[LINUX]Install CentOS on VMWare can not enable network connection

 Tested install CentOS7 on an old VMWare with ESXi 5.5.

After change VM resource memory more than 2 GB, installed CentOS7 successfully.

But anyway, I can not get the network work.

I checked any possible reason, including but not limited to VM resource, VM network, Device on CentOS, etc., everything is working fine. But CentOS will have no network.

BTW, configure on CentOS also setup properly like below: (let's suppose that you have the interface as enp0s3 with the static ip 192.168.1.11/24)

nmcli d  ## to check which interface you are using.

nmcli c modify enp0s3 ipv4.address 192.168.1.11/24  ## setup ip

nmcli c modify enp0s3 ipv4.gateway 192.168.1.1 ## setup default gateway 

nmcli c modify enp0s3 ipv4.method manual  ## static ip

It will change [BOOTPROTO=dhcp→none]

sudo systemctl restart networkmanager

Does it seem fine?

No, there is a very important thing.

You have to enable the network interface first via below:

nmcli c m enp0s3 connection.autoconnect yes 

It will change [ONBOOT=no→yes], or the interface will not work as you expected. 

You may also need below step to confirm the network to see if it can working fine.

Show network configuration.

nmcli d show enp0s3

Edit host file to obtain your host name with your ip.

192.168.1.1 your_router_name #router

192.168.1.11 your_hostname　#

Confirm [/etc/resov.conf], it should show something as below:

nameserver 192.168.1.1

Then ping local and remote URL to see if the DNS can resolve the domain name and get ICMP traffic from them. 

 

[MacOS]Add auto log function to terminal.app

Boring with Mac terminal color of white and black?

Ok, you can change the theme.

I like the homebrew theme, but it has too bright color for text.

OK, that is not my point.

For some reason, I need to add a function for terminal.app on Mac to record the command and screen output as what I can see.

You can go to the menu, [Terminal] -> [Configuration] -> Click the theme you are using [Shell]. Then you will see a startup shell command input.

 now=`date +%Y%m%d%H%M%S`;logpath=~/scriptlogs/script_${now}.txt;script ${logpath}

Just copy and paste above. It will add auto execute script when terminal.app start up and execute it with script command of unix.

You also can change the following path to where you want to keep your log. "~/scriptlogs/"  

Then check the execute in shell. You need shutdown terminal.app and start it again.

Now you have an auto log for Mac terminal.app.

But most people will ignore one thing...

If you try to execute the command [cat the log] in the terminal.app, you will get into a loop...and a fast increased size log file till your system crash. 

Because the screen out put will be written to log imediately and it was also shown as standard output then it will be recorded to log again and again. 

[CentOS]When trying to install CentOS stream on VMware, it got [kernal error] error

Just want to try new CentOS stream, so reopen the VMware machine.

It is running on a very old ESXi 5.5 via a vSphere center 5.5 from about 10 years ago.

After mounted the OS, it showed below [Kernal panic] error.

Considered it is a very old system, then I tested CentOS7. Same error occurred.

So it should be a something else.

Noticed that I created the VM machine based on ESXi default configuration. It was set the memory as 384MB as a template for CentOS 4/5/6 or any Linux version. That is it.

CentOS 7 run in a necessary requirement at least 1GB memory. Sorry, no any official document link, just got advices from many sites...

In fact, I set it as 512MB, it is also running.

[LinkedIn]How to enable #OpenToWork Tag in LinkedIn

This is nothing related to technic, just for the feature of LinkedIn.

It is really hard to find it....

 

To enable the #OpenToWork feature:

1. Click the Me icon at the top of your LinkedIn homepage.
2. Click View profile.
3. Click the Open to button.
4. Click Finding a new job.
5. Provide the requested information in the pop-up window that appears. ...
6. Click Add to profile.

[YAMAHA Router]The difference between YAMAHA Router RTX1210 and RTX1220

Have a request to compare YAMAHA Router RTX1210 and RTX1220.

For some meaning, it is a best replacement of CISCO Router which always need high price maintenance contract.

According to YAMAHA site, only below changed.

Not so much improvement.

But in auction with price, they have about 40,000 difference...

So if I should refresh the hardware, it is a problem...

項目		RTX1220	RTX1210
希望小売価格（税抜）		118,000円	125,000円
認証番号		D20-0252001/M20-0021	CD14-0216001/M14-0011
JANコード		49 57812 67103 3	49 57812 57644 4
ISDN S/Tポート		非搭載	1ポート（終端抵抗ON/OFF可能）
対応回線およびサービス網	ISDN（BRI）	非対応	対応
	高速デジタル専用線（64kbit/s, 128kbit/s）	非対応	対応
WANプロトコル	PPP	非対応	対応
	MP	非対応	対応
QoS機能（制御方式）	CBQ	非対応	対応
	WFQ	非対応	対応
認証機能	ISDN識別着信	非対応	対応
バックアップ機能	ISDNへのバックアップ	非対応	対応
設定手段	ISDN回線経由のリモートセットアップ	非対応	対応
その他機能	BOD（MP, BACP）	非対応	対応
	リモートアクセスサーバー	非対応	対応
	コールバック(無課金独自方式, Windows標準方式)	非対応	対応
状態表示ランプ	ISDN［L1/B1, B2］	非搭載	搭載
付属品	CD-ROM（1枚:［PDF］取扱説明書, コマンドリファレンス, 設定例集, ［ソフトウェア］RT-FileGuard, MD5SUM）	なし	あり
	最大1年間無償のYNOライセンス	あり	なし
ファームウェア		Rev.15.04系	Rev.14.01系

 

[Python]Use Python to send form data to page

 Consider to request a form URL to get the site accept the data.

import requests # Define the form data form_data = { 'name': 'G X', 'email': 'gx@gx.com' } # Send a POST request with the form data response = requests.post('http://gx.com/submit', data=form_data) # Check if the request was successful (status code 200) if response.status_code == 200: print('Form submitted successfully') else: print('Failed to submit the form')

But actually, it won't work for the site I had expected.

Because the site will use a one-time serial session id to identify the request. need to update.

Yes, you are right. this is a tips for company timecard registration automation. 

 

Cloud Service Comparison Cheat Sheet

 Just got one sheet for comparison 4 cloud services difference.

Hope can help someone, including me.

[Letsencrypt]Import Letsencrypt on AWS EC2 Instance

I have a site need to be implemented on AWS EC2 with SSL for my daughter.

We already have some sites with test running on it.

So we set up VirtualHost for it.

After it can work on AWS EC2, I imported Certbot for it.

It is a installed package with AWS Linux already and this is a subdomain for gxlcs.com, like temp.gxlcs.com.

We only have few steps need to do.

1. sudo yum install certbot

2. sudo systemctl start certbot-renew.timer

3. sudo certbot certonly

4. 

How would you like to authenticate with the ACME CA?

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

1: Runs an HTTP server locally which serves the necessary validation files under

the /.well-known/acme-challenge/ request path. Suitable if there is no HTTP

server already running. HTTP challenge only (wildcards not supported).

(standalone)

2: Saves the necessary validation files to a .well-known/acme-challenge/

directory within the nominated webroot path. A seperate HTTP server must be

running and serving files from the webroot path. HTTP challenge only (wildcards

not supported). (webroot)

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

Select the appropriate number [1-2] then [enter] (press 'c' to cancel): 2

Enter email address (used for urgent renewal and security notices)

 (Enter 'c' to cancel): webmaster@gxlcs.com

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

Please read the Terms of Service at

https://letsencrypt.org/documents/LE-SA-v1.4-April-3-2024.pdf. You must agree in

order to register with the ACME server. Do you agree?

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

(Y)es/(N)o: Y

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

Would you be willing, once your first certificate is successfully issued, to

share your email address with the Electronic Frontier Foundation, a founding

partner of the Let's Encrypt project and the non-profit organization that

develops Certbot? We'd like to send you email about our work encrypting the web,

EFF news, campaigns, and ways to support digital freedom.

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

(Y)es/(N)o: N

Account registered.

Please enter the domain name(s) you would like on your certificate (comma and/or

space separated) (Enter 'c' to cancel): temp.gxlcs.com

Requesting a certificate for temp.gxlcs.com

Input the webroot for temp.gxlcs.com: (Enter 'c' to cancel): 

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

 does not exist or is not a directory

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

Input the webroot for temp.gxlcs.com: (Enter 'c' to cancel): /var/www/html/temp

Successfully received certificate.

Certificate is saved at: /etc/letsencrypt/live/temp.gxlcs.com/fullchain.pem

Key is saved at:         /etc/letsencrypt/live/temp.gxlcs.com/privkey.pem

This certificate expires on 2024-07-11.

These files will be updated when the certificate renews.

Certbot has set up a scheduled task to automatically renew this certificate in the background.

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

If you like Certbot, please consider supporting our work by:

 * Donating to ISRG / Let's Encrypt:   https://letsencrypt.org/donate

 * Donating to EFF:                    https://eff.org/donate-le

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 

5. sudo systemctl is-enabled httpd

if the response is [disabled], need to run #6.

6.  sudo systemctl start httpd && sudo systemctl enable httpd

7.  sudo yum update -y

8.  sudo yum install -y mod_ssl

9. After #8, it will create a conf file with name ssl.conf in /etc/httpd/conf.d/

10. sudo nano /etc/httpd/conf.d/ssl.conf

11. specify the [SSLCertificateFile] and [SSLCertificateKeyFile] with the path where you keep the key and certificate.

12. sudo systemctl restart httpd.service

13. Because we have VirtualHost, you also may need to change VirtualHost setup with where you put the DocumentRoot and Server Name.

14. As we have permitted the 443 port traffic in AWS Console, I mean inbound rule under security group, so the traffic is not problem.

15. I use CLOUDFLARE to provide security for site (Free version), so we also need to add a CNAME DNS record for this site. You can enter the AWS EC2 Instance tag, then confirm public DNS name which will be used in CLOUDFLARE CNAME DNS record CONTENT. 

OK, Now your site will go ahead in the net with SSL.

I will add the screenshot when I have time, sorry for any inconvenience.

Additional: I also have a security test for the site.

you can refer to below URL: 

Qualys

 

 

[Python]JPG to PNG Python Program

from PIL import Image import os def convert_jpg_to_png(input_folder, output_folder): # 1. Get list up the input folder files jpg_files = [f for f in os.listdir(input_folder) if f.endswith('.jpg')] # 2. Create the output folder if it did not exist os.makedirs(output_folder, exist_ok=True) # 3. Change the JPG to PNG files for jpg_file in jpg_files: jpg_path = os.path.join(input_folder, jpg_file) # Create the PNG file output path png_path = os.path.join(output_folder, os.path.splitext(jpg_file)[0] + '.png') # Change the image img = Image.open(jpg_path) img.save(png_path, 'PNG') if __name__ == "__main__": input_folder = "path" # Define the input path of JPG output_folder = "path" # Define the output path of PNG convert_jpg_to_png(input_folder, output_folder)

Need to get them work on my site...