What's the weather LINK?

Get the average current temperature at a given location by querying Accuweather and Openweather APIs.

Note that this is not a repository that you can run, but a collection of steps and snippets that will allow you to experiment with Chainlink technology: nodes, jobs, tasks and external adapters.

Setup

To complete the following steps, setup a Metamask wallet and get some ETH and LINK in Kovan.

Step 1. Run a Chainlink node

Visit the Chainlink docs for instructions about running a node. For the purposes of this demo, Chainlink version 0.10.15 was used.

Step 2. Deploy an oracle contract

Open Remix and deploy a version of the Operator.sol contract. The source code is available at chainlink/contracts/src (v0.7 at the time of the hackathon).

To deploy, pass an owner address and the link token address in Kovan, i.e. 0xa36085F69e2889c224210F603D836748e7dC0088.

Associate your node address (Node Operator GUI Keys > Account addresses) to the oracle contract. Do this on Remix, calling setAuthorizedSenders.

E.g. Operator contract in Kovan: 0xffcb560a05183a9a0ee04ba93b624656ad61fd7b

Step 3. Run the Accuweather external adapter

Clone and start the Accuweather external adapter as per the external-adapters-js and accuweather README files.

Note that you will have to request an API Key for development purposes. This key is only valid for the dataservice Accuweather URLs, and they just allow a handful of requests per key at a time.

Run the adapater:

# Add your API_KEY
docker-compose -f docker-compose.generated.yaml run -p 8080:8080 -e "API_ENDPOINT=http://dataservice.accuweather.com" -e "API_KEY=" accuweather-adapter

Test the adapter:

curl -X POST -H "Content-Type: application/json" "http://localhost:8080" --data '{"id":"1","data":{"endpoint":"location-current-conditions","lat": 41.406909471885754, "lon": 2.1758906926877977, "units":"metric", "encodeResult": true}}'

Response example in external-adapter-templates/response-examples.

Step 4. Run the Openweather external adapter

Clone and start the external-adapters-template repository and replace the index.js file with the content in external-adapter-templates/openweather.js.

Note that you will have to request an API Key for development purposes.

Run the adapater:

yarn start

Test the adapter:

curl -X POST -H "Content-Type: application/json" "http://localhost:8081" --data '{ "id":0, "data": { "lat": "41.406909471885754", "lon": "2.1758906926877977", "units": "metric"}}'

Response example in external-adapter-templates/response-examples. Read the full tutorial at Building and Using External Adapters, by Patrick Collins.

Step 5. Further node configurations

1. Add a bridge for Accuweather (name accuweather)
2. Add a bridge for Openweather (name openweather)
3. Create a job (jobs/get-mean-temperature) - mind contractAddress

Step 6. Deploy a consumer contract

Code in contracts/TemperatureConsumer.sol.

E.g. 0x4238e4ec58dc817d569f83b02820acf28f9e117b - validated but with no transactions due to node failure

Step 7. Send Funds

1. Fund your node address with ETH
2. Fund the consumer contract with LINK

Step 8. Test

Visit the TemperatureCosumer contract. Make sure Metamask is connected.

Contract > Write contract

Call requestGeoPositionTemperature (consumer) to get the average temperature for a given lat, lon.

Contract > Read contract

Call requestIdMeanTemp to check the result (note that it is multiplied by 10), e.g.

0x72e7be3659d3f593a7f3530b0c138e5308b8cb4e99ae8a4b5e47ab5b2e5c16fd

At the time of making the request, the average temperature at Cumbre Vieja volcano was 12.2°C.

Source	T (°C)	Observation dt (GMT)
Accuweather	16.0	Thursday, 2 December 2021 06:37:00
Openweather	8.49	Thursday, 2 December 2021 06:54:18

You can use requestIdRequestParams to query get back the lat, lon.

What's next (ideas)

• Provide instructions for running Openweather adapter within a container
• Implement the Openweather adapter utilizing the external adapters official framework
• Expand the results returned from the Openweather adapter (not just temperature, but at least dt)
• Provide data from other APIs
• Consider edge cases
• A nice front end!