redisstore

README

redisstore

A Redis based session store for SCS.

Setup

You should follow the instructions to setup a connection pool, and pass the pool to redisstore.New() to establish the session store.

Example

package main

import (
	"io"
	"net/http"

	"github.com/alexedwards/scs/v2"
	"github.com/alexedwards/scs/redisstore"
	"github.com/gomodule/redigo/redis"
)

var sessionManager *scs.SessionManager

func main() {
	// Establish connection pool to Redis.
	pool := &redis.Pool{
		MaxIdle: 10,
		Dial: func() (redis.Conn, error) {
			return redis.Dial("tcp", "host:6379")
		},
	}
	
	// Initialize a new session manager and configure it to use redisstore as the session store.
	sessionManager = scs.New()
	sessionManager.Store = redisstore.New(pool)

	mux := http.NewServeMux()
	mux.HandleFunc("/put", putHandler)
	mux.HandleFunc("/get", getHandler)

	http.ListenAndServe(":4000", sessionManager.LoadAndSave(mux))
}

func putHandler(w http.ResponseWriter, r *http.Request) {
	sessionManager.Put(r.Context(), "message", "Hello from a session!")
}

func getHandler(w http.ResponseWriter, r *http.Request) {
	msg := sessionManager.GetString(r.Context(), "message")
	io.WriteString(w, msg)
}

Expired Session Cleanup

Redis will automatically remove expired session keys.

Key Collisions

By default keys are in the form scs:session:<token>. For example:

"scs:session:ZnirGwi2FiLwXeVlP5nD77IpfJZMVr6un9oZu2qtJrg"

Because the token is highly unique, key collisions are not a concern. But if you're configuring multiple session managers, both of which use redisstore, then you may want the keys to have a different prefix depending on which session manager wrote them. You can do this by using the NewWithPrefix() method like so:

pool := &redis.Pool{
    MaxIdle: 10,
    Dial: func() (redis.Conn, error) {
        return redis.Dial("tcp", "host:6379")
    },
}

sessionManagerOne = scs.New()
sessionManagerOne.Store = redisstore.NewWithPrefix(pool, "scs:session:1:")

sessionManagerTwo = scs.New()
sessionManagerTwo.Store = redisstore.NewWithPrefix(pool, "scs:session:2:")

Iterating over all Sessions

If you intend to use the sessionstore.Iterate() function to iterate over all sessions on a busy Redis server with many keys stored, be warned that this can take a long time and is therefore probably only interesting for debugging purposes.

Documentation

Index

• type RedisStore
  • func New(pool *redis.Pool) *RedisStore
  • func NewWithPrefix(pool *redis.Pool, prefix string) *RedisStore
  • func (r *RedisStore) All() (map[string][]byte, error)
  • func (r *RedisStore) Commit(token string, b []byte, expiry time.Time) error
  • func (r *RedisStore) Delete(token string) error
  • func (r *RedisStore) Find(token string) (b []byte, exists bool, err error)

Types

type RedisStore

type RedisStore struct {
	// contains filtered or unexported fields
}

RedisStore represents the session store.

func New

func New(pool *redis.Pool) *RedisStore

New returns a new RedisStore instance. The pool parameter should be a pointer to a redigo connection pool. See https://godoc.org/github.com/gomodule/redigo/redis#Pool.

func NewWithPrefix

func NewWithPrefix(pool *redis.Pool, prefix string) *RedisStore

NewWithPrefix returns a new RedisStore instance. The pool parameter should be a pointer to a redigo connection pool. The prefix parameter controls the Redis key prefix, which can be used to avoid naming clashes if necessary.

func (*RedisStore) All

func (r *RedisStore) All() (map[string][]byte, error)

All returns a map containing the token and data for all active (i.e. not expired) sessions in the RedisStore instance.

func (*RedisStore) Commit

func (r *RedisStore) Commit(token string, b []byte, expiry time.Time) error

Commit adds a session token and data to the RedisStore instance with the given expiry time. If the session token already exists then the data and expiry time are updated.

func (*RedisStore) Delete

func (r *RedisStore) Delete(token string) error

Delete removes a session token and corresponding data from the RedisStore instance.

func (*RedisStore) Find

func (r *RedisStore) Find(token string) (b []byte, exists bool, err error)

Find returns the data for a given session token from the RedisStore instance. If the session token is not found or is expired, the returned exists flag will be set to false.