adding env variables to readme

.gitignore

@@ -4,3 +4,4 @@
 .vscode/
 .idea/
 /bin/
+.envrc

README.md

@@ -132,6 +132,27 @@ CityFile = ""
 AsnFile = ""
 ```
 
+### Environment Variables for Configuration
+You can also use environment variables for configuration, most likely used for Docker.
+
+```
+ECHOIP_LISTEN=":8080"
+ECHOIP_TEMPLATE_DIR="html/"
+ECHOIP_REDIS_URL="redis://localhost:6379"
+ECHOIP_DATABASE="ipstack"
+ECHOIP_IPSTACK_API_KEY="askdfj39sjdkf29dsjfk39sdfkj3"
+ECHOIP_GEOIP_COUNTRY_FILE="/full/path/to/file.db"
+ECHOIP_GEOIP_CITY_FILE="/full/path/to/file.db"
+ECHOIP_GEOIP_ASN_FILE="/full/path/to/file.db"
+ECHOIP_CACHE_TTL=3600
+ECHOIP_REVERSE_LOOKUP=true
+ECHOIP_PORT_LOOKUP=true
+ECHOIP_SHOW_SPONSOR=true
+ECHOIP_PROFILE=false
+ECHOIP_IPSTACK_USE_HTTPS=true
+ECHOIP_IPSTACK_ENABLE_SECURITY=true
+```
+
 ### Caching with Redis
 
 You can connect EchoIP to a Redis client to cache each request per IP. You can configure the life of the key in `config.CacheTtl`.

cmd/echoip/main.go

@@ -36,49 +36,53 @@ func init() {
 
 func main() {
 	file, err := os.Open("/etc/echoip/config.toml")
-	if err != nil {
-		panic(err)
-	}
+
+	var b []byte
+
+	runConfig, err := config.GetConfig()
 	defer file.Close()
 
-	config, err := config.GetConfig()
 	if err != nil {
-		panic(err)
+		log.Fatalf("Error building configuration: %s", err)
 	}
 
-	b, err := io.ReadAll(file)
 	if err != nil {
-		panic(err)
-	}
+		log.Printf("Error opening config file (/etc/echoip/config.toml): %s", err)
 
-	err = toml.Unmarshal(b, &config)
-	if err != nil {
-		panic(err)
+		b, err = io.ReadAll(file)
+		if err != nil {
+			log.Printf("Error reading config file (/etc/echoip/config.toml): %s", err)
+		}
+
+		err = toml.Unmarshal(b, &runConfig)
+		if err != nil {
+			panic(err)
+		}
 	}
 
 	var parser parser.Parser
-	if config.Database == "geoip" {
+	if runConfig.Database == "geoip" {
 		log.Print("Using GeoIP for IP database")
 		geo, err := geo.Open(
-			config.GeoIP.CountryFile,
-			config.GeoIP.CityFile,
-			config.GeoIP.AsnFile,
+			runConfig.GeoIP.CountryFile,
+			runConfig.GeoIP.CityFile,
+			runConfig.GeoIP.AsnFile,
 		)
 		if err != nil {
 			log.Fatal(err)
 		}
 		parser = &geo
 	}
 
-	if config.Database == "ipstack" {
-		log.Print("Using GeoIP for IP database")
-		if config.IPStack.EnableSecurity {
+	if runConfig.Database == "ipstack" {
+		log.Print("Using IPStack for IP database")
+		if runConfig.IPStack.EnableSecurity {
 			log.Print("Enable Security Module ( Requires Professional Plus account )")
 		}
-		enableSecurity := ipstackApi.ParamEnableSecurity(config.IPStack.EnableSecurity)
-		apiKey := ipstackApi.ParamToken(config.IPStack.ApiKey)
-		useHttps := ipstackApi.ParamUseHTTPS(config.IPStack.UseHttps)
-		if config.IPStack.UseHttps {
+		enableSecurity := ipstackApi.ParamEnableSecurity(runConfig.IPStack.EnableSecurity)
+		apiKey := ipstackApi.ParamToken(runConfig.IPStack.ApiKey)
+		useHttps := ipstackApi.ParamUseHTTPS(runConfig.IPStack.UseHttps)
+		if runConfig.IPStack.UseHttps {
 			log.Print("Use IP Stack HTTPS API ( Requires non-free account )")
 		}
 		if err := ipstackApi.Init(apiKey, enableSecurity, useHttps); err != nil {
@@ -89,8 +93,8 @@ func main() {
 	}
 
 	var serverCache cache.Cache
-	if len(config.RedisUrl) > 0 {
-		redisCache, err := cache.RedisCache(config.RedisUrl)
+	if len(runConfig.RedisUrl) > 0 {
+		redisCache, err := cache.RedisCache(runConfig.RedisUrl)
 		serverCache = &redisCache
 		if err != nil {
 			log.Fatal(err)
@@ -99,34 +103,34 @@ func main() {
 		serverCache = &cache.Null{}
 	}
 
-	server := http.New(parser, serverCache, config.CacheTtl, config.Profile)
-	server.IPHeaders = config.TrustedHeaders
+	server := http.New(parser, serverCache, runConfig.CacheTtl, runConfig.Profile)
+	server.IPHeaders = runConfig.TrustedHeaders
 
-	if _, err := os.Stat(config.TemplateDir); err == nil {
-		server.Template = config.TemplateDir
+	if _, err := os.Stat(runConfig.TemplateDir); err == nil {
+		server.Template = runConfig.TemplateDir
 	} else {
-		log.Printf("Not configuring default handler: Template not found: %s", config.TemplateDir)
+		log.Printf("Not configuring default handler: Template not found: %s", runConfig.TemplateDir)
 	}
-	if config.ReverseLookup {
+	if runConfig.ReverseLookup {
 		log.Println("Enabling reverse lookup")
 		server.LookupAddr = iputil.LookupAddr
 	}
-	if config.PortLookup {
+	if runConfig.PortLookup {
 		log.Println("Enabling port lookup")
 		server.LookupPort = iputil.LookupPort
 	}
-	if config.ShowSponsor {
+	if runConfig.ShowSponsor {
 		log.Println("Enabling sponsor logo")
-		server.Sponsor = config.ShowSponsor
+		server.Sponsor = runConfig.ShowSponsor
 	}
-	if len(config.TrustedHeaders) > 0 {
-		log.Printf("Trusting remote IP from header(s): %s", config.TrustedHeaders)
+	if len(runConfig.TrustedHeaders) > 0 {
+		log.Printf("Trusting remote IP from header(s): %s", runConfig.TrustedHeaders)
 	}
-	if config.Profile {
+	if runConfig.Profile {
 		log.Printf("Enabling profiling handlers")
 	}
-	log.Printf("Listening on http://%s", config.Listen)
-	if err := server.ListenAndServe(config.Listen); err != nil {
+	log.Printf("Listening on http://%s", runConfig.Listen)
+	if err := server.ListenAndServe(runConfig.Listen); err != nil {
 		log.Fatal(err)
 	}
 }

config/config.go

@@ -1,6 +1,7 @@
 package config
 
 import (
+	"fmt"
 	"os"
 	"strconv"
 )
@@ -93,13 +94,15 @@ func GetConfig() (Config, error) {
 	}
 	defaultConfig.IPStack.EnableSecurity = ipStackEnableSecurity
 
+	fmt.Printf("%+v\n", defaultConfig)
+
 	return defaultConfig, nil
 }
 
 func getenv_int(key string, fallback int) (int, error) {
 	value := os.Getenv(key)
 
-	if len(value) == 0 {
+	if len(value) > 0 {
 		intValue, err := strconv.Atoi(value)
 		if err != nil {
 			return 0, err
@@ -122,7 +125,7 @@ func getenv_string(key string, fallback string) string {
 func getenv_bool(key string, fallback bool) (bool, error) {
 	value := os.Getenv(key)
 
-	if len(value) == 0 {
+	if len(value) > 0 {
 		boolValue, err := strconv.ParseBool(value)
 		if err != nil {
 			return false, err