adds schema validation to the config file parsing process

control/config.go

@@ -75,6 +75,40 @@ type Config struct {
 	Plugins           *pluginConfig     `json:"plugins,omitempty"yaml:"plugins,omitempty"`
 }
 
+const (
+	CONFIG_CONSTRAINTS = `
+			"control" : {
+				"type": ["object", "null"],
+				"properties": {
+					"plugin_trust_level": {
+						"type": "integer",
+						"minimum": 0,
+						"maximum": 2
+					},
+					"auto_discover_path": {
+						"type": "string"
+					},
+					"cache_expiration": {
+						"type": "string"
+					},
+					"max_running_plugins": {
+						"type": "integer",
+						"minimum": 1
+					},
+					"keyring_paths" : {
+						"type": "string"
+					},
+					"plugins": {
+						"type": ["object", "null"],
+						"properties" : {},
+						"additionalProperties": true
+					}
+				},
+				"additionalProperties": false
+			}
+	`
+)
+
 // get the default snapd configuration
 func GetDefaultConfig() *Config {
 	return &Config{

control/config_test.go

@@ -30,6 +30,24 @@ import (
 	. "github.com/smartystreets/goconvey/convey"
 )
 
+const (
+	MOCK_CONSTRAINTS = `{
+		"$schema": "http://json-schema.org/draft-04/schema#",
+		"title": "snapd global config schema",
+		"type": ["object", "null"],
+		"properties": {
+			"control": { "$ref": "#/definitions/control" },
+			"scheduler": { "$ref": "#/definitions/scheduler"},
+			"restapi" : { "$ref": "#/definitions/restapi"},
+			"tribe": { "$ref": "#/definitions/tribe"}
+		},
+		"additionalProperties": true,
+		"definitions": { ` +
+		CONFIG_CONSTRAINTS + `,` + `"scheduler": {}, "restapi": {}, "tribe":{}` +
+		`}` +
+		`}`
+)
+
 type mockConfig struct {
 	Control *Config
 }
@@ -68,7 +86,7 @@ func TestPluginConfig(t *testing.T) {
 			Control: GetDefaultConfig(),
 		}
 		path := "../examples/configs/snap-config-sample.json"
-		err := cfgfile.Read(path, &config)
+		err := cfgfile.Read(path, &config, MOCK_CONSTRAINTS)
 		So(err, ShouldBeNil)
 		cfg := config.Control
 		So(cfg.Plugins, ShouldNotBeNil)
@@ -124,7 +142,7 @@ func TestControlConfigJSON(t *testing.T) {
 		Control: GetDefaultConfig(),
 	}
 	path := "../examples/configs/snap-config-sample.json"
-	err := cfgfile.Read(path, &config)
+	err := cfgfile.Read(path, &config, MOCK_CONSTRAINTS)
 	var cfg *Config
 	if err == nil {
 		cfg = config.Control
@@ -187,7 +205,7 @@ func TestControlConfigYaml(t *testing.T) {
 		Control: GetDefaultConfig(),
 	}
 	path := "../examples/configs/snap-config-sample.yaml"
-	err := cfgfile.Read(path, &config)
+	err := cfgfile.Read(path, &config, MOCK_CONSTRAINTS)
 	var cfg *Config
 	if err == nil {
 		cfg = config.Control

mgmt/rest/rest_func_test.go

@@ -64,6 +64,24 @@ var (
 	UploadCount      = 0
 )
 
+const (
+	MOCK_CONSTRAINTS = `{
+		"$schema": "http://json-schema.org/draft-04/schema#",
+		"title": "snapd global config schema",
+		"type": ["object", "null"],
+		"properties": {
+			"control": { "$ref": "#/definitions/control" },
+			"scheduler": { "$ref": "#/definitions/scheduler"},
+			"restapi" : { "$ref": "#/definitions/restapi"},
+			"tribe": { "$ref": "#/definitions/tribe"}
+		},
+		"additionalProperties": true,
+		"definitions": { ` +
+		`"control": {}, "scheduler": {}, ` + CONFIG_CONSTRAINTS + `, "tribe":{}` +
+		`}` +
+		`}`
+)
+
 type restAPIInstance struct {
 	port   int
 	server *Server
@@ -560,7 +578,7 @@ func TestPluginRestCalls(t *testing.T) {
 			})
 			Convey("Plugin config is set at startup", func() {
 				cfg := getDefaultMockConfig()
-				err := cfgfile.Read("../../examples/configs/snap-config-sample.json", &cfg)
+				err := cfgfile.Read("../../examples/configs/snap-config-sample.json", &cfg, MOCK_CONSTRAINTS)
 				So(err, ShouldBeNil)
 				r := startAPI(cfg)
 				port := r.port

mgmt/rest/server.go

@@ -80,6 +80,40 @@ type Config struct {
 	RestAuthPassword string `json:"rest_auth_password,omitempty"yaml:"rest_auth_password,omitempty"`
 }
 
+const (
+	CONFIG_CONSTRAINTS = `
+			"restapi" : {
+				"type": ["object", "null"],
+				"properties" : {
+					"enable": {
+						"type": "boolean"
+					},
+					"https" : {
+						"type": "boolean"
+					},
+					"rest_auth": {
+						"type": "boolean"
+					},
+					"rest_auth_password": {
+						"type": "string"
+					},
+					"rest_certificate": {
+						"type": "string"
+					},
+					"rest_key" : {
+						"type": "string"
+					},
+					"port" : {
+						"type": "integer",
+						"minimum": 0,
+						"maximum": 65535
+					}
+				},
+				"additionalProperties": false
+			}
+	`
+)
+
 type managesMetrics interface {
 	MetricCatalog() ([]core.CatalogedMetric, error)
 	FetchMetrics(core.Namespace, int) ([]core.CatalogedMetric, error)

mgmt/rest/server_test.go

@@ -35,7 +35,7 @@ func TestRestAPIConfigJSON(t *testing.T) {
 		RestAPI: GetDefaultConfig(),
 	}
 	path := "../../examples/configs/snap-config-sample.json"
-	err := cfgfile.Read(path, &config)
+	err := cfgfile.Read(path, &config, MOCK_CONSTRAINTS)
 	var cfg *Config
 	if err == nil {
 		cfg = config.RestAPI
@@ -74,7 +74,7 @@ func TestRestAPIConfigYaml(t *testing.T) {
 		RestAPI: GetDefaultConfig(),
 	}
 	path := "../../examples/configs/snap-config-sample.yaml"
-	err := cfgfile.Read(path, &config)
+	err := cfgfile.Read(path, &config, MOCK_CONSTRAINTS)
 	var cfg *Config
 	if err == nil {
 		cfg = config.RestAPI

mgmt/tribe/config.go

@@ -59,6 +59,34 @@ type Config struct {
 	RestAPIInsecureSkipVerify string             `json:"-"yaml:"-"`
 }
 
+const (
+	CONFIG_CONSTRAINTS = `
+			"tribe": {
+				"type": ["object", "null"],
+				"properties": {
+					"enable" : {
+						"type": "boolean"
+					},
+					"bind_addr": {
+						"type": "string"
+					},
+					"bind_port": {
+						"type": "integer",
+						"minimum": 0,
+						"maximum": 65535
+					},
+					"name": {
+						"type": "string"
+					},
+					"seed": {
+						"type" : "string"
+					}
+				},
+				"additionalProperties": false
+			}
+	`
+)
+
 // get the default snapd configuration
 func GetDefaultConfig() *Config {
 	mlCfg := memberlist.DefaultLANConfig()

mgmt/tribe/config_test.go

@@ -27,6 +27,24 @@ import (
 	. "github.com/smartystreets/goconvey/convey"
 )
 
+const (
+	MOCK_CONSTRAINTS = `{
+		"$schema": "http://json-schema.org/draft-04/schema#",
+		"title": "snapd global config schema",
+		"type": ["object", "null"],
+		"properties": {
+			"control": { "$ref": "#/definitions/control" },
+			"scheduler": { "$ref": "#/definitions/scheduler"},
+			"restapi" : { "$ref": "#/definitions/restapi"},
+			"tribe": { "$ref": "#/definitions/tribe"}
+		},
+		"additionalProperties": true,
+		"definitions": { ` +
+		`"control": {}, "scheduler": {}, "restapi":{}, ` + CONFIG_CONSTRAINTS +
+		`}` +
+		`}`
+)
+
 type mockConfig struct {
 	Tribe *Config
 }
@@ -36,7 +54,7 @@ func TestTribeConfigJSON(t *testing.T) {
 		Tribe: GetDefaultConfig(),
 	}
 	path := "../../examples/configs/snap-config-sample.json"
-	err := cfgfile.Read(path, &config)
+	err := cfgfile.Read(path, &config, MOCK_CONSTRAINTS)
 	var cfg *Config
 	if err == nil {
 		cfg = config.Tribe
@@ -69,7 +87,7 @@ func TestTribeConfigYaml(t *testing.T) {
 		Tribe: GetDefaultConfig(),
 	}
 	path := "../../examples/configs/snap-config-sample.yaml"
-	err := cfgfile.Read(path, &config)
+	err := cfgfile.Read(path, &config, MOCK_CONSTRAINTS)
 	var cfg *Config
 	if err == nil {
 		cfg = config.Tribe

pkg/cfgfile/cfgfile.go

@@ -20,33 +20,73 @@ limitations under the License.
 package cfgfile
 
 import (
+	"encoding/json"
+	"errors"
 	"fmt"
 	"io/ioutil"
 	"strings"
 
 	"github.com/ghodss/yaml"
+	"github.com/intelsdi-x/snap/core/serror"
+	"github.com/xeipuuv/gojsonschema"
 )
 
 // Read an input configuration file, parsing it (as YAML or JSON)
 // into the input 'interface{}'', v
-func Read(path string, v interface{}) error {
+func Read(path string, v interface{}, schema string) []serror.SnapError {
 	// read bytes from file
 	b, err := ioutil.ReadFile(path)
 	if err != nil {
-		return err
+		return []serror.SnapError{serror.New(err)}
 	}
-	// parse the byte-stream read (above); Note that we can parse both JSON
-	// and YAML using the same yaml.Unmarshal() method since a JSON string is
-	// a valid YAML string (but the converse is not true)
-	if parseErr := yaml.Unmarshal(b, v); parseErr != nil {
+	// convert from YAML to JSON (remember, JSON is actually valid YAML)
+	jb, err := yaml.YAMLToJSON(b)
+	if err != nil {
+		return []serror.SnapError{serror.New(fmt.Errorf("error converting YAML to JSON: %v", err))}
+	}
+	// validate the resulting JSON against the input the schema
+	if errors := ValidateSchema(schema, string(jb)); errors != nil {
+		// if invalid, construct (and return?) a SnapError from the errors identified
+		// during schema validation
+		return errors
+	}
+	// if valid, parse the JSON byte-stream (above)
+	if parseErr := json.Unmarshal(jb, v); parseErr != nil {
 		// remove any YAML-specific prefix that might have been added by then
 		// yaml.Unmarshal() method or JSON-specific prefix that might have been
 		// added if the resulting JSON string could not be marshalled into our
 		// input interface correctly (note, if there is no match to either of
 		// these prefixes then the error message will be passed through unchanged)
 		tmpErr := strings.TrimPrefix(parseErr.Error(), "error converting YAML to JSON: yaml: ")
 		errRet := strings.TrimPrefix(tmpErr, "error unmarshaling JSON: json: ")
-		return fmt.Errorf("Error while parsing configuration file: %v", errRet)
+		return []serror.SnapError{serror.New(fmt.Errorf("Error while parsing configuration file: %v", errRet))}
 	}
 	return nil
 }
+
+// Validate the configuration (JSON) string against the input schema
+func ValidateSchema(schema, cfg string) []serror.SnapError {
+	schemaLoader := gojsonschema.NewStringLoader(schema)
+	testDoc := gojsonschema.NewStringLoader(cfg)
+	result, err := gojsonschema.Validate(schemaLoader, testDoc)
+	var serrors []serror.SnapError
+	// Check for invalid json
+	if err != nil {
+		serrors = append(serrors, serror.New(err))
+		return serrors
+	}
+	// check if result passes validation
+	if result.Valid() {
+		return nil
+	}
+	for _, err := range result.Errors() {
+		serr := serror.New(errors.New("Validate schema error"))
+		serr.SetFields(map[string]interface{}{
+			"value":       err.Value(),
+			"context":     err.Context().String("::"),
+			"description": err.Description(),
+		})
+		serrors = append(serrors, serr)
+	}
+	return serrors
+}