webservice

Go Minimal Webservice Example with Http Request Logging (like tomcat access-log) & Request based logging levels, Test cases and Coverage Reports

Introduction

This is a minimal project replicating Rest APIs with Http Request Logging (like tomcat access-log) & Request based logging levels, Test cases and coverage reports.

Currently using Mux & Regex for routing and using in-memory storage

Here is a table showing sample requests:

Url	Method	Request Body
/users/	GET	-
/users/	POST	{ "FirstName": "John", "LastName": "Zick" }
/users/1	PUT	{ "Id": 1,"FirstName": "John", "LastName": "Wick" }
/users/1	GET	-
/users/1	DELETE	-

Following are the CUrls for available operations:

Post Request

Adds new user in application

curl --request POST \
--url http://localhost:3000/users \
--header 'Content-Type: application/json' \
--data '{
"FirstName": "John",
"LastName": "Zick",
"Debug": true
}'

Get Request

Lists all users registered with application

curl --request GET \
--url http://localhost:3000/users \
--header 'Content-Type: application/json' \
--data '{
"Debug": true
}'

Get By ID

Get single user by id

curl --request GET \
--url http://localhost:3000/users/6 \
--header 'Content-Type: application/json' \
--data '{
"Debug": true
}'

Put Request

Updates existing user in application

curl --request PUT \
--url http://localhost:3000/users/1 \
--header 'Content-Type: application/json' \
--data '{
"Id": 1,
"FirstName": "John",
"LastName": "Wick",
"Debug": true
}'

Delete Request

Deletes user by Id

curl --request DELETE \
--url http://localhost:3000/users/6 \
--header 'Content-Type: application/json' \
--data '{
"Debug": true
}'

Note: To change the logging level to default (info), just remove the "Debug": true from request body from Http Request

Working Explanation

Access Logs

To generate access-logs (can be found in project dir as access_logs.txt), a middleware has been added by handler-function which logs on default (info) level which is held inside helper package as logger.go under accessLogger *zap.SugaredLogger

I have kept the middleware simple, but you can add application-level configurations to make it more efficient.

Application Logs

The application logs (can be found in project dir as logs.txt), I have added defaultLogger *zap.SugaredLogger & debugLogger *zap.SugaredLogger. Both are held inside helper package, callers need to ask for logger by providing http.Request object where it makes the decision by extracting the following information from Request Body:

type Param struct {
Debug bool
}

So the usage from caller perspective will be:

var logger *zap.SugaredLogger = nil

func (controller UserController) ServeHTTP(writer http.ResponseWriter, request *http.Request) {
    logger = helpers.GetLoggerByRequest(request)
    logger.Info("Inside User Controller Entrypoint")
    logger.Debugw("User Controller Entrypoint", "URL.PATH", request.URL.Path, "Method", request.Method)
    .....

Right now, I am holding the logger instance on package level, but I have plan to associate it with some mapping against current user to make it more consistent and support concurrency.

See branch user-based-logging

For file/package based logging, see branch file-based-logging

Brief Introduction on Test Coverage

Test coverage measures the percentage of your code that is executed during tests.

To generate a test coverage report, run the following command:

go test -cover

The output will show the test coverage percentage for each package and an overall summary.

You can save output to file by adding -o flag with desired filename like:

go test -coverprofile coverage.out

To view code coverage results in console.

go tool cover -func="coverage.out"

To view code coverage results in html page, use the following command:

go tool cover -html="coverage.out"

Here coverage.out is cover file generated from previous command.

Executing this command will open the default web browser with visual representation of Code Coverage

Feel free to edit/expand/explore this repository

For feedback and queries, reach me on LinkedIn at here