add n8n output

Signed-off-by: Thomas Labarussias <[email protected]>

README.md

@@ -105,6 +105,10 @@ It works as a single endpoint for as many as you want `Falco` instances :
 
 - [**AWS Security Lake**](https://aws.amazon.com/security-lake/)
 
+### Workflow
+
+- [**n8n**](https://n8n.io/)
+
 ### Other
 - [**Policy Report**](https://github.com/kubernetes-sigs/wg-policy-prototypes/tree/master/policy-report/falco-adapter)
 
@@ -585,6 +589,15 @@ telegram:
   # chatid: "" # telegram Identifier of the shared chat
   # checkcert: true # check if ssl certificate of the output is valid (default: true)
   # minimumpriority: "" # minimum priority of event for using this output, order is emergency|alert|critical|error|warning|notice|informational|debug or "" (default)
+
+n8n:
+  # address: "" # N8N address, if not empty, N8N output is enabled
+  # user: "" # Username to authenticate with N8N in basic auth
+  # password: "" # Password to authenticate with N8N in basic auth
+  # headerauthname: "" # Header Auth Key to authenticate with N8N
+  # headerauthvalue: "" # Header Auth Value to authenticate with N8N
+  # checkcert: true # check if ssl certificate of the output is valid (default: true)
+  # minimumpriority: "" # minimum priority of event for using this output, order is emergency|alert|critical|error|warning|notice|informational|debug or "" (default)
 ```
 
 Usage :
@@ -1076,6 +1089,11 @@ order is
 - **TELEGRAM_CHATID**: telegram Identifier of the shared chat
 - **TELEGRAM_CHECKCERT**: check if ssl certificate of the output is valid (default: true)
 - **TELEGRAM_MINIMUMPRIORITY**: minimum priority of event for using this output, order is emergency|alert|critical|error|warning|notice|informational|debug or "" (default)
+- **N8N_ADDRESS**: N8N address, if not empty, N8N output is enabled
+- **N8N_USER**: Password to authenticate with N8N in basic auth
+- **N8N_PASSWORD**: Header Auth Value to authenticate with N8N
+- **N8N_CHECKCERT**: check if ssl certificate of the output is valid (default: true)
+- **N8N_MINIMUMPRIORITY**: minimum priority of event for using this output, order is emergency|alert|critical|error|warning|notice|informational|debug or "" (default)
 
 #### Slack/Rocketchat/Mattermost/Googlechat Message Formatting
 

config.go

@@ -416,6 +416,14 @@ func getConfig() *types.Configuration {
 	v.SetDefault("Redis.MutualTls", false)
 	v.SetDefault("Redis.CheckCert", true)
 
+	v.SetDefault("N8n.Address", "")
+	v.SetDefault("N8n.User", "")
+	v.SetDefault("N8n.Password", "")
+	v.SetDefault("N8n.HeaderAuthName", "")
+	v.SetDefault("N8n.HeaderAuthValue", "")
+	v.SetDefault("N8n.MinimumPriority", "")
+	v.SetDefault("N8n.CheckCert", true)
+
 	v.SetDefault("Slack.Token", "")
 	v.SetDefault("Slack.ChatID", "")
 	v.SetDefault("Slack.MinimumPriority", "")

config_example.yaml

@@ -422,3 +422,12 @@ telegram:
   # chatid: "" # telegram Identifier of the shared chat
   # checkcert: true # check if ssl certificate of the output is valid (default: true)
   # minimumpriority: "" # minimum priority of event for using this output, order is emergency|alert|critical|error|warning|notice|informational|debug or "" (default)
+
+n8n:
+  # address: "" # N8N address, if not empty, N8N output is enabled
+  # user: "" # Username to authenticate with N8N in basic auth
+  # password: "" # Password to authenticate with N8N in basic auth
+  # headerauthname: "" # Header Auth Key to authenticate with N8N
+  # headerauthvalue: "" # Header Auth Value to authenticate with N8N
+  # checkcert: true # check if ssl certificate of the output is valid (default: true)
+  # minimumpriority: "" # minimum priority of event for using this output, order is emergency|alert|critical|error|warning|notice|informational|debug or "" (default)

handlers.go

@@ -386,4 +386,8 @@ func forwardEvent(falcopayload types.FalcoPayload) {
 	if config.Telegram.ChatID != "" && config.Telegram.Token != "" && (falcopayload.Priority >= types.Priority(config.Telegram.MinimumPriority) || falcopayload.Rule == testRule) {
 		go telegramClient.TelegramPost(falcopayload)
 	}
+
+	if config.N8N.Address != "" && (falcopayload.Priority >= types.Priority(config.N8N.MinimumPriority) || falcopayload.Rule == testRule) {
+		go n8nClient.N8NPost(falcopayload)
+	}
 }

main.go

@@ -66,6 +66,7 @@ var (
 	timescaleDBClient   *outputs.Client
 	redisClient         *outputs.Client
 	telegramClient      *outputs.Client
+	n8nClient           *outputs.Client
 
 	statsdClient, dogstatsdClient *statsd.Client
 	config                        *types.Configuration
@@ -680,6 +681,16 @@ func init() {
 		}
 	}
 
+	if config.N8N.Address != "" {
+		var err error
+		n8nClient, err = outputs.NewClient("n8n", config.N8N.Address, false, config.N8N.CheckCert, config, stats, promStats, statsdClient, dogstatsdClient)
+		if err != nil {
+			config.N8N.Address = ""
+		} else {
+			outputs.EnabledOutputs = append(outputs.EnabledOutputs, "n8n")
+		}
+	}
+
 	log.Printf("[INFO]  : Falco Sidekick version: %s\n", GetVersionInfo().GitVersion)
 	log.Printf("[INFO]  : Enabled Outputs : %s\n", outputs.EnabledOutputs)
 

outputs/n8n.go

@@ -0,0 +1,38 @@
+package outputs
+
+import (
+	"log"
+
+	"github.com/falcosecurity/falcosidekick/types"
+)
+
+// N8NPost posts event to an URL
+func (c *Client) N8NPost(falcopayload types.FalcoPayload) {
+	c.Stats.N8N.Add(Total, 1)
+
+	if c.Config.N8N.User != "" && c.Config.N8N.Password != "" {
+		c.httpClientLock.Lock()
+		defer c.httpClientLock.Unlock()
+		c.BasicAuth(c.Config.N8N.User, c.Config.N8N.Password)
+	}
+
+	if c.Config.N8N.HeaderAuthName != "" && c.Config.N8N.HeaderAuthValue != "" {
+		c.httpClientLock.Lock()
+		defer c.httpClientLock.Unlock()
+		c.AddHeader(c.Config.N8N.HeaderAuthName, c.Config.N8N.HeaderAuthValue)
+	}
+
+	err := c.Post(falcopayload)
+	if err != nil {
+		go c.CountMetric(Outputs, 1, []string{"output:n8n", "status:error"})
+		c.Stats.N8N.Add(Error, 1)
+		c.PromStats.Outputs.With(map[string]string{"destination": "n8n", "status": Error}).Inc()
+		log.Printf("[ERROR] : N8N - %v\n", err.Error())
+		return
+	}
+
+	// Setting the success status
+	go c.CountMetric(Outputs, 1, []string{"output:n8n", "status:ok"})
+	c.Stats.N8N.Add(OK, 1)
+	c.PromStats.Outputs.With(map[string]string{"destination": "n8n", "status": OK}).Inc()
+}

stats.go

@@ -77,6 +77,7 @@ func getInitStats() *types.Statistics {
 		TimescaleDB:       getOutputNewMap("timescaledb"),
 		Redis:             getOutputNewMap("redis"),
 		Telegram:          getOutputNewMap("telegram"),
+		N8N:               getOutputNewMap("n8n"),
 	}
 	stats.Falco.Add(outputs.Emergency, 0)
 	stats.Falco.Add(outputs.Alert, 0)

types/types.go

@@ -100,6 +100,7 @@ type Configuration struct {
 	TimescaleDB        TimescaleDBConfig
 	Redis              RedisConfig
 	Telegram           TelegramConfig
+	N8N                N8NConfig
 }
 
 // SlackOutputConfig represents parameters for Slack
@@ -649,6 +650,17 @@ type TelegramConfig struct {
 	CheckCert       bool
 }
 
+// N8NConfig represents config parameters for N8N
+type N8NConfig struct {
+	Address         string
+	User            string
+	Password        string
+	HeaderAuthName  string
+	HeaderAuthValue string
+	MinimumPriority string
+	CheckCert       bool
+}
+
 // Statistics is a struct to store stastics
 type Statistics struct {
 	Requests          *expvar.Map
@@ -710,6 +722,7 @@ type Statistics struct {
 	TimescaleDB       *expvar.Map
 	Redis             *expvar.Map
 	Telegram          *expvar.Map
+	N8N               *expvar.Map
 }
 
 // PromStatistics is a struct to store prometheus metrics