no such file or directory 'authorized_keys'

$ ssh-keygen -t rsa -P ""
Generating public/private rsa key pair.
Enter file in which to save the key (/home/dhruvhadoop1/.ssh/id_rsa): cat /home/hadoopuser/.ssh/id_rsa.pub >> /home/hadoopuser/ .ssh/authorized_keys
open cat /home/hadoopuser/.ssh/id_rsa.pub >> /home/hadoopuser/ .ssh/authorized_keys failed: No such file or directory.
Saving the key failed: cat /home/hadoopuser/.ssh/id_rsa.pub >> /home/hadoopuser/ .ssh/authorized_keys.
$ chmod 600 authorized_keys
chmod: cannot access ‘authorized_keys’: No such file or directory
$ chmod 600 authorized_keys
chmod: cannot access ‘authorized_keys’: No such file or directory

Solution 1:

This was the prompt

Enter file in which to save the key (/home/dhruvhadoop1/.ssh/id_rsa)

and you have not answered with a file path.

Therefore start the generation again via

su - hadoopuser
ssh-keygen -t rsa -P ""

and use the default value or another filename but not a command like cat ..., e.g.

/home/hadoopuser/.ssh/id_rsa.pub

After that

cat /home/hadoopuser/.ssh/id_rsa.pub | sudo tee -a /home/hadoopuser/.ssh/authorized_keys
sudo chmod 600 /home/hadoopuser/.ssh/authorized_keys/authorized_keys