[receiver/tlscheck] Implement Scraper (#35823)

<!--Ex. Fixing a bug - Describe the bug and how this fixes the issue.
Ex. Adding a feature - Explain what this achieves.-->
#### Description

Implements the scraper functionality of this receiver. It supports one
or more host-based checks which are executed in parallel.

<!-- Issue number (e.g. #1234) or full URL to issue, if applicable. -->
#### Link to tracking issue
Fixes #35842 

<!--Describe what testing was performed and which tests were added.-->
#### Testing

This includes tests for both valid and invalid certs. 

<!--Describe the documentation added.-->
#### Documentation

<!--Please delete paragraphs that you did not use before submitting.-->

.chloggen/tlscheckreceiver-implementation.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: breaking
+
+# The name of the component, or a single word describing the area of concern, (e.g. filelogreceiver)
+component: tlscheckreceiver
+
+# A brief description of the change.  Surround your text with quotes ("") if it needs to start with a backtick (`).
+note: Implement TLS Check Receiver for host-based checks
+
+# Mandatory: One or more tracking issues related to the change. You can use the PR number here if no issue exists.
+issues: [35842]
+
+# (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: Changing configuration scheme to use standard confignet TCP client
+
+# 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/tlscheckreceiver/README.md

@@ -20,12 +20,19 @@ By default, the TLS Check Receiver will emit a single metric, `tlscheck.time_lef
 
 ## Example Configuration
 
+Targets are 
+
 ```yaml
 receivers:
   tlscheck:
     targets:
-      - url: https://example.com
-      - url: https://foobar.com:8080
+      - endpoint: example.com:443
+        dialer: 
+          timeout: 15s
+      - endpoint: foobar.com:8080
+        dialer: 
+          timeout: 15s
+      - endpoint: localhost:10901
 ```
 
 ## Certificate Verification

receiver/tlscheckreceiver/config.go

@@ -6,57 +6,71 @@ package tlscheckreceiver // import "github.com/open-telemetry/opentelemetry-coll
 import (
 	"errors"
 	"fmt"
-	"net/url"
+	"net"
+	"strconv"
+	"strings"
 
+	"go.opentelemetry.io/collector/config/confignet"
 	"go.opentelemetry.io/collector/scraper/scraperhelper"
 	"go.uber.org/multierr"
 
 	"github.com/open-telemetry/opentelemetry-collector-contrib/receiver/tlscheckreceiver/internal/metadata"
 )
 
 // Predefined error responses for configuration validation failures
-var (
-	errMissingURL = errors.New(`"url" must be specified`)
-	errInvalidURL = errors.New(`"url" must be in the form of <scheme>://<hostname>[:<port>]`)
-)
+var errInvalidEndpoint = errors.New(`"endpoint" must be in the form of <hostname>:<port>`)
 
 // Config defines the configuration for the various elements of the receiver agent.
 type Config struct {
 	scraperhelper.ControllerConfig `mapstructure:",squash"`
 	metadata.MetricsBuilderConfig  `mapstructure:",squash"`
-	Targets                        []*targetConfig `mapstructure:"targets"`
+	Targets                        []*confignet.TCPAddrConfig `mapstructure:"targets"`
 }
 
-type targetConfig struct {
-	URL string `mapstructure:"url"`
+func validatePort(port string) error {
+	portNum, err := strconv.Atoi(port)
+	if err != nil {
+		return fmt.Errorf("provided port is not a number: %s", port)
+	}
+	if portNum < 1 || portNum > 65535 {
+		return fmt.Errorf("provided port is out of valid range (1-65535): %d", portNum)
+	}
+	return nil
 }
 
-// Validate validates the configuration by checking for missing or invalid fields
-func (cfg *targetConfig) Validate() error {
+func validateTarget(cfg *confignet.TCPAddrConfig) error {
 	var err error
 
-	if cfg.URL == "" {
-		err = multierr.Append(err, errMissingURL)
-	} else {
-		_, parseErr := url.ParseRequestURI(cfg.URL)
-		if parseErr != nil {
-			err = multierr.Append(err, fmt.Errorf("%s: %w", errInvalidURL.Error(), parseErr))
-		}
+	if cfg.Endpoint == "" {
+		return errMissingTargets
+	}
+
+	if strings.Contains(cfg.Endpoint, "://") {
+		return fmt.Errorf("endpoint contains a scheme, which is not allowed: %s", cfg.Endpoint)
+	}
+
+	_, port, parseErr := net.SplitHostPort(cfg.Endpoint)
+	if parseErr != nil {
+		return fmt.Errorf("%s: %w", errInvalidEndpoint.Error(), parseErr)
+	}
+
+	portParseErr := validatePort(port)
+	if portParseErr != nil {
+		return fmt.Errorf("%s: %w", errInvalidEndpoint.Error(), portParseErr)
 	}
 
 	return err
 }
 
-// Validate validates the configuration by checking for missing or invalid fields
 func (cfg *Config) Validate() error {
 	var err error
 
 	if len(cfg.Targets) == 0 {
-		err = multierr.Append(err, errMissingURL)
+		err = multierr.Append(err, errMissingTargets)
 	}
 
 	for _, target := range cfg.Targets {
-		err = multierr.Append(err, target.Validate())
+		err = multierr.Append(err, validateTarget(target))
 	}
 
 	return err

receiver/tlscheckreceiver/config_test.go

@@ -6,8 +6,10 @@ package tlscheckreceiver // import "github.com/open-telemetry/opentelemetry-coll
 import (
 	"fmt"
 	"testing"
+	"time"
 
 	"github.com/stretchr/testify/require"
+	"go.opentelemetry.io/collector/config/confignet"
 	"go.opentelemetry.io/collector/scraper/scraperhelper"
 )
 
@@ -18,61 +20,88 @@ func TestValidate(t *testing.T) {
 		expectedErr error
 	}{
 		{
-			desc: "missing url",
+			desc: "missing targets",
 			cfg: &Config{
-				Targets:          []*targetConfig{},
+				Targets:          []*confignet.TCPAddrConfig{},
 				ControllerConfig: scraperhelper.NewDefaultControllerConfig(),
 			},
-			expectedErr: errMissingURL,
+			expectedErr: errMissingTargets,
 		},
 		{
-			desc: "invalid url",
+			desc: "invalid endpoint",
 			cfg: &Config{
-				Targets: []*targetConfig{
+				Targets: []*confignet.TCPAddrConfig{
 					{
-						URL: "invalid://endpoint:  12efg",
+						Endpoint: "bad-endpoint:  12efg",
+						DialerConfig: confignet.DialerConfig{
+							Timeout: 12 * time.Second,
+						},
 					},
 				},
 				ControllerConfig: scraperhelper.NewDefaultControllerConfig(),
 			},
-			expectedErr: fmt.Errorf("%w: %s", errInvalidURL, `parse "invalid://endpoint:  12efg": invalid port ":  12efg" after host`),
+			expectedErr: fmt.Errorf("%w: %s", errInvalidEndpoint, "provided port is not a number:   12efg"),
 		},
 		{
 			desc: "invalid config with multiple targets",
 			cfg: &Config{
-				Targets: []*targetConfig{
+				Targets: []*confignet.TCPAddrConfig{
 					{
-						URL: "invalid://endpoint:  12efg",
+						Endpoint: "endpoint:  12efg",
 					},
 					{
-						URL: "https://example.com",
+						Endpoint: "https://example.com:80",
 					},
 				},
 				ControllerConfig: scraperhelper.NewDefaultControllerConfig(),
 			},
-			expectedErr: fmt.Errorf("%w: %s", errInvalidURL, `parse "invalid://endpoint:  12efg": invalid port ":  12efg" after host`),
+			expectedErr: fmt.Errorf("%w: %s", errInvalidEndpoint, `provided port is not a number:   12efg; endpoint contains a scheme, which is not allowed: https://example.com:80`),
 		},
 		{
-			desc: "missing scheme",
+			desc: "port out of range",
 			cfg: &Config{
-				Targets: []*targetConfig{
+				Targets: []*confignet.TCPAddrConfig{
 					{
-						URL: "www.opentelemetry.io/docs",
+						Endpoint: "www.opentelemetry.io:67000",
 					},
 				},
 				ControllerConfig: scraperhelper.NewDefaultControllerConfig(),
 			},
-			expectedErr: fmt.Errorf("%w: %s", errInvalidURL, `parse "www.opentelemetry.io/docs": invalid URI for request`),
+			expectedErr: fmt.Errorf("%w: %s", errInvalidEndpoint, `provided port is out of valid range (1-65535): 67000`),
+		},
+		{
+			desc: "missing port",
+			cfg: &Config{
+				Targets: []*confignet.TCPAddrConfig{
+					{
+						Endpoint: "www.opentelemetry.io/docs",
+					},
+				},
+				ControllerConfig: scraperhelper.NewDefaultControllerConfig(),
+			},
+			expectedErr: fmt.Errorf("%w: %s", errInvalidEndpoint, `address www.opentelemetry.io/docs: missing port in address`),
 		},
 		{
 			desc: "valid config",
 			cfg: &Config{
-				Targets: []*targetConfig{
+				Targets: []*confignet.TCPAddrConfig{
+					{
+						Endpoint: "opentelemetry.io:443",
+						DialerConfig: confignet.DialerConfig{
+							Timeout: 3 * time.Second,
+						},
+					},
 					{
-						URL: "https://opentelemetry.io",
+						Endpoint: "opentelemetry.io:8080",
+						DialerConfig: confignet.DialerConfig{
+							Timeout: 1 * time.Second,
+						},
 					},
 					{
-						URL: "https://opentelemetry.io:80/docs",
+						Endpoint: "111.222.33.44:10000",
+						DialerConfig: confignet.DialerConfig{
+							Timeout: 5 * time.Second,
+						},
 					},
 				},
 				ControllerConfig: scraperhelper.NewDefaultControllerConfig(),

receiver/tlscheckreceiver/documentation.md

@@ -31,4 +31,4 @@ Time in seconds until certificate expiry, as specified by `NotAfter` field in th
 
 | Name | Description | Values | Enabled |
 | ---- | ----------- | ------ | ------- |
-| tlscheck.url | Url at which the certificate was accessed. | Any Str | true |
+| tlscheck.endpoint | Endpoint at which the certificate was accessed. | Any Str | true |

receiver/tlscheckreceiver/factory.go

@@ -8,17 +8,17 @@ import (
 	"errors"
 
 	"go.opentelemetry.io/collector/component"
+	"go.opentelemetry.io/collector/config/confignet"
 	"go.opentelemetry.io/collector/consumer"
 	"go.opentelemetry.io/collector/receiver"
-	"go.opentelemetry.io/collector/scraper"
+	collectorscraper "go.opentelemetry.io/collector/scraper"
 	"go.opentelemetry.io/collector/scraper/scraperhelper"
 
 	"github.com/open-telemetry/opentelemetry-collector-contrib/receiver/tlscheckreceiver/internal/metadata"
 )
 
 var errConfigNotTLSCheck = errors.New(`invalid config`)
 
-// NewFactory creates a new filestats receiver factory.
 func NewFactory() receiver.Factory {
 	return receiver.NewFactory(
 		metadata.Type,
@@ -27,10 +27,12 @@ func NewFactory() receiver.Factory {
 }
 
 func newDefaultConfig() component.Config {
+	cfg := scraperhelper.NewDefaultControllerConfig()
+
 	return &Config{
-		ControllerConfig:     scraperhelper.NewDefaultControllerConfig(),
+		ControllerConfig:     cfg,
 		MetricsBuilderConfig: metadata.DefaultMetricsBuilderConfig(),
-		Targets:              []*targetConfig{},
+		Targets:              []*confignet.TCPAddrConfig{},
 	}
 }
 
@@ -45,8 +47,8 @@ func newReceiver(
 		return nil, errConfigNotTLSCheck
 	}
 
-	mp := newScraper(tlsCheckConfig, settings)
-	s, err := scraper.NewMetrics(mp.scrape)
+	mp := newScraper(tlsCheckConfig, settings, getConnectionState)
+	s, err := collectorscraper.NewMetrics(mp.scrape)
 	if err != nil {
 		return nil, err
 	}

receiver/tlscheckreceiver/factory_test.go

@@ -10,6 +10,7 @@ import (
 
 	"github.com/stretchr/testify/require"
 	"go.opentelemetry.io/collector/component"
+	"go.opentelemetry.io/collector/config/confignet"
 	"go.opentelemetry.io/collector/consumer/consumertest"
 	"go.opentelemetry.io/collector/receiver/receivertest"
 	"go.opentelemetry.io/collector/scraper/scraperhelper"
@@ -40,7 +41,7 @@ func TestNewFactory(t *testing.T) {
 						InitialDelay:       time.Second,
 					},
 					MetricsBuilderConfig: metadata.DefaultMetricsBuilderConfig(),
-					Targets:              []*targetConfig{},
+					Targets:              []*confignet.TCPAddrConfig{},
 				}
 
 				require.Equal(t, expectedCfg, factory.CreateDefaultConfig())

receiver/tlscheckreceiver/go.mod

@@ -7,6 +7,7 @@ require (
 	github.com/stretchr/testify v1.10.0
 	go.opentelemetry.io/collector/component v1.27.0
 	go.opentelemetry.io/collector/component/componenttest v0.121.0
+	go.opentelemetry.io/collector/config/confignet v1.27.0
 	go.opentelemetry.io/collector/confmap v1.27.0
 	go.opentelemetry.io/collector/consumer v1.27.0
 	go.opentelemetry.io/collector/consumer/consumertest v0.121.0