[receiver/httpcheck] add metrics check whether substring contains in response body

.chloggen/httpcheckreceiver-match-content.yaml

@@ -0,0 +1,27 @@
+# Use this changelog template to create an entry for release notes.
+
+# One of 'breaking', 'deprecation', 'new_component', 'enhancement', 'bug_fix'
+change_type: enhancement
+
+# The name of the component, or a single word describing the area of concern, (e.g. filelogreceiver)
+component: httpcheckreceiver
+
+# A brief description of the change.  Surround your text with quotes ("") if it needs to start with a backtick (`).
+note: Add metrics testing if the HTTP response body exact matches a specific string.
+
+# Mandatory: One or more tracking issues related to the change. You can use the PR number here if no issue exists.
+issues: [24913]
+
+# (Optional) One or more lines of additional information to render under the primary note.
+# These lines will be padded with 2 spaces and then inserted directly into the document.
+# Use pipe (|) for multiline entries.
+subtext:
+
+# If your change doesn't affect end users or the exported elements of any package,
+# you should instead start your pull request title with [chore] or use the "Skip Changelog" label.
+# Optional: The change log or logs in which this entry should be included.
+# e.g. '[user]' or '[user, api]'
+# Include 'user' if the change is relevant to end users.
+# Include 'api' if there is a change to a library API.
+# Default: '[user]'
+change_logs: [user]

receiver/httpcheckreceiver/README.md

@@ -37,6 +37,8 @@ Each target has the following properties:
 
 - `endpoint` (required): the URL to be monitored
 - `method` (optional, default: `GET`): The HTTP method used to call the endpoint
+- `body` (optional, default: ""): If set, the receiver will emit metrics based on whether the response body exact matches this string.
+- `name` (optional, default: ""): The name of this receiver.
 
 Additionally, each target supports the client configuration options of [confighttp].
 

receiver/httpcheckreceiver/config.go

@@ -31,6 +31,8 @@ type Config struct {
 type targetConfig struct {
 	confighttp.HTTPClientSettings `mapstructure:",squash"`
 	Method                        string `mapstructure:"method"`
+	Body                          string `mapstructure:"body"`
+	Name                          string `mapstructure:"name"`
 }
 
 // Validate validates the configuration by checking for missing or invalid fields

receiver/httpcheckreceiver/documentation.md

@@ -57,3 +57,28 @@ Records errors occurring during HTTP check.
 | http.status_code | HTTP response status code | Any Int |
 | http.method | HTTP request method | Any Str |
 | http.status_class | HTTP response status class | Any Str |
+
+## Optional Metrics
+
+The following metrics are not emitted by default. Each of them can be enabled by applying the following configuration:
+
+```yaml
+metrics:
+  <metric_name>:
+    enabled: true
+```
+
+### httpcheck.body
+
+Reports 1 if the HTTP response body exact matches the `body` configuration item, 0 otherwise.
+
+| Unit | Metric Type | Value Type | Aggregation Temporality | Monotonic |
+| ---- | ----------- | ---------- | ----------------------- | --------- |
+| 1 | Sum | Int | Cumulative | false |
+
+#### Attributes
+
+| Name | Description | Values |
+| ---- | ----------- | ------ |
+| http.url | Full HTTP request URL. | Any Str |
+| name | Optional name of this check. | Any Str |

receiver/httpcheckreceiver/internal/metadata/testdata/config.yaml

@@ -1,6 +1,8 @@
 default:
 all_set:
   metrics:
+    httpcheck.body:
+      enabled: true
     httpcheck.duration:
       enabled: true
     httpcheck.error:
@@ -9,6 +11,8 @@ all_set:
       enabled: true
 none_set:
   metrics:
+    httpcheck.body:
+      enabled: false
     httpcheck.duration:
       enabled: false
     httpcheck.error:

receiver/httpcheckreceiver/metadata.yaml

@@ -27,6 +27,9 @@ attributes:
   error.message:
     description: Error message recorded during check
     type: string
+  name:
+    description: Optional name of this check.
+    type: string
 
 metrics:
   httpcheck.status:
@@ -54,6 +57,15 @@ metrics:
       monotonic: false
     unit: "{error}"
     attributes: [http.url, error.message]
+  httpcheck.body:
+    description: Reports 1 if the HTTP response body exact matches the `body` configuration item, 0 otherwise.
+    enabled: false
+    sum:
+      value_type: int
+      aggregation_temporality: cumulative
+      monotonic: false
+    unit: 1
+    attributes: [http.url, name]
 
 tests:
   config:

receiver/httpcheckreceiver/scraper.go

@@ -6,7 +6,9 @@ package httpcheckreceiver // import "github.com/open-telemetry/opentelemetry-col
 import (
 	"context"
 	"errors"
+	"io"
 	"net/http"
+	"strings"
 	"sync"
 	"time"
 
@@ -62,7 +64,7 @@ func (h *httpcheckScraper) scrape(ctx context.Context) (pmetric.Metrics, error)
 
 			req, err := http.NewRequestWithContext(ctx, h.cfg.Targets[targetIndex].Method, h.cfg.Targets[targetIndex].Endpoint, http.NoBody)
 			if err != nil {
-				h.settings.Logger.Error("failed to create request", zap.Error(err))
+				h.settings.Logger.Error("failed to create request", zap.String("target endpoint", h.cfg.Targets[targetIndex].Endpoint), zap.Error(err))
 				return
 			}
 
@@ -85,6 +87,21 @@ func (h *httpcheckScraper) scrape(ctx context.Context) (pmetric.Metrics, error)
 					h.mb.RecordHttpcheckStatusDataPoint(now, int64(0), h.cfg.Targets[targetIndex].Endpoint, int64(statusCode), req.Method, class)
 				}
 			}
+
+			if err == nil && len(h.cfg.Targets[targetIndex].Body) > 0 {
+				if body, err := io.ReadAll(resp.Body); err != nil {
+					h.settings.Logger.Error("failed to read response", zap.String("target endpoint", h.cfg.Targets[targetIndex].Endpoint), zap.Error(err))
+				} else {
+					defer resp.Body.Close()
+
+					if strings.Contains(string(body), h.cfg.Targets[targetIndex].Body) {
+						h.mb.RecordHttpcheckBodyDataPoint(now, int64(1), h.cfg.Targets[targetIndex].Endpoint, h.cfg.Targets[targetIndex].Name)
+					} else {
+						h.mb.RecordHttpcheckBodyDataPoint(now, int64(0), h.cfg.Targets[targetIndex].Endpoint, h.cfg.Targets[targetIndex].Name)
+					}
+				}
+			}
+
 			mux.Unlock()
 		}(client, idx)
 	}