redis/options.go

436 lines
12 KiB
Go

package redis
import (
"context"
"crypto/tls"
"errors"
"fmt"
"net"
"net/url"
"runtime"
"sort"
"strconv"
"strings"
"time"
"github.com/go-redis/redis/v8/internal/pool"
)
// Limiter is the interface of a rate limiter or a circuit breaker.
type Limiter interface {
// Allow returns nil if operation is allowed or an error otherwise.
// If operation is allowed client must ReportResult of the operation
// whether it is a success or a failure.
Allow() error
// ReportResult reports the result of the previously allowed operation.
// nil indicates a success, non-nil error usually indicates a failure.
ReportResult(result error)
}
// Options keeps the settings to setup redis connection.
type Options struct {
// The network type, either tcp or unix.
// Default is tcp.
Network string
// host:port address.
Addr string
// Dialer creates new network connection and has priority over
// Network and Addr options.
Dialer func(ctx context.Context, network, addr string) (net.Conn, error)
// Hook that is called when new connection is established.
OnConnect func(ctx context.Context, cn *Conn) error
// 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
// Optional password. Must match the password specified in the
// requirepass server configuration option (if connecting to a Redis 5.0 instance, or lower),
// or the User Password when connecting to a Redis 6.0 instance, or greater,
// that is using the Redis ACL system.
Password string
// Database to be selected after connecting to the server.
DB int
// Maximum number of retries before giving up.
// Default is 3 retries; -1 (not 0) disables retries.
MaxRetries int
// Minimum backoff between each retry.
// Default is 8 milliseconds; -1 disables backoff.
MinRetryBackoff time.Duration
// Maximum backoff between each retry.
// Default is 512 milliseconds; -1 disables backoff.
MaxRetryBackoff time.Duration
// Dial timeout for establishing new connections.
// Default is 5 seconds.
DialTimeout time.Duration
// Timeout for socket reads. If reached, commands will fail
// with a timeout instead of blocking. Use value -1 for no timeout and 0 for default.
// Default is 3 seconds.
ReadTimeout time.Duration
// Timeout for socket writes. If reached, commands will fail
// with a timeout instead of blocking.
// Default is ReadTimeout.
WriteTimeout time.Duration
// Type of connection pool.
// true for FIFO pool, false for LIFO pool.
// Note that fifo has higher overhead compared to lifo.
PoolFIFO bool
// Maximum number of socket connections.
// Default is 10 connections per every available CPU as reported by runtime.GOMAXPROCS.
PoolSize int
// Minimum number of idle connections which is useful when establishing
// new connection is slow.
MinIdleConns int
// Connection age at which client retires (closes) the connection.
// Default is to not close aged connections.
MaxConnAge time.Duration
// Amount of time client waits for connection if all connections
// are busy before returning an error.
// Default is ReadTimeout + 1 second.
PoolTimeout time.Duration
// Amount of time after which client closes idle connections.
// Should be less than server's timeout.
// Default is 5 minutes. -1 disables idle timeout check.
IdleTimeout time.Duration
// Frequency of idle checks made by idle connections reaper.
// Default is 1 minute. -1 disables idle connections reaper,
// but idle connections are still discarded by the client
// if IdleTimeout is set.
IdleCheckFrequency time.Duration
// Enables read only queries on slave nodes.
readOnly bool
// TLS Config to use. When set TLS will be negotiated.
TLSConfig *tls.Config
// Limiter interface used to implemented circuit breaker or rate limiter.
Limiter Limiter
}
func (opt *Options) init() {
if opt.Addr == "" {
opt.Addr = "localhost:6379"
}
if opt.Network == "" {
if strings.HasPrefix(opt.Addr, "/") {
opt.Network = "unix"
} else {
opt.Network = "tcp"
}
}
if opt.DialTimeout == 0 {
opt.DialTimeout = 5 * time.Second
}
if opt.Dialer == nil {
opt.Dialer = DefaultDialer(opt)
}
if opt.PoolSize == 0 {
opt.PoolSize = 10 * runtime.GOMAXPROCS(0)
}
switch opt.ReadTimeout {
case -1:
opt.ReadTimeout = 0
case 0:
opt.ReadTimeout = 3 * time.Second
}
switch opt.WriteTimeout {
case -1:
opt.WriteTimeout = 0
case 0:
opt.WriteTimeout = opt.ReadTimeout
}
if opt.PoolTimeout == 0 {
opt.PoolTimeout = opt.ReadTimeout + time.Second
}
if opt.IdleTimeout == 0 {
opt.IdleTimeout = 5 * time.Minute
}
if opt.IdleCheckFrequency == 0 {
opt.IdleCheckFrequency = time.Minute
}
if opt.MaxRetries == -1 {
opt.MaxRetries = 0
} else if opt.MaxRetries == 0 {
opt.MaxRetries = 3
}
switch opt.MinRetryBackoff {
case -1:
opt.MinRetryBackoff = 0
case 0:
opt.MinRetryBackoff = 8 * time.Millisecond
}
switch opt.MaxRetryBackoff {
case -1:
opt.MaxRetryBackoff = 0
case 0:
opt.MaxRetryBackoff = 512 * time.Millisecond
}
}
func (opt *Options) clone() *Options {
clone := *opt
return &clone
}
// DefaultDialer returns a function that will be used as the default dialer
// when none is specified in Options.Dialer.
func DefaultDialer(opt *Options) func(context.Context, string, string) (net.Conn, error) {
return func(ctx context.Context, network, addr string) (net.Conn, error) {
netDialer := &net.Dialer{
Timeout: opt.DialTimeout,
KeepAlive: 5 * time.Minute,
}
if opt.TLSConfig == nil {
return netDialer.DialContext(ctx, network, addr)
}
return tls.DialWithDialer(netDialer, network, addr, opt.TLSConfig)
}
}
// ParseURL parses an URL into Options that can be used to connect to Redis.
// Scheme is required.
// There are two connection types: by tcp socket and by unix socket.
// Tcp connection:
// redis://<user>:<password>@<host>:<port>/<db_number>
// Unix connection:
// unix://<user>:<password>@</path/to/redis.sock>?db=<db_number>
// 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
// Examples:
// redis://user:password@localhost:6789/3?dial_timeout=3&db=1&read_timeout=6s&max_retries=2
// is equivalent to:
// &Options{
// Network: "tcp",
// Addr: "localhost:6789",
// DB: 1, // path "/3" was overridden by "&db=1"
// DialTimeout: 3 * time.Second, // no time unit = seconds
// ReadTimeout: 6 * time.Second,
// MaxRetries: 2,
// }
func ParseURL(redisURL string) (*Options, error) {
u, err := url.Parse(redisURL)
if err != nil {
return nil, err
}
switch u.Scheme {
case "redis", "rediss":
return setupTCPConn(u)
case "unix":
return setupUnixConn(u)
default:
return nil, fmt.Errorf("redis: invalid URL scheme: %s", u.Scheme)
}
}
func setupTCPConn(u *url.URL) (*Options, error) {
o := &Options{Network: "tcp"}
o.Username, o.Password = getUserPassword(u)
h, p, err := net.SplitHostPort(u.Host)
if err != nil {
h = u.Host
}
if h == "" {
h = "localhost"
}
if p == "" {
p = "6379"
}
o.Addr = net.JoinHostPort(h, p)
f := strings.FieldsFunc(u.Path, func(r rune) bool {
return r == '/'
})
switch len(f) {
case 0:
o.DB = 0
case 1:
if o.DB, err = strconv.Atoi(f[0]); err != nil {
return nil, fmt.Errorf("redis: invalid database number: %q", f[0])
}
default:
return nil, fmt.Errorf("redis: invalid URL path: %s", u.Path)
}
if u.Scheme == "rediss" {
o.TLSConfig = &tls.Config{ServerName: h}
}
return setupConnParams(u, o)
}
func setupUnixConn(u *url.URL) (*Options, error) {
o := &Options{
Network: "unix",
}
if strings.TrimSpace(u.Path) == "" { // path is required with unix connection
return nil, errors.New("redis: empty unix socket path")
}
o.Addr = u.Path
o.Username, o.Password = getUserPassword(u)
return setupConnParams(u, o)
}
type queryOptions struct {
q url.Values
err error
}
func (o *queryOptions) string(name string) string {
vs := o.q[name]
if len(vs) == 0 {
return ""
}
delete(o.q, name) // enable detection of unknown parameters
return vs[len(vs)-1]
}
func (o *queryOptions) int(name string) int {
s := o.string(name)
if s == "" {
return 0
}
i, err := strconv.Atoi(s)
if err == nil {
return i
}
if o.err == nil {
o.err = fmt.Errorf("redis: invalid %s number: %s", name, err)
}
return 0
}
func (o *queryOptions) duration(name string) time.Duration {
s := o.string(name)
if s == "" {
return 0
}
// try plain number first
if i, err := strconv.Atoi(s); err == nil {
if i <= 0 {
// disable timeouts
return -1
}
return time.Duration(i) * time.Second
}
dur, err := time.ParseDuration(s)
if err == nil {
return dur
}
if o.err == nil {
o.err = fmt.Errorf("redis: invalid %s duration: %w", name, err)
}
return 0
}
func (o *queryOptions) bool(name string) bool {
switch s := o.string(name); s {
case "true", "1":
return true
case "false", "0", "":
return false
default:
if o.err == nil {
o.err = fmt.Errorf("redis: invalid %s boolean: expected true/false/1/0 or an empty string, got %q", name, s)
}
return false
}
}
func (o *queryOptions) remaining() []string {
if len(o.q) == 0 {
return nil
}
keys := make([]string, 0, len(o.q))
for k := range o.q {
keys = append(keys, k)
}
sort.Strings(keys)
return keys
}
// setupConnParams converts query parameters in u to option value in o.
func setupConnParams(u *url.URL, o *Options) (*Options, error) {
q := queryOptions{q: u.Query()}
// compat: a future major release may use q.int("db")
if tmp := q.string("db"); tmp != "" {
db, err := strconv.Atoi(tmp)
if err != nil {
return nil, fmt.Errorf("redis: invalid database number: %w", err)
}
o.DB = db
}
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.MaxConnAge = q.duration("max_conn_age")
o.PoolTimeout = q.duration("pool_timeout")
o.IdleTimeout = q.duration("idle_timeout")
o.IdleCheckFrequency = q.duration("idle_check_frequency")
if q.err != nil {
return nil, q.err
}
// 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 getUserPassword(u *url.URL) (string, string) {
var user, password string
if u.User != nil {
user = u.User.Username()
if p, ok := u.User.Password(); ok {
password = p
}
}
return user, password
}
func newConnPool(opt *Options) *pool.ConnPool {
return pool.NewConnPool(&pool.Options{
Dialer: func(ctx context.Context) (net.Conn, error) {
return opt.Dialer(ctx, opt.Network, opt.Addr)
},
PoolFIFO: opt.PoolFIFO,
PoolSize: opt.PoolSize,
MinIdleConns: opt.MinIdleConns,
MaxConnAge: opt.MaxConnAge,
PoolTimeout: opt.PoolTimeout,
IdleTimeout: opt.IdleTimeout,
IdleCheckFrequency: opt.IdleCheckFrequency,
})
}