town/cmd/launcher/main.go

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2022-07-30 13:45:37 +00:00
package main
import (
"fmt"
"io/ioutil"
"os"
"os/exec"
"os/user"
"path/filepath"
"strings"
"github.com/spf13/cobra"
"gopkg.in/yaml.v3"
)
const binroot = "/town/commands"
var rootCmd = &cobra.Command{
Use: "town",
Short: "Run commands unique to tilde.town",
}
var adminCmd = &cobra.Command{
Use: "admin",
Short: "Run administrative commands",
}
func isAdmin() (bool, error) {
u, err := user.Current()
if err != nil {
return false, fmt.Errorf("failed to get information about current user: %w", err)
}
adminGroup, err := user.LookupGroup("admin")
if err != nil {
return false, fmt.Errorf("failed to get admin group info: %w", err)
}
groupIds, err := u.GroupIds()
if err != nil {
return false, fmt.Errorf("failed to get groups info: %w", err)
}
for _, groupId := range groupIds {
if groupId == adminGroup.Gid {
return true, nil
}
}
return false, nil
}
func parseCommands(targetCmd *cobra.Command, path string) error {
binPath := filepath.Join(binroot, path)
files, err := ioutil.ReadDir(binPath)
if err != nil {
return fmt.Errorf("failed to list directory %s: %s", binPath, err)
}
for _, file := range files {
if strings.HasSuffix(file.Name(), "yml") {
parseCommand(targetCmd, filepath.Join(binPath, file.Name()))
}
}
return nil
}
type commandDoc struct {
ShortDesc string `yaml:"shortDesc"`
LongDesc string `yaml:"longDesc"`
Examples string
Maintainer string
}
func parseCommand(targetCmd *cobra.Command, yamlPath string) {
executablePath := strings.TrimSuffix(yamlPath, ".yml")
// TODO handle when files lack executable bit
_, err := os.Stat(executablePath)
if err != nil {
fmt.Fprintf(os.Stderr, "could not find matching executable for %s; skipping...\n", yamlPath)
return
}
yamlBytes, err := ioutil.ReadFile(yamlPath)
if err != nil {
fmt.Fprintf(os.Stderr, "could not read %s; skipping...\n", yamlPath)
return
}
doc := commandDoc{}
err = yaml.Unmarshal(yamlBytes, &doc)
if err != nil {
fmt.Fprintf(os.Stderr, "could not parse %s; skipping...\n", yamlPath)
return
}
if doc.Maintainer == "" {
fmt.Fprintf(os.Stderr, "%s is missing maintainer field; skipping...\n", yamlPath)
return
}
parsedCmd := &cobra.Command{
Use: filepath.Base(executablePath),
RunE: execWrapper(executablePath),
DisableFlagParsing: true,
}
if doc.ShortDesc != "" {
parsedCmd.Short = doc.ShortDesc
}
if doc.LongDesc != "" {
parsedCmd.Long = doc.LongDesc
}
parsedCmd.Long += fmt.Sprintf("\nMaintained by %s; reach out to them via mail or chat with questions", doc.Maintainer)
if doc.Examples != "" {
parsedCmd.Example = doc.Examples
}
targetCmd.AddCommand(parsedCmd)
}
func execWrapper(executablePath string) func(*cobra.Command, []string) error {
return func(cmd *cobra.Command, args []string) error {
execCmd := exec.Command(executablePath, args...)
execCmd.Stderr = os.Stderr
execCmd.Stdout = os.Stdout
execCmd.Stdin = os.Stdin
return execCmd.Run()
}
}
func cli() int {
err := parseCommands(rootCmd, "core")
if err != nil {
fmt.Fprintf(os.Stderr, "failed to parse core commands: %s", err)
return 1
}
err = parseCommands(rootCmd, "contrib")
if err != nil {
fmt.Fprintf(os.Stderr, "failed to parse contrib commands: %s", err)
return 1
}
admin, err := isAdmin()
if err != nil {
fmt.Fprintf(os.Stderr, "failed to check admin status: %s", err)
return 2
}
if admin {
rootCmd.AddCommand(adminCmd)
err = parseCommands(adminCmd, "admin")
if err != nil {
fmt.Fprintf(os.Stderr, "failed to parse admin commands: %s", err)
return 1
}
}
// I feel like the example/documentation yaml can be frontmatter for non-binary files. to start
// i'll just do the accompanying yaml file.
rootCmd.Execute()
return 0
}
func main() {
os.Exit(cli())
}