Jihoon`s Blog

SAIT Assingment -Blog2

2022-03-18T00:00:00+00:00

Website construction phase

The purpose of this blog is to put the actual website on the server and run it. Let’s use the functionality in AWS to drive the actual website.

Create vpc What is VPC? It is not a real private network, but a virtual private network. It is vpn that makes it work as if it is actually on the same network but on another network.
Subnetting What is Subnetting? Subnetting is the process of creating a subnetwork (also known as a subnet) within a network. Network interfaces and devices within a subnet can communicate with each other directly. Routers facilitate communication between different subnets.
Create an Internet gateway what is gateway

An Internet Gateway is a redundant, horizontally scaled, and is a highly available VPC component. It allows communication between instances in your VPC and the internet using VPC route tables for internet-routable traffic.

Sequence

First of all . log in with your account in AWS

Create a VPC after logging in

Create a vpc by clicking vpc in the service menu
Set the vpc name in the Name tag section. I did it with sait_blog. Any name is possible. In case of using various vpc, it is also possible with a domain name ex) sait_blog.com.

Right-click on vpc and click Edit DNS hostnames. Then a new window will open, set DNS hostname to ENable. This is to automatically name the server created on the network I created.
Subnetting

Click Subnets in the line below your VPCS and then click “CREATE subnet”, the screen above appears. If you open the vpc ID select bar here, you can check the name of the VPC you created. Click the name of the vpc to open the subnet setting section. A total of 4 subnets were created, 2 web subnets and 2 db subnets were created. For security reasons, I created two different subnets each.
When you create a subnet, the following table is displayed. Let’s check if the subnet address is the same as the subnet address you created.
Create an Internet gateway
I create an internet gateway and match it with the IPv4 address (10.200.0.0/16) created in VPC .

click the create internet gateway and add name in my case I wrote name as sait_blog and click the create internet gateway button.

now click the actions and select attac to VPC

this is for matching gateway to VPC select vpc
Create Route table

A table is created in the vpc I created

If you click the vpc router table you just created, you can see the router information at the bottom.

Check that status is active
Create EC2 server

I create a server by clicking EC2 in the AWS service menu.

I used Amazon Linux. Use the desired Amazon Machine Image and press select

Then, set the instance type you want. I used the free version.

Subnets are automatically added when you select the VPC you selected for the network.

When creating the security group, I allowed only SSH and HTTP to the security group first. I will connect to the newly created server from the outside through SSH, and I will use apache as the web server, so I made a security group that allows HTTP(80). You can set this part according to your situation.

Finally, you can download the key used to connect to the server in the review (STEP 7). You must have the corresponding key to access the server , so make sure to keep it after downloading . It is impossible to create a server without downloading, so you must download it and never delete it.

https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/putty.html

There are two ways to access the server. There is a way to access from a Linux server and a way to access from a Windows server with putty. Please refer to the user guide on the Amazon site for this access method
DNS matching Elastic Ips After checking the connection through putty, assign a fixed authorized ips to the dns and match the server

Elastic IPs

In the navigation with the Network & Security section, select elastic ip and click allocate Elastic ip address

I set the network border group to US-East -1, so that’s how I set it. Create an IP address after setting it to the network border group that you set

If IP is set, you can set the instance by clicking Associate Elastic ip address on the Action button. Set the appropriate instance

Finally, you can see that the public ipv5 address has changed. Now a website server has been created. You can access it by entering the ipv4 address or ipv4 DNS address on the homepage.

As you can see, if you succeed in the server, you can access the ip address you created. But I don’t know why, but I was able to access it about 30 minutes after all the completion. We will end the server setting and gate and subnet setting using aws.

SAIT Assingment -Blog1

2022-02-17T00:00:00+00:00

What is Amazon Web Services

The Aws system is the most widely adopted cloud platform as of 2021. In addition, Aws offers far more services and in-service capabilities than other cloud providers, from infrastructure technologies such as computing, storage, and databases to new technologies such as machine learning and artificial intelligence, data lake and analysis, and the Internet of Things. This allows you to move existing applications to the cloud faster, easier, and more economically and build almost anything imaginable.

What is clould

In short, cloud service is a service that stores all of the software on a super-large, high-performance computer connected to the Internet and can be used whenever necessary. In general, in order to increase storage space, hard, which is storage space, is purchased on a local computer. In addition, in order to use stored hardware, you must always have it physically. However, with cloud services, you can conveniently use the information you have saved (documents, videos, etc.) as long as you connect to the Internet anywhere, regardless of location, even if you don’t have physical hardware.

Why we need for learn AWS.

Amazon Cloud Service is the most widely used in the world as of last year. The fact that it is used by many companies means that we have more opportunities to get a job.

Aws Certification

Aws is issuing certificates through its own tests.

Certificate grades are classified as follows:

Foundational.
Associate.
Professional.
Specialty.

It is divided into the following fields:

Basic.
Architect.
Developer.
Operations
Specialty.

Each must have experience to take the test before 2018, but the pre-test conditions have been abolished since 2018. If you’re confident, let’s try it. More information on the certificate can be found by following the link.AWS Certifivation

What do you need before learning AWS?

First of all, you have to create an account on the AWS site. AWS educate Various lecture videos are posted on the aws eduvate site. You can watch all lectures for free

After that, you have to create an account on AWS For the next 12 months, you’ll have free access to core AWS compute, storage, database, and application services within the limits of the Free Tier.

How to use the AWS site.

After signing up for the first time, there are three things to do. The first is account setting and configuration setting. Second, setting up the AWS Command Line Interface(CLD). The last thing is to setup cloud9 IDE.

Securing your AWS Account

1-1. Click IAM in seraching on the screen below.

1-2. Click the Add MFA

1-3. Click the Activate MFA

1-4. Choose Virtual MFA device

1-5. Install MFA Application on your phone
```
   The MFA application must be installed on the mobile phone, and the applications supported by AWS are as follows. You can download what you want, but it's easier for Google Authenticator to scan with QR code.  Note that if you have installed an MFA application on your phone and registered with AWS with that MFA application, you may not be able to access it through the access ROOT account if you lose that cell phone. Perhaps a solution can be found in some way, but it will not be easy.
```
1-6. Click the show QR Code
Run the QR code reder using the application on your phone and enter the code at MFA code 1 in number 3. You can see only one code, but wait about a minute to see that the code changes. After that, enter the changed code into MFA code 2 and click assign MFA.

1-7. Finish Securing your AWS account
If MFA is applied, the following window can be seen. If you log out and log back in to check if it is actually confirmed normally, you will see a screen asking for the MFA code.
Setting up the AWS Command Line Interface(CLD).
AWS CLD is an open-source tool that can interact with AWS services using commands from the command line interface, and uses AWS CLD with minimal configuration to enable commands to be implemented the same as those provided by browser-based AWS management console. This command helps you call the API of Amazon Web Services directly on the command line.

It can be installed and used in each operating system macos, Ubuntu and Linux, and Windows environment. It can also be installed and used in other environments, Python package, and virtualenv, a virtual environment.
AWS CLD Explanation

2-1. Follow the link below and download the file in the right environment. Dwonload
I`m install it according to the window environment.

2-2. Open Cmd and type or click AWSCLIV2.msi file
Command code for setup ->” msiexec.exe /i https://awscli.amazonaws.com/AWSCLIV2.msi “

2-3. click the Next

2-4. To confirm the installation, open the Start menu, search for cmd to open a command prompt window, and at the command prompt use the aws –version command.

2-5 If you can see the message you can skip from 2-6

2-6 If Windows is unable to find the program, you might need to close and reopen the command prompt window to refresh the path, or Adding the AWS CLI to your path.

2-7 open the cmd and type this command “msiexec.exe /i https://awscli.amazonaws.com/AWSCLIV2.msi” You have to know the AWS location. You use the location in your path.

2-8 Adding the Aws CLI to your path Enter “Edit environment variables for your account” the serch section in your computer Choose Path in “User varibales for” and and click “Edit”. Now pop-up new window call Edit environment variable. click the “New” button and type the AWS location. and click ok twice. once done. you have to chceck in the cmd and type aws–version

This completes the installation

AWS uses the IAM user system to authorize other users and can be used together on the AWS console in AWS page. When accessing with your account, you can select Root users and IAM users, and in short, IAM users can be called sub-IDs. Root users can restrict or grant IAM users various rights, and these limited rights can prevent additional charges from being imposed on Root users, so be careful when creating IAM user accounts. IAM user setting method, brief introduction, and setting method for ID security will be briefly explained through video.

In the next blog, we will learn how to use the ec2 server, how to use the database RDS, and how to link to the local computer.

Java print command

2022-02-16T00:00:00+00:00

print

Input	Output
\\	\
\”	”
\n	Change line
\t	Tap
\b	Back space(커서를 한문자 앞으로)
\0	null

printf

System.out.printf(“abcd” : %d”,10)

System.out.printf(“%d%d%d”“,10 ,10, 10)

%d: int %f : double %s : String

Java

2022-02-08T00:00:00+00:00

reminder

System.exit(0)
0 when execution went fien;
1,-1,whatever !=0 when some error occurred, you can use different values for different kind of errors.
What is different String,StirngBuffer,StirngBuilder
Explain
Sample_Code

Python

2022-02-08T00:00:00+00:00

python 공부 하고 쓸꺼임