Exploration of Akash Queries Using the Akash API Source Code | Akash Network

In this section we will use an Akash deployments query as an example of:

General use of the Akash API repository within custom code
Explore Akash API Go code generated thru protoc
Using the Protobuf generated gateway for blockchain queries
Sending receipt of Protobuf messages with HTTP API requests to Akash RPC nodes

Sections Within This Guide

gRPC Gateway Use
Example gRPC Gateway Use and Deep Dive Explanations

gRPC Gateway Use

The Protobuf generated gRPC gateway creates a HTTP handler for upstream gRPC queries. The gRPC gateway provides an interface for clients incapable of using gRPC calls directly. In this guide we use the gRPC source code for blockchain queries to remove friction and ease of development.

The gRPC gateway definitions used on our example query of Akash deployments are located here.

Example gRPC Gateway Use and Deep Dive Explanations

Subsections within Code Exploration

gRPC Gateway Use
Example gRPC Gateway Use and Deep Dive Explanations

Complete Code Example - Query Deployments with Owner Filter

NOTE - prior to execution of this code ensure package dependencies mirror those found in the source code repo go.mod file here

package main

import (
  "encoding/hex"
  "fmt"
  "io/ioutil"
  "net/http"
  "strings"

  "github.com/golang/protobuf/proto"

  "github.com/akash-network/akash-api/go/node/deployment/v1beta3"
)

func main() {
  // Replace string with preferred Akash RPC Node
  // At the time of this writing a Testnet RPC Node is utilized to utilize the latest version of the Akash API
  url := "https://rpc.testnet-02.aksh.pw:443"
  method := "GET"

  // Create the QueryDeploymentsRequest with necessary filters
  // Replace the Owner address with the account of interest and to query deplpyments associated with that account
  request := &v1beta3.QueryDeploymentsRequest{
    Filters: v1beta3.DeploymentFilters{
      // Set any filters you need to query deployments
      // For example, you can set the owner of the deployment, status, etc.
      Owner: "akash1w3k6qpr4uz44py4z68chfrl7ltpxwtkngnc6xk",
    },
    // Pagination: &v1beta3.PageRequest{
    //   // Set pagination options if needed
    //   // For example, you can set the number of results per page, the page number, etc.
    // },
  }

  // Manually serialize the struct fields into the protobuf message
  data, err := manualMarshal(request)
  if err != nil {
    fmt.Println("Error encoding protobuf:", err)
    return
  }

  // Convert the byte slice to a hexadecimal string
  protoMessage := hex.EncodeToString(data)

  // Construct the payload string and use the protoMessage variable in the data key
  payload := strings.NewReader(fmt.Sprintf(`{"jsonrpc":"2.0","id":0,"method":"abci_query","params":{"data":"%s","height":"0","path":"/akash.deployment.v1beta3.Query/Deployments","prove":false}}`, protoMessage))

  client := &http.Client{}
  req, err := http.NewRequest(method, url, payload)

  if err != nil {
    fmt.Println(err)
    return
  }
  req.Header.Add("Content-Type", "application/json")

  res, err := client.Do(req)
  if err != nil {
    fmt.Println(err)
    return
  }
  defer res.Body.Close()

  body, err := ioutil.ReadAll(res.Body)
  if err != nil {
    fmt.Println(err)
    return
  }

  // Prints protobuf encoded message that can be converted to human readable format/Go struct
  fmt.Println(string(body))

}

// Manually serialize the struct fields into the protobuf message
func manualMarshal(msg proto.Message) ([]byte, error) {
  var buf proto.Buffer
  if err := buf.Marshal(msg); err != nil {
    return nil, err
  }
  return buf.Bytes(), nil
}

Deep Code Exploration Using Query Deployments Example

Protoc Generated Go Code Overview

Within the example Deployments blockchain query we make use of:
- Deployments protobuf definitions which are originally defined here and specifically in the query.proto definition file
- Go code generated via protoc and that are located here and specifically the query.pb.gw.go and query.pb.go files

NOTE - the protoc generated Go files used in our custom code examples are the same type definitions used throughout Akash source code. For example - the Akash CLI source code and specifically Deployment/Deployments queries are defined here. Within the referenced file and CLI client definitions the types located in github.com/akash-network/akash-api/go/node/deployment/v1beta3 are utilized. These are the same definitions and types we we use in this custom client code example.

Protoc Generated File Deepdive

The example Deployments Query code uses the protoc generated gRPC gateway
The gRPC gateway registers the DeploymentsQuery endpoint
For DeploymentsQuery the HTTP GET request requires the following attributes in the payload with associated values for our use case:
- "path":"/akash.deployment.v1beta3.Query/Deployments"
- "data" - protobuf encoded message

Custom/Relevant Code

Utilize the protoc generated Go type of QueryDeploymentsRequest
Embed protobuf encoded payload in HTTP request to gRPC gateway

  // Create the QueryDeploymentsRequest with necessary filters
  // Replace the Owner address with the account of interest and to query deplpyments associated with that account
  request := &v1beta3.QueryDeploymentsRequest{
    Filters: v1beta3.DeploymentFilters{
      // Set any filters you need to query deployments
      // For example, you can set the owner of the deployment, status, etc.
      Owner: "akash1w3k6qpr4uz44py4z68chfrl7ltpxwtkngnc6xk",
    },
    // Pagination: &v1beta3.PageRequest{
    //   // Set pagination options if needed
    //   // For example, you can set the number of results per page, the page number, etc.
    // },
  }

  // Manually serialize the struct fields into the protobuf message
  data, err := manualMarshal(request)
  if err != nil {
    fmt.Println("Error encoding protobuf:", err)
    return
  }

  // Convert the byte slice to a hexadecimal string
  protoMessage := hex.EncodeToString(data)

  // Construct the payload string and use the protoMessage variable in the data key
  payload := strings.NewReader(fmt.Sprintf(`{"jsonrpc":"2.0","id":0,"method":"abci_query","params":{"data":"%s","height":"0","path":"/akash.deployment.v1beta3.Query/Deployments","prove":false}}`, protoMessage))

QueryDeploymentsRequest Type

Source code for this type is located here

// QueryDeploymentsRequest is request type for the Query/Deployments RPC method
type QueryDeploymentsRequest struct {
  Filters    DeploymentFilters  `protobuf:"bytes,1,opt,name=filters,proto3" json:"filters"`
  Pagination *query.PageRequest `protobuf:"bytes,2,opt,name=pagination,proto3" json:"pagination,omitempty"`
}