Install Mysql Specific Version on Ubuntu/Linux using debian package

In this tutorial, we are going to install MySQL version 5.7 using the Debian package(.deb)

Step 1. Add the MySQL Apt Repository

First download the Debian(.deb) package from MySQL Apt Repo. Here we are using the wget to download as below:

wget https://dev.mysql.com/get/mysql-apt-config_0.8.12-1_all.deb

Step 2. Configure the .deb file

sudo dpkg -i mysql-apt-config_0.8.12-1_all.deb

You can see the below prompt screen

If somehow we are unable to see the prompt screen then either dpkg is interrupted or broken. Use the below command to clean the config after that use the previous dpkg command, now we can see the screen

apt-get purge mysql-apt-config

Select the ubuntu bionic option and the second screen will pop up as below. Now select the first option to select the MySQL version

Now select the desired version of MySQL, Here we are selecting the MySQL 5.7

Once selected the desired version of MySQL then select ok to configure.

Now the configure suppose to get successful and we can see the output as below:

Selecting previously unselected package mysql-apt-config.
(Reading database ... 36242 files and directories currently installed.)
Preparing to unpack mysql-apt-config_0.8.12-1_all.deb ...
Unpacking mysql-apt-config (0.8.12-1) ...
Setting up mysql-apt-config (0.8.12-1) ...
Warning: apt-key should not be used in scripts (called from postinst maintainerscript of the package mysql-apt-config)
OK

Step 3. Install the MySQL Server

Now update the MySQL repository

sudo apt-get update

Install the MySQL using the following command:

sudo apt install -f mysql-client=5.7* mysql-community-server=5.7* mysql-server=5.7*

If you chose the latest version of MySQL then no need to specify the package.

Next, the screen will pop up to enter the root password. Enter the password and press ok. After that MySQL is installed and running successfully. Test the MySQL version and MySQL status by using the below command:

mysql --version
sudo systemctl status mysql

Step 4. Secure MySQL Installation

Use the following command to secure MySQL installation:

sudo mysql_secure_installation

Enter your MySQL root password and answer all of the security questions.

Now, log in using the root credential

mysql -u root -p

Step 5. Create a New Mysql User

Before creating new users we need to first log in with the root user as mentioned above. Now, create the user using the following command:

CREATE USER 'username'@'localhost' IDENTIFIED BY 'password';

Here, use your own username and password and localhost as we are working on the same machine.

For example:

CREATE USER 'testuser'@'localhost' IDENTIFIED BY 'testpassword';

If we want to create a user that can be connected from any machine then use the following command

CREATE USER 'username'@'%' IDENTIFIED BY 'password';

Now, let's grant the permission to the newly created user.

GRANT ALL PRIVILEGES ON *.* TO 'testuser'@'localhost';

Here, user have full access to the database with ALL PRIVILEGES and for all the databases as we are using *.*

However, we can grant privileges for specific databases as

GRANT ALL PRIVILEGES ON database_name.* TO 'testuser'@'localhost';

After grant privileges to user, we need to flush the privileges

FLUSH PRIVILEGES;

We can revoke privileges using the following command:

GRANT ALL PRIVILEGES ON *.* TO 'testuser'@'localhost';

Remove User:

DROP USER 'testuser'@'localhost';

Step 6: Some commands for MySQL server:

Stop the MySQL server:

sudo systemctl stop mysql

Start the MySQL server:

sudo systemctl start mysql

Check the status of MySQL server:

sudo systemctl status mysql

Restart MySQL server

sudo systemctl restart mysql

Step 7: Completly remove/uninstall MySQL server

sudo apt-get remove --purge mysql*
sudo apt-get autoremove
sudo apt-get autoclean

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How to use SiftingAppender in Gradle Groovy project

 In this tutorial, we are going to set up the SiftingAppender in our Gradle Groovy project.

Sifting Appender is useful when we want to separate the log files during runtime i.e if we want to separate the log files per thread or per user session basis.

Unfortunately, in the Gradle Groovy project, SiftingAppender is no longer supported since version 1.0.12 as mentioned in Groovy Configuration.

Let's look into the simple example where we are going to configure the SiftingAppender in logback.groovy, where we want to configure the per-user logging mechanism.

import ch.qos.logback.classic.PatternLayout
import ch.qos.logback.classic.sift.MDCBasedDiscriminator
import ch.qos.logback.classic.sift.SiftingAppender

appender("USER_ROLLING", SiftingAppender) {
    discriminator(MDCBasedDiscriminator) {
        key = 'userid'
        defaultValue = 'NONE'
    }
    sift {
        appender("FILE-${userid}", FileAppender) {
            file = "Path-to-log/${userid}.log"
            append = true
            layout(PatternLayout) {
                pattern = "%level %logger - %msg%n"
            }
        }
    }
}
logger("package-to-log",TRACE,['USER_ROLLING'], false)

This is a simple example SiftingAppender configuration; this is derived from logback sifting appender xml configuration.

We are using the Mapped Diagnostic Context for mapping the context user to create a separate file. We can do a similar for the thread as well.

Let's set up the MDC for user, the sample example looks as below.

import groovy.util.logging.Slf4j
import org.slf4j.MDC
@Slf4j
class UserLogging {

    public static void debug(String message, String userid = '') {
        setUserMDC(userid)
        log.debug(message)
    }

    public static void error(String message, String userid = '') {
        setUserMDC(userid)
        log.error(message)
    }

    public static void info(String message, String userid = '') {
        setUserMDC(userid)
        log.info(message)
    }

    public static void setUserMDC(String userid) {
        try {
            if (!userid) {
                MDC.remove("userid")
                return
            }
            MDC.put("userid", userid)
        }catch(e) {
            log.error("Error setting user Mapped Diagnostic Context due to "+e.getMessage())
        }
    }
}

Here, if the userid is available then we are setting the MDC for userid so the log file can be written in a separate file per user. If you want to do with request user do the similar in filter class or the place where it suits.

Now, if we run the application we will get the error as a result the appender doesn't work. So, here we found the solution project that extends Logback Gaffer so that SiftingAppender can be configured in Groovy DSL from this Github repo.

Simply download the jar file for that project and add it to the application.

For the Gradle project create a libs directory under the project directory and load and compile from build.gradle file.

Under build.gradle under dependencies{} section:

compile fileTree(dir: 'libs', include: '*.jar')

If we run the application it suppose to work. The log file will be created on the respective file path.

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Install OpenCv in Linux/Ubuntu for Java Application.

Table Of Contents

• - Introduction
• - Download OpenCV
  
• - Build OpenCV
• - Run Sample Example

1. Introduction:

In this blog post, we are going to install and set up OpenCV in ubuntu os for the java applications. OpenCV is a widely used great computer vision library. You can learn more about the OpenCV tutorial from here. For documentation, you can follow here. We will also cover some tutorials for Java bindings too.

 

2. Download OpenCV:

You can download OpenCV from the public Github repository of OpenCV or from their official website from here.  Select the desired version and click "Sources", which will download the zip file. Unzip the file.

unzip opencv-4.3.0.zip

 

3. Build OpenCV:

In order to build OpenCV, go to the OpenCV path in my case it's under "/opt/opencv-4.3.0" so I will use the same.

Create a directory to build.

mkdir build
  cd build

Now, if you don't have installed cmake software please install it using the below command

sudo apt-get  install cmake

Next, is to generate and configure with cmake for building executables in our system.

cmake -DBUILD_SHARED_LIBS=OFF ..

Note: When OpenCV is built as a set of static libraries (-DBUILD_SHARED_LIBS=OFF option) the Java bindings dynamic library is all-sufficient, i.e. doesn’t depend on other OpenCV libs, but includes all the OpenCV code inside. 

Make sure the output of the above command looks like below:

If it doesn't find the ant and java then you may get the following output: 

Java:
   ant:                         NO
   JNI:                         NO
   Java tests:                 YES

For this, install and setup your java and install ant

sudo apt install openjdk-8-jdk
sudo apt-get install ant

If you are still getting ant as NO then try the following command to install ant

sudo snap install ant --classic

Now start the build

make -j4

Note: Be careful not to run out of memory during the build. We need 4GB of memory per core. For example, if we compile with 4 cores (e.g. make -j4) we need a machine with at least 16GB of RAM.

The output look likes this and it will take some time.

If everything is fine, you successfully build OpenCV. Make sure the following files are packaged in the corresponding directory.

/opt/opencv-4.3.0/build/lib/libopencv_java430.so
/opt/opencv-4.3.0/build/bin/opencv-430.jar

The path of those files is created according to your OpenCV version and directory. You need to make sure the so and jar file must be created. This jar file contains the java wrapper code which we will used in the sample example.

 

4. Run Sample Example:

Now we are going to add the compiled jar file in our project library.

For IntelliJ Idea:

Go to : File >> Project Structure >> Libraries (under project settings)

you can see the + icon at the top left, to add a new project library click on it, and select java and add the path of previously created jar file i.e opencv-430.jar. 

It's time to run a sample test example.

import org.opencv.core.CvType;
import org.opencv.core.Mat;

public class SampleTest {

    public static void main(String[] args) {
        System.load("/opt/opencv-4.3.0/build/lib/libopencv_java430.so");
        Mat mat = Mat.eye(3, 3, CvType.CV_8UC1);
        System.out.println("mat = " + mat.dump());
    }
}

Make sure that you loaded your corresponding .so file.

Output:

mat = [  1,   0,   0;
   0,   1,   0;
   0,   0,   1]

For those who are running OpenCV in an existing project, you can set up with Gradle project as below:

For Gradle:

Copy the jar file in your project directory package for e.g "libs" and add following inside dependencies in build.gradle file.

dependencies {
//other dependencies

compile fileTree(dir: 'libs', include: '*.jar')
}

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How to Install and configure free SSL/TLS certificate for Tomcat using Let's Encrypt on Ubuntu.

How to set up a free SSL certificate for tomcat using let's encrypt on ubuntu.

Table Of Contents

• 1. Introduction
  
• 2. Prerequisites
• 3. Install certbort and create an SSL certificate
• 4. Tomcat configuartion for HTTPs
• 5. Renew certificate

1. Introduction:

Here, we are going to set up a free SSL certificate provided by a non-profit authority called Let's Encrypt. This is trusted and used by many to secure their website. The certificate is valid for only 90 days and can renew during that time. You can find out more about Let's Encrypt here. 

2. Prerequisites:

• Running ubuntu server
• Running tomcat server
• Domain name pointed to the server Ip address

3. Install certbort and create an SSL certificate:

SSH into the server where you want to create a certificate. In order to create an SSL certificate, we need to install certbot for this, go and select the appropriate ubuntu server version from here. As we are using ubuntu 18.04 LTS.

which will give the following command to install certbot.

Add Certbot PPA
 

 sudo apt-get update
sudo apt-get install software-properties-common
sudo add-apt-repository universe
sudo add-apt-repository ppa:certbot/certbot
sudo apt-get update

Install Certbot

sudo apt-get install certbot

If you have already running service which uses port 80, stop it first otherwise you will get Address BindException.

To obtain an SSL certificate for your domain using a built-in "standalone" webserver type the following command:

sudo certbot certonly --standalone -d example.com

Here, replace the domain name you want to secure instead of example.com 

which will create a different certificate file to the directory:   /etc/letsencrypt/live/example.com/

Now, logged in as root user and go to that directory

sudo -i
cd /etc/letsencrypt/live/example.com/

Next step is to convert those certificate PEM file to password-based PFX format so that we can use in tomcat configuration. We can do this by using OpenSSL command as below.

openssl pkcs12 -export -out bundle.pfx -inkey privkey.pem -in cert.pem -certfile chain.pem -password pass:password

Replace the password with your desired one. It will create a password-protected file bundle.pfx under the same directory "/etc/letsencrypt/live/example.com/" which we need to use in tomcat configuration.

 

4. Tomcat configuration for HTTPs:

Go to your tomcat directory, and backup the server.xml file; as we are going to change the file. It's always a good approach to backup the config file before changing it.

cp conf/server.xml conf/server-copy.xml
 

Edit the server.xml file.

sudo vi conf/server.xml  // no need to type sudo if you are logged in as root user
  

You can see the following xml tag(for tomcat 8), we are going to change this: 

Replace the above tag such that the config look like as below: 

Here, we are changing port 8443 to 443, keystoreType as "PKCS12", keystoreFile as the path of the pfx file created previously and keystorePass as your password that we used while creating PFX file. 

Change the port 8080 to 80: 

Under server.xml you can find the following tag.

change the above xml tag as below:  

Here, we are changing the port from 8080 to 80 and 8443 to 443. By doing so, if your domain running with port 8080 i.e example.com:8080, now it will open with port 80 i.e example.com. If you type your domain in the browser then you can run it with both HTTP and https i.e http://example.com and https://example.com.

Save the server.xml file by clicking "Esc" key and type ":wq!" and hit Enter. 

As we want to always redirect our domain to https. To do so, open the web.xml file under conf/web.xml.

sudo vi conf/web.xml
  

And add the below code at the end of file before the end of "/web-app" xml tag.

<security-constraint>
  <web-resource-collection>
  <web-resource-name>Entire Application</web-resource-name>
   <url-pattern>/*</url-pattern>
 </web-resource-collection>
  <!--auth-constraint goes here if you requre authentication-->
 <user-data-constraint>
 <transport-guarantee>CONFIDENTIAL</transport-guarantee>
 </user-data-constraint>
 </security-constraint>

Which will always redirect to HTTPs.

 

5. Renew certificate:

The certificate is valid for only 90 days so we need to renew before expiry. For this, stop tomcat and type the following command:

sudo certbot renew
 

sudo -i
cd /etc/letsencrypt/live/example.com/
openssl pkcs12 -export -out bundle.pfx -inkey privkey.pem -in cert.pem -certfile chain.pem -password pass:password
 

Don't forget to use your existing password. And restart the tomcat server.

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Tunnel local server to the public internet with https using Ngrok.

How to tunnel our local server to the public internet with https using Ngrok.

Table Of Contents

• 1. Introduction
  
• 2. Install and setup on windows system
• 3. Install and setup on linux system

1. Introduction:

It seems to be daunting if we need to test our application locally over Https. Generally, when we need to listen webhook from any other service provider, testing applications locally will be difficult. In this tutorial, I will show how to tunnel the local server into the live one using ngrok.

Create an account from ngrok from which we can get tunnel auth token which we will use to get persistent Https URLs even if the outage of the internet until ngrok is running.

2. Install and set up on windows system:

Download ngrok for windows system here and unzip. After that, you will see the ngrok binary file, to run that file double click it. Make sure the path of ngrok, you will see the command prompt as bellow.

Now you are ready to tunnel your local server port. Simply execute the following command.

ngrok.exe http 80

Here, port 80 is the server port running; you need to use the respective port of your running local server like 8080, 8090 etc.

We have successfully tunnel our local server running at port 80. We can see the two forwarding URLs which are accessible publicly. As we can see the session expires in about 8 hrs which means those URLs will be changes every 8 hrs; here we need an auth token to prevent this. Execute the following command.

ngrok.exe authtoken 5AXFH2DjGMu9NFHntjxZf_73wZyVZiKeCxrA1hwZWqX

Use your own auth token from your account instead. You can see the message in the command prompt.

Authtoken saved to configuration file: C:\Users\yourUser/.ngrok2/ngrok.yml

We will use this file to set up for multiple port tunnels. Now again run your local server port you will see the final tunneling URLs without session expires limit.

Now its time to tunnel more than one port if you need it. For this, we are using ngrok.yml config file as below:


ngrok.yml

tunnels:

 backend:

  addr: 8080
  proto: http
  
 frontend:

  addr: 8081
  proto: http

Here, I have running two applications on port 8080 and 8081. Now again run the ngrok.exe file and run the following command to start and tunnel all ports.

ngrok.exe start -all

We have successfully tunnel a multi-port server.

Note: if you get Invalid Host header error while running that URLs, start tunneling port with the following command instead:

ngrok.exe http 8080 -host-header="localhost:8080"

or

ngrok.exe http --host-header=rewrite 8080

For multiport tunnels

tunnels:

 backend:

  addr: 8080
  proto: http
  host_header: "localhost:8080"
  
 frontend:

  addr: 8081
  proto: http
  host_header: "localhost:8081"

3. Install and set up on Linux system:

Download ngrok for the Linux system here. Go to download path and simply right click and extract the file. You will see the ngrok binary file, we need to make it executable so, copy this file to usr/bin directory. 

sudo cp ~/Downloads/ngrok-stable-linux-amd64/ngrok /usr/bin/

Now type ngrok command in the terminal you can see the following output if it is successfully installed.

If it is not installed then go to the ngrok binary file path and open terminal and type command ./ngrok instead of ngrok to run and tunnel your server port.

For the persistent URLs, setup auth token using command:

ngrok authtoken 5AXFH2DjGMu9NFHntjxZf_73wZyVZiKeCxrA1hwZWqX

Use your auth token from your ngrok account, which will configure ngrok config file in your home directory.

Authtoken saved to configuration file: /home/36olearntocode/.ngrok2/ngrok.yml

If you want to tunnel single port then simply run following command and you will see the following output.

ngrok http 80

Use the respective port of your server.  

If you want to tunnel multiple ports then set up ngrok config file as:





ngrok.yml

tunnels:

 backend:

  addr: 8080
  proto: http
  
 frontend:

  addr: 8081
  proto: http

Now again run the command to start:

ngrok start -all

Output:

Note: if you get Invalid Host header error while running that URLs, start tunneling port with the following command instead:

ngrok http 8080 -host-header="localhost:8080"

or

ngrok http --host-header=rewrite 8080

For multiport tunnels

tunnels:

 backend:

  addr: 8080
  proto: http
  host_header: "localhost:8080"
  
 frontend:

  addr: 8081
  proto: http
  host_header: "localhost:8081"

We have successfully tunnel our two port 8080 and 8081 over https.

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Grails 3 Download Saved Documnets/Files (.pdf, .txt, .docx and others) Example.

How to Download different types of files using Grails 3.

If you want to use server-side file download for different types of files like pdf, txt, docx etc then there are different ways to do it.

We can use ServletOutputStream object for it as below:

    def download(){
            def filePath = "/opt/tomcat/webapps/savedFile/filename.pdf" //I am saving files on tomcat.
            def file = new File(filePath)
            if (file.exists()){
                response.setContentType("application/octet-stream")
                response.setHeader("Content-disposition", "filename=${file.getName()}")
                response.outputStream << file.bytes
            }else {
                //handle file not found messages.
            }
}

Here, contentType is "application/octet-stream" for all types of file. If you want to specified for specific one set contentType for specific one.

                response.setContentType("application/pdf")

Or you can do simply like this:

    def download(){
            def filePath = "/opt/tomcat/webapps/savedFile/filename.pdf" //I am saving files on tomcat.
            def file = new File(filePath)
            if (file.exists()){
                response.setContentType("application/octet-stream")
                response.setHeader("Content-disposition", "filename=${file.getName()}")
                response.outputStream << file.newInputStream()
            }else {
                //handle file not found messages.
            }
}

def download(){
            def filePath = "/opt/tomcat/webapps/savedFile/filename.pdf" //I am saving files on tomcat.
            def file = new File(filePath)
            if (file.exists()){
                response.setContentType("application/octet-stream")
                response.setHeader("Content-disposition", "filename=${file.getName()}")
                def outputStream = response.getOutputStream()
                outputStream << file.bytes
                outputStream.flush()
                outputStream.close()
            }else {
                //handle file not found messages.
            }
}

But in grails 3 latter version while deploying the war file to external tomcat(tomcat 7) server then we might get some class not found issue while downloading files.

Error 500: Internal Server Error
URI
/patient/download
Class
java.lang.ClassNotFoundException
Message
Handler dispatch failed; nested exception is java.lang.NoClassDefFoundError: javax/servlet/WriteListener
Caused by
javax.servlet.WriteListener

In order to solve this issue, we need to make the controller's action wrap with @GrailsCompileStatic annotation.

import grails.compiler.GrailsCompileStatic

@GrailsCompileStatic
def download(){
            def filePath = "/opt/tomcat/webapps/savedFile/filename.pdf" //I am saving files on tomcat.
            def file = new File(filePath)
            if (file.exists()){
                response.setContentType("application/octet-stream")
                response.setHeader("Content-disposition", "filename=${file.getName()}")
                def outputStream = response.getOutputStream()
                outputStream << file.bytes
                outputStream.flush()
                outputStream.close()
            }else {
                //handle file not found messages.
            }
}

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Securing Grails Application with Spring Security Rest | Rest API | Grails 3.x

How to Secure Grails Application with Spring Security Rest in Grails 3

Table of Contents

• - Introduction
• - Pre-requisites
• - Create Grails Application
• - Spring Security Core Plugin Configuration
• - Spring Security Rest Plugin Configuration
• - Testing Secured REST API

Introduction:

In this tutorial, we are going to secure our grails application with spring security simply refer to spring security rest login. Here we are using grails version 3.3.0 and Java 8. This tutorial describes the configuration of Spring Security Core, Spring Security Rest with Grails 3 to secure the application.

Pre-requisites:

1. Running Java
2. Running Grails

Create Grails Application:

1. Create App

In order to create grails application, open your terminal or cmd and type following command to create an app.

grails create-app spring-security-rest --profile rest-api

// Application created at (path of app)

Open your favorite text editor or IDE and open the project that we recently created.

Go to a created project folder.

cd spring-security-rest

Run grails interactive mode.

grails 

In order to run and stop an application simply type "run-app" and "stop-app"

2. Create Domain Class

Let's create a dummy class to test security called "Product". You can use either terminal or your IDE.

create-domain-class Product

Add some properties in the domain class.

class Product {
    String name
    Double price
    String companyName
    String description
    Date dateCreated = new Date()
    static constraints = {
    }
}

Add some data using BootStrap.groovy

class BootStrap {

    def init = { servletContext ->
        if (Product.count() == 0){
            new Product(name: "product1", price: 10, companyName: "company1", description:"description1").save(flush:true)
            new Product(name: "product2", price: 100, companyName: "company2", description:"description2").save(flush:true)
            new Product(name: "product3", price: 1000, companyName: "company3", description:"description3").save(flush:true)
            new Product(name: "product4", price: 10000, companyName: "company4", description:"description4").save(flush:true)
        }
    }
    def destroy = {
    }
}

Create Controller for product domain.

create-restful-controller Product

It will create controller like this:

class ProductController extends RestfulController {
    static responseFormats = ['json', 'xml']
    ProductController() {
        super(Product)
    }
}

Run application. And simply make get request, as following endpoint will results "product" data in Json format that we created in BootStrap.groovy.

http://localhost:8080/product

Spring Security Core Plugin Configuration:

Under build.gradle file within dependencies add the following configuration and run command "compile"

dependencies {
    compile 'org.grails.plugins:spring-security-core:3.2.0'
}

Now its time to create user related tables,  for this exit from the interactive console.

exit
grails s2-quickstart spring.security.rest User Role

You can see:

CONFIGURE SUCCESSFUL
Total time: 2.965 secs
| Creating User class 'User' and Role class 'Role' in package 'spring.security.rest'
| Rendered template PersonWithoutInjection.groovy.template to destination grails-app/domain/spring/security/rest/User.groovy
| Rendered template PersonPasswordEncoderListener.groovy.template to destination src/main/groovy/spring/security/rest/UserPasswordEncoderListener.groovy
| Rendered template Authority.groovy.template to destination grails-app/domain/spring/security/rest/Role.groovy
| Rendered template PersonAuthority.groovy.template to destination grails-app/domain/spring/security/rest/UserRole.groovy
| 
************************************************************
* Created security-related domain classes. Your            *
* grails-app/conf/application.groovy has been updated with *
* the class names of the configured domain classes;        *
* please verify that the values are correct.               *
************************************************************

Which will create User.groovy, Role.groovy, and UserRole.groovy Domain classes.

Now let's create a user data for testing purpose using BootStrap.groovy.

def role1 = new Role(authority:"ROLE_USER").save flush:true
        def user1 = new User(username:"user@gmail.com",password:"pwd@123").save flush:true
        UserRole.create(user1,role1)

Spring Security Rest Plugin Configuration:
Under build.gradle file within dependencies add the following configuration and run command "compile"

dependencies {
    compile "org.grails.plugins:spring-security-rest:2.0.0.M2"
}

Go to application.groovy and add chainMap configuration:

grails.plugin.springsecurity.filterChain. chainMap = [
  [pattern: '/**',filters: 'JOINED_FILTERS,-anonymousAuthenticationFilter,-exceptionTranslationFilter,-authenticationProcessingFilter,-securityContextPersistenceFilter'],
  [pattern: '/**', filters: 'JOINED_FILTERS,-restTokenValidationFilter,-restExceptionTranslationFilter'] 
]

Note: If your endpoint start with https://address.com/api or /othername then your chainMap look like

grails.plugin.springsecurity.filterChain. chainMap = [
  [pattern: '/api**',filters: 'JOINED_FILTERS,-anonymousAuthenticationFilter,-exceptionTranslationFilter,-authenticationProcessingFilter,-securityContextPersistenceFilter'],
  [pattern: '/**', filters: 'JOINED_FILTERS,-restTokenValidationFilter,-restExceptionTranslationFilter'] 
]

The final configuration looks like

// Added by the Spring Security Core plugin:
grails.plugin.springsecurity.userLookup.userDomainClassName = 'spring.security.rest.User'
grails.plugin.springsecurity.userLookup.authorityJoinClassName = 'spring.security.rest.UserRole'
grails.plugin.springsecurity.authority.className = 'spring.security.rest.Role'
grails.plugin.springsecurity.controllerAnnotations.staticRules = [
 [pattern: '/',               access: ['permitAll']],
 [pattern: '/error',          access: ['permitAll']],
 [pattern: '/index',          access: ['permitAll']],
 [pattern: '/index.gsp',      access: ['permitAll']],
 [pattern: '/shutdown',       access: ['permitAll']],
 [pattern: '/assets/**',      access: ['permitAll']],
 [pattern: '/**/js/**',       access: ['permitAll']],
 [pattern: '/**/css/**',      access: ['permitAll']],
 [pattern: '/**/images/**',   access: ['permitAll']],
 [pattern: '/**/favicon.ico', access: ['permitAll']],
 [pattern: '/**',             access: ['isFullyAuthenticated()']]
]

grails.plugin.springsecurity.filterChain. chainMap = [
  [pattern: '/**',filters: 'JOINED_FILTERS,-anonymousAuthenticationFilter,-exceptionTranslationFilter,-authenticationProcessingFilter,-securityContextPersistenceFilter'],
  [pattern: '/**', filters: 'JOINED_FILTERS,-restTokenValidationFilter,-restExceptionTranslationFilter'] 
]

Testing Secured REST API:
Now re-run the application and request the endpoint "http://localhost:8080/product"

which is our application is secured. I will make a tutorial for customizing this message format.

Next test the login endpoint with our existing user created in BootStrap.groovy. Here I am using Post-man.

Now access data via authorization.

Here, for authorization key use "Bearer access_token". You can see data as shown above. Because in our application.groovy we configure in such a way that all the login users can access data.

[pattern: '/**',             access: ['isFullyAuthenticated()']]

In the next tutorial I am going to create different customization for configuration and describe about different annotations.

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Splitting resources.groovy configuration in Grails applications

Splitting resources.groovy configuration in Grails applications

Table Of Contents

• 1. Introduction
  
• 2. How to split resources.groovy
• 3. Import external bean file

1. Introduction:

In grails, when our resources.groovy file is growing then it is better to split some logical bean configuration with a separate file and import that file in resources.groovy.  For this, Grails provides a neat way to specify Spring bean definitions with its custom Beans DSL by using importBeans or loadBeans.

2. How to split resources.groovy

You can simply create resources file under  "grails-app/conf/spring/" package: e.g

firstBean.groovy:

beans {
  beanConfiguration: yourBeanConfiguration
}

3. Import external bean file

Grails provide importBeans or loadBeans to import custom external bean file which can be done inside resources.groovy as bellow:

beans = { 
  importBeans('file:grails-app/conf/spring/firstBean.groovy') 
}

The problem is that this seems to work, but only if you run the application via  grails run-app with the embedded servlet container.

As soon we create a WAR file and deploy it into tomcat we are getting into trouble. The problem is Spring Bean Configuration file is moved on the different folder in tomcat "WEB-INF/classes/spring/" so we can get file-not-found-exception.

In order to resolve this problem, we need to locate custom resource path in resources.groovy.

def loadFromFile = { name ->
        importBeans("file:grails-app/conf/spring/"+name)
    }

    def loadFromWar = { name ->
        def resource = application.parentContext.getResource("WEB-INF/classes/spring/"+name)
        loadBeans(resource)
    }
    def loadResource = application.isWarDeployed() ? loadFromWar : loadFromFile

    loadResource "firstBean.groovy"
    loadResource "secondBean.groovy"

Here if the application is running via grails run-app then it will use the path "grails-app/conf/spring/". And if it is via external tomcat with deploying the WAR file then it uses the path "WEB-INF/classes/spring/".

Note: Be sure that your resource file is packaged on WAR with the right path.

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How to resolve grails-resolving-server-failed-to-start-for-port-8080-address-already-in-use

On Linux:

step1: if your server port already running at port 8080 then, firstly we have to kill this process for this open your terminal and type

lsof -w -n -i tcp:8080

which shows all the list of open file which is running at port 8080. if you type
lsof -w -n -i tcp:9090 if your server is running with port 9090 which shows all the list of open file which are running at port 9090. Here, lsof stand for ls = list and of = opened file. You can see list with pid number.

step2: type sudo kill -9 6911 where 6911 is pid number. Here 9 has its own meaning which is defined as kill command "SIGKILL" you can see this by type in terminal as kill -l . You can use -SIGKILL instead of -9.

step3: run your application. 

On Windows:

- Open and run command prompt as administrator and type following command:

   

   netstat -ano | findstr :8080

This command will find and list the process that uses this port.

Now, we need to kill the process, for this use following command:

   taskkill /pid 5884 /f

Where 5884 is the PID number. Use your PID number which is obtained previously.

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Error: ENOENT: no such file or directory, stat '../pancake-swap-periphery/node_modules/@uniswap/v2-core/contracts/interfaces/IPancakeFactory.sol

While trying to do pancake-swap clone, we might get the following issue while building a contract.

Error: ENOENT: no such file or directory, stat '../pancake-swap-periphery/node_modules/@uniswap/v2-core/contracts/interfaces/IPancakeFactory.sol'

It is due to the file is not found in node modules as suggested in error. If you go to the package.json file you can see the following dependency is injected inside the dependencies

"@uniswap/v2-core": "^1.0.1"

So here, pancake-swap core dependency files are not found which is imported in the contract we are building.

Let's add the required dependency from the git panackage-swap-core

replace the above dependency:

"@uniswap/v2-core": "git://github.com/pancakeswap/pancake-swap-core.git"

Now install the added dependency

npm install

After that, we can try building the contract.

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