Add ParseURL function for cluster mode (#1924)

* feat: add ParseClusterURL to allow for parsing of redis cluster urls into cluster options

Author: stephaniehingtgen

cluster.go

@@ -6,8 +6,10 @@ import (
 	"fmt"
 	"math"
 	"net"
+	"net/url"
 	"runtime"
 	"sort"
+	"strings"
 	"sync"
 	"sync/atomic"
 	"time"
@@ -131,6 +133,123 @@ func (opt *ClusterOptions) init() {
 	}
 }
 
+// ParseClusterURL parses a URL into ClusterOptions that can be used to connect to Redis.
+// The URL must be in the form:
+//		redis://<user>:<password>@<host>:<port>
+//		or
+//		rediss://<user>:<password>@<host>:<port>
+// To add additional addresses, specify the query parameter, "addr" one or more times. e.g:
+//		redis://<user>:<password>@<host>:<port>?addr=<host2>:<port2>&addr=<host3>:<port3>
+//		or
+//		rediss://<user>:<password>@<host>:<port>?addr=<host2>:<port2>&addr=<host3>:<port3>
+//
+// Most Option fields can be set using query parameters, with the following restrictions:
+//	- field names are mapped using snake-case conversion: to set MaxRetries, use max_retries
+//	- only scalar type fields are supported (bool, int, time.Duration)
+//	- for time.Duration fields, values must be a valid input for time.ParseDuration();
+//	  additionally a plain integer as value (i.e. without unit) is intepreted as seconds
+//	- to disable a duration field, use value less than or equal to 0; to use the default
+//	  value, leave the value blank or remove the parameter
+//	- only the last value is interpreted if a parameter is given multiple times
+//	- fields "network", "addr", "username" and "password" can only be set using other
+//	  URL attributes (scheme, host, userinfo, resp.), query paremeters using these
+//	  names will be treated as unknown parameters
+//	- unknown parameter names will result in an error
+// Example:
+//		redis://user:password@localhost:6789?dial_timeout=3&read_timeout=6s&addr=localhost:6790&addr=localhost:6791
+//		is equivalent to:
+//		&ClusterOptions{
+//			Addr:        ["localhost:6789", "localhost:6790", "localhost:6791"]
+//			DialTimeout: 3 * time.Second, // no time unit = seconds
+//			ReadTimeout: 6 * time.Second,
+//		}
+func ParseClusterURL(redisURL string) (*ClusterOptions, error) {
+	o := &ClusterOptions{}
+
+	u, err := url.Parse(redisURL)
+	if err != nil {
+		return nil, err
+	}
+
+	// add base URL to the array of addresses
+	// more addresses may be added through the URL params
+	h, p := getHostPortWithDefaults(u)
+	o.Addrs = append(o.Addrs, net.JoinHostPort(h, p))
+
+	// setup username, password, and other configurations
+	o, err = setupClusterConn(u, h, o)
+	if err != nil {
+		return nil, err
+	}
+
+	return o, nil
+}
+
+// setupClusterConn gets the username and password from the URL and the query parameters.
+func setupClusterConn(u *url.URL, host string, o *ClusterOptions) (*ClusterOptions, error) {
+	switch u.Scheme {
+	case "rediss":
+		o.TLSConfig = &tls.Config{ServerName: host}
+		fallthrough
+	case "redis":
+		o.Username, o.Password = getUserPassword(u)
+	default:
+		return nil, fmt.Errorf("redis: invalid URL scheme: %s", u.Scheme)
+	}
+
+	// retrieve the configuration from the query parameters
+	o, err := setupClusterQueryParams(u, o)
+	if err != nil {
+		return nil, err
+	}
+
+	return o, nil
+}
+
+// setupClusterQueryParams converts query parameters in u to option value in o.
+func setupClusterQueryParams(u *url.URL, o *ClusterOptions) (*ClusterOptions, error) {
+	q := queryOptions{q: u.Query()}
+
+	o.MaxRedirects = q.int("max_redirects")
+	o.ReadOnly = q.bool("read_only")
+	o.RouteByLatency = q.bool("route_by_latency")
+	o.RouteByLatency = q.bool("route_randomly")
+	o.MaxRetries = q.int("max_retries")
+	o.MinRetryBackoff = q.duration("min_retry_backoff")
+	o.MaxRetryBackoff = q.duration("max_retry_backoff")
+	o.DialTimeout = q.duration("dial_timeout")
+	o.ReadTimeout = q.duration("read_timeout")
+	o.WriteTimeout = q.duration("write_timeout")
+	o.PoolFIFO = q.bool("pool_fifo")
+	o.PoolSize = q.int("pool_size")
+	o.MinIdleConns = q.int("min_idle_conns")
+	o.PoolTimeout = q.duration("pool_timeout")
+	o.ConnMaxLifetime = q.duration("conn_max_lifetime")
+	o.ConnMaxIdleTime = q.duration("conn_max_idle_time")
+
+	if q.err != nil {
+		return nil, q.err
+	}
+
+	// addr can be specified as many times as needed
+	addrs := q.strings("addr")
+	for _, addr := range addrs {
+		h, p, err := net.SplitHostPort(addr)
+		if err != nil || h == "" || p == "" {
+			return nil, fmt.Errorf("redis: unable to parse addr param: %s", addr)
+		}
+
+		o.Addrs = append(o.Addrs, net.JoinHostPort(h, p))
+	}
+
+	// any parameters left?
+	if r := q.remaining(); len(r) > 0 {
+		return nil, fmt.Errorf("redis: unexpected option: %s", strings.Join(r, ", "))
+	}
+
+	return o, nil
+}
+
 func (opt *ClusterOptions) clientOptions() *Options {
 	return &Options{
 		Dialer:    opt.Dialer,
@@ -1537,7 +1656,6 @@ func (c *ClusterClient) SSubscribe(ctx context.Context, channels ...string) *Pub
 	return pubsub
 }
 
-
 func (c *ClusterClient) retryBackoff(attempt int) time.Duration {
 	return internal.RetryBackoff(attempt, c.opt.MinRetryBackoff, c.opt.MaxRetryBackoff)
 }

cluster_test.go

@@ -2,15 +2,19 @@ package redis_test
 
 import (
 	"context"
+	"crypto/tls"
+	"errors"
 	"fmt"
 	"net"
 	"strconv"
 	"strings"
 	"sync"
+	"testing"
 	"time"
 
 	. "github.com/onsi/ginkgo"
 	. "github.com/onsi/gomega"
+	"github.com/stretchr/testify/assert"
 
 	"github.com/go-redis/redis/v9"
 	"github.com/go-redis/redis/v9/internal/hashtag"
@@ -1296,3 +1300,138 @@ var _ = Describe("ClusterClient timeout", func() {
 		testTimeout()
 	})
 })
+
+func TestParseClusterURL(t *testing.T) {
+	cases := []struct {
+		test string
+		url  string
+		o    *redis.ClusterOptions // expected value
+		err  error
+	}{
+		{
+			test: "ParseRedisURL",
+			url:  "redis://localhost:123",
+			o:    &redis.ClusterOptions{Addrs: []string{"localhost:123"}},
+		}, {
+			test: "ParseRedissURL",
+			url:  "rediss://localhost:123",
+			o:    &redis.ClusterOptions{Addrs: []string{"localhost:123"}, TLSConfig: &tls.Config{ServerName: "localhost"}},
+		}, {
+			test: "MissingRedisPort",
+			url:  "redis://localhost",
+			o:    &redis.ClusterOptions{Addrs: []string{"localhost:6379"}},
+		}, {
+			test: "MissingRedissPort",
+			url:  "rediss://localhost",
+			o:    &redis.ClusterOptions{Addrs: []string{"localhost:6379"}, TLSConfig: &tls.Config{ServerName: "localhost"}},
+		}, {
+			test: "MultipleRedisURLs",
+			url:  "redis://localhost:123?addr=localhost:1234&addr=localhost:12345",
+			o:    &redis.ClusterOptions{Addrs: []string{"localhost:123", "localhost:1234", "localhost:12345"}},
+		}, {
+			test: "MultipleRedissURLs",
+			url:  "rediss://localhost:123?addr=localhost:1234&addr=localhost:12345",
+			o:    &redis.ClusterOptions{Addrs: []string{"localhost:123", "localhost:1234", "localhost:12345"}, TLSConfig: &tls.Config{ServerName: "localhost"}},
+		}, {
+			test: "OnlyPassword",
+			url:  "redis://:bar@localhost:123",
+			o:    &redis.ClusterOptions{Addrs: []string{"localhost:123"}, Password: "bar"},
+		}, {
+			test: "OnlyUser",
+			url:  "redis://foo@localhost:123",
+			o:    &redis.ClusterOptions{Addrs: []string{"localhost:123"}, Username: "foo"},
+		}, {
+			test: "RedisUsernamePassword",
+			url:  "redis://foo:bar@localhost:123",
+			o:    &redis.ClusterOptions{Addrs: []string{"localhost:123"}, Username: "foo", Password: "bar"},
+		}, {
+			test: "RedissUsernamePassword",
+			url:  "rediss://foo:bar@localhost:123?addr=localhost:1234",
+			o:    &redis.ClusterOptions{Addrs: []string{"localhost:123", "localhost:1234"}, Username: "foo", Password: "bar", TLSConfig: &tls.Config{ServerName: "localhost"}},
+		}, {
+			test: "QueryParameters",
+			url:  "redis://localhost:123?read_timeout=2&pool_fifo=true&addr=localhost:1234",
+			o:    &redis.ClusterOptions{Addrs: []string{"localhost:123", "localhost:1234"}, ReadTimeout: 2 * time.Second, PoolFIFO: true},
+		}, {
+			test: "DisabledTimeout",
+			url:  "redis://localhost:123?conn_max_idle_time=0",
+			o:    &redis.ClusterOptions{Addrs: []string{"localhost:123"}, ConnMaxIdleTime: -1},
+		}, {
+			test: "DisabledTimeoutNeg",
+			url:  "redis://localhost:123?conn_max_idle_time=-1",
+			o:    &redis.ClusterOptions{Addrs: []string{"localhost:123"}, ConnMaxIdleTime: -1},
+		}, {
+			test: "UseDefault",
+			url:  "redis://localhost:123?conn_max_idle_time=",
+			o:    &redis.ClusterOptions{Addrs: []string{"localhost:123"}, ConnMaxIdleTime: 0},
+		}, {
+			test: "UseDefaultMissing=",
+			url:  "redis://localhost:123?conn_max_idle_time",
+			o:    &redis.ClusterOptions{Addrs: []string{"localhost:123"}, ConnMaxIdleTime: 0},
+		}, {
+			test: "InvalidQueryAddr",
+			url:  "rediss://foo:bar@localhost:123?addr=rediss://foo:barr@localhost:1234",
+			err:  errors.New(`redis: unable to parse addr param: rediss://foo:barr@localhost:1234`),
+		}, {
+			test: "InvalidInt",
+			url:  "redis://localhost?pool_size=five",
+			err:  errors.New(`redis: invalid pool_size number: strconv.Atoi: parsing "five": invalid syntax`),
+		}, {
+			test: "InvalidBool",
+			url:  "redis://localhost?pool_fifo=yes",
+			err:  errors.New(`redis: invalid pool_fifo boolean: expected true/false/1/0 or an empty string, got "yes"`),
+		}, {
+			test: "UnknownParam",
+			url:  "redis://localhost?abc=123",
+			err:  errors.New("redis: unexpected option: abc"),
+		}, {
+			test: "InvalidScheme",
+			url:  "https://google.com",
+			err:  errors.New("redis: invalid URL scheme: https"),
+		},
+	}
+
+	for i := range cases {
+		tc := cases[i]
+		t.Run(tc.test, func(t *testing.T) {
+			t.Parallel()
+
+			actual, err := redis.ParseClusterURL(tc.url)
+			if tc.err == nil && err != nil {
+				t.Fatalf("unexpected error: %q", err)
+				return
+			}
+			if tc.err != nil && err == nil {
+				t.Fatalf("expected error: got %+v", actual)
+				return
+			}
+			if tc.err != nil && err != nil {
+				if tc.err.Error() != err.Error() {
+					t.Fatalf("got %q, expected %q", err, tc.err)
+				}
+				return
+			}
+			comprareOptions(t, actual, tc.o)
+		})
+	}
+}
+
+func comprareOptions(t *testing.T, actual, expected *redis.ClusterOptions) {
+	t.Helper()
+	assert.Equal(t, expected.Addrs, actual.Addrs)
+	assert.Equal(t, expected.TLSConfig, actual.TLSConfig)
+	assert.Equal(t, expected.Username, actual.Username)
+	assert.Equal(t, expected.Password, actual.Password)
+	assert.Equal(t, expected.MaxRetries, actual.MaxRetries)
+	assert.Equal(t, expected.MinRetryBackoff, actual.MinRetryBackoff)
+	assert.Equal(t, expected.MaxRetryBackoff, actual.MaxRetryBackoff)
+	assert.Equal(t, expected.DialTimeout, actual.DialTimeout)
+	assert.Equal(t, expected.ReadTimeout, actual.ReadTimeout)
+	assert.Equal(t, expected.WriteTimeout, actual.WriteTimeout)
+	assert.Equal(t, expected.PoolFIFO, actual.PoolFIFO)
+	assert.Equal(t, expected.PoolSize, actual.PoolSize)
+	assert.Equal(t, expected.MinIdleConns, actual.MinIdleConns)
+	assert.Equal(t, expected.ConnMaxLifetime, actual.ConnMaxLifetime)
+	assert.Equal(t, expected.ConnMaxIdleTime, actual.ConnMaxIdleTime)
+	assert.Equal(t, expected.PoolTimeout, actual.PoolTimeout)
+}

go.mod

@@ -7,15 +7,19 @@ require (
 	github.com/dgryski/go-rendezvous v0.0.0-20200823014737-9f7001d12a5f
 	github.com/onsi/ginkgo v1.16.5
 	github.com/onsi/gomega v1.20.2
+	github.com/stretchr/testify v1.5.1
 )
 
 require (
+	github.com/davecgh/go-spew v1.1.1 // indirect
 	github.com/fsnotify/fsnotify v1.4.9 // indirect
 	github.com/google/go-cmp v0.5.8 // indirect
 	github.com/nxadm/tail v1.4.8 // indirect
+	github.com/pmezard/go-difflib v1.0.0 // indirect
 	golang.org/x/net v0.0.0-20220722155237-a158d28d115b // indirect
 	golang.org/x/sys v0.0.0-20220722155257-8c9f86f7a55f // indirect
 	golang.org/x/text v0.3.7 // indirect
 	gopkg.in/tomb.v1 v1.0.0-20141024135613-dd632973f1e7 // indirect
+	gopkg.in/yaml.v2 v2.3.0 // indirect
 	gopkg.in/yaml.v3 v3.0.1 // indirect
 )