Lambda to receive HTTP POST with JSON payload

Users Dgraph Cloud
1

I’m working on building an SMS platform, so part of this is for the SMS gateway to forward the SMS to a public URL with a JSON Payload (which I have no control of the format) so I need to have it accepted by a lambda in Slash and then from there insert it as a record in the Graph database for later processing.

The SMS gateway will send an HTTP POST with JSON payload to the lambda function.

How can I do this with Slash?

I have deployed this type:

type InboundSMS  {
  id: String! @id
  dateTime: String!
  destinationAddress: String!
  messageId: String!
  message: String!
  resourceURL: String!
  senderAddress: String!
}

As the schema for the incoming SMS with JSON format:

HTTP POST

{
  "inboundSMSMessageList":{
      "inboundSMSMessage":[
         {
            "dateTime":"Fri Nov 22 2013 12:12:13 GMT+0000 (UTC)",
            "destinationAddress":"tel:21581234",
            "messageId":null,
            "message":"Hello",
            "resourceURL":null,
            "senderAddress":"tel:+639171234567"
         }
       ],
       "numberOfMessagesInThisBatch":1,
       "resourceURL":null,
       "totalNumberOfPendingMessages":null
   }
}
2

You will need to have a server/lambda function (outside of Slash) to intercept the POST payload, then transform it into a GraphQL mutation to Slash.

Alternatively, if you CAN pre-wrap the POST payload into a GraphQL mutation, and you really want to push the limits of your mind-bending abilities of designing a serverless architecture, you can also try something like this:

First, define a “RawJSON” type:

type Raw {
    id: ID!
    raw: String!
    msg: InboundSMS
}

Then write a new mutation:

type Mutation {
     newRaw(raw: String!): ID! @lambda
}

Then write your function:

async function foo({args, graphql}){
    sideeffects = await graphql( `mutation ($id: String ...) { 
       addInboundSMS(...) { ... } // GraphQL mutation to addInboundSMS
    }`, {"id": ___, /*your arguments here */})
    result = await graphql(`mutation {
        addRaw (...) { raw { id } ... } // GraphQL mutation to addRaw
    }`, {/*your arguments here */})
    return result.data.addRaw.raw[0].id
}

// register your function
self.addGraphQLResolvers({
    "Mutation.newRaw": foo
})

Something like that. The tricky bit is to transform your POST payload into a GraphQL mutation. That needs to be done somewhere (either clientside, or another server intercepting the POST and re-post to Slash)

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