat/current/filebeat-input-http_endpoint.html#_program).
+        show_user: false
+        multi: false
+        required: false
       - name: data_stream.dataset
         type: text
         title: Dataset name