http.Post Golang example

package mainimport (    "bytes"    "encoding/json"    "fmt"    "log"    "net/http")// Post holds the post data that we send or receive from the API server.type Post struct {    ID     string `json:"id,omitempty"`    Title  string `json:"title"`    Body   string `json:"Body"`    UserID string `json:"user_id"`}func main() {    // Before we create resource or post on the API server, we need to see the documentation of the REST API we want to use.    // Like what is the URL, version, what are the required fields in the resource object.    // Most of the companies create API docs,  it will have examples in different programming languages along with cURL commands.    // Companies also create SDKs in different programming languages.    // Difference between SDK and API: https://addevice.medium.com/difference-between-an-api-and-an-sdk-anyone-can-understand-3a95bf7fc691    // For example Okta to deal with mangement of users, they are having SDK at:https://github.com/okta/okta-sdk-golang    // Let's build response body for the server we want to post or create resource    p := new(Post)    p.Title = "Title"    p.Body = "This is body"    p.UserID = "userID"    // Now we need erializes Post 'p' to JSON    b, err := json.Marshal(p)    if err != nil {        log.Fatalf("Failed to Serialize to JSON from native Go struct type: %v", err)    }    // here http.Post method expects body as 'io.Redear' which should implement Read() method.    // So, bytes package will take care of that.    body := bytes.NewBuffer(b)    // REST APIs means, always think in terms of 'resources'.    // This is good resource: https://www.practical-go-lessons.com/chap-35-build-an-http-client    // This post method uses default http client, so timeout is NOT mentioned.    // Doc of this POST API can be found here: https://jsonplaceholder.typicode.com/guide/.    postURL := "https://jsonplaceholder.typicode.com/posts"    resp, err := http.Post(postURL, "application/json; charset=utf-8", body)    if err != nil {        log.Fatalf("Failed to create resource at: %s and the error is: %v
", postURL, err)    }    // Always close the response body    defer resp.Body.Close()    // Let us just print the response headers info from the server    log.Printf("Status received from server is: %s", resp.Status)    log.Printf("StatusCode received from server is: %d", resp.StatusCode)    log.Printf("Content Type received from Server is: %s", resp.Header["Content-Type"][0])    // Like I mentioned in my last article,    // we can read the server response to our native Golang type    // as the map data structure is close to JSON, we could use it    // in fact we could use this for most of the wire formats.    data := make(map[string]interface{})    if err := json.NewDecoder(resp.Body).Decode(&data); err != nil {        log.Fatalf("Failed to read response body: %v", err)    }    // Let's print the map data by iterating over it.    // Usually in real usecases we use this response to pass to ther functions.    for key, value := range data {        fmt.Printf("%s: %v
", key, value)    }    log.Println("We have successfully created resource and read the response from API server.")}