Move doc-comment logic to the config pkg

cmd/lotus/config.go

@@ -1,13 +1,8 @@
 package main
 
 import (
-	"bytes"
 	"fmt"
 	"github.com/filecoin-project/lotus/node/repo"
-	"reflect"
-	"strings"
-
-	"github.com/BurntSushi/toml"
 	"github.com/urfave/cli/v2"
 	"golang.org/x/xerrors"
 
@@ -35,19 +30,7 @@ var configDefaultCmd = &cli.Command{
 	Action: func(cctx *cli.Context) error {
 		c := config.DefaultFullNode()
 
-		if cctx.Bool("no-comment") {
-			buf := new(bytes.Buffer)
-			_, _ = buf.WriteString("# Default config:\n")
-			e := toml.NewEncoder(buf)
-			if err := e.Encode(c); err != nil {
-				return xerrors.Errorf("encoding default config: %w", err)
-			}
-
-			fmt.Println(buf.String())
-			return nil
-		}
-
-		cb, err := config.ConfigComment(c)
+		cb, err := config.ConfigUpdate(c, nil, !cctx.Bool("no-comment"))
 		if err != nil {
 			return err
 		}
@@ -99,64 +82,12 @@ var configUpdateCmd = &cli.Command{
 
 		cfgDef := config.DefaultFullNode()
 
-		var nodeStr, defStr string
-		{
-			buf := new(bytes.Buffer)
-			e := toml.NewEncoder(buf)
-			if err := e.Encode(cfgDef); err != nil {
-				return xerrors.Errorf("encoding default config: %w", err)
-			}
-
-			defStr = buf.String()
+		updated, err := config.ConfigUpdate(cfgNode, cfgDef, !cctx.Bool("no-comment"))
+		if err != nil {
+			return err
 		}
 
-		{
-			buf := new(bytes.Buffer)
-			e := toml.NewEncoder(buf)
-			if err := e.Encode(cfgNode); err != nil {
-				return xerrors.Errorf("encoding node config: %w", err)
-			}
-
-			nodeStr = buf.String()
-		}
-
-		if !cctx.Bool("no-comment") {
-			defLines := strings.Split(defStr, "\n")
-			defaults := map[string]struct{}{}
-			for i := range defLines {
-				l := strings.TrimSpace(defLines[i])
-				if len(l) == 0 {
-					continue
-				}
-				if l[0] == '#' || l[0] == '[' {
-					continue
-				}
-				defaults[l] = struct{}{}
-			}
-
-			nodeLines := strings.Split(nodeStr, "\n")
-			for i := range nodeLines {
-				if _, found := defaults[strings.TrimSpace(nodeLines[i])]; found {
-					nodeLines[i] = "#" + nodeLines[i]
-				}
-			}
-
-			nodeStr = strings.Join(nodeLines, "\n")
-		}
-
-		// sanity-check that the updated config parses the same way as the current one
-		{
-			cfgUpdated, err := config.FromReader(strings.NewReader(nodeStr), config.DefaultFullNode())
-			if err != nil {
-				return xerrors.Errorf("parsing updated config: %w", err)
-			}
-
-			if !reflect.DeepEqual(cfgNode, cfgUpdated) {
-				return xerrors.Errorf("updated config didn't match current config")
-			}
-		}
-
-		fmt.Println(nodeStr)
+		fmt.Print(string(updated))
 		return nil
 	},
 }

node/config/doc_gen.go

@@ -13,7 +13,7 @@ var Doc = map[string][]DocField{
 		{
 			Name: "ListenAddress",
 			Type: "string",
-			Comment: ``,
+			Comment: `Binding address for the Lotus API`,
 		},
 		{
 			Name: "RemoteListenAddress",

node/config/load.go

@@ -5,6 +5,10 @@ import (
 	"fmt"
 	"io"
 	"os"
+	"reflect"
+	"regexp"
+	"strings"
+	"unicode"
 
 	"github.com/BurntSushi/toml"
 	"github.com/kelseyhightower/envconfig"
@@ -42,15 +46,121 @@ func FromReader(reader io.Reader, def interface{}) (interface{}, error) {
 	return cfg, nil
 }
 
-func ConfigComment(t interface{}) ([]byte, error) {
-	buf := new(bytes.Buffer)
-	_, _ = buf.WriteString("# Default config:\n")
-	e := toml.NewEncoder(buf)
-	if err := e.Encode(t); err != nil {
-		return nil, xerrors.Errorf("encoding config: %w", err)
+func ConfigUpdate(cfgCur, cfgDef interface{}, comment bool) ([]byte, error) {
+	var nodeStr, defStr string
+	if cfgDef != nil {
+		buf := new(bytes.Buffer)
+		e := toml.NewEncoder(buf)
+		if err := e.Encode(cfgDef); err != nil {
+			return nil, xerrors.Errorf("encoding default config: %w", err)
+		}
+
+		defStr = buf.String()
 	}
-	b := buf.Bytes()
-	b = bytes.ReplaceAll(b, []byte("\n"), []byte("\n#"))
-	b = bytes.ReplaceAll(b, []byte("#["), []byte("["))
-	return b, nil
+
+	{
+		buf := new(bytes.Buffer)
+		e := toml.NewEncoder(buf)
+		if err := e.Encode(cfgCur); err != nil {
+			return nil, xerrors.Errorf("encoding node config: %w", err)
+		}
+
+		nodeStr = buf.String()
+	}
+
+	if comment {
+		// create a map of default lines so we can comment those out later
+		defLines := strings.Split(defStr, "\n")
+		defaults := map[string]struct{}{}
+		for i := range defLines {
+			l := strings.TrimSpace(defLines[i])
+			if len(l) == 0 {
+				continue
+			}
+			if l[0] == '#' || l[0] == '[' {
+				continue
+			}
+			defaults[l] = struct{}{}
+		}
+
+		nodeLines := strings.Split(nodeStr, "\n")
+		var outLines []string
+
+		sectionRx := regexp.MustCompile(`[\[.]([^.]+)]`)
+		var section string
+
+		for i, line := range nodeLines {
+			// if this is a section, track it
+			trimmed := strings.TrimSpace(line)
+			if len(trimmed) > 0 {
+				if trimmed[0] == '[' {
+					m := sectionRx.FindSubmatch([]byte(trimmed))
+					if len(m) != 2 {
+						return nil, xerrors.Errorf("section didn't match (line %d)", i)
+					}
+					section = string(m[1])
+
+					// never comment sections
+					outLines = append(outLines, line)
+					continue
+				}
+			}
+
+			pad := strings.Repeat(" ", len(line) - len(strings.TrimLeftFunc(line, unicode.IsSpace)))
+
+			// see if we have docs for this field
+			{
+				lf := strings.Fields(line)
+				if len(lf) > 1 {
+					var doc *DocField
+					for _, df := range Doc[section] {
+						if df.Name == lf[0] {
+							doc = &df
+							break
+						}
+					}
+
+					if doc != nil {
+						// found docfield, emit doc comment
+						if len(doc.Comment) > 0 {
+							for _, docLine := range strings.Split(doc.Comment, "\n") {
+								outLines = append(outLines, pad + "# " + docLine)
+							}
+							outLines = append(outLines, pad + "#")
+						}
+
+						outLines = append(outLines, pad + "# type: " + doc.Type)
+					}
+				}
+			}
+
+			// if there is the same line in the default config, comment it out it output
+			if _, found := defaults[strings.TrimSpace(nodeLines[i])]; (cfgDef == nil || found) && len(line) > 0 {
+				line = pad + "#" + line[len(pad):]
+				outLines = append(outLines, line, "")
+			} else {
+				outLines = append(outLines, line)
+			}
+		}
+
+		nodeStr = strings.Join(outLines, "\n")
+	}
+
+	// sanity-check that the updated config parses the same way as the current one
+	if cfgDef != nil {
+		cfgUpdated, err := FromReader(strings.NewReader(nodeStr), cfgDef)
+		if err != nil {
+			return nil, xerrors.Errorf("parsing updated config: %w", err)
+		}
+
+		if !reflect.DeepEqual(cfgCur, cfgUpdated) {
+			return nil, xerrors.Errorf("updated config didn't match current config")
+		}
+	}
+
+	return []byte(nodeStr), nil
+}
+
+func ConfigComment(t interface{}) ([]byte, error) {
+	return ConfigUpdate(t, nil, true)
 }

node/config/types.go

@@ -200,6 +200,7 @@ type MinerAddressConfig struct {
 
 // API contains configs for API endpoint
 type API struct {
+	// Binding address for the Lotus API
 	ListenAddress       string
 	RemoteListenAddress string
 	Timeout             Duration