Mnemosyne

Introduction

Mnemosyne is an open-source self-hosted session management service. It's written in Go, making it easy to build and deploy as a static binary.

It provides gRPC interface. Messages are encoded using protobuf.

Quick Start

To install and run service:

$ go get -d github.com/piotrkowalczuk/mnemosyne/...
$ cd $GOPATH/src/github.com/piotrkowalczuk/mnemosyne
$ make
$ mnemosyned -log.environment=development -postgres.address='postgres://localhost/example?sslmode=disable'

Storage Engine

Goal is to support multiple storage's, like PostgreSQL, Redis or MongoDB. Nevertheless currently supported is only PostgreSQL.

Remote Procedure Call API

For communication, Mnemosyne is exposing RPC API that uses protocol buffers, Google’s mature open source mechanism for serializing structured data.

• Create
• Get
• List
• Exists
• Abandon
• SetData
• Delete

Installation

Mnemosyne can be installed in one way, from source. Or can be used as a container using docker image. It is worth to mention that latest tag is released after each successful master branch build. Please use only images tagged using specific version anywhere else than a local development environment.

From source

To install from source both go tools and dep is required.

$ go get -d github.com/piotrkowalczuk/mnemosyne/...
$ cd $GOPATH/src/github.com/piotrkowalczuk/mnemosyne
$ make

Configuration

mnemosyned accepts command line arguments to control its behavior. Possible options are listed below.

Name	Flag	Default	Type
host	-host	127.0.0.1	string
port	-port	8080	int
grpc debug mode	-grpc.debug	false	boolean
cluster listen address	-cluster.listen		string
cluster seeds	-cluster.seeds		string
time to live	-ttl	24m	duration
time to clear	-ttc	1m	duration
logger environment	-log.environment	production	enum(development, production, stackdriver)
logger level	-log.level	info	enum(debug, info, warn, error, dpanic, panic, fatal)
storage	-storage	postgres	enum(postgres)
postgres address	-postgres.address	postgres://postgres:postgres@postgres/postgres?sslmode=disable	string
postgres table	-postgres.table	session	string
postgres schema	-postgres.schema	mnemosyne	string
tls	-tls	false	boolean
tls certificate file	-tls.crt		string
tls key file	-tls.key		string

Running

As we know, mnemosyne can be configured in many ways. For the beginning we can start simple:

$ mnemosyned postgres.address="postgres://localhost/test?sslmode=disable"

Mnemosyne will automatically create all required tables/indexes for specified database.

Monitoring

mnemosyned works well with Prometheus. It exposes multiple metrics through /metrics endpoint, it includes:

• mnemosyned_cache_hits_total
• mnemosyned_cache_misses_total
• mnemosyned_cache_refresh_total
• mnemosyned_storage_postgres_errors_total
• mnemosyned_storage_postgres_queries_total
• mnemosyned_storage_postgres_query_duration_seconds
• mnemosyned_storage_postgres_connections

Additionally to that mnemosyned is using internally promgrpc package to monitor entire incoming and outgoing RPC traffic.

Examples

Go

package main

import (
	"fmt"

	"golang.org/x/net/context"
	"github.com/piotrkowalczuk/mnemosyne"
)

func main() {
	mnemo, err := mnemosyne.New(mnemosyne.MnemosyneOpts{
		Addresses: []string{"127.0.0.1:8080"},
		Block: true,
	})
	if err != nil {
		// ...
	}
	defer mnemo.Close()

	ses, err := mnemo.Start(context.Background(), "subject-id", "subject-client", map[string]string{
		"username": "johnsnow@gmail.com",
		"first_name": "John",
		"last_name": "Snow",
	})
	if err != nil {
		// ...
	}

	fmt.Println(ses.AccessToken)
}

Python

Library is available through pypi and can be installed by typing pip install mnemosyne-client.

from  mnemosynerpc import session_pb2, session_pb2_grpc
import grpc


channel = grpc.insecure_channel('localhost:8080')
stub = session_pb2_grpc.SessionManagerStub(channel)

for i in range(0, 10):
	res = stub.Start(session_pb2.StartRequest(session=session_pb2.Session(subject_id=str(i))))

	res = stub.Get(session_pb2.GetRequest(access_token=res.session.access_token))
	print "%s - %s" % (res.session.access_token, res.session.expire_at.ToJsonString())

Contribution

TODO: describe