codelingobot/slackscot

Slack bot core/framework written in Go with support for reactions to message updates/deletes

• Overview
• Requirements
• Features
• Demo
• The Name
• Concepts
• Create Your Own Slackscot
  • Assembling the Parts and Bringing Your slackscot to Life
  • Configuration Example
  • Creating Your Own Plugins
• Contributing
• Some Credits

Overview

Slackscot is a slack bot core written in Go. Think of it as the assembly kit to making your own friendly slack bot. It comes with a set of plugins you might enjoy and a friendly API for you to realize your ambitious dreams (if you dreams include this sort of thing).

Requirements

Go 1.11 or above is required, mostly for go module support.

Features

• Support for reactions to message updates. slackscot does the following:

  • Keeps track of plugin action responses and the message that triggered them

  • On message updates:

    1. Update responses for each triggered action

    2. Delete responses that aren't triggering anymore (or result in errors during the message update)

  • On deletion of triggering messages, responses are also deleted

  • Limitation: Sending a message automatically splits it into multiple slack messages when it's too long. When updating messages, this spitting doesn't happen and results in an message too long error. Effectively, the last message in the initial response might get deleted as a result. Handling of this could be better but that is the current limitation 😕

• Support for threaded replies to user message with option to also broadcast on channels (disabled by default). See configuration example below where both are enabled.

  • Plugin actions may also explicitely reply in threads with/without broadcasting via AnswerOption

• Simple extensible storage API for persistence in two flavors: StringStorer and BytesStorer. Both are basic key:value maps. A default file-based implementation is provided backed by leveldb

• Implementation of StringStorer backed by Google Cloud Datastore. See datastoredb's godoc for documentation, usage and example.

• In-memory implementation of StringStorer wrapping any StringStorer implementation to offer low-latency and potentially cost-saving storage implementation well-suited for small datasets. Plays well with cloud storage like the [datastoredb]((https://godoc.org/github.com/alexandre-normand/slackscot/store/datastoredb) See inmemorydb's godoc for documentation, usage and example.

• Support for various configuration sources/formats via viper

• Support for various ways to implement functionality:

  1. scheduled actions: run something every second, minute, hour, week. Oh Monday is a plugin that demos this by sending a Monday greeting every Monday at 10am (or the time you configure it to).
  2. commands: respond to a command directed at your slackscot. That means something like @slackscot help or a direct message help sent to slackscot.
  3. hear actions (aka "listeners"): actions that evaluated for a match on every message that slackscot hears. You'll want to make sure your Match function isn't too heavy. An example is the "famous" finger quoter plugin

• Experimental and subject to change: Testing functions to help validate plugin action behavior (see example in triggerer_test.go). Testing functions are found in assertplugin and assertanswer

• Built-in help plugin supporting a decently formatted help message as a command listing all plugins' actions. If you'd like some actions to not be shown in the help, you can set Hidden to true in its ActionDefinition (especially useful for hear actions)

• The plugin interface as a logical grouping of one or many commands and hear actions and/or scheduled actions

• Support for injected services providing plugins easy access to an optionally caching user info and a logger.

Demo

• slackscot deleting a triggered reaction after seeing a message updated that caused the first action to not trigger anymore and a new action to now trigger (it makes sense when you see it)

• slackscot updating a triggered reaction after seeing a triggering message being updated

• slackscot deleting a reaction after seeing the triggering message being deleted

• slackscot threaded replies enabled (with broadcast => on)

The Name

The first concrete bot implementation using this code was youppi, named after the great mascot of the Montreal Expos and, when the Expos left Montreal, the Montreal Canadiens.

Slackscot is a variation on the expected theme of slackbot with the implication that this is the core to more than just a regular bot. You know, a friendly company mascot that hangs out on your slack.

Concepts

• Commands: commands are well-defined actions with a format. Slackscot handles all direct messages as implicit commands as well as @mention <command> on channels. Responses to commands are directed to the person who invoked it.

• Hear actions: those are listeners that can potentially match on any message sent on channels that slackscot is a member of. This can include actions that will randomly generate a response. Note that responses are not automatically directed to the person who authored the message triggering the response (although an implementation is free to use the user id of the triggering message if desired).

Create Your Own Slackscot

Slackscot provides the pieces to make your mascot but you'll have to assemble them for him/her to come alive. The easiest to get started is to look at a real example: youppi.

The godoc is also a good reference especially if you're looking to implement something like a new implementation of the storer interfaces.

Assembling the Parts and Bringing Your slackscot to Life

Here's an example of how youppi does it (apologies for the verbose and repetitive error handling when creating instances of plugins but it looks worse than it is):

package main

import (
	"github.com/alexandre-normand/slackscot"
	"github.com/alexandre-normand/slackscot/config"
	"github.com/alexandre-normand/slackscot/plugins"
	"github.com/alexandre-normand/slackscot/store"
	"github.com/spf13/viper"
	"gopkg.in/alecthomas/kingpin.v2"
	"log"
	"os"
)

var (
	configurationPath = kingpin.Flag("configuration", "The path to the configuration file.").Required().String()
	logfile           = kingpin.Flag("log", "The path to the log file").OpenFile(os.O_RDWR|os.O_CREATE|os.O_APPEND, 0666)
)

const (
	storagePathKey = "storagePath" // Root directory for the file-based leveldb storage
	name           = "youppi"
)

func main() {
	kingpin.Version(VERSION)
	kingpin.Parse()

	v := config.NewViperWithDefaults()
	// Enable getting configuration from the environment, especially useful for the slack token
	v.AutomaticEnv()
	// Bind the token key config to the env variable SLACK_TOKEN (case sensitive)
	v.BindEnv(config.TokenKey, "SLACK_TOKEN")

	v.SetConfigFile(*configurationPath)
	err := v.ReadInConfig()
	if err != nil {
		log.Fatalf("Error loading configuration file [%s]: %v", *configurationPath, err)
	}

	// Do this only so that we can get a global debug flag available to everything
	viper.Set(config.DebugKey, v.GetBool(config.DebugKey))

	options := make([]slackscot.Option, 0)
	if *logfile != nil {
		options = append(options, slackscot.OptionLogfile(*logfile))
	}

	youppi, err := slackscot.NewSlackscot("youppi", v, options...)
	if err != nil {
		log.Fatal(err)
	}

	if !v.IsSet(storagePathKey) {
		log.Fatalf("Missing [%s] configuration key in the top value configuration", storagePathKey)
	}

	storagePath := v.GetString(storagePathKey)
	strStorer, err := store.NewLevelDB(name, storagePath)
	if err != nil {
		log.Fatalf("Opening [%s] db failed with path [%s]", name, storagePath)
	}
	defer strStorer.Close()

	karma := plugins.NewKarma(strStorer)
	youppi.RegisterPlugin(&karma.Plugin)

	fingerQuoterConf, err := config.GetPluginConfig(v, plugins.FingerQuoterPluginName)
	if err != nil {
		log.Fatalf("Error initializing finger quoter plugin: %v", err)
	}
	fingerQuoter, err := plugins.NewFingerQuoter(fingerQuoterConf)
	if err != nil {
		log.Fatalf("Error initializing finger quoter plugin: %v", err)
	}
	youppi.RegisterPlugin(&fingerQuoter.Plugin)

	emojiBannerConf, err := config.GetPluginConfig(v, plugins.EmojiBannerPluginName)
	if err != nil {
		log.Fatalf("Error initializing emoji banner plugin: %v", err)
	}
	emojiBanner, err := plugins.NewEmojiBannerMaker(emojiBannerConf)
	if err != nil {
		log.Fatalf("Error initializing emoji banner plugin: %v", err)
	}
	defer emojiBanner.Close()
	youppi.RegisterPlugin(&emojiBanner.Plugin)

	ohMondayConf, err := config.GetPluginConfig(v, plugins.OhMondayPluginName)
	if err != nil {
		log.Fatalf("Error initializing oh monday plugin: %v", err)
	}
	ohMonday, err := plugins.NewOhMonday(ohMondayConf)
	if err != nil {
		log.Fatalf("Error initializing oh monday plugin: %v", err)
	}
	youppi.RegisterPlugin(&ohMonday.Plugin)

	versioner := plugins.NewVersioner("youppi", VERSION)
	youppi.RegisterPlugin(&versioner.Plugin)

	err = youppi.Run()
	if err != nil {
		log.Fatal(err)
	}
}

Configuration Example

You'll also need to define your configuration for the core, used built-in plugins and any configuration required by your own custom plugins (not shown here). Slackscot uses viper for loading configuration which means that you are free to use a different file format (yaml, toml, env variables, etc.) as desired.

{
   "token": "your-slack-bot-token",
   "debug": false,
   "responseCacheSize": 5000,
   "timeLocation": "America/Los_Angeles",
   "storagePath": "/your-path-to-bot-home",
   "replyBehavior": {
      "threadedReplies": true,
      "broadcast": true
   },
   "plugins": {
      "ohMonday": {
   	     "channelIDs": ["slackChannelId"]
      },
      "fingerQuoter": {
         "frequency": "100",
         "channelIDs": []
      },
      "emojiBanner": {
         "figletFontUrl": "http://www.figlet.org/fonts/banner.flf"
      }
   }
}

Creating Your Own Plugins

It might be best to look at examples in this repo to guide you through it:

• The simplest plugin with a single command is the versioner
• One example of scheduled actions is oh monday
• One example of a mix of hear actions / commands that also uses the store api for persistence is the karma

Contributing

1. Fork it (preferrably, outside the GOPATH as per the new go modules guidelines)
2. Make your changes, commit them (don't forget to go build ./... and go test ./...) and push your branch to your fork
3. Open a PR and fill in the template (you don't have to but I'd appreciate context)
4. Check the code climate and travis PR builds. You might have to fix things and there's no shame if you do. I probably won't merge something that doesn't pass CI build but I'm willing to help to get it to pass 🖖.

Some Credits

slackscot uses Norberto Lopes's Slack API Integration found at https://github.com/nlopes/slack. The core functionality of the bot is previously used James Bowman's Slack RTM API integration and was heavily inspired by talbot, also written by James Bowman.