This is a simple Go application to generate Discord messages from various media channels. Currently, this is mainly used for fantasy author Brandon Sanderson's channels.
The following channels can trigger a notification:
- Progress Updates on an author's website (e.g. Brandon Sanderson)
- YouTube videos and livestreams
Executing the application performs a single round of checks for updates, so it must be used from an external task
scheduler - such as cron - for periodic checks.
This application uses a simple plugin system that can be configured with a YAML file. We distinguish "plugins" from " connectors". Plugins provide the support for checking social media for updates, while connectors are instances of those plugins that reflect a single channel on the respective platform. This means that there can be many connectors for different channels on the same platform that all use the same plugin.
All connectors send their updates to the same Discord channel.
The basic structure of a config file is as follows
discordWebhook: '<webhook-id>'
shared:
progress:
url: https://brandon-sanderson.com
connectors:
connector1:
plugin: progress
config:
url: https://brandonsanderson.com
message: The progress bars on Brandon's website were updated!
connector2:
plugin: twitter
config:
account: BrandSandersonThe discordWebhook item is mandatory and must be the ID (i.e. channel ID + token) of a Discord webhook. Simply use the
value after https://discord.com/api/webhooks/ from the webhook URL Discord provides you with.
The shared section defines configuration values that are used across all connectors using a plugin. Keys in the map
must be a plugin ID. The shared config object is simply merged into any connector-specific one. Connector configs always
take precedence over shared ones.
The connectors section defines the actual connectors that will be used to check for updates. Each key serves as unique
identifier to keep track of the status of the channel the connector consumes. You must specify a plugin for the connector.
The config value is optional and may contain plugin-specific options.
See the respective plugin sections for which plugins and options are available in the shared and
connector-level sections.
Once you have set up your config file, simply invoke the following command:
sanderson-notifications [-config config.yaml] [-offsets offsets.json]The -config and -offsets options are not mandatory and shown here with their default values.
Respectively, they point to the config file to load as well as the location where to retrieve and store connector offsets.
Furthermore, the executing user must have write access to the working directory.
A connector always has an associated "offset", which the underlying plugin may use to keep track of what on a social media channel it has seen last. After every connector run, a new offset for it is stored.
Offsets are stored in a JSON file that contains a simple JSON object. Keys are connector names, while values are plugin-specific JSON values that contain the current offset for a connector.
Offsets for unknown connectors are retained, in case they were only temporarily removed from the configuration file.
A sample offset file may look like this:
{
"unknown-connector": {
"myCustomJson": "value"
},
"progress-connector": [
{
"Title": "Progress Bar 1",
"Link": "",
"Value": 100
},
{
"Title": "Progress Bar 2",
"Link": "https://example.com",
"Value": 61
}
],
"twitter-connector": "1439074304365264899",
"youtube-connector": {
"yt:video:--sqRKutFMI": true,
"yt:video:-Z4_2gYl_ug": true,
"yt:video:-hO7fM9EHU4": true
}
}The offsets file may be manually edited.
The plugins are listed with their IDs in parentheses. Besides available configuration options and the offset storage format, the change detection mechanism is also explained.
Checks progress bars on an author's website for changes. This plugin is only built with Brandon Sanderson's website in mind, so it will most likely not work for other author's progress bars, should they have them.
The YAML structure for this plugin's configuration is as follows:
url: https://brandonsanderson.com
message: The progress bars on Brandon's website were updated!| Field | Mandatory | Description |
|---|---|---|
url |
✔ | URL of the author's website |
message |
✔ | Message to display preceding the embed with progress updates |
Offsets are stored as a JSON array of JSON objects with the following structure
{
"Title": "Progress Bar 1",
"Link": "https://example.com",
"Value": 100
}All values refer to the respective property of a progress bar on the website. There is one object like this for each progress bar.
The offset format is generated from the HTML on the website. Afterwards, a diff between the two states is generated:
- Progress bars that exist on the website but not in the stored offset are marked as new
- Progress bars that exist on the website and in the stored offset but have different progress values are marked as changed
- Progress bars that exist on the website and in the stored offset and have the same progress values are retained
- Progress bars that exist in the stored offset but not on the website are ignored
This diff is independent of the order of the progress bars in either state. If after this process there are new or changed progress bars, a Discord message with all current progress bars is produced.
Checks a Twitter account's timeline for new tweets. This includes retweets, but omits replies.
Note: You must specify a starting offset in the offset file for this plugin to work. Use the ID of the tweet immediately before the first one you want to be posted. If you want all tweets for an account to be posted, simply use the first tweet's ID minus 1.
The YAML structure for this plugin's configuration is as follows:
account: BrandSanderson
nickname: Brandon
tweetMessage: Brandon tweeted
retweetMessage: Brandon retweeted
excludeRetweetsOf: ['DragonsteelBook']
loginUser: dummy_user
loginPassword: foobar
cookiePath: twitter-cookies.json| Field | Mandatory | Description |
|---|---|---|
account |
✔️ | Twitter handle (without @) for account to check tweets for |
nickname |
❌ | Nickname for the Twitter account to use in Discord messages |
tweetMessage |
❌ | Custom message to display for new tweets |
retweetMessage |
❌ | Custom message to display for new retweets |
excludeRetweetsOf |
❌ | List of Twitter handles (without @) for which retweets should not be posted |
loginUser |
❌ | Username for logging into Twitter to access API |
loginPassword |
❌ | Password for logging into Twitter to access API |
cookiePath |
❌ | Path to writable file where cookies can be stored to not require logging in for every run |
If nickname and tweetMessage as well as retweetMessage are all omitted,
the Twitter display name for the account will be used in a standard message.
If no login credentials are provided, a default "open account" will be used which may not work.
Offsets are stored as a JSON string such as
"943172525596405761"The stored value is the ID of the last tweet that was read from the timeline.
All tweets that were posted to the timeline since the tweet corresponding to the stored offset are retrieved. Due to Twitter's API limitations, a maximum of 3200 tweets will be retrieved.
Any tweet and retweet that has been posted since the offset and is not from an excluded account will be posted in chronological order.
Checks a YouTube channel's atom feed (see e.g. Brandon Sanderson's channel) for new videos and livestreams. If no starting offset is specified, all videos currently in the feed will be posted.
Note that this requires access to the YouTube API for identifying livestreams and related data like scheduled start times, to this end, you need to acquire an API token for the YouTube Data API.
The YAML structure for this plugin's configuration is as follows:
channelId: ChannelId
token: youtubeToken
nickname: Brandon
messages:
video: Brandon posted a video on YouTube
livestream: Brandon will be streaming live %s
excludedPostTypes:
- short| Field | Mandatory | Description |
|---|---|---|
channelId |
✔️ | The ID of the YouTube channel for which to check the feed |
token |
✔️ | Token for the YouTube Data API v3 |
nickname |
❌ | Nickname for the YouTube channel to use in Discord messages |
messages |
❌ | A dictionary where keys represent the post type and values are custom messages for that type |
excludedPostTypes |
❌ | A list of post types from the feed not to report |
Note that the ID of the channel is required here, which can differ from the username visible in a channel's URL. A channel ID can be retrieved from a channel page's source code.
If nickname and messages are all omitted, the channel name for the YouTube channel will be used in a standard message.
Both messages and excludedPostTypes support several different post types, namely short, livestream, premiere, and video.
The latter is used by default if no other type could be identified.
The messages for livestream and premiere can use %s within their definition as a placeholder for a relative timestamp in the Discord message.
Getting access to the YouTube Data API, like most other Google services, requires a Google Cloud project. See the official guide for setting that up.
Within your project's Cloud Console, you must enable the YouTube Data API v3. Then you can create API key credentials for that API, which will be the token you need to specify in the config.
Offsets are stored as a JSON object such as
{
"yt:video:--sqRKutFMI": true,
"yt:video:-Z4_2gYl_ug": true,
"yt:video:-hO7fM9EHU4": true,
"yt:video:-w5f8-Elfqo": true,
"yt:video:0cf-qdZ7GbA": true
}Keys are feed entry IDs (e.g. yt:video:<video-id> for videos) and values indicate whether the entry has been processed.
Offsets as stored by the application will always have true as value, but you may manually change an entry to false.
In this case, the video or livestream will be posted to Discord again if it's still in the feed.
The current content of the Atom feed is retrieved. Feed entries that are marked with true in the current offset are omitted.
If this list of feed entries is non-empty after this process, links to the corresponding videos or livestreams will be posted in chronological order.
Note how all feed entries are inspected again and offsets contain many entries. This is due to the fact that YouTube's Atom feed may put new videos in-between previously checked ones, so for correctness all of them must be inspected again.
The 17th Shard has set up a channel on their Discord server where several updates from Brandon Sanderson are automatically posted with this application.
Under the current configuration, these channels are currently checked for updates:
- Sanderson's Twitter account
- Dragonsteel Books Twitter account
- Progress Updates on the Sandersons's website
- Sanderson's YouTube channel
If you want to replicate this on your own server, either follow the #brandon-updates channel or set up this
application with the following configuration, adjusted for your server:
discordWebhook: '<webhook-id>'
shared:
twitter:
token: '<twitter-auth-token>'
connectors:
brandon-progress:
plugin: progress
config:
url: https://brandonsanderson.com
message: The progress bars on Brandon's website were updated!
brandon-twitter:
plugin: twitter
config:
account: BrandSanderson
nickname: Brandon
excludeRetweetsOf: [ 'DragonsteelBook' ]
dragonsteel-books-twitter:
plugin: twitter
config:
account: DragonsteelBook
excludeRetweetsOf: [ 'BrandSanderson' ]
brandon-youtube:
plugin: youtube
config:
channelId: UC3g-w83Cb5pEAu5UmRrge-A
nickname: Brandon