Merge pull request #17 from issmirnov/validation

Implement Validation Logic.

config.go

@@ -12,6 +12,7 @@ import (
 	"github.com/Jeffail/gabs"
 	"github.com/fsnotify/fsnotify"
 	"github.com/ghodss/yaml"
+	"github.com/hashicorp/go-multierror"
 )
 
 const (
@@ -20,8 +21,12 @@ const (
 	expandKey  = "expand"
 	queryKey   = "query"
 	sslKey     = "ssl_off"
+
 )
 
+// Sentinel value used to indicate set membership.
+var exists = struct{}{}
+
 // parseYaml takes a file name and returns a gabs config object.
 func parseYaml(fname string) (*gabs.Container, error) {
 	data, err := ioutil.ReadFile(fname)
@@ -38,6 +43,51 @@ func parseYaml(fname string) (*gabs.Container, error) {
 	return j, nil
 }
 
+// validateConfig verifies that there are no unexpected values in the config file.
+// at each level of the config, we should either have a KV for expansions, or a leaf node
+// with the values oneof "expand", "query", "ssl_off" that map to a string.
+func validateConfig(c *gabs.Container) (error) {
+	var errors *multierror.Error
+	children, _ := c.ChildrenMap()
+	seenKeys := make(map[string]struct{})
+	for k,v := range children {
+		// Check if key already seen
+		if _, ok := seenKeys[k]; ok {
+			log.Printf("%s detected again", k)
+			errors = multierror.Append(errors, fmt.Errorf("duplicate key detected %s", k))
+		} else {
+			seenKeys[k] = exists // mark key as seen
+		}
+
+		// Validate all children
+		switch k {
+		case
+			"expand",
+			"query":
+			// check that v is a string, else return error.
+			if _, ok := v.Data().(string); !ok {
+				errors = multierror.Append(errors, fmt.Errorf("expected string value for %T, got: %v", k, v.Data()))
+			}
+		case "ssl_off":
+			// check that v is a boolean, else return error.
+			if _, ok := v.Data().(bool); !ok {
+				errors = multierror.Append(errors, fmt.Errorf("expected bool value for %T, got: %v", k, v.Data()))
+			}
+		default:
+			// Check if we have an unknown string here.
+			if _, ok := v.Data().(string); ok {
+				fmt.Printf("unexpected key %s", k)
+				errors = multierror.Append(errors, fmt.Errorf("unexpected string value under key %s, got: %v", k, v.Data()))
+			}
+			// recurse, collect any errors.
+			if err := validateConfig(v); err != nil {
+				errors = multierror.Append(errors, err)
+			}
+		}
+	}
+	return errors.ErrorOrNil()
+}
+
 func watchChanges(watcher *fsnotify.Watcher, fname string, cb func()) {
 	for {
 		select {
@@ -100,7 +150,12 @@ func makeCallback(c *context, configName string) func() {
 	return func() {
 		data, err := parseYaml(configName)
 		if err != nil {
-			log.Printf("Error in new config: %s. Fallback to old config.", err)
+			log.Printf("Error loading new config: %s. Fallback to old config.", err)
+			return
+		}
+		err = validateConfig(data)
+		if err != nil {
+			log.Printf("Error validating new config: %s. Fallback to old config.", err)
 			return
 		}
 

config_test.go

@@ -0,0 +1,93 @@
+package main
+
+import (
+	"testing"
+
+	. "github.com/smartystreets/goconvey/convey"
+)
+
+const okYAML = `
+e:
+  expand: example.com
+  a:
+    expand: apples
+  b:
+    expand: bananas
+g:
+  expand: github.com
+  d:
+    expand: issmirnov/dotfiles
+  z:
+    expand: issmirnov/zap
+  s:
+    query: "search?q="
+z:
+  expand: zero.com
+  ssl_off: yes
+zz:
+  expand: zero.ssl.on.com
+  ssl_off: no
+`
+
+const duplicatedYAML = `
+e:
+  expand: example.com
+  a:
+    expand: apples
+  b:
+    expand: bananas
+g:
+  expand: github.com
+  d:
+    expand: issmirnov/dotfiles
+  z:
+    expand: issmirnov/zap
+  s:
+    query: "search?q="
+z:
+  expand: zero.com
+  ssl_off: yes
+zz:
+  expand: zero.ssl.on.com
+  ssl_off: no
+zz:
+  expand: secondaryexpansion.com
+`
+
+const badkeysYAML = `
+e:
+  bad_key: example.com
+  a:
+    expand: apples
+g:
+  expand: github.com
+  d:
+    expand: issmirnov/dotfiles
+`
+
+
+func TestValidateConfig(t *testing.T) {
+	Convey("Given a correctly formatted yaml config", t, func() {
+		conf, _ := parseYamlString(okYAML)
+		//fmt.Printf(err.Error())
+		Convey("The validator should pass", func() {
+			So(validateConfig(conf), ShouldBeNil)
+		})
+	})
+
+	// The YAML libraries don't have support for detecting duplicate keys
+	// at parse time. Users will have to figure this out themselves.
+	//Convey("Given a yaml config with duplicated keys", t, func() {
+	//	conf, _ := parseYamlString(duplicatedYAML)
+	//	Convey("The validator should complain", func() {
+	//		So(validateConfig(conf), ShouldNotBeNil)
+	//	})
+	//})
+
+	Convey("Given a YAML config with unknown keys", t, func() {
+		conf, _ := parseYamlString(badkeysYAML)
+		Convey("The validator should raise an error", func() {
+			So(validateConfig(conf), ShouldNotBeNil)
+		})
+	})
+}

main.go

@@ -24,6 +24,7 @@ func main() {
 		port       = flag.Int("port", 8927, "port to bind to")
 		host       = flag.String("host", "127.0.0.1", "host interface")
 		v          = flag.Bool("v", false, "print version info")
+		validate          = flag.Bool("validate", false, "load config file and check for errors")
 	)
 	flag.Parse()
 
@@ -38,6 +39,17 @@ func main() {
 		log.Printf("Error parsing config file. Please fix syntax: %s\n", err)
 		return
 	}
+
+	// Perform extended validation of config.
+	if *validate {
+		if err := validateConfig(c); err != nil {
+			fmt.Println(err.Error())
+			os.Exit(1)
+		}
+		fmt.Println("No errors detected.")
+		os.Exit(0)
+	}
+
 	context := &context{config: c}
 	updateHosts(context) // sync changes since last run.
 

main_test.go

@@ -30,13 +30,16 @@ zz:
   ssl_off: no
 `
 
-func parseDummyYaml() (*gabs.Container, error) {
-	d, jsonErr := yaml.YAMLToJSON([]byte(cYaml))
+func loadTestYaml() (*gabs.Container, error) {
+	return parseYamlString(cYaml)
+}
+
+func parseYamlString(config string) (*gabs.Container, error) {
+	d, jsonErr := yaml.YAMLToJSON([]byte(config))
 	if jsonErr != nil {
 		fmt.Printf("Error encoding input to JSON.\n%s\n", jsonErr.Error())
 		return nil, jsonErr
 	}
 	j, _ := gabs.ParseJSON(d)
 	return j, nil
-
 }

text_test.go

@@ -42,7 +42,7 @@ func TestTokenizer(t *testing.T) {
 func TestExpander(t *testing.T) {
 
 	Convey("Given 'g/z'", t, func() {
-		c, _ := parseDummyYaml()
+		c, _ := loadTestYaml()
 		l := tokenize("g/z")
 		var res bytes.Buffer
 		res.WriteString("https:/")
@@ -54,7 +54,7 @@ func TestExpander(t *testing.T) {
 		})
 	})
 	// Convey("Given 'e/n'", t, func() {
-	//     c, _ := parseDummyYaml()
+	//     c, _ := loadTestYaml()
 	//     l := tokenize("e/n ")
 	//     var res bytes.Buffer
 	//     res.WriteString("https:/")
@@ -66,7 +66,7 @@ func TestExpander(t *testing.T) {
 	//     })
 	// })
 	Convey("Given 'g/z/extratext'", t, func() {
-		c, _ := parseDummyYaml()
+		c, _ := loadTestYaml()
 		l := tokenize("g/z/extratext")
 		var res bytes.Buffer
 		res.WriteString("https:/")
@@ -78,7 +78,7 @@ func TestExpander(t *testing.T) {
 		})
 	})
 	Convey("Given 'g/'", t, func() {
-		c, _ := parseDummyYaml()
+		c, _ := loadTestYaml()
 		l := tokenize("g/")
 		var res bytes.Buffer
 		res.WriteString("https:/")
@@ -90,7 +90,7 @@ func TestExpander(t *testing.T) {
 		})
 	})
 	Convey("Given 'g/z/very/deep/path'", t, func() {
-		c, _ := parseDummyYaml()
+		c, _ := loadTestYaml()
 		l := tokenize("g/z/very/deep/path")
 		var res bytes.Buffer
 		res.WriteString("https:/")
@@ -102,7 +102,7 @@ func TestExpander(t *testing.T) {
 		})
 	})
 	Convey("Given 'g/s/foobar'", t, func() {
-		c, _ := parseDummyYaml()
+		c, _ := loadTestYaml()
 		l := tokenize("g/s/foobar")
 		var res bytes.Buffer
 		res.WriteString("https:/")
@@ -114,7 +114,7 @@ func TestExpander(t *testing.T) {
 		})
 	})
 	Convey("Given 'g/s/foo/bar/baz'", t, func() {
-		c, _ := parseDummyYaml()
+		c, _ := loadTestYaml()
 		l := tokenize("g/s/foo/bar/baz")
 		var res bytes.Buffer
 		res.WriteString("https:/")
@@ -126,7 +126,7 @@ func TestExpander(t *testing.T) {
 		})
 	})
 	Convey("Given 'g/s/foo/bar/baz/'", t, func() {
-		c, _ := parseDummyYaml()
+		c, _ := loadTestYaml()
 		l := tokenize("g/s/foo/bar/baz/")
 		var res bytes.Buffer
 		res.WriteString("https:/")

web_test.go

@@ -15,7 +15,7 @@ import (
 // See https://elithrar.github.io/article/testing-http-handlers-go/ for comments.
 func TestIndexHandler(t *testing.T) {
 	Convey("Given app is set up with default config", t, func() {
-		c, err := parseDummyYaml()
+		c, err := loadTestYaml()
 		So(err, ShouldBeNil)
 		context := &context{config: c}
 		appHandler := &ctxWrapper{context, IndexHandler}
@@ -155,7 +155,7 @@ func TestIndexHandler(t *testing.T) {
 // BenchmarkIndexHandler tests request processing geed when context is preloaded.
 // Run with go test -run=BenchmarkIndexHandler -bench=. // results: 500000x	2555 ns/op
 func BenchmarkIndexHandler(b *testing.B) {
-	c, _ := parseDummyYaml()
+	c, _ := loadTestYaml()
 	context := &context{config: c}
 	appHandler := &ctxWrapper{context, IndexHandler}
 	handler := http.Handler(appHandler)
@@ -187,7 +187,7 @@ func TestHealthCheckHandler(t *testing.T) {
 
 func TestVarzHandler(t *testing.T) {
 	Convey("Given app is set up with default config", t, func() {
-		c, err := parseDummyYaml()
+		c, err := loadTestYaml()
 		So(err, ShouldBeNil)
 		context := &context{config: c}