package cmd import ( "errors" "fmt" "github.com/urfave/cli/v2" "heckel.io/ntfy/client" "heckel.io/ntfy/log" "heckel.io/ntfy/util" "os" "os/exec" "os/user" "path/filepath" "sort" "strings" ) func init() { commands = append(commands, cmdSubscribe) } const ( clientRootConfigFileUnixAbsolute = "/etc/ntfy/client.yml" clientUserConfigFileUnixRelative = "ntfy/client.yml" clientUserConfigFileWindowsRelative = "ntfy\\client.yml" ) var flagsSubscribe = append( flagsDefault, &cli.StringFlag{Name: "config", Aliases: []string{"c"}, Usage: "client config file"}, &cli.StringFlag{Name: "since", Aliases: []string{"s"}, Usage: "return events since `SINCE` (Unix timestamp, or all)"}, &cli.StringFlag{Name: "user", Aliases: []string{"u"}, Usage: "username[:password] used to auth against the server"}, &cli.BoolFlag{Name: "from-config", Aliases: []string{"C"}, Usage: "read subscriptions from config file (service mode)"}, &cli.BoolFlag{Name: "poll", Aliases: []string{"p"}, Usage: "return events and exit, do not listen for new events"}, &cli.BoolFlag{Name: "scheduled", Aliases: []string{"sched", "S"}, Usage: "also return scheduled/delayed events"}, ) var cmdSubscribe = &cli.Command{ Name: "subscribe", Aliases: []string{"sub"}, Usage: "Subscribe to one or more topics on a ntfy server", UsageText: "ntfy subscribe [OPTIONS..] [TOPIC]", Action: execSubscribe, Category: categoryClient, Flags: flagsSubscribe, Before: initLogFunc, Description: `Subscribe to a topic from a ntfy server, and either print or execute a command for every arriving message. There are 3 modes in which the command can be run: ntfy subscribe TOPIC This prints the JSON representation of every incoming message. It is useful when you have a command that wants to stream-read incoming JSON messages. Unless --poll is passed, this command stays open forever. Examples: ntfy subscribe mytopic # Prints JSON for incoming messages for ntfy.sh/mytopic ntfy sub home.lan/backups # Subscribe to topic on different server ntfy sub --poll home.lan/backups # Just query for latest messages and exit ntfy sub -u phil:mypass secret # Subscribe with username/password ntfy subscribe TOPIC COMMAND This executes COMMAND for every incoming messages. The message fields are passed to the command as environment variables: Variable Aliases Description --------------- --------------------- ----------------------------------- $NTFY_ID $id Unique message ID $NTFY_TIME $time Unix timestamp of the message delivery $NTFY_TOPIC $topic Topic name $NTFY_MESSAGE $message, $m Message body $NTFY_TITLE $title, $t Message title $NTFY_PRIORITY $priority, $prio, $p Message priority (1=min, 5=max) $NTFY_TAGS $tags, $tag, $ta Message tags (comma separated list) $NTFY_RAW $raw Raw JSON message Examples: ntfy sub mytopic 'notify-send "$m"' # Execute command for incoming messages ntfy sub topic1 myscript.sh # Execute script for incoming messages ntfy subscribe --from-config Service mode (used in ntfy-client.service). This reads the config file and sets up subscriptions for every topic in the "subscribe:" block (see config file). Examples: ntfy sub --from-config # Read topics from config file ntfy sub --config=myclient.yml --from-config # Read topics from alternate config file ` + clientCommandDescriptionSuffix, } func execSubscribe(c *cli.Context) error { // Read config and options conf, err := loadConfig(c) if err != nil { return err } cl := client.New(conf) since := c.String("since") user := c.String("user") poll := c.Bool("poll") scheduled := c.Bool("scheduled") fromConfig := c.Bool("from-config") topic := c.Args().Get(0) command := c.Args().Get(1) if !fromConfig { conf.Subscribe = nil // wipe if --from-config not passed } var options []client.SubscribeOption if since != "" { options = append(options, client.WithSince(since)) } if user != "" { var pass string parts := strings.SplitN(user, ":", 2) if len(parts) == 2 { user = parts[0] pass = parts[1] } else { fmt.Fprint(c.App.ErrWriter, "Enter Password: ") p, err := util.ReadPassword(c.App.Reader) if err != nil { return err } pass = string(p) fmt.Fprintf(c.App.ErrWriter, "\r%s\r", strings.Repeat(" ", 20)) } options = append(options, client.WithBasicAuth(user, pass)) } if poll { options = append(options, client.WithPoll()) } if scheduled { options = append(options, client.WithScheduled()) } if topic == "" && len(conf.Subscribe) == 0 { return errors.New("must specify topic, type 'ntfy subscribe --help' for help") } // Execute poll or subscribe if poll { return doPoll(c, cl, conf, topic, command, options...) } return doSubscribe(c, cl, conf, topic, command, options...) } func doPoll(c *cli.Context, cl *client.Client, conf *client.Config, topic, command string, options ...client.SubscribeOption) error { for _, s := range conf.Subscribe { // may be nil if err := doPollSingle(c, cl, s.Topic, s.Command, options...); err != nil { return err } } if topic != "" { if err := doPollSingle(c, cl, topic, command, options...); err != nil { return err } } return nil } func doPollSingle(c *cli.Context, cl *client.Client, topic, command string, options ...client.SubscribeOption) error { messages, err := cl.Poll(topic, options...) if err != nil { return err } for _, m := range messages { printMessageOrRunCommand(c, m, command) } return nil } func doSubscribe(c *cli.Context, cl *client.Client, conf *client.Config, topic, command string, options ...client.SubscribeOption) error { cmds := make(map[string]string) // Subscription ID -> command for _, s := range conf.Subscribe { // May be nil topicOptions := append(make([]client.SubscribeOption, 0), options...) for filter, value := range s.If { topicOptions = append(topicOptions, client.WithFilter(filter, value)) } if s.User != "" && s.Password != "" { topicOptions = append(topicOptions, client.WithBasicAuth(s.User, s.Password)) } subscriptionID := cl.Subscribe(s.Topic, topicOptions...) cmds[subscriptionID] = s.Command } if topic != "" { subscriptionID := cl.Subscribe(topic, options...) cmds[subscriptionID] = command } for m := range cl.Messages { cmd, ok := cmds[m.SubscriptionID] if !ok { continue } log.Debug("%s Dispatching received message: %s", logMessagePrefix(m), m.Raw) printMessageOrRunCommand(c, m, cmd) } return nil } func printMessageOrRunCommand(c *cli.Context, m *client.Message, command string) { if command != "" { runCommand(c, command, m) } else { log.Debug("%s Printing raw message", logMessagePrefix(m)) fmt.Fprintln(c.App.Writer, m.Raw) } } func runCommand(c *cli.Context, command string, m *client.Message) { if err := runCommandInternal(c, command, m); err != nil { log.Warn("%s Command failed: %s", logMessagePrefix(m), err.Error()) } } func runCommandInternal(c *cli.Context, script string, m *client.Message) error { scriptFile := fmt.Sprintf("%s/ntfy-subscribe-%s.%s", os.TempDir(), util.RandomString(10), scriptExt) log.Debug("%s Running command '%s' via temporary script %s", logMessagePrefix(m), script, scriptFile) script = scriptHeader + script if err := os.WriteFile(scriptFile, []byte(script), 0700); err != nil { return err } defer os.Remove(scriptFile) log.Debug("%s Executing script %s", logMessagePrefix(m), scriptFile) cmd := exec.Command(scriptLauncher[0], append(scriptLauncher[1:], scriptFile)...) cmd.Stdin = c.App.Reader cmd.Stdout = c.App.Writer cmd.Stderr = c.App.ErrWriter cmd.Env = envVars(m) return cmd.Run() } func envVars(m *client.Message) []string { env := make([]string, 0) env = append(env, envVar(m.ID, "NTFY_ID", "id")...) env = append(env, envVar(m.Topic, "NTFY_TOPIC", "topic")...) env = append(env, envVar(fmt.Sprintf("%d", m.Time), "NTFY_TIME", "time")...) env = append(env, envVar(m.Message, "NTFY_MESSAGE", "message", "m")...) env = append(env, envVar(m.Title, "NTFY_TITLE", "title", "t")...) env = append(env, envVar(fmt.Sprintf("%d", m.Priority), "NTFY_PRIORITY", "priority", "prio", "p")...) env = append(env, envVar(strings.Join(m.Tags, ","), "NTFY_TAGS", "tags", "tag", "ta")...) env = append(env, envVar(m.Raw, "NTFY_RAW", "raw")...) sort.Strings(env) if log.IsTrace() { log.Trace("%s With environment:\n%s", logMessagePrefix(m), strings.Join(env, "\n")) } return append(os.Environ(), env...) } func envVar(value string, vars ...string) []string { env := make([]string, 0) for _, v := range vars { env = append(env, fmt.Sprintf("%s=%s", v, value)) } return env } func loadConfig(c *cli.Context) (*client.Config, error) { filename := c.String("config") if filename != "" { return client.LoadConfig(filename) } configFile := defaultClientConfigFile() if s, _ := os.Stat(configFile); s != nil { return client.LoadConfig(configFile) } return client.NewConfig(), nil } //lint:ignore U1000 Conditionally used in different builds func defaultClientConfigFileUnix() string { u, _ := user.Current() configFile := clientRootConfigFileUnixAbsolute if u.Uid != "0" { homeDir, _ := os.UserConfigDir() return filepath.Join(homeDir, clientUserConfigFileUnixRelative) } return configFile } //lint:ignore U1000 Conditionally used in different builds func defaultClientConfigFileWindows() string { homeDir, _ := os.UserConfigDir() return filepath.Join(homeDir, clientUserConfigFileWindowsRelative) } func logMessagePrefix(m *client.Message) string { return fmt.Sprintf("%s/%s", util.ShortTopicURL(m.TopicURL), m.ID) }