Add utility command to generate schema for config

cmd/generate-config/main.go

@@ -18,6 +18,7 @@ func main() {
 	dbURI := flag.String("db", "", "The DB URI to use for all components (PostgreSQL only)")
 	dirPath := flag.String("dir", "./", "The folder to use for paths (like SQLite databases, media storage)")
 	normalise := flag.String("normalise", "", "Normalise an existing configuration file by adding new/missing options and defaults")
+	schemaPath := flag.String("schema", "", "Path to the schema file")
 	polylith := flag.Bool("polylith", false, "Generate a config that makes sense for polylith deployments")
 	flag.Parse()
 
@@ -103,4 +104,7 @@ func main() {
 	}
 
 	fmt.Println(string(j))
+	if *schemaPath != "" {
+		fmt.Printf("# yaml-language-server: $schema=%s\n", *schemaPath)
+	}
 }

cmd/generate-jsonschema/main.go

@@ -0,0 +1,107 @@
+package main
+
+import (
+	"encoding/json"
+	"flag"
+	"os"
+	"reflect"
+	"time"
+
+	"github.com/invopop/jsonschema"
+	"github.com/matrix-org/dendrite/setup/config"
+	"github.com/uber/jaeger-client-go"
+	"gopkg.in/yaml.v2"
+)
+
+func mapper(rt reflect.Type) *jsonschema.Schema {
+
+	var d time.Duration
+	if reflect.TypeOf(d) == rt {
+		return &jsonschema.Schema{
+			Type:        "string",
+			Title:       "Duration",
+			Description: "time.Duration with h, m, s to indicate hours, minutes, seconds",
+			Pattern:     "^[0-9][0-9hms]*$",
+		}
+	}
+
+	var du config.DataUnit
+	if reflect.TypeOf(du) == rt {
+		return &jsonschema.Schema{
+			OneOf: []*jsonschema.Schema{
+				&jsonschema.Schema{
+					Type: "integer",
+				},
+				&jsonschema.Schema{
+					Type:    "string",
+					Pattern: "^[0-9]+([tgmk]b)?$",
+				},
+			},
+			Title: "Data Unit", Description: "Data unit with suffix as tb, gb, mb, kb",
+		}
+	}
+
+	// Cannot set this option in yaml config
+	var js jaeger.SamplerOption
+	if reflect.TypeOf(js) == rt {
+		return &jsonschema.Schema{
+			Type:  "string",
+			Title: "Ignore this",
+		}
+	}
+	return nil
+}
+
+func main() {
+	useJson := false
+	flag.BoolVar(&useJson, "json", useJson, "Output json instead of yaml")
+	flag.Parse()
+
+	reflector := jsonschema.Reflector{
+		RequiredFromJSONSchemaTags: true,
+		DoNotReference:             true,
+		ExpandedStruct:             true,
+		Mapper:                     mapper,
+	}
+
+	if err := reflector.AddGoComments("github.com/matrix-org/dendrite", "."); err != nil {
+		panic(err)
+	}
+
+	schema := reflector.Reflect(config.Dendrite{})
+
+	json, err := json.Marshal(schema)
+	if err != nil {
+		panic(err)
+	}
+
+	var data []byte
+	if useJson {
+		data = json
+	} else {
+		data, err = jsonToYaml(json)
+		if err != nil {
+			panic(err)
+		}
+	}
+
+	if _, err := os.Stdout.Write(data); err != nil {
+		panic(err)
+	}
+}
+
+func jsonToYaml(json []byte) ([]byte, error) {
+	var (
+		a   any
+		yml []byte
+		err error
+	)
+	if err = yaml.Unmarshal(json, &a); err != nil {
+		return nil, err
+	}
+
+	if yml, err = yaml.Marshal(a); err != nil {
+		return nil, err
+	}
+	return yml, nil
+}

go.mod

@@ -17,6 +17,7 @@ require (
 	github.com/google/uuid v1.3.0
 	github.com/gorilla/mux v1.8.0
 	github.com/gorilla/websocket v1.5.0
+	github.com/invopop/jsonschema v0.4.0
 	github.com/kardianos/minwinsvc v1.0.0
 	github.com/lib/pq v1.10.7
 	github.com/matrix-org/dugong v0.0.0-20210921133753-66e6b1c67e2e
@@ -89,6 +90,7 @@ require (
 	github.com/golang/protobuf v1.5.2 // indirect
 	github.com/golang/snappy v0.0.4 // indirect
 	github.com/h2non/filetype v1.1.3 // indirect
+	github.com/iancoleman/orderedmap v0.0.0-20190318233801-ac98e3ecb4b0 // indirect
 	github.com/json-iterator/go v1.1.12 // indirect
 	github.com/juju/errors v1.0.0 // indirect
 	github.com/klauspost/compress v1.15.11 // indirect

go.sum

@@ -322,8 +322,12 @@ github.com/hashicorp/hcl v1.0.0/go.mod h1:E5yfLk+7swimpb2L/Alb/PJmXilQ/rhwaUYs4T
 github.com/hpcloud/tail v1.0.0/go.mod h1:ab1qPbhIpdTxEkNHXyeSf5vhxWSCs/tWer42PpOxQnU=
 github.com/huandu/xstrings v1.0.0 h1:pO2K/gKgKaat5LdpAhxhluX2GPQMaI3W5FUz/I/UnWk=
 github.com/huandu/xstrings v1.0.0/go.mod h1:4qWG/gcEcfX4z/mBDHJ++3ReCw9ibxbsNJbcucJdbSo=
+github.com/iancoleman/orderedmap v0.0.0-20190318233801-ac98e3ecb4b0 h1:i462o439ZjprVSFSZLZxcsoAe592sZB1rci2Z8j4wdk=
+github.com/iancoleman/orderedmap v0.0.0-20190318233801-ac98e3ecb4b0/go.mod h1:N0Wam8K1arqPXNWjMo21EXnBPOPp36vB07FNRdD2geA=
 github.com/ianlancetaylor/demangle v0.0.0-20181102032728-5e5cf60278f6/go.mod h1:aSSvb/t6k1mPoxDqO4vJh6VOCGPwU4O0C2/Eqndh1Sc=
 github.com/inconshreveable/mousetrap v1.0.0/go.mod h1:PxqpIevigyE2G7u3NXJIT2ANytuPF1OarO4DADm73n8=
+github.com/invopop/jsonschema v0.4.0 h1:Yuy/unfgCnfV5Wl7H0HgFufp/rlurqPOOuacqyByrws=
+github.com/invopop/jsonschema v0.4.0/go.mod h1:O9uiLokuu0+MGFlyiaqtWxwqJm41/+8Nj0lD7A36YH0=
 github.com/jellevandenhooff/dkim v0.0.0-20150330215556-f50fe3d243e1/go.mod h1:E0B/fFc00Y+Rasa88328GlI/XbtyysCtTHZS8h7IrBU=
 github.com/jpillora/backoff v1.0.0/go.mod h1:J/6gKK9jxlEcS3zixgDgUAsiuZ7yrSoa/FX5e0EB2j4=
 github.com/json-iterator/go v0.0.0-20171115153421-f7279a603ede/go.mod h1:+SdeFBvtyEkXs7REEP0seUULqWtbJapLOCVDaaPEHmU=
@@ -553,6 +557,7 @@ github.com/stretchr/objx v0.4.0/go.mod h1:YvHI0jy2hoMjB+UWwv71VJQ9isScKT/TqJzVSS
 github.com/stretchr/testify v1.2.1/go.mod h1:a8OnRcib4nhh0OaRAV+Yts87kKdq0PP7pXfy6kDkUVs=
 github.com/stretchr/testify v1.2.2/go.mod h1:a8OnRcib4nhh0OaRAV+Yts87kKdq0PP7pXfy6kDkUVs=
 github.com/stretchr/testify v1.3.0/go.mod h1:M5WIy9Dh21IEIfnGCwXGc5bZfKNJtfHm1UVUgZn+9EI=
+github.com/stretchr/testify v1.3.1-0.20190311161405-34c6fa2dc709/go.mod h1:M5WIy9Dh21IEIfnGCwXGc5bZfKNJtfHm1UVUgZn+9EI=
 github.com/stretchr/testify v1.4.0/go.mod h1:j7eGeouHqKxXV5pUuKE4zz7dFj8WfuZ+81PSLYec5m4=
 github.com/stretchr/testify v1.5.1/go.mod h1:5W2xD1RspED5o8YsWQXVCued0rvSQ+mT+I5cxcmMvtA=
 github.com/stretchr/testify v1.7.0/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=