Permission denied for git dependencies in package.json

I try setup git dependencies in package.json:

"dependencies": {
    "myLib": "git+ssh://git@domain.com:user/myLib.git"
  }

When I do sudo npm install I got errors:

Warning: Permanently added the RSA host key for IP address 'myIp' to the list of known hosts.

 Permission denied (publickey).

Allthough I can clone successfully the same lib to that machine:

git clone git@domain.com:user/myLib.git

So I have valid ssh keys.

My os is OsX but I have the same problem on linux.

I should run npm install without sudo.

If can not, then change permissions for node.js apps folder:

sudo chown -R `whoami` ~/pathToAll/node/apps.

So git ssh dependencies work well in package.json

Here is a solution that allows for continued use of sudo npm install.

Add the following to a text file /root/.ssh/config:

Host domain.com
    User git 
    Port 22
    Hostname domain.com
    IdentityFile "/home/user/.ssh/id_rsa"
    TCPKeepAlive yes 
    IdentitiesOnly yes 
    StrictHostKeyChecking no

This configuration references the original key file even while using the sudo command for things like sudo npm install.