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stripe.go
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stripe.go
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// Package stripe provides the binding for Stripe REST APIs.
package stripe
import (
"bytes"
"context"
"crypto/tls"
"crypto/x509"
"encoding/json"
"errors"
"fmt"
"io"
"io/ioutil"
"math/rand"
"net/http"
"net/url"
"os/exec"
"reflect"
"regexp"
"runtime"
"strings"
"sync"
"time"
"github.com/stripe/stripe-go/v72/form"
)
//
// Public constants
//
const (
// APIVersion is the currently supported API version
APIVersion string = "2020-08-27"
// APIBackend is a constant representing the API service backend.
APIBackend SupportedBackend = "api"
// APIURL is the URL of the API service backend.
APIURL string = "https://api.stripe.com"
// ConnectURL is the URL for OAuth.
ConnectURL string = "https://connect.stripe.com"
// ConnectBackend is a constant representing the connect service backend for
// OAuth.
ConnectBackend SupportedBackend = "connect"
// DefaultMaxNetworkRetries is the default maximum number of retries made
// by a Stripe client.
DefaultMaxNetworkRetries int64 = 2
// UnknownPlatform is the string returned as the system name if we couldn't get
// one from `uname`.
UnknownPlatform string = "unknown platform"
// UploadsBackend is a constant representing the uploads service backend.
UploadsBackend SupportedBackend = "uploads"
// UploadsURL is the URL of the uploads service backend.
UploadsURL string = "https://files.stripe.com"
)
//
// Public variables
//
// EnableTelemetry is a global override for enabling client telemetry, which
// sends request performance metrics to Stripe via the `X-Stripe-Client-Telemetry`
// header. If set to true, all clients will send telemetry metrics. Defaults to
// true.
//
// Telemetry can also be disabled on a per-client basis by instead creating a
// `BackendConfig` with `EnableTelemetry: false`.
var EnableTelemetry = true
// Key is the Stripe API key used globally in the binding.
var Key string
//
// Public types
//
// APIResponse encapsulates some common features of a response from the
// Stripe API.
type APIResponse struct {
// Header contain a map of all HTTP header keys to values. Its behavior and
// caveats are identical to that of http.Header.
Header http.Header
// IdempotencyKey contains the idempotency key used with this request.
// Idempotency keys are a Stripe-specific concept that helps guarantee that
// requests that fail and need to be retried are not duplicated.
IdempotencyKey string
// RawJSON contains the response body as raw bytes.
RawJSON []byte
// RequestID contains a string that uniquely identifies the Stripe request.
// Used for debugging or support purposes.
RequestID string
// Status is a status code and message. e.g. "200 OK"
Status string
// StatusCode is a status code as integer. e.g. 200
StatusCode int
}
// StreamingAPIResponse encapsulates some common features of a response from the
// Stripe API whose body can be streamed. This is used for "file downloads", and
// the `Body` property is an io.ReadCloser, so the user can stream it to another
// location such as a file or network request without buffering the entire body
// into memory.
type StreamingAPIResponse struct {
Header http.Header
IdempotencyKey string
Body io.ReadCloser
RequestID string
Status string
StatusCode int
}
func newAPIResponse(res *http.Response, resBody []byte) *APIResponse {
return &APIResponse{
Header: res.Header,
IdempotencyKey: res.Header.Get("Idempotency-Key"),
RawJSON: resBody,
RequestID: res.Header.Get("Request-Id"),
Status: res.Status,
StatusCode: res.StatusCode,
}
}
func newStreamingAPIResponse(res *http.Response, body io.ReadCloser) *StreamingAPIResponse {
return &StreamingAPIResponse{
Header: res.Header,
IdempotencyKey: res.Header.Get("Idempotency-Key"),
Body: body,
RequestID: res.Header.Get("Request-Id"),
Status: res.Status,
StatusCode: res.StatusCode,
}
}
// APIResource is a type assigned to structs that may come from Stripe API
// endpoints and contains facilities common to all of them.
type APIResource struct {
LastResponse *APIResponse `json:"-"`
}
// APIStream is a type assigned to streaming responses that may come from Stripe API
type APIStream struct {
LastResponse *StreamingAPIResponse
}
// SetLastResponse sets the HTTP response that returned the API resource.
func (r *APIResource) SetLastResponse(response *APIResponse) {
r.LastResponse = response
}
// SetLastResponse sets the HTTP response that returned the API resource.
func (r *APIStream) SetLastResponse(response *StreamingAPIResponse) {
r.LastResponse = response
}
// AppInfo contains information about the "app" which this integration belongs
// to. This should be reserved for plugins that wish to identify themselves
// with Stripe.
type AppInfo struct {
Name string `json:"name"`
PartnerID string `json:"partner_id"`
URL string `json:"url"`
Version string `json:"version"`
}
// formatUserAgent formats an AppInfo in a way that's suitable to be appended
// to a User-Agent string. Note that this format is shared between all
// libraries so if it's changed, it should be changed everywhere.
func (a *AppInfo) formatUserAgent() string {
str := a.Name
if a.Version != "" {
str += "/" + a.Version
}
if a.URL != "" {
str += " (" + a.URL + ")"
}
return str
}
// Backend is an interface for making calls against a Stripe service.
// This interface exists to enable mocking for during testing if needed.
type Backend interface {
Call(method, path, key string, params ParamsContainer, v LastResponseSetter) error
CallStreaming(method, path, key string, params ParamsContainer, v StreamingLastResponseSetter) error
CallRaw(method, path, key string, body *form.Values, params *Params, v LastResponseSetter) error
CallMultipart(method, path, key, boundary string, body *bytes.Buffer, params *Params, v LastResponseSetter) error
SetMaxNetworkRetries(maxNetworkRetries int64)
}
// BackendConfig is used to configure a new Stripe backend.
type BackendConfig struct {
// EnableTelemetry allows request metrics (request id and duration) to be sent
// to Stripe in subsequent requests via the `X-Stripe-Client-Telemetry` header.
//
// This value is a pointer to allow us to differentiate an unset versus
// empty value. Use stripe.Bool for an easy way to set this value.
//
// Defaults to false.
EnableTelemetry *bool
// HTTPClient is an HTTP client instance to use when making API requests.
//
// If left unset, it'll be set to a default HTTP client for the package.
HTTPClient *http.Client
// LeveledLogger is the logger that the backend will use to log errors,
// warnings, and informational messages.
//
// LeveledLoggerInterface is implemented by LeveledLogger, and one can be
// initialized at the desired level of logging. LeveledLoggerInterface
// also provides out-of-the-box compatibility with a Logrus Logger, but may
// require a thin shim for use with other logging libraries that use less
// standard conventions like Zap.
//
// Defaults to DefaultLeveledLogger.
//
// To set a logger that logs nothing, set this to a stripe.LeveledLogger
// with a Level of LevelNull (simply setting this field to nil will not
// work).
LeveledLogger LeveledLoggerInterface
// MaxNetworkRetries sets maximum number of times that the library will
// retry requests that appear to have failed due to an intermittent
// problem.
//
// This value is a pointer to allow us to differentiate an unset versus
// empty value. Use stripe.Int64 for an easy way to set this value.
//
// Defaults to DefaultMaxNetworkRetries (2).
MaxNetworkRetries *int64
// URL is the base URL to use for API paths.
//
// This value is a pointer to allow us to differentiate an unset versus
// empty value. Use stripe.String for an easy way to set this value.
//
// If left empty, it'll be set to the default for the SupportedBackend.
URL *string
}
// BackendImplementation is the internal implementation for making HTTP calls
// to Stripe.
//
// The public use of this struct is deprecated. It will be unexported in a
// future version.
type BackendImplementation struct {
Type SupportedBackend
URL string
HTTPClient *http.Client
LeveledLogger LeveledLoggerInterface
MaxNetworkRetries int64
enableTelemetry bool
// networkRetriesSleep indicates whether the backend should use the normal
// sleep between retries.
//
// See also SetNetworkRetriesSleep.
networkRetriesSleep bool
requestMetricsBuffer chan requestMetrics
}
func extractParams(params ParamsContainer) (*form.Values, *Params) {
var formValues *form.Values
var commonParams *Params
if params != nil {
// This is a little unfortunate, but Go makes it impossible to compare
// an interface value to nil without the use of the reflect package and
// its true disciples insist that this is a feature and not a bug.
//
// Here we do invoke reflect because (1) we have to reflect anyway to
// use encode with the form package, and (2) the corresponding removal
// of boilerplate that this enables makes the small performance penalty
// worth it.
reflectValue := reflect.ValueOf(params)
if reflectValue.Kind() == reflect.Ptr && !reflectValue.IsNil() {
commonParams = params.GetParams()
formValues = &form.Values{}
form.AppendTo(formValues, params)
}
}
return formValues, commonParams
}
// Call is the Backend.Call implementation for invoking Stripe APIs.
func (s *BackendImplementation) Call(method, path, key string, params ParamsContainer, v LastResponseSetter) error {
body, commonParams := extractParams(params)
return s.CallRaw(method, path, key, body, commonParams, v)
}
// CallStreaming is the Backend.Call implementation for invoking Stripe APIs
// without buffering the response into memory.
func (s *BackendImplementation) CallStreaming(method, path, key string, params ParamsContainer, v StreamingLastResponseSetter) error {
formValues, commonParams := extractParams(params)
var body string
if formValues != nil && !formValues.Empty() {
body = formValues.Encode()
// On `GET`, move the payload into the URL
if method == http.MethodGet {
path += "?" + body
body = ""
}
}
bodyBuffer := bytes.NewBufferString(body)
req, err := s.NewRequest(method, path, key, "application/x-www-form-urlencoded", commonParams)
if err != nil {
return err
}
if err := s.DoStreaming(req, bodyBuffer, v); err != nil {
return err
}
return nil
}
// CallMultipart is the Backend.CallMultipart implementation for invoking Stripe APIs.
func (s *BackendImplementation) CallMultipart(method, path, key, boundary string, body *bytes.Buffer, params *Params, v LastResponseSetter) error {
contentType := "multipart/form-data; boundary=" + boundary
req, err := s.NewRequest(method, path, key, contentType, params)
if err != nil {
return err
}
if err := s.Do(req, body, v); err != nil {
return err
}
return nil
}
// CallRaw is the implementation for invoking Stripe APIs internally without a backend.
func (s *BackendImplementation) CallRaw(method, path, key string, form *form.Values, params *Params, v LastResponseSetter) error {
var body string
if form != nil && !form.Empty() {
body = form.Encode()
// On `GET`, move the payload into the URL
if method == http.MethodGet {
path += "?" + body
body = ""
}
}
bodyBuffer := bytes.NewBufferString(body)
req, err := s.NewRequest(method, path, key, "application/x-www-form-urlencoded", params)
if err != nil {
return err
}
if err := s.Do(req, bodyBuffer, v); err != nil {
return err
}
return nil
}
// NewRequest is used by Call to generate an http.Request. It handles encoding
// parameters and attaching the appropriate headers.
func (s *BackendImplementation) NewRequest(method, path, key, contentType string, params *Params) (*http.Request, error) {
if !strings.HasPrefix(path, "/") {
path = "/" + path
}
path = s.URL + path
// Body is set later by `Do`.
req, err := http.NewRequest(method, path, nil)
if err != nil {
s.LeveledLogger.Errorf("Cannot create Stripe request: %v", err)
return nil, err
}
authorization := "Bearer " + key
req.Header.Add("Authorization", authorization)
req.Header.Add("Content-Type", contentType)
req.Header.Add("Stripe-Version", APIVersion)
req.Header.Add("User-Agent", encodedUserAgent)
req.Header.Add("X-Stripe-Client-User-Agent", encodedStripeUserAgent)
if params != nil {
if params.Context != nil {
req = req.WithContext(params.Context)
}
if params.IdempotencyKey != nil {
idempotencyKey := strings.TrimSpace(*params.IdempotencyKey)
if len(idempotencyKey) > 255 {
return nil, errors.New("cannot use an idempotency key longer than 255 characters")
}
req.Header.Add("Idempotency-Key", idempotencyKey)
} else if isHTTPWriteMethod(method) {
req.Header.Add("Idempotency-Key", NewIdempotencyKey())
}
if params.StripeAccount != nil {
req.Header.Add("Stripe-Account", strings.TrimSpace(*params.StripeAccount))
}
for k, v := range params.Headers {
for _, line := range v {
// Use Set to override the default value possibly set before
req.Header.Set(k, line)
}
}
}
return req, nil
}
func (s *BackendImplementation) maybeSetTelemetryHeader(req *http.Request) {
if s.enableTelemetry {
select {
case metrics := <-s.requestMetricsBuffer:
metricsJSON, err := json.Marshal(&requestTelemetry{LastRequestMetrics: metrics})
if err == nil {
req.Header.Set("X-Stripe-Client-Telemetry", string(metricsJSON))
} else {
s.LeveledLogger.Warnf("Unable to encode client telemetry: %v", err)
}
default:
// There are no metrics available, so don't send any.
// This default case needs to be here to prevent Do from blocking on an
// empty requestMetricsBuffer.
}
}
}
func (s *BackendImplementation) maybeEnqueueTelemetryMetrics(res *http.Response, requestDuration time.Duration) {
if s.enableTelemetry && res != nil {
reqID := res.Header.Get("Request-Id")
if len(reqID) > 0 {
metrics := requestMetrics{
RequestDurationMS: int(requestDuration / time.Millisecond),
RequestID: reqID,
}
// If the metrics buffer is full, discard the new metrics. Otherwise, add
// them to the buffer.
select {
case s.requestMetricsBuffer <- metrics:
default:
}
}
}
}
func resetBodyReader(body *bytes.Buffer, req *http.Request) {
// This might look a little strange, but we set the request's body
// outside of `NewRequest` so that we can get a fresh version every
// time.
//
// The background is that back in the era of old style HTTP, it was
// safe to reuse `Request` objects, but with the addition of HTTP/2,
// it's now only sometimes safe. Reusing a `Request` with a body will
// break.
//
// See some details here:
//
// https://github.com/golang/go/issues/19653#issuecomment-341539160
//
// And our original bug report here:
//
// https://github.com/stripe/stripe-go/issues/642
//
// To workaround the problem, we put a fresh `Body` onto the `Request`
// every time we execute it, and this seems to empirically resolve the
// problem.
if body != nil {
// We can safely reuse the same buffer that we used to encode our body,
// but return a new reader to it everytime so that each read is from
// the beginning.
reader := bytes.NewReader(body.Bytes())
req.Body = nopReadCloser{reader}
// And also add the same thing to `Request.GetBody`, which allows
// `net/http` to get a new body in cases like a redirect. This is
// usually not used, but it doesn't hurt to set it in case it's
// needed. See:
//
// https://github.com/stripe/stripe-go/issues/710
//
req.GetBody = func() (io.ReadCloser, error) {
reader := bytes.NewReader(body.Bytes())
return nopReadCloser{reader}, nil
}
}
}
// requestWithRetriesAndTelemetry uses s.HTTPClient to make an HTTP request,
// and handles retries, telemetry, and emitting log statements. It attempts to
// avoid processing the *result* of the HTTP request. It receives a
// "handleResponse" func from the caller, and it defers to that to determine
// whether the request was a failure or success, and to convert the
// response/error into the appropriate type of error or an appropriate result
// type.
func (s *BackendImplementation) requestWithRetriesAndTelemetry(
req *http.Request,
body *bytes.Buffer,
handleResponse func(*http.Response, error) (interface{}, error),
) (*http.Response, interface{}, error) {
s.LeveledLogger.Infof("Requesting %v %v%v", req.Method, req.URL.Host, req.URL.Path)
s.maybeSetTelemetryHeader(req)
var resp *http.Response
var err error
var requestDuration time.Duration
var result interface{}
for retry := 0; ; {
start := time.Now()
resetBodyReader(body, req)
resp, err = s.HTTPClient.Do(req)
requestDuration = time.Since(start)
s.LeveledLogger.Infof("Request completed in %v (retry: %v)", requestDuration, retry)
result, err = handleResponse(resp, err)
// If the response was okay, or an error that shouldn't be retried,
// we're done, and it's safe to leave the retry loop.
shouldRetry, noRetryReason := s.shouldRetry(err, req, resp, retry)
if !shouldRetry {
s.LeveledLogger.Infof("Not retrying request: %v", noRetryReason)
break
}
sleepDuration := s.sleepTime(retry)
retry++
s.LeveledLogger.Warnf("Initiating retry %v for request %v %v%v after sleeping %v",
retry, req.Method, req.URL.Host, req.URL.Path, sleepDuration)
time.Sleep(sleepDuration)
}
s.maybeEnqueueTelemetryMetrics(resp, requestDuration)
if err != nil {
return nil, nil, err
}
return resp, result, nil
}
func (s *BackendImplementation) logError(statusCode int, err error) {
if stripeErr, ok := err.(*Error); ok {
// The Stripe API makes a distinction between errors that were
// caused by invalid parameters or something else versus those
// that occurred *despite* valid parameters, the latter coming
// back with status 402.
//
// On a 402, log to info so as to not make an integration's log
// noisy with error messages that they don't have much control
// over.
//
// Note I use the constant 402 instead of an `http.Status*`
// constant because technically 402 is "Payment required". The
// Stripe API doesn't comply to the letter of the specification
// and uses it in a broader sense.
if statusCode == 402 {
s.LeveledLogger.Infof("User-compelled request error from Stripe (status %v): %v",
statusCode, stripeErr.redact())
} else {
s.LeveledLogger.Errorf("Request error from Stripe (status %v): %v",
statusCode, stripeErr.redact())
}
} else {
s.LeveledLogger.Errorf("Error decoding error from Stripe: %v", err)
}
}
// DoStreaming is used by CallStreaming to execute an API request. It uses the
// backend's HTTP client to execure the request. In successful cases, it sets
// a StreamingLastResponse onto v, but in unsuccessful cases handles unmarshaling
// errors returned by the API.
func (s *BackendImplementation) DoStreaming(req *http.Request, body *bytes.Buffer, v StreamingLastResponseSetter) error {
handleResponse := func(res *http.Response, err error) (interface{}, error) {
// Some sort of connection error
if err != nil {
s.LeveledLogger.Errorf("Request failed with error: %v", err)
return res.Body, err
}
// Successful response, return the body ReadCloser
if res.StatusCode < 400 {
return res.Body, err
}
// Failure: try and parse the json of the response
// when logging the error
var resBody []byte
resBody, err = ioutil.ReadAll(res.Body)
res.Body.Close()
if err == nil {
err = s.ResponseToError(res, resBody)
} else {
s.logError(res.StatusCode, err)
}
return res.Body, err
}
resp, result, err := s.requestWithRetriesAndTelemetry(req, body, handleResponse)
if err != nil {
return err
}
v.SetLastResponse(newStreamingAPIResponse(resp, result.(io.ReadCloser)))
return nil
}
// Do is used by Call to execute an API request and parse the response. It uses
// the backend's HTTP client to execute the request and unmarshals the response
// into v. It also handles unmarshaling errors returned by the API.
func (s *BackendImplementation) Do(req *http.Request, body *bytes.Buffer, v LastResponseSetter) error {
handleResponse := func(res *http.Response, err error) (interface{}, error) {
var resBody []byte
if err == nil {
resBody, err = ioutil.ReadAll(res.Body)
res.Body.Close()
}
if err != nil {
s.LeveledLogger.Errorf("Request failed with error: %v", err)
} else if res.StatusCode >= 400 {
err = s.ResponseToError(res, resBody)
s.logError(res.StatusCode, err)
}
return resBody, err
}
res, result, err := s.requestWithRetriesAndTelemetry(req, body, handleResponse)
if err != nil {
return err
}
resBody := result.([]byte)
s.LeveledLogger.Debugf("Response: %s", string(resBody))
err = s.UnmarshalJSONVerbose(res.StatusCode, resBody, v)
v.SetLastResponse(newAPIResponse(res, resBody))
return err
}
// ResponseToError converts a stripe response to an Error.
func (s *BackendImplementation) ResponseToError(res *http.Response, resBody []byte) error {
var raw rawError
if s.Type == ConnectBackend {
// If this is an OAuth request, deserialize as Error because OAuth errors
// are a different shape from the standard API errors.
var topLevelError Error
if err := s.UnmarshalJSONVerbose(res.StatusCode, resBody, &topLevelError); err != nil {
return err
}
raw.Error = &topLevelError
} else {
if err := s.UnmarshalJSONVerbose(res.StatusCode, resBody, &raw); err != nil {
return err
}
}
// no error in resBody
if raw.Error == nil {
err := errors.New(string(resBody))
return err
}
raw.Error.HTTPStatusCode = res.StatusCode
raw.Error.RequestID = res.Header.Get("Request-Id")
var typedError error
switch raw.Error.Type {
case ErrorTypeAPI:
typedError = &APIError{stripeErr: raw.Error}
case ErrorTypeAPIConnection:
typedError = &APIConnectionError{stripeErr: raw.Error}
case ErrorTypeAuthentication:
typedError = &AuthenticationError{stripeErr: raw.Error}
case ErrorTypeCard:
cardErr := &CardError{stripeErr: raw.Error}
// `DeclineCode` was traditionally only available on `CardError`, but
// we ended up moving it to the top-level error as well. However, keep
// it on `CardError` for backwards compatibility.
if raw.Error.DeclineCode != "" {
cardErr.DeclineCode = raw.Error.DeclineCode
}
typedError = cardErr
case ErrorTypeIdempotency:
typedError = &IdempotencyError{stripeErr: raw.Error}
case ErrorTypeInvalidRequest:
typedError = &InvalidRequestError{stripeErr: raw.Error}
case ErrorTypePermission:
typedError = &PermissionError{stripeErr: raw.Error}
case ErrorTypeRateLimit:
typedError = &RateLimitError{stripeErr: raw.Error}
}
raw.Error.Err = typedError
raw.Error.SetLastResponse(newAPIResponse(res, resBody))
return raw.Error
}
// SetMaxNetworkRetries sets max number of retries on failed requests
//
// This function is deprecated. Please use GetBackendWithConfig instead.
func (s *BackendImplementation) SetMaxNetworkRetries(maxNetworkRetries int64) {
s.MaxNetworkRetries = maxNetworkRetries
}
// SetNetworkRetriesSleep allows the normal sleep between network retries to be
// enabled or disabled.
//
// This function is available for internal testing only and should never be
// used in production.
func (s *BackendImplementation) SetNetworkRetriesSleep(sleep bool) {
s.networkRetriesSleep = sleep
}
// UnmarshalJSONVerbose unmarshals JSON, but in case of a failure logs and
// produces a more descriptive error.
func (s *BackendImplementation) UnmarshalJSONVerbose(statusCode int, body []byte, v interface{}) error {
err := json.Unmarshal(body, v)
if err != nil {
// If we got invalid JSON back then something totally unexpected is
// happening (caused by a bug on the server side). Put a sample of the
// response body into the error message so we can get a better feel for
// what the problem was.
bodySample := string(body)
if len(bodySample) > 500 {
bodySample = bodySample[0:500] + " ..."
}
// Make sure a multi-line response ends up all on one line
bodySample = strings.Replace(bodySample, "\n", "\\n", -1)
newErr := fmt.Errorf("Couldn't deserialize JSON (response status: %v, body sample: '%s'): %v",
statusCode, bodySample, err)
s.LeveledLogger.Errorf("%s", newErr.Error())
return newErr
}
return nil
}
// Regular expressions used to match a few error types that we know we don't
// want to retry. Unfortunately these errors aren't typed so we match on the
// error's message.
var (
redirectsErrorRE = regexp.MustCompile(`stopped after \d+ redirects\z`)
schemeErrorRE = regexp.MustCompile(`unsupported protocol scheme`)
)
// Checks if an error is a problem that we should retry on. This includes both
// socket errors that may represent an intermittent problem and some special
// HTTP statuses.
//
// Returns a boolean indicating whether a client should retry. If false, a
// second string parameter is also returned with a short message indicating why
// no retry should occur. This can be used for logging/informational purposes.
func (s *BackendImplementation) shouldRetry(err error, req *http.Request, resp *http.Response, numRetries int) (bool, string) {
if numRetries >= int(s.MaxNetworkRetries) {
return false, "max retries exceeded"
}
stripeErr, _ := err.(*Error)
// Don't retry if the context was was canceled or its deadline was
// exceeded.
if req.Context() != nil && req.Context().Err() != nil {
switch req.Context().Err() {
case context.Canceled:
return false, "context canceled"
case context.DeadlineExceeded:
return false, "context deadline exceeded"
default:
return false, fmt.Sprintf("unknown context error: %v", req.Context().Err())
}
}
// We retry most errors that come out of HTTP requests except for a curated
// list that we know not to be retryable. This list is probably not
// exhaustive, so it'd be okay to add new errors to it. It'd also be okay to
// flip this to an inverted strategy of retrying only errors that we know
// to be retryable in a future refactor, if a good methodology is found for
// identifying that full set of errors.
if stripeErr == nil && err != nil {
if urlErr, ok := err.(*url.Error); ok {
// Don't retry too many redirects.
if redirectsErrorRE.MatchString(urlErr.Error()) {
return false, urlErr.Error()
}
// Don't retry invalid protocol scheme.
if schemeErrorRE.MatchString(urlErr.Error()) {
return false, urlErr.Error()
}
// Don't retry TLS certificate validation problems.
if _, ok := urlErr.Err.(x509.UnknownAuthorityError); ok {
return false, urlErr.Error()
}
}
// Do retry every other type of non-Stripe error.
return true, ""
}
// The API may ask us not to retry (e.g. if doing so would be a no-op), or
// advise us to retry (e.g. in cases of lock timeouts). Defer to those
// instructions if given.
if resp.Header.Get("Stripe-Should-Retry") == "false" {
return false, "`Stripe-Should-Retry` header returned `false`"
}
if resp.Header.Get("Stripe-Should-Retry") == "true" {
return true, ""
}
// 409 Conflict
if resp.StatusCode == http.StatusConflict {
return true, ""
}
// 429 Too Many Requests
//
// There are a few different problems that can lead to a 429. The most
// common is rate limiting, on which we *don't* want to retry because
// that'd likely contribute to more contention problems. However, some 429s
// are lock timeouts, which is when a request conflicted with another
// request or an internal process on some particular object. These 429s are
// safe to retry.
if resp.StatusCode == http.StatusTooManyRequests {
if stripeErr != nil && stripeErr.Code == ErrorCodeLockTimeout {
return true, ""
}
}
// 500 Internal Server Error
//
// We only bother retrying these for non-POST requests. POSTs end up being
// cached by the idempotency layer so there's no purpose in retrying them.
if resp.StatusCode >= http.StatusInternalServerError && req.Method != http.MethodPost {
return true, ""
}
// 503 Service Unavailable
if resp.StatusCode == http.StatusServiceUnavailable {
return true, ""
}
return false, "response not known to be safe for retry"
}
// sleepTime calculates sleeping/delay time in milliseconds between failure and a new one request.
func (s *BackendImplementation) sleepTime(numRetries int) time.Duration {
// We disable sleeping in some cases for tests.
if !s.networkRetriesSleep {
return 0 * time.Second
}
// Apply exponential backoff with minNetworkRetriesDelay on the
// number of num_retries so far as inputs.
delay := minNetworkRetriesDelay + minNetworkRetriesDelay*time.Duration(numRetries*numRetries)
// Do not allow the number to exceed maxNetworkRetriesDelay.
if delay > maxNetworkRetriesDelay {
delay = maxNetworkRetriesDelay
}
// Apply some jitter by randomizing the value in the range of 75%-100%.
jitter := rand.Int63n(int64(delay / 4))
delay -= time.Duration(jitter)
// But never sleep less than the base sleep seconds.
if delay < minNetworkRetriesDelay {
delay = minNetworkRetriesDelay
}
return delay
}
// Backends are the currently supported endpoints.
type Backends struct {
API, Connect, Uploads Backend
mu sync.RWMutex
}
// LastResponseSetter defines a type that contains an HTTP response from a Stripe
// API endpoint.
type LastResponseSetter interface {
SetLastResponse(response *APIResponse)
}
// StreamingLastResponseSetter defines a type that contains an HTTP response from a Stripe
// API endpoint.
type StreamingLastResponseSetter interface {
SetLastResponse(response *StreamingAPIResponse)
}
// SupportedBackend is an enumeration of supported Stripe endpoints.
// Currently supported values are "api" and "uploads".
type SupportedBackend string
//
// Public functions
//
// Bool returns a pointer to the bool value passed in.
func Bool(v bool) *bool {
return &v
}
// BoolValue returns the value of the bool pointer passed in or
// false if the pointer is nil.
func BoolValue(v *bool) bool {
if v != nil {
return *v
}
return false
}
// BoolSlice returns a slice of bool pointers given a slice of bools.
func BoolSlice(v []bool) []*bool {
out := make([]*bool, len(v))
for i := range v {
out[i] = &v[i]
}
return out
}
// Float64 returns a pointer to the float64 value passed in.
func Float64(v float64) *float64 {
return &v
}
// Float64Value returns the value of the float64 pointer passed in or
// 0 if the pointer is nil.
func Float64Value(v *float64) float64 {
if v != nil {
return *v
}
return 0
}
// Float64Slice returns a slice of float64 pointers given a slice of float64s.
func Float64Slice(v []float64) []*float64 {
out := make([]*float64, len(v))
for i := range v {
out[i] = &v[i]
}
return out
}
// FormatURLPath takes a format string (of the kind used in the fmt package)
// representing a URL path with a number of parameters that belong in the path
// and returns a formatted string.
//
// This is mostly a pass through to Sprintf. It exists to make it
// it impossible to accidentally provide a parameter type that would be
// formatted improperly; for example, a string pointer instead of a string.
//
// It also URL-escapes every given parameter. This usually isn't necessary for
// a standard Stripe ID, but is needed in places where user-provided IDs are
// allowed, like in coupons or plans. We apply it broadly for extra safety.
func FormatURLPath(format string, params ...string) string {
// Convert parameters to interface{} and URL-escape them
untypedParams := make([]interface{}, len(params))
for i, param := range params {
untypedParams[i] = interface{}(url.QueryEscape(param))
}
return fmt.Sprintf(format, untypedParams...)
}
// GetBackend returns one of the library's supported backends based off of the
// given argument.
//