config: switch to yaml

1. Configuration is now strongly typed everywhere
2. Sample file is autogenerated from the Config struct
3. Strict parsing - specifying an illegal option will now panic

Makefile

@@ -10,7 +10,7 @@ yanfd: clean
 install:
 	install -m 755 yanfd /usr/local/bin
 	mkdir -p /usr/local/etc/ndn
-	install -m 644 yanfd.toml.sample /usr/local/etc/ndn
+	install -m 644 yanfd.sample.yml /usr/local/etc/ndn
 
 clean:
 	rm -f yanfd coverage.out

README.md

@@ -29,27 +29,27 @@ Get it from: https://www.microsoft.com/store/apps/9NBK3ZJT4CL8
 
 ### On MacOS/Linux
 ```bash
-curl -o ./yanfd.toml https://raw.githubusercontent.com/named-data/YaNFD/master/yanfd.toml.sample
+curl -o ./yanfd.yml https://raw.githubusercontent.com/named-data/YaNFD/master/yanfd.sample.yml
 mkdir -p /usr/local/etc/ndn
-install -m 644 ./yanfd.toml /usr/local/etc/ndn
-rm ./yanfd.toml
+install -m 644 ./yanfd.yml /usr/local/etc/ndn
+rm ./yanfd.yml
 ```
 
 On MacOS, one also needs to change `socket_path` to `/var/run/nfd/nfd.sock` in the copied configuration file.
 
 ### On Windows 10/11
 
 ```powershell
-curl -o yanfd.toml https://raw.githubusercontent.com/named-data/YaNFD/master/yanfd.toml.sample
+curl -o yanfd.yml https://raw.githubusercontent.com/named-data/YaNFD/master/yanfd.sample.yml
 mkdir %APPDATA%\ndn
-move yanfd.toml %APPDATA%\ndn\
+move yanfd.yml %APPDATA%\ndn\
 ```
 
 One needs to change `socket_path` to `${TEMP}\\nfd\\nfd.sock` in the copied configuration file.
 Also, to execute YaNFD on Windows 10, one needs to explicitly specify the configuration path:
 
-```bash
-yanfd.exe --config=%APPDATA%\ndn\yanfd.toml
+```powershell
+yanfd.exe --config=%APPDATA%\ndn\yanfd.yml
 ```
 
 # Building from source
@@ -71,7 +71,7 @@ To build and install YaNFD on Windows, please run the `go build` command in the
 go build github.com/named-data/YaNFD/cmd/yanfd
 ```
 
-At the moment, you will need to manually install the executable (`yanfd.exe`) and the configuration file (`yanfd.toml.sample`) to a location of your choice.
+At the moment, you will need to manually install the executable (`yanfd.exe`) and the configuration file (`yanfd.sample.yml`) to a location of your choice.
 
 # Configuration
 
@@ -81,8 +81,8 @@ Meanwhile, runtime configuration is used to create NDN faces, set routes and str
 
 ## Startup configuration
 
-Startup configuration for YaNFD is performed via a TOML file, by default read from `/usr/local/etc/ndn/yanfd.toml` on Unix-like systems.
-Note that you will need to copy the sample config file installed to `/usr/local/etc/ndn/yanfd.toml.sample` to this location before running YaNFD for the first time.
+Startup configuration for YaNFD is performed via a YAML file, by default read from `/usr/local/etc/ndn/yanfd.yml` on Unix-like systems.
+Note that you will need to copy the sample config file installed to `/usr/local/etc/ndn/yanfd.sample.yml` to this location before running YaNFD for the first time.
 The configuration options are documented via comments in the sample file.
 
 On Windows, at this time, you will need to specify the location of the configuration file manually when starting YaNFD via the `--config` argument.

cmd/make_sample_config.go

@@ -0,0 +1,88 @@
+package main
+
+import (
+	"fmt"
+	"go/ast"
+	"go/parser"
+	"go/token"
+	"os"
+	"reflect"
+	"strings"
+
+	"github.com/goccy/go-yaml"
+	"github.com/named-data/YaNFD/core"
+)
+
+func getDocstrings(
+	cm yaml.CommentMap,
+	jstr string,
+	srt *ast.StructType,
+	obj reflect.Type,
+) {
+	for _, field := range srt.Fields.List {
+		name := field.Names[0].Name
+		obj2, _ := obj.FieldByName(name)
+		jstr2 := jstr + "." + obj2.Tag.Get("json")
+
+		text := strings.TrimSpace(field.Doc.Text())
+		if len(text) > -1 {
+			lines := strings.Split(text, "\n")
+			for i, line := range lines {
+				lines[i] = " " + strings.TrimSpace(line)
+			}
+
+			cm[jstr2] = []*yaml.Comment{{
+				Texts:    lines,
+				Position: yaml.CommentHeadPosition,
+			}}
+		}
+
+		if srt2, ok := field.Type.(*ast.StructType); ok {
+			getDocstrings(cm, jstr2, srt2, obj2.Type)
+		}
+	}
+}
+
+func main() {
+	f, err := parser.ParseFile(token.NewFileSet(), "core/config.go", nil, parser.ParseComments)
+	if err != nil {
+		fmt.Println(err)
+		return
+	}
+
+	cObj := *core.DefaultConfig()
+	cSrt := f.Scope.
+		Lookup("Config").
+		Decl.(*ast.TypeSpec).
+		Type.(*ast.StructType)
+	cm := yaml.CommentMap{}
+	getDocstrings(cm, "$", cSrt, reflect.TypeOf(cObj))
+
+	file, err := os.Create("yanfd.sample.yml")
+	if err != nil {
+		panic(err)
+	}
+	defer file.Close()
+
+	bytes, err := yaml.MarshalWithOptions(cObj, yaml.WithComment(cm))
+	if err != nil {
+		panic(err)
+	}
+
+	// This is a hack to get the right spacing. For each line, if it is
+	// just a comment (#), then get rid of it altogether
+	lines := strings.Split(string(bytes), "\n")
+	for i, line := range lines {
+		if strings.TrimSpace(line) == "#" {
+			lines[i] = ""
+		}
+	}
+
+	// Join all lines with newline
+	output := strings.Join(lines, "\n")
+
+	// Write to file
+	file.WriteString("# YaNFD Sample Configuration\n")
+	file.WriteString("# This file is autogenerated by cmd/make_sample_config.go\n")
+	file.WriteString(output)
+}

cmd/yanfd/main.go

@@ -26,7 +26,7 @@ func main() {
 	var shouldPrintVersion bool
 	flag.BoolVar(&shouldPrintVersion, "version", false, "Print version and exit")
 	var configFileName string
-	flag.StringVar(&configFileName, "config", "/usr/local/etc/ndn/yanfd.toml", "Configuration file location")
+	flag.StringVar(&configFileName, "config", "/usr/local/etc/ndn/yanfd.yml", "Configuration file location")
 	var disableUnix bool
 	flag.BoolVar(&disableUnix, "disable-unix", false,
 		"Disable Unix stream transports (deprecated; set.faces.unix.enabled=false in config file instead)")