CA add Replacing your lost SSH key pair on Public Cloud

pages/cloud/public-cloud/replacing_lost_ssh_key/guide.en-ca.md

@@ -0,0 +1,87 @@
+---
+title: 'Replacing your lost SSH key pair'
+slug: replacing_your_lost_ssh_key_pair
+excerpt: 'This guide explains how to configure the authorized_keys file for the admin user, so that you can add a new SSH key to regain access to your instance'
+legacy_guide_number: g2069
+section: Troubleshooting
+---
+
+**Last updated 2018/10/05**
+
+## Objective
+
+If you have lost your SSH key, you might be unable to connect to your instance if you have not configured any alternative way to do so.
+
+To regain access, we have provided you with a [rescue mode](https://docs.ovh.com/gb/en/public-cloud/put_an_instance_in_rescue_mode/){.external}, which allows you to log in with a password and then change your files.
+
+**This guide explains how to configure the authorized_keys file for the admin user, so that you can add a new SSH key to regain access to your instance.**
+
+## Requirements
+
+* root access to your server via SSH
+
+## Instructions
+
+After mounting your instance's disk in [rescue mode](https://docs.ovh.com/gb/en/public-cloud/put_an_instance_in_rescue_mode/){.external}, you will be able to access all your files. The file containing your SSH keys is shown below:
+
+```
+/home/USER_NAME/.ssh/authorized_keys
+```
+
+If you want to add your new SSH key, you just have to edit this file as follows:
+
+```
+admin@instance:~$ sudo vim /mnt/home/USER_NAME/.ssh/authorized_keys
+
+ssh-rsa 1111111111122222222222333333333333444444444555555555556666666666
+777777777778888888888999999900000000000000000000000000== old@sshkey
+ssh-rsa AAAAAAAAABBBBBBBBBBBCCCCCCCCCCCCCCCCDDDDDDDDDDDDDDDDDDDEEEEEEEEE
+EEFFFFFFFFFFFFFGGGGGGGGGGGGGhhhhhhhhhhhhhhhhhhhhhhhhhh== new@sshkey
+```
+
+### Change the SSH key for the default user
+To change your default user's SSH key, you just have to go to the user's personal file.
+
+For example, for the admin user, the file you need is in the following folder:
+
+```
+/home/admin/.ssh/authorized_keys
+```
+
+For an Ubuntu instance, the default user will be ubuntu and the file will therefore be in the following folder:
+
+```
+/home/ubuntu/.ssh/authorized_keys
+```
+
+### Change the password for the default user
+
+You can also change your default user's password by using rescue mode and the following commands (if the user is admin).
+
+First, change the root directory so that it is placed directly on the instance's disk:
+
+> [!primary]
+>
+In the example below, we have used **vdb1** as the name of the server's disk and **mnt** as the mount point.
+>
+
+
+```
+root@instance:/home/admin# mount /dev/vdb1 /mnt/
+root@instance:/home/admin# chroot /mnt/
+```
+
+Then change the admin password.
+
+```
+root@instance:/# passwd 
+admin
+```
+
+Once this change has taken place and been backed up, you need to reboot your instance on its disk, so that you can log in with your new SSH key.
+
+## Go further
+
+[Become root and select a password](https://docs.ovh.com/gb/en/public-cloud/become_root_and_select_a_password/){.external}
+
+Join our community of users on <https://community.ovh.com/en/>.