[receiver/redis] Add username parameter for connecting to redis (#24408)

**Description:** Adding a feature - Adding username for redis receiver
for connecting to redis over ACL

**Testing:** Running go test is ok. Generating my custom OpenTelemetry
Collector binary with redis receiver and otlp exporter (using ocb). This
custom Opentelemetry Collector collecting redis data by connecting with
a username and password work fine. I test to collect data using password
only, it works too.

**Documentation:** Mardown file has been updated

.chloggen/add-username-parameter-for-connection.yaml

@@ -0,0 +1,20 @@
+# Use this changelog template to create an entry for release notes.
+# If your change doesn't affect end users, such as a test fix or a tooling change,
+# you should instead start your pull request title with [chore] or use the "Skip Changelog" label.
+
+# 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: redisreceiver
+
+# A brief description of the change.  Surround your text with quotes ("") if it needs to start with a backtick (`).
+note: Adding username parameter for connecting to redis 
+
+# Mandatory: One or more tracking issues related to the change. You can use the PR number here if no issue exists.
+issues: [24408]
+
+# (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:

receiver/redisreceiver/config.go

@@ -20,8 +20,14 @@ type Config struct {
 
 	// TODO allow users to add additional resource key value pairs?
 
+	// Optional username. Use the specified Username to authenticate the current connection
+	// with one of the connections defined in the ACL list when connecting
+	// to a Redis 6.0 instance, or greater, that is using the Redis ACL system.
+	Username string `mapstructure:"username"`
+
 	// Optional password. Must match the password specified in the
-	// requirepass server configuration option.
+	// requirepass server configuration option, or the user's password when connecting
+	// to a Redis 6.0 instance, or greater, that is using the Redis ACL system.
 	Password configopaque.String `mapstructure:"password"`
 
 	TLS configtls.TLSClientSetting `mapstructure:"tls,omitempty"`

receiver/redisreceiver/config.md

@@ -12,7 +12,8 @@ and extend it with more fields if needed.
 | collection_interval |[time-Duration](#time-Duration)| 10s |  |
 | endpoint |string|  | Endpoint configures the address for this network connection. For TCP and UDP networks, the address has the form "host:port". The host must be a literal IP address, or a host name that can be resolved to IP addresses. The port must be a literal port number or a service name. If the host is a literal IPv6 address it must be enclosed in square brackets, as in "[2001:db8::1]:80" or "[fe80::1%zone]:80". The zone specifies the scope of the literal IPv6 address as defined in RFC 4007.  |
 | transport |string| tcp | Transport to use. Known protocols are "tcp", "tcp4" (IPv4-only), "tcp6" (IPv6-only), "udp", "udp4" (IPv4-only), "udp6" (IPv6-only), "ip", "ip4" (IPv4-only), "ip6" (IPv6-only), "unix", "unixgram" and "unixpacket".  |
-| password |string|  | Optional password. Must match the password specified in the requirepass server configuration option.  |
+| username |string|  | Optional username. Use the specified username to authenticate the current connection with one of the connections defined in the ACL list when connecting to a Redis 6.0 instance, or greater, that is using the Redis ACL system. |
+| password |string|  | Optional password. Must match the password specified in the requirepass server configuration option or the user's password when connecting to a Redis 6.0 instance, or greater, that is using the Redis ACL system. |
 | tls |[tls-TLSClientSetting](#tls-TLSClientSetting)| <no value> | TLSClientSetting contains TLS configurations that are specific to client connections in addition to the common configurations. This should be used by components configuring TLS client connections.  |
 | metrics |[metrics-MetricsSettings](#metrics-MetricsSettings)| <no value> | MetricsSettings provides settings for redisreceiver metrics.  |
 

receiver/redisreceiver/config_test.go

@@ -38,6 +38,7 @@ func TestConfig(t *testing.T) {
 			TLS: configtls.TLSClientSetting{
 				Insecure: true,
 			},
+			Username: "test",
 			Password: "test",
 			ScraperControllerSettings: scraperhelper.ScraperControllerSettings{
 				CollectionInterval: 10 * time.Second,

receiver/redisreceiver/redis_scraper.go

@@ -35,6 +35,7 @@ const redisMaxDbs = 16 // Maximum possible number of redis databases
 func newRedisScraper(cfg *Config, settings receiver.CreateSettings) (scraperhelper.Scraper, error) {
 	opts := &redis.Options{
 		Addr:     cfg.Endpoint,
+		Username: cfg.Username,
 		Password: string(cfg.Password),
 		Network:  cfg.Transport,
 	}

receiver/redisreceiver/testdata/config.yaml

@@ -1,5 +1,6 @@
 redis:
   endpoint: "localhost:6379"
+  username: "test"
   password: "test"
   collection_interval: 10s
   tls: