Very fast editing over sshfs

Update: this can cause some of your ssh sessions to hang, so be aware of that.

Add this to your ~/.ssh/config

Host myserver.mydomain.com
  ControlMaster auto
  ControlPath /tmp/%r@%h:%p

Then, say you have root access via your ssh pub key

mkdir tmp001
sshfs -o uid=1000 root@myserver.mydomain.com:/var/www tmp001

Now, the files in tmp001 map to your remote /var/www directory. And access to them uses an ssh session that is maintained in your /tmp directory, i.e. all interactions are performed over the same ssh session.

To see the tmp file, if you just opened the sshfs session in the last 10 mins

find /tmp -mmin -10 -ls

OpenVPN: push all LAN traffic through an OpenVPN client to the other side

1. Local variables for this post, adjust to fit your setup:
1. OpenVPN client server IP
1. 192.168.1.200
2. Remote network
1. 172.16.1.0/24

1. Add this to the client server that is using OpenVPN to connect to the remote server:
1. sudo iptables -A POSTROUTING -o tun0 -j MASQUERADE
2. as root user, do
1. echo 1 > /proc/sys/net/ipv4/ip_forward
2. Add this to your local computer 
1. Linux: 
1. ip route add 172.16.1.0/24 via 192.168.1.200
2. Mac:
1. route -n add 172.16.1.0/24 192.168.1.200

Now, you should be able to ping from your local computer, through the client machine, and to a server in the remote network. Once that works, try ssh.

NOTE: take a look at /etc/sysctl.conf if you want the ip_forward to last through reboots of client server: net.ipv4.ip_forward=1

Edit remote files with local editor using ssh and sshfs

1. apt-get -y install sshfs
2. Add your local user to the fuse group
3. mkdir ~/mylocaldir
4. sshfs -o idmap=user mylocaluser@myremoteserver.com:/remotepath ~/mylocaldir
5. Edit files under ~/mylocaldir, and as you save them, they are automatically updated in /remotepath

Note: the "-o uid=500" can be used if you get permission errors, but replace "500" with you local id number

Errors

1. "Couldn't read packet: Connection reset by peer"
1. change this line in your /etc/ssh/sshd_config file to match what's here
1. Subsystem sftp internal-sftp
2. happens on RedHat Enterprise 6.1 for sure

Run one command on many Linux servers, install pssh, works on Mac

1. sudo easy_install pip
2. sudo pip install pssh
3. Create a file with the list of servers you want to control, call it servers or something similar
4. pssh -h servers "date"
5. Put your ssh pub key up to all of them
1. pssh -h servers -i "echo 'ssh-rsa AA...wh me@myfqdn' >> /home/user/.ssh/authorized_keys"

Taken: http://kaspergrubbe.dk/2012/using-pssh-for-executing-parallel-ssh-commands/

Note: csshX is very nice if you want to see all terminals at once as you type, more later