Description :-

This project prints a 'Hello World' statement when a web browser connects to URL http://192.168.99.101:30080 for the Development environment. It prints the 'Hello World' statement by retrieving the text from a MySQL database.

The same concepts apply for the Production environment just that the web application is connecting to a different database server.
The Production URL is http://192.168.99.101:30081.

Bundled Files :-

After cloning the Git repository using the command - git clone https://github.com/dkelim1/webapps-dkelim.git, below files will be presented in webapps-dkelim.

ddl@dockers:~/webapps-dkelim$ ls -ltr total 2020 -rw-rw-r-- 1 ddl ddl 50284 Dec 6 14:55 Artifact_HelloWorld_Test.png <-- Evidence for the working solution. -rw-rw-r-- 1 ddl ddl 10979 Dec 6 15:37 Prod_Steps.txt <-- Sample steps for Production deployment
-rw-rw-r-- 1 ddl ddl 998838 Dec 6 14:55 Development.zip <-- Archive for the Development environment. -rw-rw-r-- 1 ddl ddl 41 Dec 6 14:55 README.md <-- Instructions on how to deploy the solution.
-rw-rw-r-- 1 ddl ddl 1001196 Dec 6 14:55 Production.zip <-- Archive for the Production environment.

Upon unzipping the 2 archives, below contents will be presented.

ddl@dockers:~/webapps-dkelim/Development$ ls -ltr total 12 drwxrwxr-x 4 ddl ddl 4096 Dec 6 2020 dev-webapps <-- HELM Charts for Web application drwxrwxr-x 4 ddl ddl 4096 Dec 6 2020 dev-mysqldb <-- HELM Charts for MySQL DB drwxrwxr-x 4 ddl ddl 4096 Dec 6 2020 nodejs <-- The Web application itself including the DockerFile

ddl@dockers:~/webapps-dkelim/Production$ ls -ltr total 12 drwxrwxr-x 5 ddl ddl 4096 Dec 6 2020 prod-webapps drwxrwxr-x 4 ddl ddl 4096 Dec 6 2020 prod-mysqldb drwxrwxr-x 4 ddl ddl 4096 Dec 6 2020 nodejs

Pre-requisites :-

• A stable Internet connection to download the necessary softwares/docker images.
• A working Kubernete Cluster running on minikube.
• HELM installed for deployment and templating.

Procedures :-

Note that

a) for Production deployment, the same steps can be applied by changing the respective HELM chart folders respectively. For eg, dev-webapps becomes prod-webapps.

b) the below steps need to be executed at the machine that hosts the minikube service as a normal user. In my case this is the MacBook itself which hosts the minikube service running within a VirtualBox VM.

1. After cloning the repository, navigate to the webapps-dkelim folder.
   merrylee:~ merrylee$ cd webapps-dkelim; ls -l

You will see the below files.

merrylee:~/webapps-dkelim merrylee$ ls -ltr total 2012 -rw-rw-r-- 1 ddl ddl 50284 Dec 6 14:55 Artifact_HelloWorld_Test.png -rw-rw-r-- 1 ddl ddl 10979 Dec 6 15:37 Prod_Steps.txt -rw-rw-r-- 1 ddl ddl 998838 Dec 6 14:55 Development.zip -rw-rw-r-- 1 ddl ddl 41 Dec 6 14:55 README.md -rw-rw-r-- 1 ddl ddl 1001196 Dec 6 14:55 Production.zip

2. Unzip the Development.zip archive. Then navigate to the Development folder.

merrylee:~/webapps-dkelim merrylee$ unzip Development.zip Archive: Development.zip creating: Development/ creating: Development/dev-mysqldb/ inflating: Development/dev-mysqldb/.helmignore inflating: Development/dev-mysqldb/Chart.yaml creating: Development/dev-mysqldb/charts/ creating: Development/dev-mysqldb/templates/ inflating: Development/dev-mysqldb/templates/config.yaml inflating: Development/dev-mysqldb/templates/Deployment.yaml inflating: Development/dev-mysqldb/templates/pvc.yaml inflating: Development/dev-mysqldb/templates/service.yaml inflating: Development/dev-mysqldb/values.yaml creating: Development/dev-webapps/ inflating: Development/dev-webapps/.helmignore inflating: Development/dev-webapps/Chart.yaml creating: Development/dev-webapps/charts/ creating: Development/dev-webapps/templates/ inflating: Development/dev-webapps/templates/deployment.yaml inflating: Development/dev-webapps/templates/service.yaml inflating: Development/dev-webapps/templates/service_ext.yaml inflating: Development/dev-webapps/values.yaml ... .... ......

merrylee:~/webapps-dkelim merrylee$ cd Development; ls -ltr total 12 drwxrwxr-x 4 ddl ddl 4096 Dec 6 2020 dev-webapps drwxrwxr-x 4 ddl ddl 4096 Dec 6 2020 dev-mysqldb drwxrwxr-x 4 ddl ddl 4096 Dec 6 2020 nodejs

3. Execute the mysql deployment by executing the below command.

merrylee:~/webapps-dkelim/Development merrylee$ helm install dev-mysqldb ./dev-mysqldb NAME: dev-mysqldb LAST DEPLOYED: Sun Dec 6 14:32:50 2020 NAMESPACE: default STATUS: deployed REVISION: 1 TEST SUITE: None

4. Check that the mysql deployment is running properly as follow.

merrylee:~/webapps-dkelim/Development merrylee$ kubectl get all NAME READY STATUS RESTARTS AGE pod/dev-mysqldb-ddff4c64f-qxwvz 1/1 Running 0 21m

NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE service/dev-mysqldb ClusterIP 10.104.191.68 3306/TCP 21m service/kubernetes ClusterIP 10.96.0.1 443/TCP 4d16h

NAME READY UP-TO-DATE AVAILABLE AGE deployment.apps/dev-mysqldb 1/1 1 1 21m

NAME DESIRED CURRENT READY AGE replicaset.apps/dev-mysqldb-ddff4c64f 1 1 1 21m

5. Configure mysql DB. Retrieve the random root password.

$ logs dev-mysqldb-ddff4c64f-qxwvz

Note down the random root password from the below line. Password is after 'PASSWORD: '.
[Entrypoint] GENERATED ROOT PASSWORD: UqjyBuR5Yw]YJ@PiqIf@x@j-iJ^

Launch a root shell to the mysql DB pod.
$ kubectl exec --stdin --tty dev-mysqldb-ddff4c64f-qxwvz -- /bin/bash

Login to the mysql console.

Eg :-

merrylee:~/webapps-dkelim/Development merrylee$ kubectl logs dev-mysqldb-ddff4c64f-qxwvz [Entrypoint] MySQL Docker Image 8.0.22-1.1.18 [Entrypoint] No password option specified for new database. [Entrypoint] A random onetime password will be generated. [Entrypoint] Initializing database 2020-12-06T06:33:00.006528Z 0 [System] [MY-013169] [Server] /usr/sbin/mysqld (mysqld 8.0.22) initializing of server in progress as process 20 2020-12-06T06:33:00.014637Z 1 [System] [MY-013576] [InnoDB] InnoDB initialization has started. 2020-12-06T06:33:00.748498Z 1 [System] [MY-013577] [InnoDB] InnoDB initialization has ended. 2020-12-06T06:33:02.386019Z 6 [Warning] [MY-010453] [Server] root@localhost is created with an empty password ! Please consider switching off the --initialize-insecure option. [Entrypoint] Database initialized 2020-12-06T06:33:06.537633Z 0 [System] [MY-010116] [Server] /usr/sbin/mysqld (mysqld 8.0.22) starting as process 63 2020-12-06T06:33:06.557228Z 1 [System] [MY-013576] [InnoDB] InnoDB initialization has started. 2020-12-06T06:33:06.774297Z 1 [System] [MY-013577] [InnoDB] InnoDB initialization has ended. 2020-12-06T06:33:06.946292Z 0 [System] [MY-011323] [Server] X Plugin ready for connections. Socket: /var/run/mysqld/mysqlx.sock 2020-12-06T06:33:07.147791Z 0 [Warning] [MY-010068] [Server] CA certificate ca.pem is self signed. 2020-12-06T06:33:07.148183Z 0 [System] [MY-013602] [Server] Channel mysql_main configured to support TLS. Encrypted connections are now supported for this channel. 2020-12-06T06:33:07.200939Z 0 [System] [MY-010931] [Server] /usr/sbin/mysqld: ready for connections. Version: '8.0.22' socket: '/var/lib/mysql/mysql.sock' port: 0 MySQL Community Server - GPL. Warning: Unable to load '/usr/share/zoneinfo/iso3166.tab' as time zone. Skipping it. Warning: Unable to load '/usr/share/zoneinfo/leapseconds' as time zone. Skipping it. Warning: Unable to load '/usr/share/zoneinfo/tzdata.zi' as time zone. Skipping it. Warning: Unable to load '/usr/share/zoneinfo/zone.tab' as time zone. Skipping it. Warning: Unable to load '/usr/share/zoneinfo/zone1970.tab' as time zone. Skipping it. [Entrypoint] GENERATED ROOT PASSWORD: UqjyBuR5Yw]YJ@PiqIf@x@j-iJ^

merrylee:~/webapps-dkelim/Development merrylee$ kubectl exec --stdin --tty dev-mysqldb-ddff4c64f-qxwvz -- /bin/bash

bash-4.2# mysql -h localhost -uroot -p Enter password: Welcome to the MySQL monitor. Commands end with ; or \g. Your MySQL connection id is 9 Server version: 8.0.22

Copyright (c) 2000, 2020, Oracle and/or its affiliates. All rights reserved.

Oracle is a registered trademark of Oracle Corporation and/or its affiliates. Other names may be trademarks of their respective owners.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

mysql>

6. Change root user password in mysql by executing the below SQL queries.

ALTER USER 'root'@'localhost' IDENTIFIED BY 'password';

Eg :-

mysql> ALTER USER 'root'@'localhost' IDENTIFIED BY 'password'; Query OK, 0 rows affected (0.01 sec)

7. Create required database and table by executing the below SQL queries.

<<< Start of SQL queries >>>

CREATE DATABASE messages; use messages; CREATE TABLE messages(text VARCHAR(100)); SHOW TABLES; INSERT INTO messages VALUES ('Hello World'); select * from messages;

<<< End of SQL queries >>>

Eg :-

mysql> CREATE DATABASE messages; Query OK, 1 row affected (0.00 sec)

mysql> use messages; Database changed mysql> CREATE TABLE messages(text VARCHAR(100)); Query OK, 0 rows affected (0.02 sec)

mysql> SHOW TABLES; +--------------------+ | Tables_in_messages | +--------------------+ | messages | +--------------------+ 1 row in set (0.00 sec)

mysql> INSERT INTO messages VALUES ('Hello World'); Query OK, 1 row affected (0.01 sec)

mysql> select * from messages; +-------------+ | text | +-------------+ | Hello World | +-------------+ 1 row in set (0.00 sec)

8. Grant permissions for root and mysqluser by executing the below SQL queries. 'mysqluser' is the account that will login to the database from the web application.

<<< Start of SQL queries >>>

CREATE USER 'root'@'%' IDENTIFIED BY 'password'; GRANT ALL ON . TO 'root'@'%' WITH GRANT OPTION;

ALTER USER 'root'@'%' IDENTIFIED WITH mysql_native_password BY 'password';

CREATE USER 'mysqluser'@'%' IDENTIFIED BY 'password'; GRANT ALL ON messages.* TO 'mysqluser'@'%' WITH GRANT OPTION;

ALTER USER 'mysqluser'@'%' IDENTIFIED WITH mysql_native_password BY 'password';

FLUSH PRIVILEGES;

exit

<<< End of SQL queries >>>

At this point, the database setup is completed. Exit to the minikube host by typing 'exit'.

Eg :-

mysql> CREATE USER 'root'@'%' -> IDENTIFIED BY 'password'; Query OK, 0 rows affected (0.01 sec)

mysql> GRANT ALL -> ON . -> TO 'root'@'%' -> WITH GRANT OPTION; Query OK, 0 rows affected (0.01 sec)

mysql> mysql> ALTER USER 'root'@'%' IDENTIFIED WITH mysql_native_password BY 'password'; Query OK, 0 rows affected (0.01 sec)

mysql> mysql> mysql> CREATE USER 'mysqluser'@'%' -> IDENTIFIED BY 'password'; Query OK, 0 rows affected (0.01 sec)

mysql> GRANT ALL -> ON messages.* -> TO 'mysqluser'@'%' -> WITH GRANT OPTION; Query OK, 0 rows affected (0.00 sec)

mysql> mysql> mysql> ALTER USER 'mysqluser'@'%' IDENTIFIED WITH mysql_native_password BY 'password'; Query OK, 0 rows affected (0.01 sec)

mysql> mysql> FLUSH PRIVILEGES; Query OK, 0 rows affected (0.01 sec)

mysql> exit Bye bash-4.2# exit exit merrylee:~ merrylee$

9. Execute the web application deployment by executing the below command.

merrylee:~/webapps-dkelim/Development merrylee$ helm install dev-webapps ./dev-webapps NAME: dev-webapps LAST DEPLOYED: Sun Dec 6 15:07:23 2020 NAMESPACE: default STATUS: deployed REVISION: 1 TEST SUITE: None

10. Check that the web deployment is running properly as follow.

merrylee:~/webapps-dkelim/Development merrylee$ kubectl get all NAME READY STATUS RESTARTS AGE pod/dev-mysqldb-ddff4c64f-qxwvz 1/1 Running 0 35m pod/dev-webapps-76f7567cb4-b48sr 1/1 Running 0 61s pod/dev-webapps-76f7567cb4-qxfm7 1/1 Running 0 61s pod/dev-webapps-76f7567cb4-ztbzm 1/1 Running 0 61s

NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE service/dev-mysqldb ClusterIP 10.104.191.68 3306/TCP 35m service/dev-webapps ClusterIP 10.103.80.254 80/TCP 61s service/dev-webapps-ext NodePort 10.106.67.208 80:30080/TCP 61s service/kubernetes ClusterIP 10.96.0.1 443/TCP 4d16h

NAME READY UP-TO-DATE AVAILABLE AGE deployment.apps/dev-mysqldb 1/1 1 1 35m deployment.apps/dev-webapps 3/3 3 3 61s

NAME DESIRED CURRENT READY AGE replicaset.apps/dev-mysqldb-ddff4c64f 1 1 1 35m replicaset.apps/dev-webapps-76f7567cb4 3 3 3 61s

11. Retrieve the public URL to connect from outside the minikube environment by executing the below command.

merrylee:~/webapps-dkelim/Development merrylee$ minikube service dev-webapps-ext --url http://192.168.99.101:30080

12. For an initial test, utilize 'curl' to access the URL. The 'Hello World' text should be displayed.

merrylee:/webapps-dkelim/Development merrylee$ curl http://192.168.99.101:30080 [{"text":"Hello World"}]merrylee:/webapps-dkelim/Development merrylee$

See file 'Artifact_HelloWorld_Test.png' for screenshots taken from other hosts.

=====================================================================

Future Enhancements :-

1. The database hostname, connection user and password are hard coded in the app.js script. For Development and Production environment, it will have different values.
   A more elegant way is to pass in the parameters as environment variables so that the script need not be updated when there is an environment change.

   // parse application/json app.use(bodyParser.json());

   //create database connection const conn = mysql.createConnection({ host: 'db', <--- user: 'mysqluser', <--- password: 'password', <--- database: 'messages' });

2. Build the dependency in the HELM' s project so that the web application depends on the database service to startup.

3. Build the CI component utilizing Jenkin pipelines.