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multi.go
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multi.go
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// Code generated by zanzibar
// @generated
// Copyright (c) 2018 Uber Technologies, Inc.
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.
package multiclient
import (
"context"
"fmt"
"time"
"github.com/afex/hystrix-go/hystrix"
zanzibar "github.com/uber/zanzibar/runtime"
"github.com/uber/zanzibar/runtime/jsonwrapper"
module "github.com/uber/zanzibar/examples/example-gateway/build/clients/multi/module"
)
// CircuitBreakerConfigKey is key value for qps level to circuit breaker parameters mapping
const CircuitBreakerConfigKey = "circuitbreaking-configurations"
// Client defines multi client interface.
type Client interface {
HTTPClient() *zanzibar.HTTPClient
HelloA(
ctx context.Context,
reqHeaders map[string]string,
timeoutAndRetryCfg *zanzibar.TimeoutAndRetryOptions,
) (context.Context, string, map[string]string, error)
HelloB(
ctx context.Context,
reqHeaders map[string]string,
timeoutAndRetryCfg *zanzibar.TimeoutAndRetryOptions,
) (context.Context, string, map[string]string, error)
}
// multiClient is the http client.
type multiClient struct {
clientID string
httpClient *zanzibar.HTTPClient
jsonWrapper jsonwrapper.JSONWrapper
circuitBreakerDisabled bool
requestUUIDHeaderKey string
requestProcedureHeaderKey string
}
// NewClient returns a new http client.
func NewClient(deps *module.Dependencies) Client {
ip := deps.Default.Config.MustGetString("clients.multi.ip")
port := deps.Default.Config.MustGetInt("clients.multi.port")
baseURL := fmt.Sprintf("http://%s:%d", ip, port)
timeoutVal := int(deps.Default.Config.MustGetInt("clients.multi.timeout"))
timeout := time.Millisecond * time.Duration(
timeoutVal,
)
defaultHeaders := make(map[string]string)
if deps.Default.Config.ContainsKey("http.defaultHeaders") {
deps.Default.Config.MustGetStruct("http.defaultHeaders", &defaultHeaders)
}
if deps.Default.Config.ContainsKey("clients.multi.defaultHeaders") {
deps.Default.Config.MustGetStruct("clients.multi.defaultHeaders", &defaultHeaders)
}
var requestUUIDHeaderKey string
if deps.Default.Config.ContainsKey("http.clients.requestUUIDHeaderKey") {
requestUUIDHeaderKey = deps.Default.Config.MustGetString("http.clients.requestUUIDHeaderKey")
}
var requestProcedureHeaderKey string
if deps.Default.Config.ContainsKey("http.clients.requestProcedureHeaderKey") {
requestProcedureHeaderKey = deps.Default.Config.MustGetString("http.clients.requestProcedureHeaderKey")
}
followRedirect := true
if deps.Default.Config.ContainsKey("clients.multi.followRedirect") {
followRedirect = deps.Default.Config.MustGetBoolean("clients.multi.followRedirect")
}
methodNames := map[string]string{
"HelloA": "ServiceABack::helloA",
"HelloB": "ServiceBBack::helloB",
}
// circuitBreakerDisabled sets whether circuit-breaker should be disabled
circuitBreakerDisabled := false
if deps.Default.Config.ContainsKey("clients.multi.circuitBreakerDisabled") {
circuitBreakerDisabled = deps.Default.Config.MustGetBoolean("clients.multi.circuitBreakerDisabled")
}
//get mapping of client method and it's timeout
//if mapping is not provided, use client's timeout for all methods
clientMethodTimeoutMapping := make(map[string]int64)
if deps.Default.Config.ContainsKey("clients.multi.methodTimeoutMapping") {
deps.Default.Config.MustGetStruct("clients.multi.methodTimeoutMapping", &clientMethodTimeoutMapping)
} else {
//override the client overall-timeout with the client's method level timeout
for methodName := range methodNames {
clientMethodTimeoutMapping[methodName] = int64(timeoutVal)
}
}
qpsLevels := map[string]string{
"multi-HelloA": "default",
"multi-HelloB": "default",
}
if !circuitBreakerDisabled {
for methodName, methodTimeout := range clientMethodTimeoutMapping {
circuitBreakerName := "multi" + "-" + methodName
qpsLevel := "default"
if level, ok := qpsLevels[circuitBreakerName]; ok {
qpsLevel = level
}
configureCircuitBreaker(deps, int(methodTimeout), circuitBreakerName, qpsLevel)
}
}
return &multiClient{
clientID: "multi",
httpClient: zanzibar.NewHTTPClientContext(
deps.Default.ContextLogger, deps.Default.ContextMetrics, deps.Default.JSONWrapper,
"multi",
methodNames,
baseURL,
defaultHeaders,
timeout,
followRedirect,
),
circuitBreakerDisabled: circuitBreakerDisabled,
requestUUIDHeaderKey: requestUUIDHeaderKey,
requestProcedureHeaderKey: requestProcedureHeaderKey,
}
}
// CircuitBreakerConfig is used for storing the circuit breaker parameters for each qps level
type CircuitBreakerConfig struct {
Parameters map[string]map[string]int
}
func configureCircuitBreaker(deps *module.Dependencies, timeoutVal int, circuitBreakerName string, qpsLevel string) {
// sleepWindowInMilliseconds sets the amount of time, after tripping the circuit,
// to reject requests before allowing attempts again to determine if the circuit should again be closed
sleepWindowInMilliseconds := 5000
// maxConcurrentRequests sets how many requests can be run at the same time, beyond which requests are rejected
maxConcurrentRequests := 20
// errorPercentThreshold sets the error percentage at or above which the circuit should trip open
errorPercentThreshold := 20
// requestVolumeThreshold sets a minimum number of requests that will trip the circuit in a rolling window of 10s
// For example, if the value is 20, then if only 19 requests are received in the rolling window of 10 seconds
// the circuit will not trip open even if all 19 failed.
requestVolumeThreshold := 20
// parses circuit breaker configurations
if deps.Default.Config.ContainsKey(CircuitBreakerConfigKey) {
var config CircuitBreakerConfig
deps.Default.Config.MustGetStruct(CircuitBreakerConfigKey, &config)
parameters := config.Parameters
// first checks if level exists in configurations then assigns parameters
// if "default" qps level assigns default parameters from circuit breaker configurations
if settings, ok := parameters[qpsLevel]; ok {
if sleep, ok := settings["sleepWindowInMilliseconds"]; ok {
sleepWindowInMilliseconds = sleep
}
if max, ok := settings["maxConcurrentRequests"]; ok {
maxConcurrentRequests = max
}
if errorPercent, ok := settings["errorPercentThreshold"]; ok {
errorPercentThreshold = errorPercent
}
if reqVolThreshold, ok := settings["requestVolumeThreshold"]; ok {
requestVolumeThreshold = reqVolThreshold
}
}
}
// client settings override parameters
if deps.Default.Config.ContainsKey("clients.multi.sleepWindowInMilliseconds") {
sleepWindowInMilliseconds = int(deps.Default.Config.MustGetInt("clients.multi.sleepWindowInMilliseconds"))
}
if deps.Default.Config.ContainsKey("clients.multi.maxConcurrentRequests") {
maxConcurrentRequests = int(deps.Default.Config.MustGetInt("clients.multi.maxConcurrentRequests"))
}
if deps.Default.Config.ContainsKey("clients.multi.errorPercentThreshold") {
errorPercentThreshold = int(deps.Default.Config.MustGetInt("clients.multi.errorPercentThreshold"))
}
if deps.Default.Config.ContainsKey("clients.multi.requestVolumeThreshold") {
requestVolumeThreshold = int(deps.Default.Config.MustGetInt("clients.multi.requestVolumeThreshold"))
}
hystrix.ConfigureCommand(circuitBreakerName, hystrix.CommandConfig{
MaxConcurrentRequests: maxConcurrentRequests,
ErrorPercentThreshold: errorPercentThreshold,
SleepWindow: sleepWindowInMilliseconds,
RequestVolumeThreshold: requestVolumeThreshold,
Timeout: timeoutVal,
})
}
// HTTPClient returns the underlying HTTP client, should only be
// used for internal testing.
func (c *multiClient) HTTPClient() *zanzibar.HTTPClient {
return c.httpClient
}
// HelloA calls "/multi/serviceA_b/hello" endpoint.
func (c *multiClient) HelloA(
ctx context.Context,
headers map[string]string,
timeoutAndRetryCfg *zanzibar.TimeoutAndRetryOptions,
) (context.Context, string, map[string]string, error) {
reqUUID := zanzibar.RequestUUIDFromCtx(ctx)
if headers == nil {
headers = make(map[string]string)
}
if reqUUID != "" {
headers[c.requestUUIDHeaderKey] = reqUUID
}
if c.requestProcedureHeaderKey != "" {
headers[c.requestProcedureHeaderKey] = "ServiceABack::helloA"
}
var defaultRes string
req := zanzibar.NewClientHTTPRequest(ctx, c.clientID, "HelloA", "ServiceABack::helloA", c.httpClient, timeoutAndRetryCfg)
// Generate full URL.
fullURL := c.httpClient.BaseURL + "/multi" + "/serviceA_b" + "/hello"
err := req.WriteJSON("GET", fullURL, headers, nil)
if err != nil {
return ctx, defaultRes, nil, err
}
var res *zanzibar.ClientHTTPResponse
if c.circuitBreakerDisabled {
res, err = req.Do()
} else {
// We want hystrix ckt-breaker to count errors only for system issues
var clientErr error
circuitBreakerName := "multi" + "-" + "HelloA"
err = hystrix.DoC(ctx, circuitBreakerName, func(ctx context.Context) error {
res, clientErr = req.Do()
if res != nil {
// This is not a system error/issue. Downstream responded
return nil
}
return clientErr
}, nil)
if err == nil {
// ckt-breaker was ok, bubble up client error if set
err = clientErr
}
}
if err != nil {
return ctx, defaultRes, nil, err
}
respHeaders := make(map[string]string)
for k := range res.Header {
respHeaders[k] = res.Header.Get(k)
}
defer func() {
respHeaders[zanzibar.ClientResponseDurationKey] = res.Duration.String()
}()
res.CheckOKResponse([]int{200})
switch res.StatusCode {
case 200:
var responseBody string
rawBody, err := res.ReadAll()
if err != nil {
return ctx, defaultRes, respHeaders, err
}
err = res.UnmarshalBody(&responseBody, rawBody)
if err != nil {
return ctx, defaultRes, respHeaders, err
}
return ctx, responseBody, respHeaders, nil
default:
_, err = res.ReadAll()
if err != nil {
return ctx, defaultRes, respHeaders, err
}
}
return ctx, defaultRes, respHeaders, &zanzibar.UnexpectedHTTPError{
StatusCode: res.StatusCode,
RawBody: res.GetRawBody(),
}
}
// HelloB calls "/multi/serviceB_b/hello" endpoint.
func (c *multiClient) HelloB(
ctx context.Context,
headers map[string]string,
timeoutAndRetryCfg *zanzibar.TimeoutAndRetryOptions,
) (context.Context, string, map[string]string, error) {
reqUUID := zanzibar.RequestUUIDFromCtx(ctx)
if headers == nil {
headers = make(map[string]string)
}
if reqUUID != "" {
headers[c.requestUUIDHeaderKey] = reqUUID
}
if c.requestProcedureHeaderKey != "" {
headers[c.requestProcedureHeaderKey] = "ServiceBBack::helloB"
}
var defaultRes string
req := zanzibar.NewClientHTTPRequest(ctx, c.clientID, "HelloB", "ServiceBBack::helloB", c.httpClient, timeoutAndRetryCfg)
// Generate full URL.
fullURL := c.httpClient.BaseURL + "/multi" + "/serviceB_b" + "/hello"
err := req.WriteJSON("GET", fullURL, headers, nil)
if err != nil {
return ctx, defaultRes, nil, err
}
var res *zanzibar.ClientHTTPResponse
if c.circuitBreakerDisabled {
res, err = req.Do()
} else {
// We want hystrix ckt-breaker to count errors only for system issues
var clientErr error
circuitBreakerName := "multi" + "-" + "HelloB"
err = hystrix.DoC(ctx, circuitBreakerName, func(ctx context.Context) error {
res, clientErr = req.Do()
if res != nil {
// This is not a system error/issue. Downstream responded
return nil
}
return clientErr
}, nil)
if err == nil {
// ckt-breaker was ok, bubble up client error if set
err = clientErr
}
}
if err != nil {
return ctx, defaultRes, nil, err
}
respHeaders := make(map[string]string)
for k := range res.Header {
respHeaders[k] = res.Header.Get(k)
}
defer func() {
respHeaders[zanzibar.ClientResponseDurationKey] = res.Duration.String()
}()
res.CheckOKResponse([]int{200})
switch res.StatusCode {
case 200:
var responseBody string
rawBody, err := res.ReadAll()
if err != nil {
return ctx, defaultRes, respHeaders, err
}
err = res.UnmarshalBody(&responseBody, rawBody)
if err != nil {
return ctx, defaultRes, respHeaders, err
}
return ctx, responseBody, respHeaders, nil
default:
_, err = res.ReadAll()
if err != nil {
return ctx, defaultRes, respHeaders, err
}
}
return ctx, defaultRes, respHeaders, &zanzibar.UnexpectedHTTPError{
StatusCode: res.StatusCode,
RawBody: res.GetRawBody(),
}
}