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https://github.com/impredicative/irc-rss-feed-bot

Dockerized IRC bot to post RSS/Atom and scraped HTML/JSON/CSV feeds to channels
https://github.com/impredicative/irc-rss-feed-bot

irc-bot irc-rss-bot rss

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Dockerized IRC bot to post RSS/Atom and scraped HTML/JSON/CSV feeds to channels

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README 

        
# irc-rss-feed-bot

**irc-rss-feed-bot** is a dockerized Python 3.11 and IRC based RSS/Atom and scraped HTML/JSON/CSV feed posting bot.

It essentially posts the entries of feeds in IRC channels, one entry per message.

More specifically, it posts the titles and shortened URLs of entries.



## Contents

- [Features](#features)

- [Links](#links)

- [Examples](#examples)

- [Development](#development)

- [Usage](#usage)

  * [Configuration: secret](#configuration-secret)

  * [Configuration: non-secret](#configuration-non-secret)

    + [Global settings](#global-settings)

      - [Mandatory](#mandatory)

      - [Recommended](#recommended)

      - [Developer](#developer)

    + [Feed-specific settings](#feed-specific-settings)

      - [Mandatory](#mandatory-1)

      - [Optional](#optional)

      - [Parser](#parser)

      - [Conditional](#conditional)

    + [Feed default settings](#feed-default-settings)

  * [Commands](#commands)

    + [Administrative](#administrative)

- [Deployment](#deployment)

- [Maintenance](#maintenance)

  * [Service](#service)

  * [Config](#config)

  * [Database](#database)

  * [Disk cache](#disk-cache)



## Features

* Multiple channels on an IRC server are supported, with each channel having its own set of feeds.

For use with multiple servers, a separate instance of the bot process can be run for each server.

* Entries are posted only if the channel has not had any conversation for a certain minimum amount of time, 

thereby avoiding the interruption of any preexisting conversations.

This amount of time is 15 minutes for any feed which has a polling period greater than 12 minutes.

There is however no delay for any feed which has a polling period less than or equal to 12 minutes as such a feed is

considered urgent.

* A SQLite database file records hashes of the entries that have been posted, thereby preventing them from being

reposted.

* Posted URLs are shortened using the [da.gd](https://da.gd/) service.

* The [`hext`](https://pypi.org/project/hext/), [`jmespath`](https://pypi.org/project/jmespath/), and 

[`pandas`](https://pandas.pydata.org/) DSLs are supported for flexibly parsing arbitrary HTML, JSON, and CSV content 

respectively. These parsers also support configurable recursive crawling.

* Entry titles are formatted for neatness.

Any HTML tags and excessive whitespace are stripped, all-caps are replaced,

and excessively long titles are sanely truncated. 

* A TTL and ETag based compressed disk cache of URL content is used for preventing unnecessary URL reads.

Any websites with a mismatched _strong_ ETag are probabilistically detected, and this caching is then disabled for them

for the duration of the process. Note that this detection is skipped for a _weak_ ETag.

* Encoded Google News and FeedBurner URLs are decoded.



For several more features, see the customizable [global](#global-settings) and [feed-specific](#feed-specific-settings) settings, and [commands](#commands).



## Links

| Caption   | Link                                                       |

|-----------|------------------------------------------------------------|

| Repo      | https://github.com/impredicative/irc-rss-feed-bot          |

| Changelog | https://github.com/impredicative/irc-rss-feed-bot/releases |

| Image     | https://hub.docker.com/r/ascensive/irc-rss-feed-bot        |



## Examples

```text

 [ArXiv:cs.AI] Concurrent Meta Reinforcement Learning → https://arxiv.org/abs/1903.02710v1

 [ArXiv:cs.AI] Attack Graph Obfuscation → https://arxiv.org/abs/1903.02601v1

 [InfoWorld] What is a devops engineer? And how do you become one? → https://da.gd/dvXh9

 [InfoWorld] What is Jupyter Notebook? Data analysis made easier → https://da.gd/yrCi

 [AWS:OpenData] COVID-19 Open Research Dataset (CORD-19): Full-text and metadata dataset of

            COVID-19 research articles. → https://registry.opendata.aws/cord-19

```

![](images/sample_posts.png)



## Development

For software development purposes only, the project can be set up on Ubuntu as below.

```bash

make setup-ppa

make install-py

make setup-venv

make shell

make install

make test

make build

```



## Usage

### Configuration: secret

Prepare a private `secrets.env` environment file using the sample below.

```ini

IRC_PASSWORD=YourActualPassword

GITHUB_TOKEN=c81a62ca23caa140715bbfc175997c02d0fdd768

```



#### GITHUB_TOKEN

This is optional. Refer to the [`publish.github`](#optional) feature.



### Configuration: non-secret

Prepare a version-controlled `config.yaml` file using the sample below.

A full-fledged real-world example is also

[available](https://github.com/impredicative/irc-bots/blob/master/libera/news-bot/config.yaml).

```yaml

host: irc.libera.chat

ssl_port: 6697

#ssl_verify: true

nick: MyFeedBot

admin: mynick!myident@myhost

alerts_channel: '#mybot-alerts'

mode:

#mirror: '#mybot-mirror'

#publish:

#  github: MyGithubServiceAccountUsername/IrcServerName-MyBotName-live

#defaults:

#  new: all

feeds:

  "##mybot-alerts":

    irc-rss-feed-bot:

      url: https://github.com/impredicative/irc-rss-feed-bot/releases.atom

      period: 12

      shorten: false

  "#some_chan1":

    AWS:OpenData:

      url: https://registry.opendata.aws/rss.xml

      message:

        summary: true

    CDC:FoodSafety:

      url: https://tools.cdc.gov/api/v2/resources/media/316422.rss

      redirect: true

    j:AJCN:

      url: https://academic.oup.com/rss/site_6122/3981.xml

      mirror: false

      period: 12

      blacklist:

        title:

          - ^Calendar\ of\ Events$

    LitCovid:

      url: https://www.ncbi.nlm.nih.gov/research/coronavirus-api/export

      pandas: |-

        read_csv(file, comment="#", sep="\t") \

        .assign(link=lambda r: "https://pubmed.ncbi.nlm.nih.gov/" + r["pmid"].astype("str")) \

        .convert_dtypes()

    MedicalXpress:nutrition:

      url: https://medicalxpress.com/rss-feed/search/?search=nutrition

    r/FoodNerds:

      url: https://www.reddit.com/r/FoodNerds/new/.rss

      shorten: false

      sub:

        url:

          pattern: ^https://www\.reddit\.com/r/.+?/comments/(?P.+?)/.+$

          repl: https://redd.it/\g

  "##some_chan2":

    ArXiv:cs.AI: &ArXiv

      url: http://export.arxiv.org/rss/cs.AI

      period: 1.5

      https: true

      shorten: false

      group: ArXiv:cs

      alerts:

        empty: false

      format:

        re:

          title: '^(?P.+?)\.?\ \(arXiv:.+(?Pv\d+)\ '

        str:

          title: '{name}'

          url: '{url}{ver}'

    ArXiv:cs.NE:

      <<: *ArXiv

      url: http://export.arxiv.org/rss/cs.NE

    ArXiv:stat.ML:

      <<: *ArXiv

      url: http://export.arxiv.org/rss/stat.ML

      group: null

    AWS:status:

      url: https://status.aws.amazon.com/rss/all.rss

      period: .2

      https: true

      new: none

      sub:

        title:

          pattern: ^(?:Informational\ message|Service\ is\ operating\ normally):\ \[RESOLVED\]

          repl: '[RESOLVED]'

      format:

        re:

          id: /\#(?P[^_]+)

        str:

          title: '[{service}] {title} | {summary}'

          url: '{id}'

    Fb:Research:

      url: https://research.fb.com/publications/

      hext: |-

        


            


            


        


        


      whitelist:

        category:

          - ^(?:Facebook\ AI\ Research|Machine\ Learning|Natural\ Language\ Processing\ \&\ Speech)$

    InfoWorld:

      url: https://www.infoworld.com/index.rss

      order: reverse

    j:MDPI:N:  # https://www.mdpi.com/journal/nutrients (open access)

      url: https://www.mdpi.com/rss/journal/nutrients

      www: false

    KDnuggets:

      url: https://us-east1-ml-feeds.cloudfunctions.net/kdnuggets

      new: some

    libraries.io/pypi/scikit-learn:

      url: https://libraries.io/pypi/scikit-learn/versions.atom

      new: none

      period: 8

      shorten: false

    MedRxiv:

      url:

        - https://connect.medrxiv.org/medrxiv_xml.php?subject=Health_Informatics

        - https://connect.medrxiv.org/medrxiv_xml.php?subject=Nutrition

      alerts:

        read: false

      https: true

    r/MachineLearning:100+:

      url: https://www.reddit.com/r/MachineLearning/hot/.json?limit=50

      jmespath: 'data.children[*].data | [?score >= `100`].{title: title, link: join(``, [`https://redd.it/`, id])}'

      shorten: false

    r/wallstreetbets:50+:

      url: https://www.reddit.com/r/wallstreetbets/hot/.json?limit=98

      jmespath: 'data.children[*].data | [?(not_null(link_flair_text) && score >= `50`)].{title: join(``, [`[`, link_flair_text, `] `, title]), link: join(``, [`https://redd.it/`, id]), category: link_flair_text}'

      emoji: false

      shorten: false

      blacklist:

        category:

          - ^(?:Daily\ Discussion|Gain|Loss|Meme|Weekend\ Discussion|YOLO)$

    PwC:Latest:

      url: https://us-east1-ml-feeds.cloudfunctions.net/pwc/latest

      period: 0.5

      dedup: channel

    PwC:Trending:

      url: https://us-east1-ml-feeds.cloudfunctions.net/pwc/trending

      period: 0.5

      dedup: channel

    SeekingAlpha:

      period: 0.2

      sub:

        url:

          pattern: ^(?Phttps://seekingalpha\.com/[a-z]+/[0-9]+).*$

          repl: \g

      shorten: false

      topic:

        "Daily calendar": \b(?i:economic\ calendar)\b

        "Daily prep": '^Wall\ Street\ Breakfast:\ '

        "Hourly status": ^On\ the\ hour$

      url:

        - https://seekingalpha.com/market_currents.xml

        - https://seekingalpha.com/feed.xml

        - https://seekingalpha.com/tag/etf-portfolio-strategy.xml

        - https://seekingalpha.com/tag/wall-st-breakfast.xml

    SSRN:

      url: https://papers.ssrn.com/sol3/Jeljour_results.cfm?form_name=journalBrowse&journal_id=3526423&Network=no&lim=false&npage=1

      hext:

        select: 

        follow: 

      period: 6

    TalkRL:

      url: https://www.talkrl.com/feed

      period: 8

      message:

        title: false

        summary: true

    YT:3Blue1Brown: &YT

      url: https://www.youtube.com/feeds/videos.xml?channel_id=UCYO_jab_esuFRV4b17AJtAw

      period: 12

      shorten: false

      style:

        name:

          bg: red

          fg: white

          bold: true

      sub:

        url:

          pattern: ^https://www\.youtube\.com/watch\?v=(?P.+?)$

          repl: https://youtu.be/\g

    YT:AGI:

      url: https://www.youtube.com/results?search_query=%22artificial+general+intelligence%22&sp=CAISBBABGAI%253D

      hext: 

      period: 12

      shorten: false

      alerts:

        emptied: true

      blacklist:

        title:

          - \bWikipedia\ audio\ article\b

    YT:LexFridman:

      <<: *YT

      url: https://www.youtube.com/feeds/videos.xml?channel_id=UCSHZKyawb77ixDdsGog4iWA

      whitelist:

        title:

          - \bAGI\b

```



#### Global settings



##### Mandatory

* **`host`**: IRC server address.

* **`ssl_port`**: IRC server SSL port.

* **`ssl_verify`**: If `false`, the TLS/SSL certificate is not verified. Its default is `true`.

* **`nick`**: This is a registered IRC nick. If the nick is in use, it will be regained.

Ensure that the email verification of the registered nick, as applicable to many IRC servers, is complete.

Without this email verification being completed, the bot can fail to receive the required event 900 and therefore fail to function.



##### Recommended

* **`admin`**: Administrative commands by this user pattern are accepted and executed.

Its format is `nick!ident@host`. An example is `JDoe11!sid654321@gateway/web/irccloud.com/x-*`.

A case-insensitive pattern match is tested for using [`fnmatch`](https://docs.python.org/3/library/fnmatch.html).

* **`alerts_channel`**: Some but not all warning and error alerts are sent to this channel.

Its default value is `##{nick}-alerts`. The key `{nick}`, if present in the value, is formatted with the actual nick.

For example, if the nick is `MyFeedBot`, alerts will by default be sent to `##MyFeedBot-alerts`.

Since a channel name starts with #, the name if provided **must be quoted**.

It is recommended that the alerts channel be registered and monitored.

* **`mode`**: This can for example be `+igR` for [Libera](https://libera.chat/guides/usermodes) 

and `+igpR` for [Rizon](https://wiki.rizon.net/index.php?title=User_Modes).

  

##### Optional

* **`mirror`**: If specified as a channel name, all posts across all channels are mirrored to this channel.

This however doubles the time between consecutive posts in any given channel.

Mirroring can however individually be disabled for a feed by setting `.mirror`.

* **`publish.github`**: This is the username and repo name of a GitHub repo, e.g. [`feedarchive/libera-feedbot-live`](https://github.com/feedarchive/libera-feedbot-live).

All posts are published to the repo, thereby providing a basic option to archive them.

A new CSV file is written to the repo for each posted feed having one or more new posts.

The following requirements apply:

  * The repo must exist; it is not created by the bot. It is recommended that an empty new repo is used.

If the repo is of public interest, it can be requested to be moved into the [`feedarchive`](https://github.com/feedarchive) organization by filing an issue.

  * The GitHub user must have access to write to the repo. It is recommended that a dedicated new service account be used, not your primary user account.

  * A GitHub [personal access token](https://github.com/settings/tokens) is required with access to the entire `repo` scope.

The `repo` scope is used for making commits.

The token is provisioned for the bot via the `GITHUB_TOKEN` secret environment variable.



##### Developer

* **`log.irc`**: If `true`, low level IRC events are logged by `miniirc`. These are quite noisy. Its default is `false`.

* **`once`**: If `true`, each feed is queued only once. It is for testing purposes. Its default is `false`.

* **`tracemalloc`**: If `true`, memory allocation tracing is enabled. The top usage and positive-diff statistics are then logged hourly.

It is for diagnostic purposes. Its default is `false`.



#### Feed-specific settings

A feed is defined under a channel as in the sample configuration. The feed's key represents its name.



The order of execution of the interacting operations is:

`redirect`, `blacklist`, `whitelist`, `https`, `www`, `emoji`, `sub`, `format`, `shorten`.

Refer to the sample configuration for usage examples.



YAML [anchors and references](https://en.wikipedia.org/wiki/YAML#Advanced_components) can be used to reuse nodes.

Examples of this are in the sample.



##### Mandatory

* **`.url`**: This is either a single URL or a list of URLs of the feed.

If a list, the URLs are read in sequence with an interval of one second between them.



##### Optional

These are optional and are independent of each other:

* **`.alerts.empty`**: If `true`, an alert is sent if any source URL of the feed has no entries before their validation. 

If `false`, such an alert is not sent. Its default value is `true`.

* **`.alerts.emptied`**: If `true`, an alert is sent if the feed has entries before but not after their validation.

If `false`, such an alert is not sent. Its default value is `false`.

* **`.alerts.read`**: If `true`, an alert is sent if an error occurs three or more consecutive times 

when reading or processing the feed, but no more than once every 15 minutes.

If `false`, such an alert is not sent. Its default value is `true`.

* **`.blacklist.category`**: This is an arbitrarily nested dictionary or list or their mix of regular 

expression patterns that result in an entry being skipped if a 

[search](https://docs.python.org/3/library/re.html#re.search) finds any of the patterns in any of the categories of the 

entry.

The nesting permits lists to be creatively reused between feeds via YAML anchors and references.

* **`.blacklist.title`**: This is an arbitrarily nested dictionary or list or their mix of regular 

expression patterns that result in an entry being skipped if a 

[search](https://docs.python.org/3/library/re.html#re.search) finds any of the patterns in the title.

The nesting permits lists to be creatively reused between feeds via YAML anchors and references.

* **`.blacklist.url`**: Similar to `.blacklist.title`.

* **`.dedup`**: This indicates how to deduplicate posts for the feed, thereby preventing them from being 

reposted.

The default value is `feed` (per-feed per-channel), and an alternate possible value is `channel` (per-channel).

* **`.emoji`**: If `false`, emojis in entry titles are removed. Its default value is `null`.

* **`.group`**: If a string, this delays the processing of a feed that has just been read until all 

other feeds having the same group are also read.

This encourages multiple feeds having the same group to be be posted in succession, except if interrupted by

conversation.

It is however possible that unrelated feeds of any channel gets posted between ones having the same group.

To explicitly specify the absence of a group when using a YAML reference, the value can be specified as `null`.

It is recommended that feeds in the same group have the same `period`.

* **`.https`**: If `true`, entry links that start with `http://` are changed to start with `https://` 

instead. Its default value is `false`.

* **`.message.summary`**: If `true`, the entry summary (description) is included in its message.

The entry title, if included, is then formatted bold.

This is applied using IRC formatting if a `style` is defined for the feed, otherwise using unicode formatting.

The default value is `false`.

* **`.message.title`**: If `false`, the entry title is not included in its message.

Its default value is `true`.

* **`.mirror`**: If `false`, mirroring is disabled for this feed. 

  Its default value is `true`, subject to the global-setting for mirroring.

* **`.new`**: This indicates up to how many entries of a new feed to post.

A new feed is defined as one with no prior posts in its channel.

The default value is `some` which is interpreted as 3.

The default is intended to limit flooding a channel when one or more new feeds are added.

A string value of `none` is interpreted as 0 and will skip all entries for a new feed.

A value of `all` will skip no entries for a new feed; it is not recommended and should be used sparingly if at all.

In any case, future entries in the feed are not affected by this option on subsequent reads,

and they are all forwarded without a limit.

* **`.order`**: If `reverse`, the order of the entries is reversed.

* **`.period`**: This indicates how frequently to read the feed in hours on an average.

Its default value is 1.

Conservative polling is recommended. Any value below 0.2 is changed to a minimum of 0.2.

Note that 0.2 hours is equal to 12 minutes.

To make service restarts safer by preventing excessive reads, the first read is delayed by half the period.

To better distribute the load of reading multiple feeds, a uniformly distributed random ±5% is applied to the period for

each read.

* **`.redirect`**: This indicates whether to substitute each entry URL with its redirect target.

The default value is `false`.

* **`.shorten`**: This indicates whether to post shortened URLs for the feed.

The default value is `true`.

The alternative value `false` is recommended if the URL is naturally small, or if `sub` or `format` can be used to make

it small.

If a "Blacklisted long URL" error is experienced for a reasonable website which should not be blacklisted, it can be reported [here](https://github.com/dagd/dagd/issues), using [this](https://github.com/dagd/dagd/issues/50) issue as an example.

* **`.style.name.bg`**: This is a string representing the name of a background color applied to the 

feed's name.

It can be one of: white, black, blue, green, red, brown, purple, orange, yellow, lime, teal, aqua, royal, pink, grey,

silver. The channel modes must allow formatting for this option to be effective.

* **`.style.name.bold`**: If `true`, bold formatting is applied to the feed's name. 

Its default value is `false`.

The channel modes must allow formatting for this option to be effective.

* **`.style.name.fg`**: Foreground color similar to `.style.name.bg`.

* **`.topic`**: This updates the channel topic with the short URL of a matching entry.

It requires auto-op (+O) to allow the topic to be updated.

The topic is divided into logical sections separated by ` | ` (``).

For any matching entry, only its matching section in the topic is updated.

Its value can be a dictionary in which each key is a section name and each value is a regular expression pattern.

If a regular expression [search](https://docs.python.org/3/library/re.html#re.search) matches an entry's title,

the section in the topic is updated with the entry's short URL.

The topic's length is not checked.

* **`.whitelist.category`**: This is an arbitrarily nested dictionary or list or their mix of regular 

expression patterns that result in an entry being skipped unless a 

[search](https://docs.python.org/3/library/re.html#re.search) finds any of the patterns in any of the categories of the 

entry.

The nesting permits lists to be creatively reused between feeds via YAML anchors and references.

* **`.whitelist.explain`**: This applies only to `.whitelist.title`.

It can be useful for understanding which portion of a post's title matched the whitelist.

If `true`, the first match of each posted title is italicized.

This is applied using IRC formatting if a `style` is defined for the feed, otherwise using unicode formatting.

For example, "This is a _matching sample_ title".

The default value is `false`.

* **`.whitelist.title`**: This is an arbitrarily nested dictionary or list from which all leaf values are used.

The leaf values are regular expression patterns.

This result in an entry being skipped unless a [search](https://docs.python.org/3/library/re.html#re.search) finds any 

of the patterns in the title.

The nesting permits lists to be creatively reused between feeds via YAML anchors and references.

* **`.whitelist.url`**: Similar to `.whitelist.title`.

* **`.www`**: If `false`, entry links that contain the `www.` prefix are changed to remove this prefix.

Its default value is `null`.



##### Parser

For a non-XML feed, one of the following non-default parsers can be used.

Multiple parsers cannot be used for a feed.

The parsers are searched for in the alphabetical order listed below, and the first to be found is used.

Each parsed entry must at a minimum return a `title`, a `link`, an optional `summary` (description),

and zero or more values for `category`

The `title` can be a string or a list of strings.



* **`.hext`**: This is a string representing the [hext](https://hext.thomastrapp.com/documentation) DSL 

for parsing a list of entry [dictionaries](https://en.wikipedia.org/wiki/Associative_array#Example) from an HTML web 

page. 

Before using, it can be tested in the form [here](https://hext.thomastrapp.com/).

Note that `max_searches` is set to 100_000 to protect against resource exhaustion.

* **`.jmespath`**: This is a string representing the [jmespath](http://jmespath.org/examples.html) DSL 

for parsing a list of entry [dictionaries](https://en.wikipedia.org/wiki/Associative_array#Example) from JSON.

Before using, it can be tested in the form [here](http://jmespath.org/).

* **`.pandas`**: This is a string command evaluated using [pandas](https://pandas.pydata.org/) for 

parsing a dataframe of entries. The raw content is made available to the parser as a file-like object named `file`.

This parser uses [`eval`](https://docs.python.org/3/library/functions.html?#eval) which is unsafe, and so its

use must be confirmed to be safe.

The provisioned packages are `json`, `numpy` (as `np`), and `pandas` (as `pd`).

The value requires compatibility with the versions of `pandas` and `numpy` defined in 

[`requirements.txt`](requirements.txt), noting that these version requirements are expected to be routinely updated.



For recursive crawling, the value of a parser can alternatively be:

* **`..select`**: This is the string which was hitherto documented as the value for 

`..`. The parser uses it to return the entries to post.

* **`..follow`**: The is an optional string which the parser uses to return zero or more 

additional URLs to read.

The returned URLs can a list of strings or a list of dictionaries with the key `url`.

Crawling applies recursively to each returned URL. Each unique URL is read once.

There is an interval of at least one second between the end of a read and the start of the next read.

Care should nevertheless be taken to avoid crawling a large number of URLs.



Some sites require a custom user agent or other custom headers for successful scraping; such a customization can be

requested by creating an issue.



##### Conditional

The sample configuration above contains examples of these:

* **`.format.re.title`**: This is a single regular expression pattern that is

[searched](https://docs.python.org/3/library/re.html#re.search) for in the title.

It is used to collect named [key-value pairs](https://docs.python.org/3/library/re.html#re.Match.groupdict) from the

match if there is one.

* **`.format.re.url`**: Similar to `.format.re.title`.

* **`.format.str.title`**: The key-value pairs collected using `.format.re.title` and 

`.format.re.url`, 

both of which are optional, are combined along with the default additions of `title`, `url`, `categories`, and `feed.url` as keys.

Any additional keys returned by the parser are also available.

The key-value pairs are used to [format](https://docs.python.org/3/library/stdtypes.html#str.format_map) the provided

quoted title string.

If the title formatting fails for any reason, a warning is logged, and the title remains unchanged.

The default value is `{title}`.

* **`.format.str.url`**: Similar to `.format.str.title`. The default value is `{url}`.

If this is specified, it can sometimes be relevant to set `shorten` to `false` for the feed.

* **`.sub.summary.pattern`**: This is a single regular expression pattern that if found results in the 

entry summary being [substituted](https://docs.python.org/3/library/re.html#re.sub).

* **`.sub.summary.repl`**: If `.sub.summary.pattern` is found, the entry summary is replaced 

with this replacement, otherwise it is forwarded unchanged.

* **`.sub.title.pattern`**: Similar to `.sub.summary.pattern`.

* **`.sub.title.repl`**: Similar to `.sub.summary.repl`.

* **`.sub.url.pattern`**: Similar to `.sub.summary.pattern`.

If a pattern is specified, it can sometimes be relevant to set `shorten` to `false` for the feed.

* **`.sub.url.repl`**: Similar to `.sub.summary.repl`.



#### Feed default settings

A global default value can optionally be set under `defaults` for some feed-specific settings, 

namely `new` and `shorten`.

This value overrides its internal default.

It facilitates not having to set the same value individually for many feeds.



Refer to "Feed-specific settings" for the possible values and internal defaults of these settings.

Refer to the embedded sample configuration for a usage example.



### Commands

Commands can be sent to the bot either as a private message or as a directed public message.

Private messages may however be prohibited for security purposes using the `mode` configuration.

Public messages to the bot must be directed as `MyBotNick: my_command`.

#### Administrative

Administrative commands are accepted from the configured `admin`. If `admin` is not configured, the commands are not processed.

It is expected but not required that administrative commands to the bot will typically be sent in the `alerts_channel`.

The supported commands are:

* **`exit`**: Gracefully exit with code 0. The exit is delayed until any feeds that are currently being posted finish posting and being written to the database.

If running the bot as a Docker Compose service, using this command with `restart: on-failure` will (due to code 0) prevent the bot from automatically restarting.

Note that a repeated invocation of this command has no effect.

* **`fail`**: Similar to `exit` but with code 1.

If running the bot as a Docker Compose service, using this command with `restart: on-failure` will (due to a nonzero code) cause the bot to automatically be restarted.

* **`quit`**: Alias of `exit`.



## Deployment

* As a reminder, it is recommended that the alerts channel be registered and monitored.



* It is recommended that the bot be auto-voiced (+V) in each channel.

Failing this, messages from the bot risk being silently dropped by the server.

This is despite the bot-enforced limit of two seconds per message across the server.



* It is recommended that the bot be run as a Docker container using using Docker ≥18.09.2, possibly with

Docker Compose ≥1.24.0.

To run the bot using Docker Compose, create or add to a version-controlled `docker-compose.yml` file such as:

```yaml

version: '3.7'

services:

  irc-rss-feed-bot:

    container_name: irc-rss-feed-bot

    image: ascensive/irc-rss-feed-bot:

#    network_mode: host  # If having DNS name resolution issues.

    restart: on-failure

#    restart: always

    logging:

      options:

        max-size: 2m

        max-file: "5"

    volumes:

      - ./irc-rss-feed-bot:/config

    env_file:

      - ./irc-rss-feed-bot/secrets.env

    environment:

      TZ: America/New_York  # Select TZ database name from https://en.wikipedia.org/wiki/List_of_tz_database_time_zones

```



* In the above service definition in `docker-compose.yml`:

  * `image`: Use a specific

  [versioned tag](https://hub.docker.com/r/ascensive/irc-rss-feed-bot/tags?ordering=last_updated), e.g. `0.12.0`.

  * `volumes`: Customize the relative path to the previously created `config.yaml` file, e.g. `./irc-rss-feed-bot`.

  This volume source directory must be writable by the container using the UID defined in the Dockerfile; it is 999.

  A simple way to ensure it is writable is to run a command such as `chmod -R a+w ./irc-rss-feed-bot` once on the host.

  * `env_file`: Customize the relative path to `secrets.env`.

  * `environment`: Optionally customize the environment variable `TZ` to the preferred time zone 

  as represented by a [TZ database name](https://en.wikipedia.org/wiki/List_of_tz_database_time_zones#List).

  Note that the date and time are prefixed in each log message.



* From the directory containing `docker-compose.yml`, run `docker-compose up -d irc-rss-feed-bot`.

Use `docker logs -f irc-rss-feed-bot` to see and follow informational logs.



## Maintenance

### Service

It is recommended that the supported administrative commands be used together with Docker Compose or a comparable container service manager to shutdown or restart the service.

### Config

* If `config.yaml` is updated, the container must be restarted to use the updated file.

* If `secrets.env` or the service definition in `docker-compose.yml` are updated, the container must be recreated

(and not merely restarted) to use the updated file.

### Database

* A `posts.v2.db` database file is written by the bot in the same directory as `config.yaml`.

This database file must be preserved with routine backups. After restoring a backup, before starting the container,

ensure the database file is writable by running a command such as `chmod a+w ./irc-rss-feed-bot/posts.v2.db`.

* The database file grows as new posts are made. For the most part this indefinite growth can be ignored.

Currently, the standard approach for handling this, if necessary, is to stop the bot and delete the

database file if it has grown unacceptably large.

Restarting the bot after deleting the database will then create a new database file, and all configured feeds will be

handled as new.

This deletion is however discouraged as a routine measure.

### Disk cache

* An ephemeral directory `/app/.ircrssfeedbot_cache` is written by the bot in the container.

It contains one or more independent disk caches.

The size of each independent disk cache in this directory is limited to approximately 2 GiB.

If needed, this directory can optionally be mounted as an external volume.