first commit

config.go

@@ -0,0 +1,88 @@
+package config
+
+import (
+	"log"
+	"os"
+	"strconv"
+	"time"
+)
+
+const (
+	RealIpHeader                = "X-Real-Ip"
+	ForwardHeader               = "X-Forwarded-For"
+	CrowdsecAuthHeader          = "X-Api-Key"
+	CrowdsecBouncerRoute        = "v1/decisions"
+	CrowdsecBouncerStreamRoute  = "v1/decisions/stream"
+)
+
+/*
+	Check for an environment variable value, if absent use a default value
+*/
+func OptionalEnv(varName string, optional string) string {
+	envVar := os.Getenv(varName)
+	if envVar == "" {
+		return optional
+	}
+	return envVar
+}
+
+/*
+	Check for an environment variable value, exit program if not found
+*/
+func RequiredEnv(varName string) string {
+	envVar := os.Getenv(varName)
+	if envVar == "" {
+		log.Fatalf("The required env var %s is not provided. Exiting", varName)
+	}
+	return envVar
+}
+
+/*
+	Check for an environment variable value with expected possibilities, exit program if value not expected
+*/
+func ExpectedEnv(varName string, expected []string) string {
+	envVar := RequiredEnv(varName)
+	if !contains(expected, envVar) {
+		log.Fatalf("The value for env var %s is not expected. Expected values are %v", varName, expected)
+	}
+	return envVar
+}
+
+func contains(source []string, target string) bool {
+	for _, a := range source {
+		if a == target {
+			return true
+		}
+	}
+	return false
+}
+
+/*
+	Function for custom validation of configuration that will panic if values are not expected.
+	//FIXME it's a first start before centralizing configuration then injection of dependency.
+*/
+func ValidateEnv() {
+	// Validate Ban response code is a valid http response code
+	banResponseCode := OptionalEnv("CROWDSEC_BOUNCER_BAN_RESPONSE_CODE", "403")
+	parsedCode, err := strconv.Atoi(banResponseCode)
+	if err != nil {
+		log.Fatalf("The value for env var %s is not an int. It should be a valid http response code.", "CROWDSEC_BOUNCER_BAN_RESPONSE_CODE")
+	}
+	if parsedCode < 100 || parsedCode > 599 {
+		log.Fatalf("The value for env var %s should be a valid http response code between 100 and 599 included.", "CROWDSEC_BOUNCER_BAN_RESPONSE_CODE")
+	}
+	cacheMode := OptionalEnv("CROWDSEC_BOUNCER_CACHE_MODE", "none")
+	if !contains([]string{"none", "live", "stream"}, cacheMode) {
+		log.Fatalf("Cache mode must be one of 'none', 'stream' or 'live'")
+	}
+  cacheStreamInterval := OptionalEnv("CROWDSEC_BOUNCER_CACHE_STREAM_INTERVAL", "1m")
+	duration, err := time.ParseDuration(cacheStreamInterval)
+	if err != nil && duration.Seconds() < 3600 {
+		log.Fatalf("Cache stream interval provided is not valid")
+	}
+	defaultCacheDuration := OptionalEnv("CROWDSEC_DEFAULT_CACHE_DURATION", "5m")
+	duration2, err := time.ParseDuration(defaultCacheDuration)
+	if err != nil && duration2.Seconds() < 3600 {
+		log.Fatalf("Cache default duration provided is not valid")
+	}
+}