redis 101

list all keys
redis-cli
> keys *




count item in keys
> llen key_name

> type key

if type is hash, then use hgetall to view

>hgetall key

force client close connection tcp reset

I have ssh client connect to my server for reverse tunnel.

But sometime the connection idle(I cant ssh to the tunnel(no respond)).
So need to find a way to force client close the connection. (my script on the client will reconnect everytime connection closed)


If I just kill the process on the server, by looking the process id via 'netstat -punat', the process will terminated. But the client does not re-initiate the connection. I believe, on the client side, the process still somehow believe the connection is still on going.
Thus, this not is my attempt to find a solution how to safely force the client to close the connection, so that my script will re-connect back to the server.



First suggestion:
On linux kernel >= 4.9 you can use the ss command from iproute2 with key -K

ss -K dst 192.168.1.214 dport = 49029

  the kernel have to be compiled with CONFIG_INET_DIAG_DESTROY option enabled.

Unfortunately this method is not workable on my server, maybe the kernel no compiled with those features


2nd approach:
Using killcx
On centos:
yum --enablerepo=extras install epel-release
yum install perl-Net-IP

yum install cpanspec


ref: https://unix.stackexchange.com/questions/71940/killing-tcp-connection-in-linux

ref 2: https://superuser.com/questions/127863/manually-closing-a-port-from-commandline/668155#668155

ref3: https://www.tecmint.com/install-perl-modules-using-cpan-on-centos/

git tag

Get all tags from remote repo

$ git fetch --all --tags

List all tags:

$git tag

Checkout tag

$ git checkout tags/_tag-name_ -b __branch-name__

do some changess here... or merge with latest branch

$ git merge branch_with_new_features

Create new tag

$ git tag vX.x

Push to remote Repo

$ git push origin vX.x 

ref: https://devconnected.com/how-to-checkout-git-tags/

become a CA, and force device to trust the CA

ref   https://deliciousbrains.com/ssl-certificate-authority-for-local-https-development/

auto mount smb folder on boot

1- manual mount:

sudo mount -t cifs -o username=pakAbu,password=takselamat //1.1.1.1/sharefolder  /mnt/mount_disini/



2- mount on boot

/etc/fstab:

//1.1.1.1/sharefolder /mnt/mount_disini cifs username=pakAbu,password=takselamat 0 0



3- use third file to store credential

/etc/mywinlogin.txt:
username=pakAbu
password=takselamat
domain=WORKGROUP

/etc/fstab:
//1.1.1.1/sharefolder /mnt/mount_disini cifs credential=/etc/mywinlogin.txt 0 0


This will make folder /mnt/mount_disini own by user root, and group root.


4- to change mount dir to normal user
//1.1.1.1/sharefolder /mnt/mount_disini cifs credential=/etc/mywinlogin.txt,uid=1001,guid=1001 0 0

Notice parameter uid and gid. uid number refer to /etc/passwd. gid refer to /etc/group

ssh legacy option

some older ssh server only support limited key exchange algorithm.

When you get this error:

no matching key exchange method found. Their offer: diffie-hellman-group-exchange-sha1,diffie-hellman-group1-sha1

Use this option :
-oKexAlgorithms=+diffie-hellman-group1-sha1

eg:

ssh -oKexAlgorithms=+diffie-hellman-group1-sha1 user@legacyhost

or put this in your .ssh/config file:

Host myhost.example.org
 KexAlgorithms +diffie-hellman-group1-sha1

ref: https://www.openssh.com/legacy.html

list of regripper plugin

# rip.pl -l


or check here: http://hexacorn.com/tools/3r.html