nyaa/README.md

# NyaaV2

## Setting up for development
This project uses Python 3.6. There are features used that do not exist in 3.5, so make sure to use Python 3.6.   
This guide also assumes you 1) are using Linux and 2) are somewhat capable with the commandline.   
It's not impossible to run Nyaa on Windows, but this guide doesn't focus on that.

### Code Quality:
- Before we get any deeper, remember to follow PEP8 style guidelines and run `./lint.sh` before committing.
    - You may also use `pycodestyle nyaa/ --show-source --max-line-length=100´ to see a list of warnings/problems instead of having `lint.sh` making modifications for you
- Other than PEP8, try to keep your code clean and easy to understand, as well. It's only polite!

### Setting up Pyenv
pyenv eases the use of different Python versions, and as not all Linux distros offer 3.6 packages, it's right up our alley.
- Install dependencies https://github.com/pyenv/pyenv/wiki/Common-build-problems
- Install `pyenv` https://github.com/pyenv/pyenv/blob/master/README.md#installation
- Install `pyenv-virtualenv` https://github.com/pyenv/pyenv-virtualenv/blob/master/README.md
- Install Python 3.6.1 with `pyenv` and create a virtualenv for the project:
    - `pyenv install 3.6.1`
    - `pyenv virtualenv 3.6.1 nyaa`
    - `pyenv activate nyaa`
- Install dependencies with `pip install -r requirements.txt`
- Copy `config.example.py` into `config.py`
    - Change `SITE_FLAVOR` in your `config.py` depending on which instance you want to host

### Setting up MySQL/MariaDB database
You *may* use SQLite but the current support for it in this project is outdated and rather unsupported.
- Enable `USE_MYSQL` flag in config.py
- Install latest mariadb by following instructions here https://downloads.mariadb.org/mariadb/repositories/
    - Tested versions: `mysql  Ver 15.1 Distrib 10.0.30-MariaDB, for debian-linux-gnu (x86_64) using readline 5.2`
- Run the following commands logged in as your root db user (substitute for your own `config.py` values if desired):
    - `CREATE USER 'test'@'localhost' IDENTIFIED BY 'test123';`
    - `GRANT ALL PRIVILEGES ON *.* TO 'test'@'localhost';`
    - `FLUSH PRIVILEGES;`
    - `CREATE DATABASE nyaav2 DEFAULT CHARACTER SET utf8 COLLATE utf8_bin;`

### Finishing up
- Run `python db_create.py` to create the database and import categories
    - Follow the advice of `db_create.py` and run `./db_migrate.py stamp head` to mark the database version for Alembic
- Start the dev server with `python run.py`
- When you are finished developing, deactivate your virtualenv with `pyenv deactivate` or `source deactivate` (or just close your shell session)

You're now ready for simple testing and development!   
Continue below to learn about database migrations and enabling the advanced search engine, Elasticsearch.


## Database migrations
- Database migrations are done with [flask-Migrate](https://flask-migrate.readthedocs.io/), a wrapper around [Alembic](http://alembic.zzzcomputing.com/en/latest/).
- If someone has made changes in the database schema and included a new migration script:
    - If your database has never been marked by Alembic (you're on a database from before the migrations), run `./db_migrate.py stamp head` before pulling the new migration script(s).
        - If you already have the new scripts, check the output of `./db_migrate.py history` instead and choose a hash that matches your current database state, then run `./db_migrate.py stamp <hash>`.
    - Update your branch (eg. `git fetch && git rebase origin/master`)
    - Run `./db_migrate.py upgrade head` to run the migration. Done!
- If *you* have made a change in the database schema:
    - Save your changes in `models.py` and ensure the database schema matches the previous version (ie. your new tables/columns are not added to the live database)
    - Run `./db_migrate.py migrate -m "Short description of changes"` to automatically generate a migration script for the changes
      - Check the script (`migrations/versions/...`) and make sure it works! Alembic may not able to notice all changes.
    - Run `./db_migrate.py upgrade` to run the migration and verify the upgrade works.
       - (Run `./db_migrate.py downgrade` to verify the downgrade works as well, then upgrade again)


## Setting up and enabling Elasticsearch

### Installing Elasticsearch
- Install JDK with `sudo apt-get install openjdk-8-jdk`
- Install [Elasticsearch](https://www.elastic.co/downloads/elasticsearch)
    - [From packages...](https://www.elastic.co/guide/en/elasticsearch/reference/current/deb.html)
        - Enable the service:
            - `sudo systemctl enable elasticsearch.service`
            - `sudo systemctl start elasticsearch.service`
    - or [simply extracting the archives and running the files](https://www.elastic.co/guide/en/elasticsearch/reference/current/_installation.html), if you don't feel like permantently installing ES
- Run `curl -XGET 'localhost:9200'` and make sure ES is running
    - Optional: install [Kibana](https://www.elastic.co/products/kibana) as a search debug frontend for ES

### Setting up ES
- Run `./create_es.sh` to create the indices for the torrents: `nyaa` and `sukebei`
    - The output should show `acknowledged: true` twice
- Stop the Nyaa app if you haven't already
- Run `python import_to_es.py` to import all the torrents (on nyaa and sukebei) into the ES indices.
    - This may take some time to run if you have plenty of torrents in your database.

Enable the `USE_ELASTIC_SEARCH` flag in `config.py` and (re)start the application.   
Elasticsearch should now be functional! The ES indices won't be updated "live" with the current setup, continue below for instructions on how to hook Elasticsearch up to MySQL binlog.   

However, take note that binglog is not necessary for simple ES testing and development; you can simply run `import_to_es.py` from time to time to reindex all the torrents.

### Enabling MySQL Binlogging
- Edit your MariaDB/MySQL server configuration and add the following under `[mariadb]`:
    ```
    log-bin
    server_id=1
    log-basename=master1
    binlog-format=row
    ```
- Restart MariaDB/MySQL (`sudo service mysql restart`)
- Copy the example configuration (`es_sync_config.example.json`) as `es_sync_config.json` and adjust options in it to your liking (verify the connection options!)
- Connect to mysql as root
    - Verify that the result of `SHOW VARIABLES LIKE 'binlog_format';` is `ROW`
    - Execute `GRANT REPLICATION SLAVE ON *.* TO 'username'@'localhost';` to allow your configured user access to the binlog


### Setting up sync_es.py
`sync_es.py` keeps the Elasticsearch indices updated by reading the binlog and pushing the changes to the ES indices.
- Make sure `es_sync_config.json` is configured with the user you grated the `REPLICATION` permissions
- Run `import_to_es.py` and copy the outputted JSON into the file specified by `save_loc` in your `es_sync_config.json`
- Run `sync_es.py` as-is *or*, for actual deployment, set it up as a service and run it, preferably as the system/root
    - Make sure `sync_es.py` runs within the venv with the right dependencies!

You're done! The script should now be feeding updates from the database to Elasticsearch.   
Take note, however, that the specified ES index refresh interval is 30 seconds, which may feel like a long time on local development. Feel free to adjust it or [poke Elasticsearch yourself!](https://www.elastic.co/guide/en/elasticsearch/reference/current/indices-refresh.html)