Enhance the application backend with RediSearch

[simonprickett]

This application stores its station data in two places... a Redis geo key containing all stations, and a series of Redis Hashes - one for each station. Currently, the application does nothing with the data in the Hashes whose keys are of the form station:<stationName>.

Here's Ashby for example:

127.0.0.1:6379> hgetall station:ashby
 1) "altitudeMode"
 2) "clampToGround"
 3) "City"
 4) "Berkeley"
 5) "AssetType"
 6) "Station"
 7) "Long"
 8) "-122.269981"
 9) "Street"
10) "3100 Adeline Street"
11) "FID"
12) "45"
13) "Lat"
14) "37.85257"
15) "Field_1"
16) "Ashby"

Update the application to use RediSearch as follows:

• Change the Redis container used in docker-compose.yml from the current redis:6.2.1-alpine image to instead use the latest RediSearch container: https://hub.docker.com/r/redislabs/redisearch
• Add code to create a RediSearch index in load_stations.py. Give your index the name idx:stations - you'll need to index the City field of hashes whose keys begin with the prefix station:*. Use the RediSearch library for this https://pypi.org/project/redisearch/ (note you are working with RediSearch 2 here)
• Add a new route in app.py:

@app.route("/api/search/bycity/<city_name>")
def search_by_city_name(city_name):
  # TODO code here...

• This route should:
  • Use RediSearch and your search index that you created in load_stations.py to find all stations where the "City" field has the value ""
  • Return an array of JSON objects that looks like this for each match:

[
  {
    "name": "<station name>",
    "city": "<station city>",
    "location": {
        "latitude": <station latitude>,
        "longitude": <station longitude>
    }
  }
]

• When sending RediSearch commands to Redis, use the redisearch library to make your search queries (see examples here https://github.com/simonprickett/introducing-redis-talk/tree/main/full_text_search_and_secondary_indexing)

• Test your route by calling GET localhost:8080/api/search/bycity/Oakland and GET localhost:8080/api/search/bycity/San Francisco

• Make sure that the existing front end maps search functionality still works :)

• Make sure you updated requirements.txt with the new redisearch library dependency.

This is part of our participation in Hacktoberfest 2021. Learn how to complete this issue here: https://developer.redis.com/hacktoberfest/

Need help or want to talk to us? Join us on Discord where we have a dedicated Hacktoberfest channel: https://discord.gg/ueQwKUh5Z3

[teezzan]

Can I hop on this?

[SuzeShardlow]

Yes @teezzan :) Please check out our guidelines at developer.redis.com/hacktoberfest and we look forward to seeing something from you in a couple of days :)

[simonprickett]

@teezzan hope all is well. Let us know if you need help or advice here.

[teezzan]

I'm sorry. I am starting ~tomorrow~ now. Thanks for checking on me.