Add ParseRedisURI helper function

asynq.go

@@ -7,6 +7,9 @@ package asynq
 import (
 	"crypto/tls"
 	"fmt"
+	"net/url"
+	"strconv"
+	"strings"
 
 	"github.com/go-redis/redis/v7"
 )
@@ -94,6 +97,79 @@ type RedisFailoverClientOpt struct {
 	TLSConfig *tls.Config
 }
 
+// ParseRedisURI parses redis uri string and returns RedisConnOpt if uri is valid.
+// It returns a non-nil error if uri cannot be parsed.
+//
+// Three URI schemes are supported, which are redis:, redis-socket:, and redis-sentinel:.
+// Supported formats are:
+//     redis://[:password@]host[:port][/dbnumber]
+//     redis-socket://[:password@]path[?db=dbnumber]
+//     redis-sentinel://[:password@]host1[:port][,host2:[:port]][,hostN:[:port]][?master=masterName]
+func ParseRedisURI(uri string) (RedisConnOpt, error) {
+	u, err := url.Parse(uri)
+	if err != nil {
+		return nil, fmt.Errorf("asynq: could not parse redis uri: %v", err)
+	}
+	switch u.Scheme {
+	case "redis":
+		return parseRedisURI(u)
+	case "redis-socket":
+		return parseRedisSocketURI(u)
+	case "redis-sentinel":
+		return parseRedisSentinelURI(u)
+	default:
+		return nil, fmt.Errorf("asynq: unsupported uri scheme: %q", u.Scheme)
+	}
+}
+
+func parseRedisURI(u *url.URL) (RedisConnOpt, error) {
+	var db int
+	var err error
+	if len(u.Path) > 0 {
+		xs := strings.Split(strings.Trim(u.Path, "/"), "/")
+		db, err = strconv.Atoi(xs[0])
+		if err != nil {
+			return nil, fmt.Errorf("asynq: could not parse redis uri: database number should be the first segment of the path")
+		}
+	}
+	var password string
+	if v, ok := u.User.Password(); ok {
+		password = v
+	}
+	return RedisClientOpt{Addr: u.Host, DB: db, Password: password}, nil
+}
+
+func parseRedisSocketURI(u *url.URL) (RedisConnOpt, error) {
+	const errPrefix = "asynq: could not parse redis socket uri"
+	if len(u.Path) == 0 {
+		return nil, fmt.Errorf("%s: path does not exist", errPrefix)
+	}
+	q := u.Query()
+	var db int
+	var err error
+	if n := q.Get("db"); n != "" {
+		db, err = strconv.Atoi(n)
+		if err != nil {
+			return nil, fmt.Errorf("%s: query param `db` should be a number", errPrefix)
+		}
+	}
+	var password string
+	if v, ok := u.User.Password(); ok {
+		password = v
+	}
+	return RedisClientOpt{Network: "unix", Addr: u.Path, DB: db, Password: password}, nil
+}
+
+func parseRedisSentinelURI(u *url.URL) (RedisConnOpt, error) {
+	addrs := strings.Split(u.Host, ",")
+	master := u.Query().Get("master")
+	var password string
+	if v, ok := u.User.Password(); ok {
+		password = v
+	}
+	return RedisFailoverClientOpt{MasterName: master, SentinelAddrs: addrs, Password: password}, nil
+}
+
 // createRedisClient returns a redis client given a redis connection configuration.
 //
 // Passing an unexpected type as a RedisConnOpt argument will cause panic.