Passing ssh options to git clone

I'm trying to run git clone without ssh checking the repository host's key. I can do it from ssh like that:

ssh -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no user@host

Is there any way to pass the same ssh options to the git clone command?

Edit: There is a restriction that I can't modify ~/.ssh/config or any other files on that machine.

Solution 1:

The recently released git 2.3 supports a new variable "GIT_SSH_COMMAND" which can be used to define a command WITH parameters.

GIT_SSH_COMMAND="ssh -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no" git clone user@host

$GIT_SSH_COMMAND takes precedence over $GIT_SSH, and is interpreted by the shell, which allows additional arguments to be included.

Solution 2:

Add them to your ~/.ssh/config:

Host host
    HostName host
    User user
    SshOption1 Value1
    SshOption2 Value2

The Host entry is what you’ll specify on the command line, and the HostName is the true hostname. They can be the same, or the Host entry can be an alias. The User entry is used if you do not specify user@ on the command line.

If you must configure this on the command line, set the GIT_SSH environment variable to point to a script with your options in it.

Solution 3:

Another option made to specify different keys is git config core.sshCommand with git 2.10 + (Q3 2016).

This is an alternative to the environment variable described in Boris's answer)

See commit 3c8ede3 (26 Jun 2016) by Nguyễn Thái Ngọc Duy (pclouds).
^{(Merged by Junio C Hamano -- gitster -- in commit dc21164, 19 Jul 2016)}

A new configuration variable core.sshCommand has been added to specify what value for GIT_SSH_COMMAND to use per repository.

Similar to $GIT_ASKPASS or $GIT_PROXY_COMMAND, we also read from config file first then fall back to $GIT_SSH_COMMAND.

This is useful for selecting different private keys targetting the same host (e.g. github)

core.sshCommand:

If this variable is set, git fetch and git push will use the specified command instead of ssh when they need to connect to a remote system.
The command is in the same form as the GIT_SSH_COMMAND environment variable and is overridden when the environment variable is set.

It means the git clone can be:

cd /path/to/my/repo
git config core.sshCommand 'ssh -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no' 
# later on
git clone host:repo.git

If you want to apply that for all repos, as user1300959 adds in the comments, you would use a global configuration.

git config --global core.sshCommand 'ssh -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no'