Add config validation

6 files changed, 190 insertions, 6 deletions

diff --git a/config/config.go b/config/config.go
index 2ec6706..cd2883b 100644
--- a/config/config.go
+++ b/config/config.go
@@ -1,9 +1,11 @@
 package config
 
 import (
+	"fmt"
 	"github.com/pkg/errors"
 	"io/ioutil"
 
+	"github.com/santhosh-tekuri/jsonschema"
 	"gopkg.in/yaml.v2"
 )
 
@@ -47,7 +49,7 @@ type TelegramTdlibClientConfig struct {
 	UseChatInfoDatabase bool   `yaml:":use_chat_info_database"`
 }
 
-func ReadConfig(path string) (Config, error) {
+func ReadConfig(path string, schema_path string) (Config, error) {
 	var config Config
 
 	file, err := ioutil.ReadFile(path)
@@ -60,5 +62,85 @@ func ReadConfig(path string) (Config, error) {
 		return config, errors.Wrap(err, "Error parsing config")
 	}
 
+	err = validateConfig(file, schema_path)
+	if err != nil {
+		return config, errors.Wrap(err, "Validation error")
+	}
+
 	return config, nil
 }
+
+func validateConfig(file []byte, schema_path string) error {
+	schema, err := jsonschema.Compile(schema_path)
+	if err != nil {
+		return errors.Wrap(err, "Corrupted JSON schema")
+	}
+
+	var config_generic interface{}
+
+	err = yaml.Unmarshal(file, &config_generic)
+	if err != nil {
+		return errors.Wrap(err, "Error re-parsing config")
+	}
+
+	config_generic, err = convertToStringKeysRecursive(config_generic, "")
+	if err != nil {
+		return errors.Wrap(err, "Config conversion error")
+	}
+
+	err = schema.ValidateInterface(config_generic)
+	if err != nil {
+		return errors.Wrap(err, "Config validation error")
+	}
+
+	return nil
+}
+
+// copied and adapted from https://github.com/docker/docker-ce/blob/de14285fad39e215ea9763b8b404a37686811b3f/components/cli/cli/compose/loader/loader.go#L330
+func convertToStringKeysRecursive(value interface{}, keyPrefix string) (interface{}, error) {
+	if mapping, ok := value.(map[interface{}]interface{}); ok {
+		dict := make(map[string]interface{})
+		for key, entry := range mapping {
+			str, ok := key.(string)
+			if !ok {
+				return nil, formatInvalidKeyError(keyPrefix, key)
+			}
+			var newKeyPrefix string
+			if keyPrefix == "" {
+				newKeyPrefix = str
+			} else {
+				newKeyPrefix = fmt.Sprintf("%s.%s", keyPrefix, str)
+			}
+			convertedEntry, err := convertToStringKeysRecursive(entry, newKeyPrefix)
+			if err != nil {
+				return nil, err
+			}
+			dict[str] = convertedEntry
+		}
+		return dict, nil
+	}
+	if list, ok := value.([]interface{}); ok {
+		var convertedList []interface{}
+		for index, entry := range list {
+			newKeyPrefix := fmt.Sprintf("%s[%d]", keyPrefix, index)
+			convertedEntry, err := convertToStringKeysRecursive(entry, newKeyPrefix)
+			if err != nil {
+				return nil, err
+			}
+			convertedList = append(convertedList, convertedEntry)
+		}
+		return convertedList, nil
+	}
+
+	return value, nil
+}
+
+func formatInvalidKeyError(keyPrefix string, key interface{}) error {
+	var location string
+	if keyPrefix == "" {
+		location = "at top level"
+	} else {
+		location = fmt.Sprintf("in %s", keyPrefix)
+	}
+	return errors.Errorf("Non-string key %s: %#v", location, key)
+}
diff --git a/config/config_test.go b/config/config_test.go
index 34009d7..6fce23b 100644
--- a/config/config_test.go
+++ b/config/config_test.go
@@ -4,23 +4,27 @@ import (
 	"testing"
 )
 
+const SCHEMA_PATH string = "../config_schema.json"
+
 func TestNoConfig(t *testing.T) {
-	_, err := ReadConfig("../test/sfklase.yml")
+	_, err := ReadConfig("../test/sfklase.yml", SCHEMA_PATH)
 	if err == nil {
 		t.Errorf("Non-existent config was successfully read")
 	}
 }
 
 func TestGoodConfig(t *testing.T) {
-	_, err := ReadConfig("../test/good_config.yml")
+	_, err := ReadConfig("../test/good_config.yml", SCHEMA_PATH)
 	if err != nil {
 		t.Errorf("Good config is not accepted: %v", err)
 	}
 }
 
 func TestBadConfig(t *testing.T) {
-	_, err := ReadConfig("../test/bad_config.yml")
+	_, err := ReadConfig("../test/bad_config.yml", SCHEMA_PATH)
 	if err == nil {
-		t.Errorf("Bad config is accepted but it shoudn't!")
+		t.Errorf("Bad config is accepted but it shouldn't!")
+	} else {
+		t.Log(err)
 	}
 }
diff --git a/config_schema.json b/config_schema.json
new file mode 100644
index 0000000..434bde5
--- /dev/null
+++ b/config_schema.json
@@ -0,0 +1,94 @@
+{
+  "$schema": "http://json-schema.org/draft-04/schema#",
+  "type": "object",
+  "required": [":telegram", ":xmpp"],
+  "properties": {
+    ":telegram": {
+      "type": "object",
+      "required": [":loglevel", ":content", ":tdlib"],
+      "properties": {
+        ":loglevel": {
+          "$ref": "#/definitions/non-empty-string"
+        },
+        ":content": {
+          "type": "object",
+          "properties": {
+            ":path": {
+              "type": "string"
+            },
+            ":link": {
+              "type": "string"
+            },
+            ":upload": {
+              "type": "string"
+            }
+          }
+        },
+        ":tdlib_verbosity": {
+          "type": "integer"
+        },
+        ":tdlib": {
+          "required": [":lib_path", ":client"],
+          "type": "object",
+          "properties": {
+            ":lib_path": {
+              "$ref": "#/definitions/non-empty-string"
+            },
+            ":client": {
+              "type": "object",
+              "required": [":api_id", ":api_hash"],
+              "properties": {
+                ":api_id": {
+                  "$ref": "#/definitions/non-empty-string"
+                },
+                ":api_hash": {
+                  "$ref": "#/definitions/non-empty-string"
+                },
+                ":device_model": {
+                  "type": "string"
+                },
+                ":application_version": {
+                  "type": "string"
+                },
+                ":use_chat_info_database": {
+                  "type": "boolean"
+                }
+              }
+            }
+          }
+        }
+      }
+    },
+    ":xmpp": {
+      "type": "object",
+      "required": [":loglevel", ":jid", ":host", ":port", ":password", ":db"],
+      "properties": {
+        ":loglevel": {
+          "$ref": "#/definitions/non-empty-string"
+        },
+        ":jid": {
+          "$ref": "#/definitions/non-empty-string"
+        },
+        ":host": {
+          "$ref": "#/definitions/non-empty-string"
+        },
+        ":port": {
+          "type": "integer",
+          "minimum": 1
+        },
+        ":password": {
+          "$ref": "#/definitions/non-empty-string"
+        },
+        ":db": {
+          "$ref": "#/definitions/non-empty-string"
+        }
+      }
+    }
+  },
+  "definitions": {
+    "non-empty-string": {
+      "type": "string",
+      "minLength": 1
+    }
+  }
+}
diff --git a/go.mod b/go.mod
index 0193f42..c6f2878 100644
--- a/go.mod
+++ b/go.mod
@@ -4,6 +4,7 @@ go 1.13
 
 require (
 	github.com/pkg/errors v0.8.1
+	github.com/santhosh-tekuri/jsonschema v1.2.4
 	gopkg.in/yaml.v2 v2.2.4
 	gosrc.io/xmpp v0.1.3
 )
diff --git a/go.sum b/go.sum
index e273364..4734020 100644
--- a/go.sum
+++ b/go.sum
@@ -1,6 +1,8 @@
 github.com/google/go-cmp v0.3.0/go.mod h1:8QqcDgzrUqlUb/G2PQTWiueGozuR1884gddMywk6iLU=
 github.com/pkg/errors v0.8.1 h1:iURUrRGxPUNPdy5/HRSm+Yj6okJ6UtLINN0Q9M4+h3I=
 github.com/pkg/errors v0.8.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
+github.com/santhosh-tekuri/jsonschema v1.2.4 h1:hNhW8e7t+H1vgY+1QeEQpveR6D4+OwKPXCfD2aieJis=
+github.com/santhosh-tekuri/jsonschema v1.2.4/go.mod h1:TEAUOeZSmIxTTuHatJzrvARHiuO9LYd+cIxzgEHCQI4=
 golang.org/x/xerrors v0.0.0-20190717185122-a985d3407aa7 h1:9zdDQZ7Thm29KFXgAX/+yaf3eVbP7djjWp/dXAppNCc=
 golang.org/x/xerrors v0.0.0-20190717185122-a985d3407aa7/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
diff --git a/telegabber.go b/telegabber.go
index 6c17c91..d924822 100644
--- a/telegabber.go
+++ b/telegabber.go
@@ -8,9 +8,10 @@ import (
 )
 
 const CONFIG_PATH string = "config.yml"
+const SCHEMA_PATH string = "./config_schema.json"
 
 func main() {
-	config, err := config.ReadConfig(CONFIG_PATH)
+	config, err := config.ReadConfig(CONFIG_PATH, SCHEMA_PATH)
 	if err != nil {
 		log.Fatal(err)
 	}