Jobs
****

Jobs are the kind of things that *urlwatch* can monitor.

The list of jobs to run are contained in the configuration file
"urls.yaml", accessed with the command "urlwatch --edit", each
separated by a line containing only "---".

While optional, it is recommended that each job starts with a "name"
entry:

   name: "This is a human-readable name/label of the job"


URL
===

This is the main job type -- it retrieves a document from a web
server:

   name: "urlwatch homepage"
   url: "https://thp.io/2008/urlwatch/"

Required keys:

* "url": The URL to the document to watch for changes

Job-specific optional keys:

* "cookies": Cookies to send with the request (see Advanced Topics)

* "method": HTTP method to use (default: "GET")

* "data": HTTP POST/PUT data

* "ssl_no_verify": Do not verify SSL certificates (true/false)

* "ignore_cached": Do not use cache control (ETag/Last-Modified)
  values (true/false)

* "http_proxy": Proxy server to use for HTTP requests

* "https_proxy": Proxy server to use for HTTPS requests

* "headers": HTTP header to send along with the request

* "encoding": Override the character encoding from the server (see
  Advanced Topics)

* "timeout": Override the default socket timeout (see Advanced Topics)

* "ignore_connection_errors": Ignore (temporary) connection errors
  (see Advanced Topics)

* "ignore_http_error_codes": List of HTTP errors to ignore (see
  Advanced Topics)

* "ignore_timeout_errors": Do not report errors when the timeout is
  hit

* "ignore_too_many_redirects": Ignore redirect loops (see Advanced
  Topics)

* "user_visible_url": Different URL to show in reports (e.g. when
  watched URL is a REST API URL, and you want to show a webpage)

(Note: "url" implies "kind: url")


Browser
=======

This job type is a resource-intensive variant of "URL" to handle web
pages requiring JavaScript in order to render the content to be
monitored.

The optional "pyppeteer" package must be installed to run "Browser"
jobs (see Dependencies).

At the moment, the Chromium version used by "pyppeteer" only supports
macOS (x86_64), Windows (both x86 and x64) and Linux (x86_64). See
this issue in the Pyppeteer issue tracker for progress on getting ARM
devices supported (e.g. Raspberry Pi).

Because "pyppeteer" downloads a special version of Chromium (~ 100
MiB), the first execution of a "browser" job could take some time (and
bandwidth). It is possible to run "pyppeteer-install" to pre-download
Chromium.

   name: "A page with JavaScript"
   navigate: "https://example.org/"

Required keys:

* "navigate": URL to navigate to with the browser

Job-specific optional keys:

* "wait_until":  Either "load", "domcontentloaded", "networkidle0", or
  "networkidle2" (see Advanced Topics)

As this job uses Pyppeteer to render the page in a headless Chromium
instance, it requires massively more resources than a "URL" job. Use
it only on pages where "url" does not give the right results.

Hint: in many instances instead of using a "Browser" job you can
monitor the output of an API called by the site during page loading
containing the information you're after using the much faster "URL"
job type.

(Note: "navigate" implies "kind: browser")


Shell
=====

This job type allows you to watch the output of arbitrary shell
commands, which is useful for e.g. monitoring an FTP uploader folder,
output of scripts that query external devices (RPi GPIO), etc...

   name: "What is in my Home Directory?"
   command: "ls -al ~"

Required keys:

* "command": The shell command to execute

Job-specific optional keys:

* none

(Note: "command" implies "kind: shell")


Optional keys for all job types
===============================

* "name": Human-readable name/label of the job

* "filter": *filters* (if any) to apply to the output (can be tested
  with "--test-filter")

* "max_tries": Number of times to retry fetching the resource

* "diff_tool": Command to a custom tool for generating diff text

* "diff_filter": *filters* (if any) to apply to the diff result (can
  be tested with "--test-diff-filter")

* "treat_new_as_changed": Will treat jobs that don't have any historic
  data as "CHANGED" instead of "NEW" (and create a diff for new jobs)

* "compared_versions": Number of versions to compare for similarity

* "kind" (redundant): Either "url", "shell" or "browser".
  Automatically derived from the unique key ("url", "command" or
  "navigate") of the job type


Settings keys for all jobs at once
==================================

See Job Defaults for how to configure keys for all jobs at once.
