Test Free Connect LDAP or AD

LDAP Server Information (read-only access): 
Server: ldap.forumsys.com  
Port: 389
Bind DN: cn=read-only-admin,dc=example,dc=com
Bind Password: password
All user passwords are password.
You may also bind to individual Users (uid) or the two Groups (ou) that include:

SFTP restrict user with IP address access home directory only

1. Add user and group

>useradd warawich
>groupadd sftponly
>usermod -G sftponly warawich
>usermod warawich -g sftponly -s /sbin/nologin
>passwd warawich
>cd /home/warawich
>mkdir .ssh
>cd .ssh && touch authorized_keys

2. Paste public key in authorized_keys file then save

Then change permission directory and file
>chmod 700 -R /home/warawich
>chmod 600 /home/warawich/.ssh/authorized_keys

3. Edit sshd_config

Example: We want to limit access from and for user warawich and allows access from anywhere for other users
vim /etc/ssh/sshd_config 

UseDNS no
Subsystem sftp internal-sftp
    AllowUsers [email protected] [email protected] user1 user2
    Match Group sftponly
    ChrootDirectory /home
    ForceCommand internal-sftp
    PermitTunnel no
    AllowAgentForwarding no
    X11Forwarding no
    AllowTcpForwarding no
systemctl restart sshd

Memory Leak , use minimum cost for droplet , Let’s create swap file.

I use wordpress, nginx, mysql, php-fpm with minimun cost on DigitalOcean and found the memory leak problem. This cause MySQL stop working and my websit goes down.

I also found there are lots child processes of php-fpm. I thought I should consider to increase the memory (use 1 GB) or not. Anyway I don’t want to spent my money for my website as I’m person to check it out only one HaHa if you came across to read this. You are second.

These are I did for fix the memory issue.

Create swap file https://www.digitalocean.com/community/tutorials/how-to-add-swap-on-centos-7 I create 2GB swapfile because my memory has 1 GB . If you have memory more than 1 GB , you should multiply 1.5 of physical memory.

//Check Swap usage
swapon -s
//if no return message, it mean no swap 

//create swap file
sudo dd if=/dev/zero of=/swapfile count=2096 bs=1MiB

//change permission read write only
sudo chmod 600 /swapfile

//make a swapfile
mkswap /swapfile

//enable swap 
swapon /swapfile

//Check Swap usage again
swapon -s
//should return swap size
[[email protected] warawich.com]# swapon -s
Filename Type Size Used Priority
/swapfile file 2097148 264 -2

Make the Swap File Permanent

vi /etc/fstab

/swapfile   swap    swap    sw  0   0

Then reboot OS

Now, you have memory more but the root cause is php-fpm create lots of child process and consume your memory , so you need to limit php-fpm create child process too.

vim /etc/php-fpm.d/www.conf

//change configure as below
pm = ondemand
pm.max_children = 20
pm.start_servers = 5
pm.process_idle_timeout = 10s
pm.max_requests = 100

save and restart php-fpm service

systemctl restart php-fpm 
//check memory free
[email protected] warawich.com]# free -m
total used free shared buff/cache available
Mem: 990 544 111 12 335 294
Swap: 2047 0 2047

All of these what i did! Please suguest me if what you think or what I miss. Thank you.

Google Cloud Registry too long not read

1. Install Google SDK on your computer Ref. https://cloud.google.com/sdk/docs/install

2. Login google account and gcloud project with command below

gcloud auth login

gcloud auth configure-docker
  • Incase , you use docker-compose file or use CI/CD pipeline , we recommend use service account with json key file to authen with google cloud

Create service account with google cloud storage role (read, write,admin)
Example login with JSON key

cat keyfile.json | docker login -u _json_key --password-stdin https://HOSTNAME
where HOSTNAME is gcr.io, us.gcr.io, eu.gcr.io, or asia.gcr.io.
cat box-in-the-box-7ab21e41seb57.json|  docker login -u _json_key --password-stdin https://asia.gcr.io

3. Build image by use image path details as below



4. Docker build , tag, push , pull

docker build -t asia.gcr.io/box-in-the-box/social:latest .
docker push asia.gcr.io/box-in-the-box/social:latest 
docker pull asia.gcr.io/box-in-the-box/social:latest 

5. Docker Compose example

version: '3'

    container_name: social
      - "NODE_ENV=${NODE_ENV}"
    #  context: .
    #  dockerfile: Dockerfile-live
    image: asia.gcr.io/box-in-the-box/social
      - "2000:3000"
      - "/opt/app/"
    restart: on-failure:5

Use Gmail SMTP for relay server on Postfix

  1. Install Postfix on your server:
    • On Debian/Ubuntu systems, you can use the following command: sudo apt-get install postfix
    • On CentOS/Red Hat systems, you can use the following command: sudo yum install postfix
  2. Once Postfix is installed, open the main configuration file using your favorite text editor: sudo nano /etc/postfix/main.cf
  3. Find the following lines in the configuration file and modify them as follows:
    • relayhost = [smtp.gmail.com]:587
    • smtp_sasl_auth_enable = yes
    • smtp_sasl_security_options = noanonymous
    • smtp_sasl_password_maps = hash:/etc/postfix/sasl_passwd
  4. Next, create a new file called sasl_passwd in the /etc/postfix directory: sudo nano /etc/postfix/sasl_passwd
  5. Add the following line to the sasl_passwd file, replacing [email protected] and password with your Gmail address and password: [smtp.gmail.com]:587 [email protected]:password
  6. Save and close the sasl_passwd file, then run the following command to create a hashed version of the file: sudo postmap /etc/postfix/sasl_passwd
  7. Finally, restart the Postfix service to apply the changes: sudo service postfix restart

You should now be able to use Gmail’s SMTP server to send emails through Postfix.

สร้าง Line notify สำหรับ System Administrator

Line Notify ของเดิมทำง่ายมาก แต่พอเปลี่ยนมาเป็น Version ใหม่ (ให้ secure มากขึ้น) ก็ทำแบบเดิมไม่ได้แล้ว ยุ่งยาก โชคดีหาเจอ แต่ต้นฉบับเป็นภาษาจีน (แปลด้วย google เอานะ) tool ที่ใช้ทำมี ngrok, postman, line account