fix(godday): panic when retryAfter is 0

[rayshoo]

… process

Description

Handles panic when the retryAfter header is parsed as 0 or less or blank when responding 429 from GoDaddy API.

Fixes #ISSUE
This is a code fix for the issue #4864

Checklist

• Unit tests updated
• End user documentation updated

[linux-foundation-easycla]

The committers listed above are authorized under a signed CLA.

• ✅ login: rayshoo / name: rayshoo (8a0548b, 67ff232, 7fb8be1)

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[mloiseleur]

Thanks for this PR.
Would you please add some tests on this ?

[mloiseleur]

/retitle fix(godday): panic when retryAfter is 0

[mloiseleur]

Fixes #4864

[rayshoo]

Is it correct to add the test code to the provider/godaddy/godaddy_test.go file?
Actually I am not very experienced in writing test code.
I will try to understand and write as much as I can, but I don't know how long it will take.
It would be nice if there was a gopher around that could help me, but unfortunately there isn't one other than me.. :(
Still, I think this could be another experience, so I'll give it a try when I have time. thank you!

[mloiseleur]

Is it correct to add the test code to the provider/godaddy/godaddy_test.go file?

Yes it is.

Actually I am not very experienced in writing test code.

This step is clearly mandatory. It's not that difficult, you will see :).

[mloiseleur]

In go, developers prefer readability.
Would you please rewrite this code with this pesudo pattern:

retryAfter = 30
receivedValue := resp.Header.Get("Retry-After")
if receivedValue != "" {
  // [...]
  retryAfter = somethingElse
}

[rayshoo]

Based on your review, I modified the code and made it more concise while maintaining the default value of 30. thank you!

[rayshoo]

@mloiseleur As I wringing the test code, I took a closer look at the code as a whole. I realized that even if I take care to prevent an error from occurring in Client.Do, the status code value is 429, so the subsequent function, UnmarshalResponse, returns an error, which leads to log.Fatal(err) in the main function and terminates the server.

Therefore, if I receive a 429 error within the client.
Repeat the process with an appropriate interval, it is expected that will be able to return 200 and exit the loop when the quota is released. (I don't know if the godaddy server will like this. I think we need an interval setting that can be mutually agreed upon.)

// provider/godaddy/client.go:224
func (c *Client) Do(req *http.Request) (*http.Response, error) {
	// [...]
	resp, err := c.Client.Do(req)
	/*
	Before
	for i := 1; i < 3 && err == nil && resp.StatusCode == 429; i++ {
	*/
	// After
	for err == nil && resp.StatusCode == 429 {
	// [...]

Also, during this time, I think the readiness probe needs to be taken down to tell Kubernetes that the server is not ready.

// somePackage/someFilename.go
var Ready bool = true

// provider/godaddy/client.go:224
func (c *Client) Do(req *http.Request) (*http.Response, error) {
	for err == nil && resp.StatusCode == 429 {
		somePackage.Ready = false
	// [...]
	}
	somePackage.Ready = true

// main.go:447
func serveMetrics(address string) {
	http.HandleFunc("/live", func(w http.ResponseWriter, _ *http.Request) {
		w.WriteHeader(http.StatusOK)
		w.Write([]byte("OK"))
	})
	http.HandleFunc("/ready", func(w http.ResponseWriter, _ *http.Request) {
		if somePackage.Ready {
			w.WriteHeader(http.StatusOK)
			w.Write([]byte("OK"))
		} else {
			w.WriteHeader(http.StatusPreconditionRequired)
			w.Write([]byte("NOT READY"))
		}
	})
}

However, this level of code requires more modifications than initially thought, so I don't know if it is desirable. I wrote my opinion carefully.

[alexstojda]

Hey @rayshoo @mloiseleur! I have another PR open to address this issue, with tests as well ;)

Please let me know what you think: #4866