In the previous recipe, we saw how we can access the repository using the username and password. In this section, we will use SSH private and public keys to access the repository. We will be accessing the repository using SSH connections.

This topic assumes that you already have, or know how to create, a pair of public/private keys. You should be familiar with SSH and its configuration files.

Before setting up CodeCommit for SSH users, we need the AWS CLI installed and configured with the respective AWS account. To install the AWS CLI on our development machine, we need to perform these steps:

1. We need to install python-pip and AWS CLI tools. Usually, in CentOS/RHEL, python-pip comes with EPEL (Extra Package for Enterprise Linux):

    # yum install epel-release python-pip
    # pip install awscli

2. Once we have the awscli command installed in our system, we have to configure it using the access and secret Key, as well as the region we will use the AWS account in. If you remember, we had created a user while generating the https git credentials, but at that moment, we also downloaded another type of credentials, the secret and access key. So, we need that over here.
3. Now, let's configure AWS CLI:

    awsstar@awsstar:~$ aws configure
     AWS Access Key ID [None]: AKIxxxxxxxxxxxxxDDA
     AWS Secret Access Key [None]: b+GEuc2u3xxxxxxxxxxxxxx+av/5eK
     Default region name [None]: us-east-1
     Default output format [None]:

4. Once the configuration is done, let's try to list the repository:

    awsstar@awsstar:~$ aws codecommit list-repositories
     {
     "repositories": [
     {
     "repositoryName": "NixSrj",
     "repositoryId": "73caf1e3-65a9-44bf-8c6a-a3bd3e0260b0"
     },
     {
     "repositoryName": "ECS-POC",
     "repositoryId": "62063220-b0fc-4519-9d54-896be46a7521"
     },
     {
     "repositoryName": "terraform-Openshift",
     "repositoryId": "20f88492-81bb-4068-8867-5d17a1d3ec5b"
     }
     ]
     }

5. So it's showing the repository, which means the credentials are working fine and we are good to go to create a repository now.

1. Create a repository, HelloWorld:

    awsstar@awsstar:~$ aws codecommit create-repository --repository-    name HelloWorld --repository-description "This repository includes     static page of HelloWorld"
     {
     "repositoryMetadata": {
     "repositoryName": "HelloWorld",
     "cloneUrlSsh": "ssh://git-codecommit.us-east-    1.amazonaws.com/v1/repos/HelloWorld",
 "lastModifiedDate": 1501778613.664,
 "repositoryDescription": "This repository includes static page of     HelloWorld",
 "cloneUrlHttp": "https://git-codecommit.us-east-    1.amazonaws.com/v1/repos/HelloWorld",
 "creationDate": 1501778613.664,
 "repositoryId": "53866a81-8576-4e79-ab5a-36882c33b717",
 "Arn": "arn:aws:codecommit:us-east-1:160384169139:HelloWorld",
 "accountId": "160384169139"
 }
 }

2. Now, check it using the following command:

    awsstar@awsstar:~$ aws codecommit list-repositories
     {
     "repositories": [
     {
     "repositoryName": "HelloWorld",
     "repositoryId": "53866a81-8576-4e79-ab5a-36882c33b717"
     }
     ]
 }    

3. Let's try to clone the HelloWorld repository from CodeCommit to our development machine; but before that, we have to establish SSH authentication. To do that, we have to perform the following operations to generate the SSH keys:

    awsstar@awsstar:~$ ssh-keygen
     Generating public/private rsa key pair.
     Enter file in which to save the key (/home/awsstar/.ssh/id_rsa):
     Created directory '/home/awsstar/.ssh'.
     Enter passphrase (empty for no passphrase):
     Enter same passphrase again:
     Your identification has been saved in /home/awsstar/.ssh/id_rsa.
     Your public key has been saved in /home/awsstar/.ssh/id_rsa.pub.
     The key fingerprint is:
     SHA256:NMUiRSDRD9SxrSIcYm9A4BYau2TOaeEfk5TgRmy3i4o     root@aa21529d724f
     The key's randomart image is:
     +---[RSA 2048]----+
     |+=. o+o=+o. |
     |=*o...+ o+. |
     |+O=oo ++.. |
     |Oo+*.. ..o |
     |.*.+* . S |
     |...oo. . |
     |o . |
     |E |
     | |
     +----[SHA256]-----+

4. The preceding command will create two keys; one is the public key (id_rsa.pub) and the other one is the private key (id_rsa).
5. Now, we have to upload the public key to the user of AWS we created:

    awsstar@awsstar:~$ cd .ssh
    awsstar@awsstar:~/.ssh$ aws iam upload-ssh-public-key --user-name     awsccuser --ssh-public-key-body "ssh-rsa     AAAAB3NzaC1yc2EAAAADAQABAAABAQCk437p8/JmhGOdM9oYNK/r1xpOnuA2cQNfYys7lnE9gXJdTEjniHNFcJZMkIVmtYQGAqEh37BWGfXl4s5iw/NSfkDuZf8zegAgyPryR0KTTUG2f/rrtyLtlAPlSXjtCmHakZzhwIoRJtzkDbSpKoUOD8fNnS3kKIwk7Dp3+gGLLgo9eoZdud9h/E5+NpORog7wg7xaTgg3mwa9StaPHKMxJNwNc71dIuUyAh2S6bDbHB3QWLNfrJABYqPq5HGFh3KLogH9GHBMajshLEOS4Ygk3uC8FzB+eP4oneuWd2n68N3qg5RmX0U5lAL8s3+ppuhmjlbSvDOdBUJdpgEL/AQZ awsstar@awsstar"

6. We need to make a note of some details, such as the SSHPublicKeyId provided as output in thew JSON format, while uploading the SSH public key.
7. We have to bring about some modification in the config file lying in $HOME/.ssh/config:

    awsstar@awsstar:~$ vi .ssh/config
    Host git-codecommit.us-east-1.amazonaws.com
    User APKAIGJDPRJL3INHSJ6Q
    IdentityFile ~/.ssh/id_rsa

8. Once we are done saving the config file, let's see the connectivity between the development machine and AWS CodeCommit:

    awsstar@awsstar:~$ ssh git-codecommit.us-east-1.amazonaws.com
     The authenticity of host 'git-codecommit.us-east-1.amazonaws.com     (54.239.20.155)' can't be established.
     RSA key fingerprint is     SHA256:eLMY1j0DKA4uvDZcl/KgtIayZANwX6t8+8isPtotBoY.
     Are you sure you want to continue connecting (yes/no)? yes
     Warning: Permanently added 'git-codecommit.us-east-    1.amazonaws.com,54.239.20.155' (RSA) to the list of known hosts.
     You have successfully authenticated over SSH. You can use Git to     interact with AWS CodeCommit. Interactive shells are not     supported.Connection to git-codecommit.us-east-1.amazonaws.com closed     by remote host.
     Connection to git-codecommit.us-east-1.amazonaws.com closed.

9. We get the output that says Successfully authenticated over SSH, so now we are ready to clone the repository. We can clone the SSH URL of the repository, which we obtain from the JSON output while creating the repository:

    awsstar@awsstar:~$ git clone ssh://git-codecommit.us-east-    1.amazonaws.com/v1/repos/HelloWorld
     Cloning into 'HelloWorld'...
     warning: You appear to have cloned an empty repository.
     checking connectivity... done
    awsstar@awsstar:~$ ls
    HelloWorld
    awsstar@awsstar:~$

10. So, we cloned an empty repository; now it's time to put a sample index.html file in the CodeCommit HelloWorld repository:

     awsstar@awsstar:~/HelloWorld$ echo '<h1> Hello World </h1>' >     index.html
     awsstar@awsstar:~/HelloWorld$ git add .
     awsstar@awsstar:~/HelloWorld$ git commit -m " index.html push "
     [master (root-commit) bc76f76] index.html push
     1 file changed, 1 insertion(+)
     create mode 100644 index.html
     root@awsstar:~/HelloWorld# git push origin master
     Counting objects: 3, done.
     Writing objects: 100% (3/3), 233 bytes | 0 bytes/s, done.
     Total 3 (delta 0), reused 0 (delta 0)
     To ssh://git-codecommit.us-east-    1.amazonaws.com/v1/repos/HelloWorld
     * [new branch] master -> master

11. In this stage, we successfully pushed our local file into the AWS CodeCommit HelloWorld repository.