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5.2. Using SSH Keys for Authentication

In addition to the username and password authentication, CloudStack supports using SSH keys to log in to the cloud infrastructure for additional security. You can use the createSSHKeyPair API to generate the SSH keys.
Because each cloud user has their own SSH key, one cloud user cannot log in to another cloud user's instances unless they share their SSH key files. Using a single SSH key pair, you can manage multiple instances.

5.2.1.  Creating an Instance Template that Supports SSH Keys

Create a instance template that supports SSH Keys.
  1. Create a new instance by using the template provided by cloudstack.
    For more information on creating a new instance, see
  2. Download the cloudstack script from The SSH Key Gen Scriptto the instance you have created.
    wget http://downloads.sourceforge.net/project/cloudstack/SSH%20Key%20Gen%20Script/cloud-set-guest-sshkey.in?r=http%3A%2F%2Fsourceforge.net%2Fprojects%2Fcloudstack%2Ffiles%2FSSH%2520Key%2520Gen%2520Script%2F&ts=1331225219&use_mirror=iweb
  3. Copy the file to /etc/init.d.
    cp cloud-set-guest-sshkey.in /etc/init.d/
  4. Give the necessary permissions on the script:
    chmod +x /etc/init.d/cloud-set-guest-sshkey.in
  5. Run the script while starting up the operating system:
    chkconfig --add cloud-set-guest-sshkey.in
  6. Stop the instance.

5.2.2. Creating the SSH Keypair

You must make a call to the createSSHKeyPair api method. You can either use the CloudStack Python API library or the curl commands to make the call to the cloudstack api.
For example, make a call from the cloudstack server to create a SSH keypair called "keypair-doc" for the admin account in the root domain:

Note

Ensure that you adjust these values to meet your needs. If you are making the API call from a different server, your URL/PORT will be different, and you will need to use the API keys.
  1. Run the following curl command:
    curl --globoff "http://localhost:8096/?command=createSSHKeyPair&name=keypair-doc&account=admin&domainid=5163440e-c44b-42b5-9109-ad75cae8e8a2"
    The output is something similar to what is given below:
    <?xml version="1.0" encoding="ISO-8859-1"?><createsshkeypairresponse cloud-stack-version="3.0.0.20120228045507"><keypair><name>keypair-doc</name><fingerprint>f6:77:39:d5:5e:77:02:22:6a:d8:7f:ce:ab:cd:b3:56</fingerprint><privatekey>-----BEGIN RSA PRIVATE KEY-----
    MIICXQIBAAKBgQCSydmnQ67jP6lNoXdX3noZjQdrMAWNQZ7y5SrEu4wDxplvhYci
    dXYBeZVwakDVsU2MLGl/K+wefwefwefwefwefJyKJaogMKn7BperPD6n1wIDAQAB
    AoGAdXaJ7uyZKeRDoy6wA0UmF0kSPbMZCR+UTIHNkS/E0/4U+6lhMokmFSHtu
    mfDZ1kGGDYhMsdytjDBztljawfawfeawefawfawfawQQDCjEsoRdgkduTy
    QpbSGDIa11Jsc+XNDx2fgRinDsxXI/zJYXTKRhSl/LIPHBw/brW8vzxhOlSOrwm7
    VvemkkgpAkEAwSeEw394LYZiEVv395ar9MLRVTVLwpo54jC4tsOxQCBlloocK
    lYaocpk0yBqqOUSBawfIiDCuLXSdvBo1Xz5ICTM19vgvEp/+kMuECQBzm
    nVo8b2Gvyagqt/KEQo8wzH2THghZ1qQ1QRhIeJG2aissEacF6bGB2oZ7Igim5L14
    4KR7OeEToyCLC2k+02UCQQCrniSnWKtDVoVqeK/zbB32JhW3Wullv5p5zUEcd
    KfEEuzcCUIxtJYTahJ1pvlFkQ8anpuxjSEDp8x/18bq3
    -----END RSA PRIVATE KEY-----
    </privatekey></keypair></createsshkeypairresponse>
  2. Copy the key data into a file. The file looks like this:
    -----BEGIN RSA PRIVATE KEY-----
    MIICXQIBAAKBgQCSydmnQ67jP6lNoXdX3noZjQdrMAWNQZ7y5SrEu4wDxplvhYci
    dXYBeZVwakDVsU2MLGl/K+wefwefwefwefwefJyKJaogMKn7BperPD6n1wIDAQAB
    AoGAdXaJ7uyZKeRDoy6wA0UmF0kSPbMZCR+UTIHNkS/E0/4U+6lhMokmFSHtu
    mfDZ1kGGDYhMsdytjDBztljawfawfeawefawfawfawQQDCjEsoRdgkduTy
    QpbSGDIa11Jsc+XNDx2fgRinDsxXI/zJYXTKRhSl/LIPHBw/brW8vzxhOlSOrwm7
    VvemkkgpAkEAwSeEw394LYZiEVv395ar9MLRVTVLwpo54jC4tsOxQCBlloocK
    lYaocpk0yBqqOUSBawfIiDCuLXSdvBo1Xz5ICTM19vgvEp/+kMuECQBzm
    nVo8b2Gvyagqt/KEQo8wzH2THghZ1qQ1QRhIeJG2aissEacF6bGB2oZ7Igim5L14
    4KR7OeEToyCLC2k+02UCQQCrniSnWKtDVoVqeK/zbB32JhW3Wullv5p5zUEcd
    KfEEuzcCUIxtJYTahJ1pvlFkQ8anpuxjSEDp8x/18bq3
    -----END RSA PRIVATE KEY-----
  3. Save the file.

5.2.3. Creating an Instance

After you save the SSH keypair file, you must create an instance by using the template that you created at Section 5.2.1, “ Creating an Instance Template that Supports SSH Keys”. Ensure that you use the same SSH key name that you created at Section 5.2.2, “Creating the SSH Keypair”.

Note

You cannot create the instance by using the GUI at this time and associate the instance with the newly created SSH keypair.
A sample curl command to create a new instance is:
curl --globoff http://localhost:<port numbet>/?command=deployVirtualMachine\&zoneId=1\&serviceOfferingId=18727021-7556-4110-9322-d625b52e0813\&templateId=e899c18a-ce13-4bbf-98a9-625c5026e0b5\&securitygroupids=ff03f02f-9e3b-48f8-834d-91b822da40c5\&account=admin\&domainid=1\&keypair=keypair-doc
Substitute the template, service offering and security group IDs (if you are using the security group feature) that are in your cloud environment.

5.2.4. Logging In Using the SSH Keypair

To test your SSH key generation is successful, check whether you can log in to the cloud setup.
For exaple, from a Linux OS, run:
ssh -i ~/.ssh/keypair-doc <ip address>
The -i parameter tells the ssh client to use a ssh key found at ~/.ssh/keypair-doc.