Redis driver, changing name of the package

README.md

@@ -9,7 +9,7 @@ servers instead. Each server runs one or more instances of lobby daemon and it r
 about its hostname and configured labels.
 
 Labels are similar what you could know from AWS. It's basically alternative to resources' tags feature
-with the only different that you can use this anywhere. Every server sends something called
+with the only different that you can use this anywhere including AWS. Every server sends something called
 "discovery packet" which is basically a json that looks like this:
 
 ```json
@@ -19,14 +19,14 @@ with the only different that you can use this anywhere. Every server sends somet
         "service:smtp",
         "public_ip4:1.2.3.4",
         "public_ip6:2a03::1"
-    ],
+    ]
-    "last_check": 1630612478
 }
 ```
 
 The packet contains information what's the server's hostname and then list of labels describing
-what's running on it and what are the IP addresses. What's in the labels is completely up to you
+what's running on it, what are the IP addresses, services, directories to backup or server's location for example.
-but in some use-cases (Node Exporter API endpoint) it expects "NAME:VALUE" format.
+What's in the labels is completely up to you but in some use-cases (Node Exporter API endpoint) it
+expects "NAME:VALUE" format.
 
 The labels can be configured via environment variables but also as files located in
 */etc/lobby/labels* (configurable path) so it can dynamically change. Another way is to use
@@ -88,22 +88,29 @@ To test if local instance is running call this:
 
 There are other config directives you can use to fine-tune lobbyd to exactly what you need.
 
-| Environment variable    | Type   | Default           | Required | Note                                                                                                                                                    |
+| Environment variable    | Type   | Default           | Required          | Note                                                                                                                                                    |
-| ----------------------- | ------ | ----------------- | -------- | ------------------------------------------------------------------------------------------------------------------------------------------------------- |
+| ----------------------- | ------ | ----------------- | ----------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------- |
-| TOKEN                   | string |                   | no       | Authentication token for API, if empty auth is disabled                                                                                                 |
+| TOKEN                   | string |                   | no                | Authentication token for API, if empty auth is disabled                                                                                                 |
-| HOST                    | string | 127.0.0.1         | no       | IP address used for the REST server to listen                                                                                                           |
+| HOST                    | string | 127.0.0.1         | no                | IP address used for the REST server to listen                                                                                                           |
-| PORT                    | int    | 1313              | no       | Port related to the address above                                                                                                                       |
+| PORT                    | int    | 1313              | no                | Port related to the address above                                                                                                                       |
-| NATS_URL                | string |                   | yes      | NATS URL used to connect to the NATS server                                                                                                             |
+| DISABLE_API             | bool   | false             | no                | If true API interface won't start                                                                                                                       |
-| NATS_DISCOVERY_CHANNEL  | string | lobby.discovery   | no       | Channel where the keep-alive packets are sent                                                                                                           |
+| DRIVER                  | string | NATS              | yes               | Selects which driver is used to exchange the discovery packets.                                                                                         |
-| LABELS                  | string |                   | no       | List of labels, labels should be separated by comma                                                                                                     |
+| NATS_URL                | string |                   | yes (NATS driver) | NATS URL used to connect to the NATS server                                                                                                             |
-| LABELS_PATH             | string | /etc/lobby/labels | no       | Path where filesystem based labels are located, one label per line, filename is not important for lobby                                                 |
+| NATS_DISCOVERY_CHANNEL  | string | lobby.discovery   | no                | Channel where the keep-alive packets are sent                                                                                                           |
-| RUNTIME_LABELS_FILENAME | string | _runtime          | no       | Filename for file created in LabelsPath where runtime labels will be added                                                                              |
+| REDIS_HOST              | string | 127.0.0.1"        | no                | Redis host                                                                                                                                              |
-| HOSTNAME                | string |                   | no       | Override local machine's hostname                                                                                                                       |
+| REDIS_PORT              | uint16 | 6379              | no                | Redis port                                                                                                                                              |
-| CLEAN_EVERY             | int    | 15                | no       | How often to clean the list of discovered servers to get rid of the not alive ones [secs]                                                               |
+| REDIS_DB                | string | 0                 | no                | Redis DB                                                                                                                                                |
-| KEEP_ALIVE              | int    | 5                 | no       | how often to send the keep-alive discovery message with all available information [secs]                                                                |
+| REDIS_CHANNEL           | string | lobby:discovery   | no                | Redis channel                                                                                                                                           |
-| TTL                     | int    | 30                | no       | After how many secs is discovery record considered as invalid                                                                                           |
+| REDIS_PASSWORD          | string |                   | no                | Redis password                                                                                                                                          |
-| NODE_EXPORTER_PORT      | int    | 9100              | no       | Default port where node_exporter listens on all registered servers, this is used when the special prometheus labels doesn't contain port                |
+| LABELS                  | string |                   | no                | List of labels, labels should be separated by comma                                                                                                     |
-| REGISTER                | bool   | true              | no       | If true (default) then local instance is registered with other instance (discovery packet is sent regularly), if false the daemon runs only as a client |
+| LABELS_PATH             | string | /etc/lobby/labels | no                | Path where filesystem based labels are located, one label per line, filename is not important for lobby                                                 |
+| RUNTIME_LABELS_FILENAME | string | _runtime          | no                | Filename for file created in LabelsPath where runtime labels will be added                                                                              |
+| HOSTNAME                | string |                   | no                | Override local machine's hostname                                                                                                                       |
+| CLEAN_EVERY             | int    | 15                | no                | How often to clean the list of discovered servers to get rid of the not alive ones [secs]                                                               |
+| KEEP_ALIVE              | int    | 5                 | no                | how often to send the keep-alive discovery message with all available information [secs]                                                                |
+| TTL                     | int    | 30                | no                | After how many secs is discovery record considered as invalid                                                                                           |
+| NODE_EXPORTER_PORT      | int    | 9100              | no                | Default port where node_exporter listens on all registered servers, this is used when the special prometheus labels doesn't contain port                |
+| REGISTER                | bool   | true              | no                | If true (default) then local instance is registered with other instance (discovery packet is sent regularly), if false the daemon runs only as a client |
 
 
 ### Service discovery for Prometheus
@@ -197,12 +204,25 @@ If there is an error the error message is returned as plain text.
 * Golang client is part of this repository.
 * There is also [Python client](https://github.com/by-cx/lobby-python) available.
 
+## Notes
+
+I wanted to use SQS or SNS as backend but when I checked the services I found out
+it wouldn't work. SNS would require open HTTP server whicn is hard to do in our
+infrastructure and I couldn't find a way how SQS could deliver every message
+to all instances of lobbyd.
+
+Instead I decided to implement Redis because it's much easier to use for
+development and testing. But there is no reason why it couldn't work in production
+too.
+
+
 ## TODO
 
 * [X] Tests
 * [ ] Command hooks - script or list of scripts that are triggered when discovery status has changed
 * [ ] Support for multiple active backend drivers
-* [ ] SNS driver
+* [ ] Redis driver
+* [X] Remove the 5 secs waiting when daemon is stopped
 * [X] API to allow add labels at runtime
 
 

client/main.go

@@ -6,8 +6,8 @@ import (
 	"fmt"
 	"strings"
 
+	"github.com/by-cx/lobby/server"
 	"github.com/go-resty/resty/v2"
-	"github.com/rosti-cz/server_lobby/server"
 )
 
 // Encapsulation of Lobby's client code

common/types.go

@@ -1,6 +1,6 @@
 package common
 
-import "github.com/rosti-cz/server_lobby/server"
+import "github.com/by-cx/lobby/server"
 
 // Listener is a function that returns received discovery
 type Listener func(server.Discovery)

ctl/format.go

@@ -7,8 +7,8 @@ import (
 	"strconv"
 	"strings"
 
+	"github.com/by-cx/lobby/server"
 	"github.com/fatih/color"
-	"github.com/rosti-cz/server_lobby/server"
 )
 
 func printDiscovery(discovery server.Discovery) {

ctl/main.go

@@ -6,8 +6,8 @@ import (
 	"os"
 	"strings"
 
-	"github.com/rosti-cz/server_lobby/client"
+	"github.com/by-cx/lobby/client"
-	"github.com/rosti-cz/server_lobby/server"
+	"github.com/by-cx/lobby/server"
 )
 
 func Usage() {

daemon/config.go

@@ -3,8 +3,8 @@ package main
 import (
 	"log"
 
+	"github.com/by-cx/lobby/server"
 	"github.com/kelseyhightower/envconfig"
-	"github.com/rosti-cz/server_lobby/server"
 )
 
 // Config keeps info about configuration of this daemon
@@ -12,8 +12,15 @@ type Config struct {
 	Token                 string        `envconfig:"TOKEN" required:"false"`                                            // Authentication token, if empty auth is disabled
 	Host                  string        `envconfig:"HOST" required:"false" default:"127.0.0.1"`                         // IP address used for the REST server to listen
 	Port                  uint16        `envconfig:"PORT" required:"false" default:"1313"`                              // Port related to the address above
-	NATSURL               string        `envconfig:"NATS_URL" required:"true"`                                          // NATS URL used to connect to the NATS server
+	DisableAPI            bool          `envconfig:"DISABLE_API" required:"false" default:"false"`                      // If true API interface won't start
+	Driver                string        `envconfig:"DRIVER" required:"false" default:"NATS"`                            // Select driver to use to communicate with the group of nodes. The possible values are NATS and Redis
+	NATSURL               string        `envconfig:"NATS_URL" required:"false"`                                         // NATS URL used to connect to the NATS server
 	NATSDiscoveryChannel  string        `envconfig:"NATS_DISCOVERY_CHANNEL" required:"false" default:"lobby.discovery"` // Channel where the kepp alive packets are sent
+	RedisHost             string        `envconfig:"REDIS_HOST" required:"false" default:"127.0.0.1"`                   // Redis host
+	RedisPort             uint16        `envconfig:"REDIS_PORT" required:"false" default:"6379"`                        // Redis port
+	RedisDB               uint          `envconfig:"REDIS_DB" required:"false" default:"0"`                             // Redis DB
+	RedisChannel          string        `envconfig:"REDIS_CHANNEL" required:"false" default:"lobby:discovery"`          // Redis channel
+	RedisPassword         string        `envconfig:"REDIS_PASSWORD" required:"false" default:""`                        // Redis password
 	Labels                server.Labels `envconfig:"LABELS" required:"false" default:""`                                // List of labels
 	LabelsPath            string        `envconfig:"LABELS_PATH" required:"false" default:"/etc/lobby/labels"`          // Path where filesystem based labels are located
 	RuntimeLabelsFilename string        `envconfig:"RUNTIME_LABELS_FILENAME" required:"false" default:"_runtime"`       // Filename for file created in LabelsPath where runtime labels will be added
@@ -34,5 +41,13 @@ func GetConfig() *Config {
 		log.Fatal(err.Error())
 	}
 
+	if config.Driver != "Redis" && config.Driver != "NATS" {
+		log.Fatal("ERROR: the only supported drivers are Redis and NATS (default)")
+	}
+
+	if config.Driver == "NATS" && len(config.NATSURL) == 0 {
+		log.Fatal("ERROR: NATS_URL cannot be empty when driver is set to NATS")
+	}
+
 	return &config
 }

daemon/handlers.go

@@ -6,8 +6,8 @@ import (
 	"net/http"
 	"strings"
 
+	"github.com/by-cx/lobby/server"
 	"github.com/labstack/echo"
-	"github.com/rosti-cz/server_lobby/server"
 )
 
 func listHandler(c echo.Context) error {

daemon/main.go

@@ -9,11 +9,12 @@ import (
 	"syscall"
 	"time"
 
+	"github.com/by-cx/lobby/common"
+	"github.com/by-cx/lobby/nats_driver"
+	"github.com/by-cx/lobby/redis_driver"
+	"github.com/by-cx/lobby/server"
 	"github.com/labstack/echo"
 	"github.com/labstack/echo/middleware"
-	"github.com/rosti-cz/server_lobby/common"
-	"github.com/rosti-cz/server_lobby/nats_driver"
-	"github.com/rosti-cz/server_lobby/server"
 )
 
 var discoveryStorage server.Discoveries = server.Discoveries{}
@@ -41,12 +42,27 @@ func init() {
 	}
 
 	// Setup driver
-	driver = &nats_driver.Driver{
+	if config.Driver == "NATS" {
-		NATSUrl:              config.NATSURL,
+		driver = &nats_driver.Driver{
-		NATSDiscoveryChannel: config.NATSDiscoveryChannel,
+			NATSUrl:              config.NATSURL,
+			NATSDiscoveryChannel: config.NATSDiscoveryChannel,
 
-		LogChannel: discoveryStorage.LogChannel,
+			LogChannel: discoveryStorage.LogChannel,
+		}
+	} else if config.Driver == "Redis" {
+		driver = &redis_driver.Driver{
+			Host:     config.RedisHost,
+			Port:     uint(config.RedisPort),
+			Password: config.RedisPassword,
+			Channel:  config.RedisChannel,
+			DB:       uint(config.RedisDB),
+
+			LogChannel: discoveryStorage.LogChannel,
+		}
+	} else {
+		log.Fatalf("unsupported driver %s", config.Driver)
 	}
+
 }
 
 // cleanDiscoveryPool clears the local server map and keeps only the alive servers
@@ -147,12 +163,14 @@ func main() {
 	e.Use(middleware.Recover())
 
 	// Routes
-	e.GET("/", listHandler)
+	if config.DisableAPI {
-	e.GET("/v1/discovery", getIdentificationHandler)
+		e.GET("/", listHandler)
-	e.GET("/v1/discoveries", listHandler)
+		e.GET("/v1/discovery", getIdentificationHandler)
-	e.POST("/v1/labels", addLabelsHandler)
+		e.GET("/v1/discoveries", listHandler)
-	e.DELETE("/v1/labels", deleteLabelsHandler)
+		e.POST("/v1/labels", addLabelsHandler)
-	e.GET("/v1/prometheus/:name", prometheusHandler)
+		e.DELETE("/v1/labels", deleteLabelsHandler)
+		e.GET("/v1/prometheus/:name", prometheusHandler)
+	}
 
 	// ------------------------------
 	// Termination signals processing
@@ -167,7 +185,7 @@ func main() {
 		if config.Register {
 			log.Printf("%s signal received, sending goodbye packet\n", sig.String())
 			sendGoodbyePacket()
-			time.Sleep(5 * time.Second) // we wait for a few seconds to let background jobs to finish their job
+			time.Sleep(1 * time.Second) // we wait for a few seconds to let background jobs to finish their job
 		} else {
 			log.Printf("%s signal received", sig.String())
 		}
@@ -175,5 +193,6 @@ func main() {
 	}(e, config)
 
 	// Start server
-	e.Logger.Error(e.Start(config.Host + ":" + strconv.Itoa(int(config.Port))))
+	// In most cases this will end expectedly so it doesn't make sense to use the echo's approach to treat this message as an error.
+	e.Logger.Info(e.Start(config.Host + ":" + strconv.Itoa(int(config.Port))))
 }

daemon/prometheus.go

@@ -4,7 +4,7 @@ import (
 	"strconv"
 	"strings"
 
-	"github.com/rosti-cz/server_lobby/server"
+	"github.com/by-cx/lobby/server"
 )
 
 // [

go.mod

@@ -1,19 +1,21 @@
-module github.com/rosti-cz/server_lobby
+module github.com/by-cx/lobby
 
 go 1.16
 
 require (
 	github.com/dgrijalva/jwt-go v3.2.0+incompatible // indirect
 	github.com/fatih/color v1.12.0
+	github.com/go-redis/redis v6.15.9+incompatible
 	github.com/go-resty/resty/v2 v2.6.0
-	github.com/golang/protobuf v1.5.2 // indirect
 	github.com/kelseyhightower/envconfig v1.4.0
 	github.com/labstack/echo v3.3.10+incompatible
 	github.com/labstack/gommon v0.3.0 // indirect
 	github.com/nats-io/nats-server/v2 v2.4.0 // indirect
 	github.com/nats-io/nats.go v1.12.0
+	github.com/onsi/gomega v1.16.0 // indirect
 	github.com/shirou/gopsutil/v3 v3.21.7
 	github.com/stretchr/testify v1.7.0
 	github.com/valyala/fasttemplate v1.2.1 // indirect
+	golang.org/x/net v0.0.0-20210614182718-04defd469f4e // indirect
 	google.golang.org/protobuf v1.27.1 // indirect
 )

go.sum

@@ -1,15 +1,23 @@
 github.com/StackExchange/wmi v1.2.1 h1:VIkavFPXSjcnS+O8yTq7NI32k0R5Aj+v39y29VYDOSA=
 github.com/StackExchange/wmi v1.2.1/go.mod h1:rcmrprowKIVzvc+NUiLncP2uuArMWLCbu9SBzvHz7e8=
-github.com/davecgh/go-spew v1.1.0 h1:ZDRjVQ15GmhC3fiQ8ni8+OwkZQO4DARzQgrnXU1Liz8=
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
+github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/dgrijalva/jwt-go v3.2.0+incompatible h1:7qlOGliEKZXTDg6OTjfoBKDXWrumCAMpl/TFQ4/5kLM=
 github.com/dgrijalva/jwt-go v3.2.0+incompatible/go.mod h1:E3ru+11k8xSBh+hMPgOLZmtrrCbhqsmaPHjLKYnJCaQ=
 github.com/fatih/color v1.12.0 h1:mRhaKNwANqRgUBGKmnI5ZxEk7QXmjQeCcuYFMX2bfcc=
 github.com/fatih/color v1.12.0/go.mod h1:ELkj/draVOlAH/xkhN6mQ50Qd0MPOk5AAr3maGEBuJM=
+github.com/fsnotify/fsnotify v1.4.7/go.mod h1:jwhsz4b93w/PPRr/qN1Yymfu8t87LnFCMoQvtojpjFo=
+github.com/fsnotify/fsnotify v1.4.9 h1:hsms1Qyu0jgnwNXIxa+/V/PDsU6CfLf6CNO8H7IWoS4=
+github.com/fsnotify/fsnotify v1.4.9/go.mod h1:znqG4EE+3YCdAaPaxE2ZRY/06pZUdp0tY4IgpuI1SZQ=
 github.com/go-ole/go-ole v1.2.5 h1:t4MGB5xEDZvXI+0rMjjsfBsD7yAgp/s9ZDkL1JndXwY=
 github.com/go-ole/go-ole v1.2.5/go.mod h1:pprOEPIfldk/42T2oK7lQ4v4JSDwmV0As9GaiUsvbm0=
+github.com/go-redis/redis v6.15.9+incompatible h1:K0pv1D7EQUjfyoMql+r/jZqCLizCGKFlFgcHWWmHQjg=
+github.com/go-redis/redis v6.15.9+incompatible/go.mod h1:NAIEuMOZ/fxfXJIrKDQDz8wamY7mA7PouImQ2Jvg6kA=
 github.com/go-resty/resty/v2 v2.6.0 h1:joIR5PNLM2EFqqESUjCMGXrWmXNHEU9CEiK813oKYS4=
 github.com/go-resty/resty/v2 v2.6.0/go.mod h1:PwvJS6hvaPkjtjNg9ph+VrSD92bi5Zq73w/BIH7cC3Q=
+github.com/go-task/slim-sprig v0.0.0-20210107165309-348f09dbbbc0/go.mod h1:fyg7847qk6SyHyPtNmDHnmrv/HOrqktSC+C9fM+CJOE=
+github.com/golang/protobuf v1.2.0/go.mod h1:6lQm79b+lXiMfvg/cZm0SGofjICqVBUtrP5yJMmIC1U=
 github.com/golang/protobuf v1.4.0-rc.1/go.mod h1:ceaxUfeHdC40wWswd/P6IGgMaK3YpKi5j83Wpe3EHw8=
 github.com/golang/protobuf v1.4.0-rc.1.0.20200221234624-67d41d38c208/go.mod h1:xKAWHe0F5eneWXFV3EuXVDTCmh+JuBKY0li0aMyXATA=
 github.com/golang/protobuf v1.4.0-rc.2/go.mod h1:LlEzMj4AhA7rCAGe4KMBDvJI+AwstrUpVNzEA03Pprs=
@@ -24,6 +32,7 @@ github.com/google/go-cmp v0.3.0/go.mod h1:8QqcDgzrUqlUb/G2PQTWiueGozuR1884gddMyw
 github.com/google/go-cmp v0.3.1/go.mod h1:8QqcDgzrUqlUb/G2PQTWiueGozuR1884gddMywk6iLU=
 github.com/google/go-cmp v0.4.0/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/gNBxE=
 github.com/google/go-cmp v0.5.5/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/gNBxE=
+github.com/hpcloud/tail v1.0.0/go.mod h1:ab1qPbhIpdTxEkNHXyeSf5vhxWSCs/tWer42PpOxQnU=
 github.com/kelseyhightower/envconfig v1.4.0 h1:Im6hONhd3pLkfDFsbRgu68RDNkGF1r3dvMUtDTo2cv8=
 github.com/kelseyhightower/envconfig v1.4.0/go.mod h1:cccZRl6mQpaq41TPp5QxidR+Sa3axMbJDNb//FQX6Gg=
 github.com/klauspost/compress v1.13.4 h1:0zhec2I8zGnjWcKyLl6i3gPqKANCCn5e9xmviEEeX6s=
@@ -54,12 +63,24 @@ github.com/nats-io/nkeys v0.3.0 h1:cgM5tL53EvYRU+2YLXIK0G2mJtK12Ft9oeooSZMA2G8=
 github.com/nats-io/nkeys v0.3.0/go.mod h1:gvUNGjVcM2IPr5rCsRsC6Wb3Hr2CQAm08dsxtV6A5y4=
 github.com/nats-io/nuid v1.0.1 h1:5iA8DT8V7q8WK2EScv2padNa/rTESc1KdnPw4TC2paw=
 github.com/nats-io/nuid v1.0.1/go.mod h1:19wcPz3Ph3q0Jbyiqsd0kePYG7A95tJPxeL+1OSON2c=
+github.com/nxadm/tail v1.4.4/go.mod h1:kenIhsEOeOJmVchQTgglprH7qJGnHDVpk1VPCcaMI8A=
+github.com/nxadm/tail v1.4.8 h1:nPr65rt6Y5JFSKQO7qToXr7pePgD6Gwiw05lkbyAQTE=
+github.com/nxadm/tail v1.4.8/go.mod h1:+ncqLTQzXmGhMZNUePPaPqPvBxHAIsmXswZKocGu+AU=
+github.com/onsi/ginkgo v1.6.0/go.mod h1:lLunBs/Ym6LB5Z9jYTR76FiuTmxDTDusOGeTQH+WWjE=
+github.com/onsi/ginkgo v1.12.1/go.mod h1:zj2OWP4+oCPe1qIXoGWkgMRwljMUYCdkwsT2108oapk=
+github.com/onsi/ginkgo v1.16.4 h1:29JGrr5oVBm5ulCWet69zQkzWipVXIol6ygQUe/EzNc=
+github.com/onsi/ginkgo v1.16.4/go.mod h1:dX+/inL/fNMqNlz0e9LfyB9TswhZpCVdJM/Z6Vvnwo0=
+github.com/onsi/gomega v1.7.1/go.mod h1:XdKZgCCFLUoM/7CFJVPcG8C1xQ1AJ0vpAezJrB7JYyY=
+github.com/onsi/gomega v1.10.1/go.mod h1:iN09h71vgCQne3DLsj+A5owkum+a2tYe+TOCB1ybHNo=
+github.com/onsi/gomega v1.16.0 h1:6gjqkI8iiRHMvdccRJM8rVKjCWk6ZIm6FTm3ddIe4/c=
+github.com/onsi/gomega v1.16.0/go.mod h1:HnhC7FXeEQY45zxNK3PPoIUhzk/80Xly9PcubAlGdZY=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/shirou/gopsutil/v3 v3.21.7 h1:PnTqQamUjwEDSgn+nBGu0qSDV/CfvyiR/gwTH3i7HTU=
 github.com/shirou/gopsutil/v3 v3.21.7/go.mod h1:RGl11Y7XMTQPmHh8F0ayC6haKNBgH4PXMJuTAcMOlz4=
 github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
 github.com/stretchr/testify v1.4.0/go.mod h1:j7eGeouHqKxXV5pUuKE4zz7dFj8WfuZ+81PSLYec5m4=
+github.com/stretchr/testify v1.5.1/go.mod h1:5W2xD1RspED5o8YsWQXVCued0rvSQ+mT+I5cxcmMvtA=
 github.com/stretchr/testify v1.7.0 h1:nwc3DEeHmmLAfoZucVR881uASk0Mfjw8xYJ99tb5CcY=
 github.com/stretchr/testify v1.7.0/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
 github.com/tklauser/go-sysconf v0.3.7 h1:HT7h4+536gjqeq1ZIJPgOl1rg1XFatQGVZWp7Py53eg=
@@ -71,36 +92,63 @@ github.com/valyala/bytebufferpool v1.0.0/go.mod h1:6bBcMArwyJ5K/AmCkWv1jt77kVWyC
 github.com/valyala/fasttemplate v1.0.1/go.mod h1:UQGH1tvbgY+Nz5t2n7tXsz52dQxojPUpymEIMZ47gx8=
 github.com/valyala/fasttemplate v1.2.1 h1:TVEnxayobAdVkhQfrfes2IzOB6o+z4roRkPF52WA1u4=
 github.com/valyala/fasttemplate v1.2.1/go.mod h1:KHLXt3tVN2HBp8eijSv/kGJopbvo7S+qRAEEKiv+SiQ=
+github.com/yuin/goldmark v1.2.1/go.mod h1:3hX8gzYuyVAZsxl0MRgGTJEmQBFcNTphYh9decYSb74=
 golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
+golang.org/x/crypto v0.0.0-20191011191535-87dc89f01550/go.mod h1:yigFU9vqHzYiE8UmvKecakEJjdnWj3jj499lnFckfCI=
 golang.org/x/crypto v0.0.0-20200323165209-0ec3e9974c59/go.mod h1:LzIPMQfyMNhhGPhUkYOs5KpL4U8rLKemX1yGLhDgUto=
+golang.org/x/crypto v0.0.0-20200622213623-75b288015ac9/go.mod h1:LzIPMQfyMNhhGPhUkYOs5KpL4U8rLKemX1yGLhDgUto=
 golang.org/x/crypto v0.0.0-20210314154223-e6e6c4f2bb5b/go.mod h1:T9bdIzuCu7OtxOm1hfPfRQxPLYneinmdGuTeoZ9dtd4=
 golang.org/x/crypto v0.0.0-20210616213533-5ff15b29337e h1:gsTQYXdTw2Gq7RBsWvlQ91b+aEQ6bXFUngBGuR8sPpI=
 golang.org/x/crypto v0.0.0-20210616213533-5ff15b29337e/go.mod h1:GvvjBRRGRdwPK5ydBHafDWAxML/pGHZbMvKqRZ5+Abc=
+golang.org/x/mod v0.3.0/go.mod h1:s0Qsj1ACt9ePp/hMypM3fl4fZqREWJwdYDEqhRiZZUA=
+golang.org/x/net v0.0.0-20180906233101-161cd47e91fd/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
 golang.org/x/net v0.0.0-20190404232315-eb5bcb51f2a3/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
+golang.org/x/net v0.0.0-20190620200207-3b0461eec859/go.mod h1:z5CRVTTTmAJ677TzLLGU+0bjPO0LkuOLi4/5GtJWs/s=
+golang.org/x/net v0.0.0-20200520004742-59133d7f0dd7/go.mod h1:qpuaurCH72eLCgpAm/N6yyVIVM9cpaDIP3A8BGJEC5A=
+golang.org/x/net v0.0.0-20201021035429-f5854403a974/go.mod h1:sp8m0HH+o8qH0wwXwYZr8TS3Oi6o0r6Gce1SSxlDquU=
 golang.org/x/net v0.0.0-20210226172049-e18ecbb05110/go.mod h1:m0MpNAwzfU5UDzcl9v0D8zg8gWTRqZa9RBIspLL5mdg=
-golang.org/x/net v0.0.0-20210405180319-a5a99cb37ef4 h1:4nGaVu0QrbjT/AK2PRLuQfQuh6DJve+pELhqTdAj3x0=
 golang.org/x/net v0.0.0-20210405180319-a5a99cb37ef4/go.mod h1:p54w0d4576C0XHj96bSt6lcn1PtDYWL6XObtHCRCNQM=
+golang.org/x/net v0.0.0-20210428140749-89ef3d95e781/go.mod h1:OJAsFXCWl8Ukc7SiCT/9KSuxbyM7479/AVlXFRxuMCk=
+golang.org/x/net v0.0.0-20210614182718-04defd469f4e h1:XpT3nA5TvE525Ne3hInMh6+GETgn27Zfm9dxsThnX2Q=
+golang.org/x/net v0.0.0-20210614182718-04defd469f4e/go.mod h1:9nx3DQGgdP8bBQD5qxJ1jj9UTztislL4KSBs9R2vV5Y=
+golang.org/x/sync v0.0.0-20180314180146-1d60e4601c6f/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
+golang.org/x/sync v0.0.0-20190423024810-112230192c58/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
+golang.org/x/sync v0.0.0-20201020160332-67f06af15bc9/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
+golang.org/x/sys v0.0.0-20180909124046-d0be0721c37e/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
 golang.org/x/sys v0.0.0-20190130150945-aca44879d564/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
 golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
 golang.org/x/sys v0.0.0-20190222072716-a9d3bda3a223/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
 golang.org/x/sys v0.0.0-20190412213103-97732733099d/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20190813064441-fde4db37ae7a/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20190904154756-749cb33beabd/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20190916202348-b4ddaad3f8a3/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20191005200804-aed5e4c7ecf9/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20191120155948-bd437916bb0e/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20200116001909-b77594299b42/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20200223170610-d5e6a3e2c0ae/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20200323222414-85ca7c5b95cd/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20200930185726-fdedc70b468f/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20201119102817-f84b799fce68/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20210112080510-489259a85091/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20210330210617-4fbd30eecc44/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20210423082822-04245dca01da/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20210615035016-665e8c7367d1/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.0.0-20210630005230-0f9fa26af87c h1:F1jZWGFhYfh0Ci55sIpILtKKK8p3i2/krTr0H1rg74I=
 golang.org/x/sys v0.0.0-20210630005230-0f9fa26af87c/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/term v0.0.0-20201126162022-7de9c90e9dd1/go.mod h1:bj7SfCRtBDWHUb9snDiAeCFNEtKQo2Wmx5Cou7ajbmo=
 golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
-golang.org/x/text v0.3.3 h1:cokOdA+Jmi5PJGXLlLllQSgYigAEfHXJAERHVMaCc2k=
 golang.org/x/text v0.3.3/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
+golang.org/x/text v0.3.6 h1:aRYxNxv6iGQlyVaZmk6ZgYEDa+Jg18DxebPSrd6bg1M=
+golang.org/x/text v0.3.6/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
 golang.org/x/time v0.0.0-20200416051211-89c76fbcd5d1 h1:NusfzzA6yGQ+ua51ck7E3omNUX/JuqbFSaRGqU8CcLI=
 golang.org/x/time v0.0.0-20200416051211-89c76fbcd5d1/go.mod h1:tRJNPiyCQ0inRvYxbN9jk5I+vvW/OXSQhTDSoE431IQ=
 golang.org/x/tools v0.0.0-20180917221912-90fa682c2a6e/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
+golang.org/x/tools v0.0.0-20191119224855-298f0cb1881e/go.mod h1:b+2E5dAYhXwXZwtnZ6UAqBI28+e2cm9otk0dWdXHAEo=
+golang.org/x/tools v0.0.0-20201224043029-2b0845dc783e/go.mod h1:emZCQorbCU4vsT4fOWvOPXz4eW1wZW4PmDk9uLelYpA=
+golang.org/x/xerrors v0.0.0-20190717185122-a985d3407aa7/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
+golang.org/x/xerrors v0.0.0-20191011141410-1b5146add898/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
 golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
+golang.org/x/xerrors v0.0.0-20200804184101-5ec99f83aff1/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
 google.golang.org/protobuf v0.0.0-20200109180630-ec00e32a8dfd/go.mod h1:DFci5gLYBciE7Vtevhsrf46CRTquxDuWsQurQQe4oz8=
 google.golang.org/protobuf v0.0.0-20200221191635-4d8936d0db64/go.mod h1:kwYJMbMJ01Woi6D6+Kah6886xMZcty6N08ah7+eCXa0=
 google.golang.org/protobuf v0.0.0-20200228230310-ab0ca4ff8a60/go.mod h1:cfTl7dwQJ+fmap5saPgwCLgHXTUD7jkjRqWcaiX5VyM=
@@ -113,6 +161,13 @@ google.golang.org/protobuf v1.27.1 h1:SnqbnDw1V7RiZcXPx5MEeqPv2s79L9i7BJUlG/+Rur
 google.golang.org/protobuf v1.27.1/go.mod h1:9q0QmTI4eRPtz6boOQmLYwt+qCgq0jsYwAQnmE0givc=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/fsnotify.v1 v1.4.7/go.mod h1:Tz8NjZHkW78fSQdbUxIjBTcgA1z1m8ZHf0WmKUhAMys=
+gopkg.in/tomb.v1 v1.0.0-20141024135613-dd632973f1e7 h1:uRGJdciOHaEIrze2W8Q3AKkepLTh2hOroT7a+7czfdQ=
+gopkg.in/tomb.v1 v1.0.0-20141024135613-dd632973f1e7/go.mod h1:dt/ZhP58zS4L8KSrWDmTeBkI65Dw0HsyUHuEVlX15mw=
 gopkg.in/yaml.v2 v2.2.2/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
+gopkg.in/yaml.v2 v2.2.4/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
+gopkg.in/yaml.v2 v2.3.0/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
+gopkg.in/yaml.v2 v2.4.0 h1:D8xgwECY7CYvx+Y2n4sBz93Jn9JRvxdiyyo8CTfuKaY=
+gopkg.in/yaml.v2 v2.4.0/go.mod h1:RDklbk79AGWmwhnvt/jBztapEOGDOx6ZbXqjP6csGnQ=
 gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c h1:dUUwHk2QECo/6vqA44rthZ8ie2QXMNeKRTHCNY2nXvo=
 gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

nats_driver/main.go

@@ -4,11 +4,12 @@ import (
 	"encoding/json"
 	"fmt"
 
+	"github.com/by-cx/lobby/common"
+	"github.com/by-cx/lobby/server"
 	"github.com/nats-io/nats.go"
-	"github.com/rosti-cz/server_lobby/common"
-	"github.com/rosti-cz/server_lobby/server"
 )
 
+// NATS drivers is used to send discovery packet to other nodes into the group via NATS messenging protocol.
 type Driver struct {
 	NATSUrl              string
 	NATSDiscoveryChannel string
@@ -65,18 +66,22 @@ func (d *Driver) Init() error {
 	return nil
 }
 
+// Close is called when all is done.
 func (d *Driver) Close() error {
 	return d.nc.Drain()
 }
 
+// RegisterSubscribeFunction sets the function that will process the incoming messages
 func (d *Driver) RegisterSubscribeFunction(listener common.Listener) {
 	d.subscribeListener = listener
 }
 
+// RegisterUnsubscribeFunction sets the function that will process the goodbye incoming messages
 func (d *Driver) RegisterUnsubscribeFunction(listener common.Listener) {
 	d.unsubscribeListener = listener
 }
 
+// SendDiscoveryPacket send discovery packet to the group.
 func (d *Driver) SendDiscoveryPacket(discovery server.Discovery) error {
 	envelope := discoveryEnvelope{
 		Discovery: discovery,
@@ -94,6 +99,7 @@ func (d *Driver) SendDiscoveryPacket(discovery server.Discovery) error {
 	return nil
 }
 
+// SendGoodbyePacket deregister node from the group. It tells everybody that it's going to die.
 func (d *Driver) SendGoodbyePacket(discovery server.Discovery) error {
 	envelope := discoveryEnvelope{
 		Discovery: discovery,

nats_driver/types.go

@@ -3,7 +3,7 @@ package nats_driver
 import (
 	"encoding/json"
 
-	"github.com/rosti-cz/server_lobby/server"
+	"github.com/by-cx/lobby/server"
 )
 
 // discoveryEnvelope adds a message to the standard discovery format. The message

redis_driver/main.go

@@ -0,0 +1,142 @@
+package redis_driver
+
+import (
+	"encoding/json"
+
+	"github.com/by-cx/lobby/common"
+	"github.com/by-cx/lobby/server"
+	"github.com/go-redis/redis"
+
+	"fmt"
+)
+
+// Redis drivers is used to send discovery packet to other nodes into the group via Redis's pubsub protocol.
+type Driver struct {
+	Host     string
+	Port     uint
+	Password string
+	Channel  string
+	DB       uint
+
+	LogChannel chan string
+
+	subscribeListener   common.Listener
+	unsubscribeListener common.Listener
+
+	redis *redis.Client
+}
+
+// handler is called asynchronously so and because it cannot log directly to stderr there
+// is channel called LogChannel that can be used to log error messages from this
+func (d *Driver) handler(payload string) {
+	message := discoveryEnvelope{}
+	err := json.Unmarshal([]byte(payload), &message)
+	if err != nil && d.LogChannel != nil {
+		d.LogChannel <- fmt.Errorf("decoding message error: %v", err).Error()
+	}
+
+	err = message.Discovery.Validate()
+	if err != nil && d.LogChannel != nil {
+		d.LogChannel <- fmt.Errorf("validation error: %v", err).Error()
+	}
+
+	if message.Message == "hi" {
+		d.subscribeListener(message.Discovery)
+	} else if message.Message == "goodbye" {
+		d.unsubscribeListener(message.Discovery)
+	} else {
+		if d.LogChannel != nil {
+			d.LogChannel <- "incompatible message"
+		}
+	}
+}
+
+// Init connect to Redis, subscribes to the channel and waits for the messages.
+// It runs goroutine in background that listens for new messages.
+func (d *Driver) Init() error {
+	if d.LogChannel == nil {
+		return fmt.Errorf("please initiate LogChannel variable")
+	}
+
+	if len(d.Host) == 0 {
+		return fmt.Errorf("parameter Host cannot be empty")
+	}
+
+	if len(d.Channel) == 0 {
+		return fmt.Errorf("pattern cannot be empty")
+	}
+
+	if d.Port <= 0 || d.Port > 65536 {
+		return fmt.Errorf("port has to be in range of 0-65536")
+	}
+
+	d.redis = redis.NewClient(&redis.Options{
+		Addr:     fmt.Sprintf("%s:%d", d.Host, d.Port),
+		Password: d.Password,
+		DB:       int(d.DB),
+	})
+
+	pubsub := d.redis.Subscribe(d.Channel)
+
+	go func(pubsub *redis.PubSub, d *Driver) {
+		channel := pubsub.Channel()
+
+		for message := range channel {
+			d.handler(message.Payload)
+		}
+	}(pubsub, d)
+
+	return nil
+}
+
+// Close is called when all is done.
+func (d *Driver) Close() error {
+	return d.redis.Close()
+}
+
+// RegisterSubscribeFunction sets the function that will process the incoming messages
+func (d *Driver) RegisterSubscribeFunction(listener common.Listener) {
+	d.subscribeListener = listener
+}
+
+// RegisterUnsubscribeFunction sets the function that will process the goodbye incoming messages
+func (d *Driver) RegisterUnsubscribeFunction(listener common.Listener) {
+	d.unsubscribeListener = listener
+}
+
+// SendDiscoveryPacket send discovery packet to the group.
+func (d *Driver) SendDiscoveryPacket(discovery server.Discovery) error {
+	envelope := discoveryEnvelope{
+		Discovery: discovery,
+		Message:   "hi",
+	}
+
+	data, err := envelope.Bytes()
+	if err != nil {
+		return fmt.Errorf("sending discovery formating message error: %v", err)
+	}
+
+	err = d.redis.Publish(d.Channel, data).Err()
+	if err != nil {
+		return fmt.Errorf("sending discovery error: %v", err)
+	}
+	return nil
+}
+
+// SendGoodbyePacket deregister node from the group. It tells everybody that it's going to die.
+func (d *Driver) SendGoodbyePacket(discovery server.Discovery) error {
+	envelope := discoveryEnvelope{
+		Discovery: discovery,
+		Message:   "goodbye",
+	}
+
+	data, err := envelope.Bytes()
+	if err != nil {
+		return fmt.Errorf("sending discovery formating message error: %v", err)
+	}
+	err = d.redis.Publish(d.Channel, data).Err()
+	if err != nil {
+		return fmt.Errorf("sending discovery error: %v", err)
+	}
+	return nil
+}

redis_driver/types.go

@@ -0,0 +1,20 @@
+package redis_driver
+
+import (
+	"encoding/json"
+
+	"github.com/by-cx/lobby/server"
+)
+
+// discoveryEnvelope adds a message to the standard discovery format. The message
+// can be "hi" or "goodbye" where "hi" is used when the node is sending keep alive
+// packets and "goodbye" means the node is leaving.
+type discoveryEnvelope struct {
+	Discovery server.Discovery `json:"discovery"`
+	Message   string           `json:"message"` // can be hi or goodbye
+}
+
+func (e *discoveryEnvelope) Bytes() ([]byte, error) {
+	body, err := json.Marshal(e)
+	return body, err
+}