Go: Posting with Payload/Post Body

Trying to accomplish a HTTP Post in Go:

Posting to: apiUrl

Payload/Post Body (expected as a json string): postBody

Here is the error I'm getting:

cannot use postBodyJson (type []byte) as type io.Reader in argument to http.Post: 
    []byte does not implement io.Reader (missing Read method)

What am I doing wrong?

Code:

package main
    
import (
	"encoding/json"
    "fmt"
	"net/http"
)

func main() {
	var postBody = []string{
		"http://google.com",
		"http://facebook.com",
		"http://youtube.com",
		"http://yahoo.com",
		"http://twitter.com",
		"http://live.com",
	}
	requestUrl := "http://lsapi.seomoz.com/linkscape/url-metrics"

    postBodyJson, _ := json.Marshal(postBody)

    resp, err := http.Post(requestUrl, "application/json", postBodyJson)
    fmt.Println(resp)
}

package main

import (
	"bytes"
	"encoding/json"
	"fmt"
	"log"
	"net/http"
)

func main() {
	var postBody = []string{
		"http://google.com",
		"http://facebook.com",
		"http://youtube.com",
		"http://yahoo.com",
		"http://twitter.com",
		"http://live.com",
	}
	apiUrl := "http://lsapi.seomoz.com/linkscape/url-metrics"

	buf := bytes.NewBuffer(nil)
	enc := json.NewEncoder(buf)
	err := enc.Encode(postBody)
	if err != nil {
		log.Fatal(err)
	}
	resp, err := http.Post(apiUrl, "application/json", buf)
	if err != nil {
		log.Fatal(err)
	}
	fmt.Println(resp)
}

Something like this might work. But as I already said in the comments, you should familiarize yourself with the language a little more. When you post code, make sure it compiles.