NAME

urlwatch-jobs - Job types and configuration for urlwatch

SYNOPSIS

urlwatch --edit

DESCRIPTION

Jobs are the kind of things that urlwatch(1) 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 ---. The command urlwatch --list prints the name of each job, along with its index number (1, 2, 3, ...) which gets assigned automatically according to its position in the configuration file.

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

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

The following job types are available:

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)

(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 <https://github.com/pyppeteer/pyppeteer/issues/155> 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 <https://github.com/pyppeteer/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:

•: stderr: Change how standard error is treated, see below

(Note: command implies kind: shell)

Configuring stderr behavior for shell jobs

By default urlwatch captures stderr for error reporting (non-zero exit code), but ignores the output when the shell job exits with exit code 0.

This behavior can be customized using the stderr key:

ignore: Capture stderr, report on non-zero exit code, ignore otherwise (default)
urlwatch: stderr of the shell job is sent to stderr of the urlwatch process; any error message on stderr will not be visible in the error message from the reporter (legacy default behavior of urlwatch 2.24 and older)
fail: Treat the job as failed if there is any output on stderr, even with exit status 0
stdout: Merge stderr output into stdout, which means stderr output is also considered for the change detection/diff part of urlwatch (this is similar to 2>&1 in a shell)

For example, this job definition will make the job appear as failed, even though the script exits with exit code 0:

command: |
  echo "Normal standard output."
  echo "Something goes to stderr, which makes this job fail." 1>&2
  exit 0
stderr: fail

On the other hand, if you want to diff both stdout and stderr of the job, use this:

command: |
  echo "An important line on stdout."
  echo "Another important line on stderr." 1>&2
stderr: stdout

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
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)

SETTING KEYS FOR ALL JOBS AT ONCE

The main configuration file has a job_defaults key that can be used to configure keys for all jobs at once.

See urlwatch-config(5) for how to configure job defaults.

EXAMPLES

See urlwatch-cookbook(7) for example job configurations.

FILES

$XDG_CONFIG_HOME/urlwatch/urls.yaml

COPYRIGHT

2022 Thomas Perl