Zube API Client

zube.go

package main

import (
	"crypto/rsa"
	"encoding/json"
	"fmt"
	"io"
	"io/ioutil"
	"log"
	"net/http"
	"os"
	"time"

	"github.com/dgrijalva/jwt-go"
)

func zubeRequest(method, url string, body io.Reader, clientId, token string) (*http.Request, error) {
	req, err := http.NewRequest(method, url, nil)
	if err != nil {
		return nil, err
	}
	req.Header.Add("Authorization", "Bearer "+token)
	req.Header.Add("X-Client-ID", clientId)
	req.Header.Add("Accept", "application/json")
	return req, nil
}

func access(clientId, refreshToken string) (string, error) {
	req, _ := zubeRequest(http.MethodPost, "https://zube.io/api/users/tokens", nil, clientId, refreshToken)
	rsp, err := http.DefaultClient.Do(req)
	if err != nil {
		return "", err
	}
	var accessTokenRsp struct {
		AccessToken string `json:"access_token"`
	}
	if err := json.NewDecoder(rsp.Body).Decode(&accessTokenRsp); err != nil {
		return "", err
	}
	return accessTokenRsp.AccessToken, nil
}

func refresh(clientId string, key *rsa.PrivateKey) (string, error) {
	now := time.Now()
	claims := &jwt.StandardClaims{
		IssuedAt:  now.Unix(),
		ExpiresAt: (now.Add(time.Minute)).Unix(),
		Issuer:    clientId,
	}
	if err := claims.Valid(); err != nil {
		log.Fatalf("invalid claims: %s", err)
	}
	token := jwt.NewWithClaims(jwt.SigningMethodRS256, claims)
	return token.SignedString(key)
}

func dump(clientId, accessToken, api string) (string, error) {
	req, _ := zubeRequest(http.MethodGet, "https://zube.io/api/"+api, nil, clientId, accessToken)
	rsp, err := http.DefaultClient.Do(req)
	if err != nil {
		return "", err
	}
	body, err := ioutil.ReadAll(rsp.Body)
	return string(body), err
}

func main() {
	api := os.Args[1]
	clientId := "here"
	privateKey, err := ioutil.ReadFile("zube_api_key.pem")
	if err != nil {
		log.Fatal(err)
	}
	key, err := jwt.ParseRSAPrivateKeyFromPEM(privateKey)
	if err != nil {
		log.Fatal(err)
	}

	refreshToken, err := refresh(clientId, key)
	if err != nil {
		log.Fatal(err)
	}
	accessToken, err := access(clientId, refreshToken)
	if err != nil {
		log.Fatal(err)
	}
	if body, err := dump(clientId, accessToken, api); err != nil {
		log.Println(err)
	} else {
		fmt.Println(body)
	}
}