copy paste launcher

cmd/launcher/README.md

@@ -0,0 +1,50 @@
+This is an implementation of an idea we discussed a while ago; a launcher for town-specific
+commands.
+
+The idea is to put town commands in one of three places:
+
+- /town/launcher/core
+- /town/launcher/contrib
+- /town/launcher/admin
+
+and pair each command with a corresponding .yml file.
+
+For example, the `aup` command is a simple wrapper around elinks that opens our code of conduct. I
+put the executable `aup` in /town/launcher/core and matched it with /town/launcher/aup.yml. The
+purpose of the yaml file is to provide documentation for your executable, so `aup.yml` looks like:
+
+```yaml
+shortDesc: View the town's Acceptable Use Policy
+longDesc: |
+  This command will open our code of conduct, a type of document that evokes the Acceptable Use
+  Policies that governed servers like this in the past. It will open the elinks browser to a
+  page on the wiki.
+examples: |
+  $ town aup           # open the aup
+  $ town aup --rainbow # open the aup with rainbow colors
+maintainer: vilmibm
+```
+
+ and using the launcher is like:
+
+     $ town aup
+     $ town aup --rainbow
+     $ town writo
+     $ town admin ban vilmibm
+
+You can see all the commands with `town help` as well as their descriptions; `town help
+aup` would show you the docs from `aup.yml`.
+
+I'd love feedback on this approach while I wrap up this implementation. I can put it up on
+git.tilde.town if anyone desires to collaborate (and let me know if you want a git.tilde.town
+account).
+
+Remaining TODOs:
+
+- [ ] make tab completion available for common shells
+- [ ] document / script submitting a tool for inclusion in contrib
+- [x] make little wrappers for things like `mail` and `chat`
+- [x] fix arg passing
+- [x] test with a command that makes use of stdin/stdout
+- [x] add all existing commands to the buckets
+- [x] add to users' paths

cmd/launcher/main.go

@@ -0,0 +1,174 @@
+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())
+}

go.mod

@@ -1,3 +1,8 @@
 module git.tilde.town/tildetown/town
 
 go 1.14
+
+require (
+	github.com/spf13/cobra v1.5.0
+	gopkg.in/yaml.v3 v3.0.1
+)

go.sum

@@ -0,0 +1,13 @@
+github.com/cpuguy83/go-md2man/v2 v2.0.2/go.mod h1:tgQtvFlXSQOSOSIRvRPT7W67SCa46tRHOmNcaadrF8o=
+github.com/inconshreveable/mousetrap v1.0.0 h1:Z8tu5sraLXCXIcARxBp/8cbvlwVa7Z1NHg9XEKhtSvM=
+github.com/inconshreveable/mousetrap v1.0.0/go.mod h1:PxqpIevigyE2G7u3NXJIT2ANytuPF1OarO4DADm73n8=
+github.com/russross/blackfriday/v2 v2.1.0/go.mod h1:+Rmxgy9KzJVeS9/2gXHxylqXiyQDYRxCVz55jmeOWTM=
+github.com/spf13/cobra v1.5.0 h1:X+jTBEBqF0bHN+9cSMgmfuvv2VHJ9ezmFNf9Y/XstYU=
+github.com/spf13/cobra v1.5.0/go.mod h1:dWXEIy2H428czQCjInthrTRUg7yKbok+2Qi/yBIJoUM=
+github.com/spf13/pflag v1.0.5 h1:iy+VFUOCP1a+8yFto/drg2CJ5u0yRoB7fZw3DKv/JXA=
+github.com/spf13/pflag v1.0.5/go.mod h1:McXfInJRrz4CZXVZOBLb0bTZqETkiAhM9Iw0y3An2Bg=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/yaml.v2 v2.4.0/go.mod h1:RDklbk79AGWmwhnvt/jBztapEOGDOx6ZbXqjP6csGnQ=
+gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
+gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=