Example spider for scrapyd-k8s

Somewhat a work in progress.

Scrapyd-k8s is an application for deploying and running Scrapy spiders as either Docker instances or Kubernetes jobs. Its intention is to be compatible with scrapyd, but adapt to a container-based environment.

This spider is an example spider, used in the standard configuration of scrapyd-k8s, so that one can get started easily.

Scraped site

This project contains two spiders. The quotes spider returns quotes from quotes.toscrape.com.

The static spider returns a single dummy quote without accessing the network. This can be used for testing. There are several settings and environment variables that modify its behaviour:

• spider setting STATIC_TEXT - quote text (default To be, or not to be)
• spider setting STATIC_AUTHOR - quote author (default Shakespeare)
• environment variable STATIC_TAGS - quote tags (default static)
• spider setting STATIC_SLEEP - time to sleep in the spider (default 0)

Running locally

Make sure you have this project checked out.

git clone https://github.com/q-m/scrapyd-k8s-spider-example.git
cd scrapyd-k8s-spider-example

From the console

When you have Python and Scrapy installed, you can run this directly from the command-line:

$ scrapy list

quotes
static

$ scrapy crawl quotes

[scrapy.utils.log] INFO: Scrapy 2.9.0 started (bot: example)
[scrapy.core.engine] INFO: Spider opened
[scrapy.core.engine] DEBUG: Crawled (200) <GET http://quotes.toscrape.com/> (referer: None)
[scrapy.core.scraper] DEBUG: Scraped from <200 http://quotes.toscrape.com/>
{'text': 'The world as we have created it is a process of our thinking. It cannot be changed without changing our thinking.', 'author': 'Albert Einstein', 'tags': 'change'}
...
[scrapy.core.engine] INFO: Spider closed (shutdown)

(output redacted for readability)

With Docker

This spider is really meant to be run with Docker. First you need to build an image.

docker build -t example --label org.scrapy.spiders=quote .
docker inspect example -f '{{ .Config.Labels | json }}'

{"org.scrapy.project":"example","org.scrapy.spiders":"quote"}

Now you can run scrapy as usual, with Docker:

docker run --rm example scrapy list

quotes
static

docker run --rm example scrapy crawl quotes

[scrapy.utils.log] INFO: Scrapy 2.11.0 started (bot: example)
[scrapy.core.engine] INFO: Spider opened
[scrapy.core.engine] DEBUG: Crawled (200) <GET http://quotes.toscrape.com/> (referer: None)
[scrapy.core.scraper] DEBUG: Scraped from <200 http://quotes.toscrape.com/>
{'text': 'The world as we have created it is a process of our thinking. It cannot be changed without changing our thinking.', 'author': 'Albert Einstein', 'tags': 'change'}
...
[scrapy.core.engine] INFO: Spider closed (shutdown)

(output redacted for readability)

Spider as Docker image

• Spiders are distributed as Docker images.
• One can run scrapy crawl <spider> in the container to run a spider, without any additional setup (so set SCRAPY_SETTINGS_MODULE).
• Each Docker image has specific labels to indicate its project and spiders.
  • org.scrapy.project - the project name
  • org.scrapy.spiders - the spiders (those returned by scrapy list, comma-separated)

Please see the Github Action for an example of how to build such a container. In short, first build the container, then run the container to obtain the list of spiders, then add labels to the container so it can work with scrapyd-k8s.

License

This software is distributed under the MIT license.