进行Golang发布时禁止使用403

Question

I have a REST endpoint provided by a Java Spring Boot app that I am trying to hit with a simple Go (go1.8 darwin/amd64) program. I have tried to hit it in 2 separate ways:

const (
    LOCAL_BASE         = "http://localhost:11400"
    ADD_FUNDS_ENDPOINT = "/sub-accounts/%d/add-funds"
)

type InputArgumentsJson struct {
    Amount           float64 `json:"amount"`
    BufferAmount     float64 `json:"bufferAmount"`
    FromSubAccountID int     `json:"fromSubAccountId"`
}

...

// set up json body
inputArguments := &InputArgumentsJson{Amount: 1100, BufferAmount: 0,
    FromSubAccountID: spendFundId}
bytes := new(bytes.Buffer)
json.NewEncoder(bytes).Encode(inputArguments)

// set up the url to call
endpoint := fmt.Sprintf(ADD_FUNDS_ENDPOINT, billSetAsideId)
url := LOCAL_BASE + endpoint

client := &http.Client{}

req, err := http.NewRequest("POST", url, bytes)
if err != nil {
    fmt.Println("ERROR WHILE BUILDING REQUEST")
    fmt.Println(err)
}

req.Header.Add("Content-Type", "application/json")
resp, err := client.Do(req)
if err != nil {
    fmt.Println("ERROR WHILE MAKING REQUEST")
    fmt.Println(err)
}
fmt.Println(resp)

and:

resp, err := http.Post(url, "application/json; charset=utf-8", bytes)
if err != nil {
    fmt.Println("ERROR WHILE MAKING REQUEST")
    fmt.Println(err)
}
fmt.Println(resp)

I added a print out to see if the URL and JSON body were right and they appeared to be:

fmt.Printf("
Making request to %s with:
 %s
", url, bytes)

printed out

Making request to http://localhost:11400/sub-accounts/167/add-funds with:
{"amount":1100,"bufferAmount":0,"fromSubAccountId":166}

but I am getting a 403 Forbidden when running it.

I can hit this endpoint without fail using both Postman and the following Curl command:

curl -H "Content-Type: application/json" -X POST -d '{"amount":1100,"bufferAmount":0,"fromSubAccountId":166}' http://localhost:11400/sub-accounts/167/add-funds

Does anyone have any thoughts on what I may be missing here? To add further to the intrigue I can successfully hit a different GET endpoint from the Go program.

Thanks in advance!

Edited to show that I was catching the errors and the surrounding logic for creating the URL and JSON body

Answer 1

You did not show what bytes is but that's most probably the problem: both NewRequest and Post take an io.Reader and read the body from that reader. This reading typically can happen only once (think of a stream). When you fmt.Printf("%s") the io.Reader this printing will consume the content (most probably by invoking a String() method) and the actual request is done with an empty body.

Always show whole code. And do not try to read twice from an io.Reader.