Reopening PR-211 - Populate toxics at startup from a json string #211

README.md

@@ -287,8 +287,12 @@ Toxiproxy.
 
 For large application we recommend storing the Toxiproxy configurations in a
 separate configuration file. We use `config/toxiproxy.json`. This file can be
-passed to the server using the `-config` option, or loaded by the application
+passed to the server using the `-configFile` option, or loaded by the application
 to use with the `populate` function.
+Alternatively you can pass a json string with the `-configJson` option to populate
+these configurations. This is specially useful when running Toxiproxy as a docker container, e.g.:
+
+```docker run -it shopify/toxiproxy -configJson '[{"name": "redis","listen": "0.0.0.0:9092","upstream": "redis:6379"}]'```
 
 Use ports outside the ephemeral port range to avoid random port conflicts.
 It's `32,768` to `61,000` on Linux by default, see

api.go

@@ -1,8 +1,10 @@
 package toxiproxy
 
 import (
+	"bytes"
 	"encoding/json"
 	"fmt"
+	"io"
 	"log"
 	"net"
 	"net/http"
@@ -24,26 +26,34 @@ func NewServer() *ApiServer {
 	}
 }
 
-func (server *ApiServer) PopulateConfig(filename string) {
+func (server *ApiServer) PopulateConfigFromFile(filename string) {
 	file, err := os.Open(filename)
 	if err != nil {
 		logrus.WithFields(logrus.Fields{
 			"config": filename,
 			"error":  err,
 		}).Error("Error reading config file")
 	} else {
-		proxies, err := server.Collection.PopulateJson(file)
-		if err != nil {
-			logrus.WithFields(logrus.Fields{
-				"config": filename,
-				"error":  err,
-			}).Error("Failed to populate proxies from file")
-		} else {
-			logrus.WithFields(logrus.Fields{
-				"config":  filename,
-				"proxies": len(proxies),
-			}).Info("Populated proxies from file")
-		}
+		server.populateConfig(file)
+	}
+}
+
+func (server *ApiServer) PopulateConfigFromJsonString(json string) {
+	var data = bytes.NewReader([]byte(json))
+
+	server.populateConfig(data)
+}
+
+func (server *ApiServer) populateConfig(data io.Reader) {
+	proxies, err := server.Collection.PopulateJson(data)
+	if err != nil {
+		logrus.WithFields(logrus.Fields{
+			"error": err,
+		}).Error("Failed to populate proxies from file")
+	} else {
+		logrus.WithFields(logrus.Fields{
+			"proxies": len(proxies),
+		}).Info("Populated proxies from file")
 	}
 }
 

api_test.go

@@ -323,7 +323,7 @@ func TestPopulateProxyWithBadDataShouldReturnError(t *testing.T) {
 
 		for _, p := range proxies {
 			if p.Name == "two" || p.Name == "three" {
-				t.Fatalf("Proxy %s exists, populate did not fail correctly.")
+				t.Fatalf("Proxy %s exists, populate did not fail correctly.", p.Name)
 			}
 		}
 	})

cmd/toxiproxy.go

@@ -9,25 +9,39 @@ import (
 	"time"
 
 	"github.com/Shopify/toxiproxy"
+	"github.com/sirupsen/logrus"
 )
 
 var host string
 var port string
-var config string
+var configJson string
+var configFile string
 
 func init() {
 	flag.StringVar(&host, "host", "localhost", "Host for toxiproxy's API to listen on")
 	flag.StringVar(&port, "port", "8474", "Port for toxiproxy's API to listen on")
-	flag.StringVar(&config, "config", "", "JSON file containing proxies to create on startup")
+	flag.StringVar(&configFile, "configFile", "", "JSON file containing proxies to create on startup")
+	flag.StringVar(&configJson, "configJson", "", "JSON literal containing proxies to create on startup")
 	seed := flag.Int64("seed", time.Now().UTC().UnixNano(), "Seed for randomizing toxics with")
 	flag.Parse()
 	rand.Seed(*seed)
 }
 
 func main() {
 	server := toxiproxy.NewServer()
-	if len(config) > 0 {
-		server.PopulateConfig(config)
+
+	if len(configFile) > 0 && len(configJson) > 0 {
+		logrus.WithFields(logrus.Fields{
+			"configFile": configFile,
+			"configJson": configJson,
+		}).Error("configFile and configJson are mutually exclusive")
+	} else {
+		if len(configFile) > 0 {
+			server.PopulateConfigFromFile(configFile)
+		}
+		if len(configJson) > 0 {
+			server.PopulateConfigFromJsonString(configJson)
+		}
 	}
 
 	// Handle SIGTERM to exit cleanly