Working grpc example with slash graphql

Users Dgraph Cloud
,
1

Can someone provide a working example of GRPC with Slash graphql using Go.

I understand there are some example but they all seem to use WithInsecure field and documentation was helpful with which method to use.

Thanks

2

Hi Harshad,

Thanks for the question.

We’ve recently moved the documentation for this over here: https://dgraph.io/docs/slash-graphql/advanced-queries/

This contains an example of connecting to Slash GraphQL over secure GRPC with python.

If you are looking for a golang example, then you can look at how we connect to Slash GraphQL from dgraph in order to run the bank test: dgraph/main.go at master · dgraph-io/dgraph · GitHub

Posting the relevant bits for posterity:

type authorizationCredentials struct {
	token string
}

func (a *authorizationCredentials) GetRequestMetadata(ctx context.Context, uri ...string) (map[string]string, error) {
	return map[string]string{"Authorization": a.token}, nil
}

func (a *authorizationCredentials) RequireTransportSecurity() bool {
	return true
}

func grpcConnection(grpcEndpoint string, slashToken string) (*grpc.ClientConn, error) {
	pool, err := x509.SystemCertPool()
	if err != nil {
		return nil, err
	}
	return grpc.Dial(
		grpcEndpoint,
		grpc.WithTransportCredentials(credentials.NewTLS(&tls.Config{
			RootCAs:    pool,
			ServerName: strings.Split(grpcEndpoint, ":")[0],
		})),
		grpc.WithPerRPCCredentials(&authorizationCredentials{*slashToken}),
	)
}

Tejas

2 Likes
3

Hi @gja,

I was able to get something working . Thanks. However, I am getting the following error.

dc := api.NewDgraphClient(conn)
	dg := dgo.NewDgraphClient(dc)

	op := &api.Operation{}
	op.Schema = `
		name: string @index(exact) .
		age: int .
		married: bool .
		loc: geo .
		dob: datetime .
	`

	ctx := context.Background()
	err = dg.Alter(ctx, op)
	if err != nil {
		log.Fatal(err)
	}

	resp, err := dg.NewTxn().Query(ctx, `schema(pred: [name, age]) {type}`)
	if err != nil {
		log.Fatal(err)
	}

	fmt.Println(string(resp.Json))

This is code i am trying to execute. The error message as below.

rpc error: code = Unknown desc = Alter is not allowed. Please switch your Slash GraphQL backend to flexible mode.
4

Can you DM me and @slotlocker2 your endpoint? We’ll make the appropriate changes to get this to work. The UI for getting this to work will go live in a few days

5

Not sure how to DM on this thing. I have send a question via slash.

6

Hey @harshadbhatia,

I have enabled the changes on your backend. Could you validate if it looks alright at your end?

1 Like
7

Yes thanks it is now working! Thanks :smiley:

8

Would anyone be able to provide the same for Node? (let me know if I should post this separately)

I’ve got this mostly working:

export const SLASH_ADDR = '<NAME>.grpc.us-west-2.aws.cloud.dgraph.io:443';
export const SLASH_SSL = grpc.credentials.createSsl();
export const SLASH_TOKEN = grpc.credentials.createFromMetadataGenerator(
  (_url, cb) => {
    const meta = new grpc.Metadata();
    meta.add('authorization', '<API-KEY>');
    cb(null, meta);
  }
);
export const SLASH_CREDENTIALS = grpc.credentials.combineChannelCredentials(
  SLASH_SSL,
  SLASH_TOKEN
);
const stub = new dgraph.DgraphClientStub(SLASH_ADDR, SLASH_CREDENTIALS);
// ...

But I receive an error on every call Error: 14 UNAVAILABLE: failed to connect to all addresses which I believe is related to the cert.

9

@jpstrikesback This PR Update gRPC library in dgraph-js to use gRPC-js by anurags92 · Pull Request #125 · dgraph-io/dgraph-js · GitHub extends dgraph-js client. You can use

const clientStub = new dgraph.clientStubFromSlashGraphQLEndpoint(
  graphQlEndpoint,
  apiKey
);
const dgraphClient = new dgraph.DgraphClient(clientStub);

to connect directly to dgraph. Keep in mind that if your cluster has been asleep for a while, it will fail for the first couple of minutes while the cluster re-starts.