A small and simple DOM detection changer for when you're in desperate need of a new Nvidia graphics card or anything else that tickles your pickle.

• ✅ Monitor multiple URLs to detect DOM changes.
• ✅ Use a valid crontab selector to run monitoring jobs.
• ✅ Integrates with SMTP email and Slack.
• ✅ Easy use with Docker or running on bare metal.
• ✅ Comprehensive HTTP client that follows redirects.
• ✅ Extremely lightweight with few dependencies.

In the ever-changing world of online shopping, sometimes it's merely impossible to get your favorite product. This tiny package allows you to monitor changes on the DOM to detect when a element has changed. It's not just limited to products, but anything you like.

pages:
  - url: https://test.com # URL to monitor
    selector: .class-selector # DOM selector
    schedule: "* * * * *" # Run every minute
notify:
  email:
    address: smtp.gmail.com
    port: 587
    user: [email protected]
    password: password
    receivers:
      - [email protected]
  slack:
    token: token
    channel_id: id

Informer can either be run in Docker or using the prebuilt binaries in the releases section, information on both methods are shown below.

The following platforms that are supported are listed below. The examples used are for Darwin amd64, please change the release name if you intend to use a different OS.

• Darwin amd64
• Darin arm64
• Linux amd64
• Linux arm64
• Windows amd64

Head over to the releases page and download the relevant release to your operating system.

$ wget "https://github.com/ainsleyclark/stock-informer/releases/download/v0.0.1/informer_0.0.1_darwin_amd64.tar.gz"
> ‘informer_0.0.1_darwin_amd64.tar.gz’ saved

$ tar -xf informer_0.0.1_darwin_amd64.tar.gz && cd informer

Change config.example.yml to config.yml and change to your liking.

$ ./informer -path=/path/to/config/config.yml
> [INFORMER] 2022-12-14 08:14:05 | LOG | [INFO] | [msg] Loading Configuration
> [INFORMER] 2022-12-14 08:14:05 | LOG | [INFO] | [msg] Booting Informer

Docker images are located at the packages page. Be sure to use the latest version number when pulling the image.

Head over to the packages page and pull the latest image version to your local machine.

$ docker pull ghcr.io/ainsleyclark/stock-informer:0.0.1

Running the image requires two required arguments/flags.

• The path to the configuration file stored on the local machine, with the arg v.
• The -path argument for the binary which should correlate to the path passed in. This will allow you to attach your configuration file from your local machine to the docker image.

$ docker run -it --rm -v /path/to/config/config.yml:/mnt/config.yml ghcr.io/ainsleyclark/stock-informer:0.0.1 -path=/mnt/config.yml
> [INFORMER] 2022-12-14 08:14:05 | LOG | [INFO] | [msg] Loading Configuration
> [INFORMER] 2022-12-14 08:14:05 | LOG | [INFO] | [msg] Booting Informer

The configuration for the informer is super simple, you can see it below. The yaml file can be named whatever you want, but it must follow some conventions.

pages:
  - url: https://test.com # URL to monitor
    selector: .class-selector # DOM selector
    schedule: "* * * * *" # Run every minute
notify:
  email:
    address: smtp.gmail.com
    port: 587
    user: [email protected]
    password: password
    receivers:
      - [email protected]
  slack:
    token: token
    channel_id: id

Pages is a collection of URLs to monitor. The URL is the page you want to monitor, the selector should be a valid CSS selector and the schedule is a crontab expression defining when the scrape should happen.

Currently, SMTP email and Slack notifiers are supported, but there are more to come. The settings for each notifier are self explanatory but all required.

• Add App Debug to the configuration to hide or show the log debug messages.
• Add more notifiers, github.com/nikoksr/notify has been used as a package and there are an abundance of notification methods that can be used.
• Call cron monitoring recursively to eradicate waiting for new change.
• Validation on configuration struct.

To set up the application for development first, clone the repository.

git clone https://github.com/ainsleyclark/stock-informer.git

Run the setup command to install the necessary dependencies for Krang.

make setup

Common commands are detailed in the Makefile to list usage run:

make help

setup            Setup dependencies
run              Run
dist             Creates and build dist folder
format           Run gofmt
lint             Run linter
test             Test uses race and coverage
test-v           Test with -v
cover            Run all the tests and opens the coverage report
docker-clean		 Removes the docker image
docker-build 		 Builds the docker image
docker-run			 Run the docker image
mock             Generate mocks keeping directory tree
bench						 Runs benchmarks
doc              Runs go doc
all              Make format, lint and test
todo             Show to-do items per file
help             Display this help

We welcome contributors, but please read the contributing document before making a pull request.

Shout out to the incredible Maria Letta for her excellent Gopher illustrations.

Code Copyright 2023 Stock Informer. Code released under the MIT Licence.