Obtaining the certificates
Obtain private and public keys from exported pfx file:
openssl pkcs12 -in ldaps.pfx -nocerts -nodes -out ldap.key
openssl pkcs12 -in ldaps.pfx -clcerts -nokeys -out ldap.crt
Category Archives: Ubuntu
Nginx TCP proxy with SSL Termination
An error occurred when accepting connection in the local socket. Code: 24
Tried the following
sysctl net.core.somaxconn
net.core.somaxconn = 4096
sudo sysctl -w net.core.somaxconn=8192
but without a success.
(more…)Configuring a TCP proxy with Nginx on Ubuntu 24.04
Install Nginx with stream module:
sudo apt install nginx-full
The output of the command
nginx -V
should contain with-stream=dynamic.
And add the following to /etc/nginx/nginx.conf:
stream {
server {
listen 12345; # The port that Nginx listens to
proxy_pass 192.168.0.121:389; # Where to forward connections
}
}
Exporting and importing WSL distributions
Exporting
In PowerShell:
wsl --export Ubuntu Ubuntu-01.tar
where Ubuntu is the distro name.
Importing
wsl --import UbuntuA C:\Users\dmitriano\wsl\UbuntuA Ubuntu-24.01.tar
probably the folder C:\Users\dmitriano\wsl\UbuntuA should exist.
Using lb to measure LDAP performance
Download and install latest Go:
wget https://go.dev/dl/go1.25.1.linux-amd64.tar.gz
tar xf ../distrib/go1.25.1.linux-amd64.tar.gz
realpath go
export GOROOT=/home/dmitriano/dev/tools/go
export GOPATH=$HOME/go
export PATH=$GOPATH/bin:$GOROOT/bin:$PATH
Install the package:
go install github.com/hamano/lb@latest
Using Apache JMeter to measure LDAP performance
Extract the archive:
tar xf /mnt/c/Users/dmitriano/Downloads/apache-jmeter-5.6.3.tgz
Install Java runtime:
sudo apt install default-jre
java --version
openjdk 21.0.8 2025-07-15
OpenJDK Runtime Environment (build 21.0.8+9-Ubuntu-0ubuntu124.04.1)
OpenJDK 64-Bit Server VM (build 21.0.8+9-Ubuntu-0ubuntu124.04.1, mixed mode, sharing)
Running v2rayN client on WSL
unzip /mnt/c/Users/dmitr/Downloads/v2rayN-linux-64.zip
sudo apt install libice6 libsm6
./v2rayN &
curl -s https://api.ipify.org
Investigating Kerboros with kinit and Wireshark
On the domain controller:
nslookup -q=SRV _kerberos._tcp.other.local
Server: localhost
Address: 127.0.0.1
_kerberos._tcp.other.local SRV service location:
priority = 0
weight = 100
port = 88
svr hostname = 7-dev-de-dc16.other.local
7-dev-de-dc16.other.local internet address = 10.15.7.16
Squid unexpectedly stopped working
Squid unexpectedly stopped working with my home internet connection. I created a temporary user:
cd /etc/squid/
sudo htpasswd -B squid-password temp
sudo service squid reload
tried the following command
curl -v -x https://developernote.com:3129 --proxy-user temp:<password> -I https://api.ipify.org/
with another internet provider and it succeeded.
(more…)Reducing image size with command line
With the command below
mogrify -path . -strip -quality 50% *.jpg
I reduces the size of the following images
-rwxrwxrwx 1 def def 4.0M Apr 9 16:48 20250409_164822.jpg*
-rwxrwxrwx 1 def def 3.6M Apr 9 16:48 20250409_164831.jpg*
-rwxrwxrwx 1 def def 4.2M Apr 9 16:49 20250409_164902.jpg*
-rwxrwxrwx 1 def def 4.1M Apr 9 16:49 20250409_164910.jpg*
-rwxrwxrwx 1 def def 3.7M Apr 9 16:49 20250409_164917.jpg*
-rwxrwxrwx 1 def def 3.8M Apr 9 16:49 20250409_164924.jpg*
