add wrapper files

Author: abhinav-codealchemist

HTTPWrapper.go

@@ -0,0 +1,239 @@
+package http_wrapper
+
+import (
+	"bytes"
+	"context"
+	"encoding/json"
+	"fmt"
+	error "github.com/abhinav-codealchemist/custom-error-go"
+	"github.com/ajg/form"
+	"io"
+	"io/ioutil"
+	"net/http"
+	"net/url"
+	"strings"
+	"time"
+)
+
+const (
+	NOT_ASSIGNED     = ""
+	DEFAULT_TIMEOUT                           = 20 * time.Second
+	AUTHORIZATION_TOKEN_PREFIX                = "Token"
+	CONTENT_TYPE_APP_JSON         ContentType = "application/json"
+	CONTENT_TYPE_FORM_URL_ENCODED ContentType = "application/x-www-form-urlencoded"
+)
+
+type ContentType string
+
+type HttpRequestParams struct {
+	endpoint      string            // the api endpoint
+	method        string            // the http request method, get/post
+	body          interface{}       // the request body, should be json serializable
+	queryParams   map[string]string // the request query url params
+	authUserName  string            // basic auth user name
+	authPassword  string            // basic auth password
+	basicAuth     string            // basic auth
+	authToken     string            // to be used in cases where token based authentication is required
+	host          string            // to specify host header
+	customHeaders map[string]string // to set any custom headers, if any
+	contentType   ContentType       // to set content type
+	timeout       time.Duration     // to set custom request timeout if needed, default is 20 secs
+}
+
+func NewHttpRequestParams(endpoint string, method string) *HttpRequestParams {
+	return &HttpRequestParams{endpoint: endpoint, method: method, body: nil, queryParams: make(map[string]string, 0), customHeaders: make(map[string]string, 0), contentType: CONTENT_TYPE_APP_JSON}
+}
+
+func (a *HttpRequestParams) SetAuthPassword(authPassword string) {
+	a.authPassword = authPassword
+}
+
+func (a *HttpRequestParams) SetAuthUserName(authUserName string) {
+	a.authUserName = authUserName
+}
+
+func (a *HttpRequestParams) SetAuth(username string, password string) {
+	a.authPassword = password
+	a.authUserName = username
+}
+
+func (a *HttpRequestParams) SetAuthToken(authToken string) {
+	a.authToken = authToken
+}
+
+func (a *HttpRequestParams) SetBody(requestBody interface{}) {
+	a.body = requestBody
+}
+
+func (a *HttpRequestParams) SetQueryParams(requestQueryParams map[string]string) {
+	a.queryParams = requestQueryParams
+}
+
+func (a *HttpRequestParams) AddQueryParam(key, val string) {
+	if a.queryParams == nil {
+		a.queryParams = make(map[string]string, 0)
+	}
+	a.queryParams[key] = val
+}
+
+func (a *HttpRequestParams) AddHeader(key, val string) {
+	if a.customHeaders == nil {
+		a.customHeaders = make(map[string]string, 0)
+	}
+	a.customHeaders[key] = val
+}
+
+func (a *HttpRequestParams) Host() string {
+	return a.host
+}
+
+func (a *HttpRequestParams) SetHost(host string) {
+	a.host = host
+}
+
+func (a *HttpRequestParams) SetContentType(contentType ContentType) {
+	a.contentType = contentType
+}
+
+func (a *HttpRequestParams) BasicAuth() string {
+	return a.basicAuth
+}
+
+func (a *HttpRequestParams) SetBasicAuth(basicAuth string) {
+	a.basicAuth = basicAuth
+}
+
+func (a *HttpRequestParams) SetTimeout(timeout time.Duration) {
+	a.timeout = timeout
+}
+
+func MakeApiCallWithRetries(ctx context.Context, request *HttpRequestParams, responseAddr interface{}, retriesCount int) (customError error.CustomError) {
+	for i := 0; i <= retriesCount; i++ {
+		customError = MakeApiCall(ctx, request, responseAddr)
+		if customError.Exists() && (customError.ErrorCode() == error.API_REQUEST_ERROR || customError.ErrorCode() == error.API_REQUEST_STATUS_ERROR) {
+			continue
+		} else {
+			return
+		}
+	}
+	return
+}
+
+// responseAddr is the the address of the struct to put the api response
+func MakeApiCall(ctx context.Context, request *HttpRequestParams, responseAddr interface{}) (customError error.CustomError) {
+	body, customError := MakeApiCallWithRawResponse(ctx, request)
+	if customError.Exists() {
+		return
+	}
+	err := json.Unmarshal(body, &responseAddr)
+	if err != nil {
+		customError = error.NewCustomError(error.JSON_DESERIALIZATION_ERROR, err.Error()).
+			WithParam("response", string(body)).
+			WithParam("request", fmt.Sprintf("%+v", request))
+		customError.Log()
+	}
+	return customError
+}
+
+func MakeApiCallWithRawResponse(ctx context.Context, request *HttpRequestParams) (body []byte, customError error.CustomError) {
+	var requestBuffer io.Reader
+	if request.body != nil {
+		switch request.contentType {
+		case CONTENT_TYPE_FORM_URL_ENCODED:
+			values, err := form.EncodeToValues(request.body)
+			if err != nil {
+				customError = error.NewCustomError(error.FORM_SERIALIZATION_ERROR, fmt.Sprintf("request: %+v, error: %s", request.body, err.Error()))
+				customError.Log()
+				return
+			}
+			requestBuffer = strings.NewReader(values.Encode())
+		case CONTENT_TYPE_APP_JSON:
+			requestJSONForm, err := json.Marshal(request.body)
+			if err != nil {
+				customError = error.NewCustomError(error.JSON_SERIALIZATION_ERROR, fmt.Sprintf("request: %+v, error: %s", request.body, err.Error()))
+				customError.Log()
+				return
+			}
+			requestBuffer = bytes.NewBuffer(requestJSONForm)
+		}
+	} else {
+		requestBuffer = nil
+	}
+
+	url, err := url.Parse(request.endpoint)
+	if err != nil {
+		customError = error.NewCustomError(error.API_URL_PARSING_ERROR, fmt.Sprintf("url: %s; error: %s", request.endpoint, err.Error()))
+		customError.Log()
+		return
+	}
+
+	httpRequest, err := http.NewRequest(request.method, url.String(), requestBuffer)
+	if request.queryParams != nil {
+		q := httpRequest.URL.Query()
+		for k, v := range request.queryParams {
+			q.Add(k, v)
+		}
+		httpRequest.URL.RawQuery = q.Encode()
+	}
+
+	if err != nil {
+		customError = error.NewCustomError(error.API_REQUEST_CREATION_ERROR, fmt.Sprintf("url: %s; error: %s", url.String(), err.Error()))
+		customError.Log()
+		return
+	}
+
+	client := &http.Client{Timeout: DEFAULT_TIMEOUT}
+	if request.timeout != time.Duration(0) {
+		client.Timeout = request.timeout
+	}
+
+	httpRequest.Header.Set("Content-Type", string(request.contentType))
+
+	if request.authToken != NOT_ASSIGNED {
+		httpRequest.Header.Set("Authorization", fmt.Sprintf("%s %s", AUTHORIZATION_TOKEN_PREFIX, request.authToken))
+	}
+
+	if request.host != NOT_ASSIGNED {
+		httpRequest.Host = request.host
+	}
+
+	if request.authUserName != NOT_ASSIGNED && request.authPassword != NOT_ASSIGNED {
+		httpRequest.SetBasicAuth(request.authUserName, request.authPassword) // move to config
+	}
+
+	if request.basicAuth != NOT_ASSIGNED {
+		httpRequest.Header.Set("Authorization", "Basic "+request.basicAuth)
+	}
+
+	if request.customHeaders != nil {
+		for k, v := range request.customHeaders {
+			httpRequest.Header.Add(k, v)
+		}
+	}
+
+	response, httpErr := client.Do(httpRequest)
+
+	if httpErr != nil {
+		customError = error.NewCustomError(error.API_REQUEST_ERROR, fmt.Sprintf("url: %s; error: %s", url.String(), httpErr.Error())).
+			WithParam("request", fmt.Sprintf("%+v", request))
+		customError.Log()
+		return
+	}
+
+	defer response.Body.Close()
+
+	if response.StatusCode != http.StatusOK {
+		body, _ = ioutil.ReadAll(response.Body)
+		responseMap := map[string]string{}
+		err = json.Unmarshal(body, &responseMap)
+		customError = error.NewCustomError(error.API_REQUEST_STATUS_ERROR, fmt.Sprintf("url: %s; status code: %d; status: %s; body: %+v", url.String(), response.StatusCode, response.Status, responseMap)).
+			WithParam("response", string(body)).
+			WithParam("request", fmt.Sprintf("%+v", request))
+		customError.WithParam("response-json", string(body))
+		customError.Log()
+		return
+	}
+
+	body, _ = ioutil.ReadAll(response.Body)
+	return
+}

go.mod

@@ -0,0 +1,8 @@
+module github.com/abhinav-codealchemist/http-wrapper-go
+
+go 1.16
+
+require (
+	github.com/abhinav-codealchemist/custom-error-go v0.0.0-20210502113441-01e78117fd9d
+	github.com/ajg/form v1.5.1
+)

go.sum

@@ -0,0 +1,2 @@
+github.com/abhinav-codealchemist/custom-error-go v0.0.0-20210502113441-01e78117fd9d/go.mod h1:80nTTGlA2EzKuRRm2yTGRTlATo0o4BIUhV3LoJdh9aM=
+github.com/ajg/form v1.5.1/go.mod h1:uL1WgH+h2mgNtvBq0339dVnzXdBETtL2LeUXaIv25UY=