How can a novice configure multiple SSH Key（ Easy to understand hand-in-hand teaching ）

One 、 Understand the background

1. One Github There can be multiple accounts SSH-Key It's related to .
   Simply speaking , You use your home computer to generate a SSH-Key Set to account , meanwhile , You can also generate a SSH-Key Set to the same account . here , You can submit the code to the warehouse at home or in the company ~
   

2. A computer （ terminal ） You can configure multiple SSH-Key For more than one Git account number .
   for instance , You need to use Gitlab Do internal development , But sometimes I want to use my own Github Account for personal development . here , Don't learn to configure multiple SSH-Key Can't do anything ！

3. Github stay 2021 year 8 month 13 The day begins , Will be right in Git The account password is no longer accepted when the operation is authenticated , And will require the use of token based (token) Authentication of .
   good heavens , No match SSH Key, Even the code commit No ！

Two 、 Quick start

Now I want to be in Github To configure SSH keys For example .

1. Check if there is SSH-Key

Open your Git bash, Get into ~/.ssh Catalog , adopt ll Command to see if there is SSH-Key There are no relevant documents ！

$ cd ~/.ssh
$ ls

If it shows id_rsa and id_rsa.pub file , It shows that there is already SSH Key 了 . without , Then follow the steps 2 Generate a ！

2. Generate a （ Or more ）SSH-Key

Generate a Github With SSH-Key, among github_id_rsa Is the file name of the key ,~/.ssh/github_id_rsa Is the key directory location ：

$ ssh-keygen -t rsa -C '[ mailbox ]' -f ~/.ssh/github_id_rsa

Generate a Gitlab With SSH-Key, among gitlab_id_rsa Is the file name of the key ,~/.ssh/gitlab_id_rsa Is the key directory location ：

$ ssh-keygen -t rsa -C '[ mailbox ]' -f ~/.ssh/gitlab_id_rsa

3. newly build config And configuration

stay ~/.ssh Under the table of contents , adopt touch Command NEW config file , And use vim Editor open config file .

#  newly build  config  file 
$ touch config
#  use  vim  Editor open  config  file 
$ vim config

stay config file in , Add the following ：

# github
Host github.com
HostName github.com
PreferredAuthentications publickey
IdentityFile ~/.ssh/github_id_rsa

# gitlab
Host gitlab.com
HostName gitlab.com
PreferredAuthentications publickey
IdentityFile ~/.ssh/gitlab_id_rsa

#  If multiple  SSH-Key ,  Then continue to write down according to the above format 

among Host and HostName Fill in Git Domain name of the server ,IdentityFile Specifies the path to the private key （ In the second step, generate SSH-Key when , We have specified the path , Just copy it ）.

4. obtain SSH Key

Go to ~/.ssh/ View the generated files in the directory ：

Generated files to [xxx]_rsa start , [xxx]_rsa It's the private key , [xxx]_rsa.pub It's the public key .

adopt cat Command to view the contents of the public key file , Copy content to Github It can be used normally on .

$ cat [xxx]_rsa.pub

5. stay Github Or others Git New server SSH Key

stay Github Personal settings page , Click on “New SSH Key” . Take a name , Take what you got in the last step SSH Key Copy in .

6. use ssh Command test whether the configuration is successful SSH Key（ If there are more than one, test them separately ）

$ ssh -T [email protected]

Here we use Github For example , Success will return to Hi [ user name ]!You've successfully authenticated, but GitHub does not provide shell access.

3、 ... and 、 Other questions

1. SSH The configuration. , The project needs to be switched to SSH Cloning .
   
2. My project passed HTTPS The way of cloning , Now I want to use SSH How to submit by ？
   In the project .git Folder , find config File and open , Modify the url.
   
   
3. ssh-keygen Description of common parameters ：

• -t : Key type , You can choose dsa | ecdsa | ed25519 | rsa ;
• -f : Key directory location , Default to current user home The next path .ssh Hide directory , That is to say ~/.ssh/ , At the same time, the default key file name is id_rsa start . If it is root user , It's in /root/.ssh/id_rsa , For other users , It's in /home/username/.ssh/id_rsa;
• -C : Specify the comment information for this key , When multiple password free logins need to be configured , It is recommended to carry ;

thank

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