Launching hammr

Hammr is a command-line tool, allowing you to specify commands that get executed by hammr. Each command may have one or more sub-commands and optional parameters. Hammr provides inbuilt help. To list all the main options, use the -h, --help flags or TAB.

$ hammr -h
usage: hammr [-a URL] [-u USER] [-p PASSWORD] [-k PUBLICKEY] [-s SECRETKEY]
             [-c CREDENTIALS] [-v] [-h]
             [cmds [cmds ...]]
To get more information on a sub-command, use the -h, --help flags or TAB for more information

$ hammr template -h
Template help
build                         | Builds a machine image from the template
clone                         | Clones the template. The clone is copying the meta-data of the template
create                        | Create a new template and save to the UForge server
delete                        | Deletes an existing template
export                        | Exports a template by creating an archive (compressed tar file)
help                          | List available commands with "help" or detailed help with "help cmd".
import                        | Creates a template from an archive
list                          | Displays all the created templates
validate                      | Validates the syntax of a template configuration file


There are three different modes when launching hammr:

  • Classic command-line: used in shell scripts or via a terminal
  • Interactive mode: where hammr is launched once, providing you a prompt to execute hammr commands
  • Batch mode: allowing hammr to execute a series of commands from a file

When using the classic mode, the command hammr is used, followed by a command, sub-command and any options. For example:

$ hammr os list --url -u username -p password

To enter interactive mode, launch the hammr command on its own. This provides a prompt, allowing you to enter commands and sub-commands the same way as you would in classic mode.

To use batch mode, create a file containing the list of commands you wish to launch in sequence and then provide this file to hammr via the batch command. For example if you wanted to list all the operating system available to you in batch mode, firstly create a file with the commands to launch, in this case os list:

$ vi batchfile
os list

Launch hammr providing the batch file:

$ hammr batch --file batchfile --url -u username -p password
os list
Getting distributions for [root] ...
| Id  |  Name  | Version | Architecture |    Release Date     |    Profiles     |
| 121 | CentOS | 6.4     | x86_64       | 2013-03-01 14:01:26 | Server No X     |
|     |        |         |              |                     | Server          |
|     |        |         |              |                     | Minimal         |
| 87  | Ubuntu | 12.04   | x86_64       | 2012-02-24 19:04:45 | Minimal Desktop |
|     |        |         |              |                     | Server          |
|     |        |         |              |                     | Minimal         |


Communication between hammr and the UForge server is done via HTTPS. To send requests to the UForge server, hammr requires the following information:

  • UForge Server URL endpoint
  • Your account user name
  • Your password

This information can be passed to hammr either from command-line options or from a file.

Command-line Parameters

Authentication information can be passed to hammr via command-line options. These options are:

  • -a or --url: the UForge Server URL endpoint. If the URL uses HTTPS, then the connection will be done securely (recommended), otherwise connection will be done via HTTP
  • -u or --user: the user name to use for authentication
  • -p or --password: the password to use for authentication

For example

$ hammr os list --url -u username -p password

These parameters need to be passed each time you wish to use the command-line.

Using a Credential File

Rather than passing the authentication information as part of the command-line, you can instead store this information in a credential file (credentials.json or credentials.yml) that will be used every time hammr is launched. Hammr searches for this file in a sub-directory named .hammr located in the home directory of the user launching hammr.


If your AppCenter has a self-signed certificate, in order to use hammr with your AppCenter you must use a credentials file.

To use a credential file, go to the .hammr sub-directory and create the file credentials.yml.


You can also use JSON. In which case you need to create a file credentials.json.

$ cd ~/.hammr
$ vi credentials.yml

For authentication using password, add the authentication and UForge URL endpoint to this file using the following format:

user: root
password: password
acceptAutoSigned: false

If you are using JSON:

  "user" : "root",
  "password" : "password",
  "url" : "",
  "acceptAutoSigned": false

For authentication using API keys, add the authentication and UForge URL endpoint to this file using the following format:

user: root
publickey: P7LFcJKFm9mrchZQfPo2DX7ECeVO-Tlen0nU7qf2YR0HOuwO9ZjQJJbQV7Nr7pyfrq-iUrlNinwiBpAth7
secretkey: wbG7rl402wgTrSd_Enga9HpnxE-PQxtxeMnruyoUIqduaQ9UFmYxfI1l0gf05cgoWfZAd6V_aOyQAlUnYQ
acceptAutoSigned: false

If you are using JSON:

  "user" : "root",
  "publickey" : "P7LFcJKFm9mrchZQfPo2DX7ECeVO-Tlen0nU7qf2YR0HOuwO9ZjQJJbQV7Nr7pyfrq-iUrlNinwiBpAth7",
  "secretkey" : "wbG7rl402wgTrSd_Enga9HpnxE-PQxtxeMnruyoUIqduaQ9UFmYxfI1l0gf05cgoWfZAd6V_aOyQAlUnYQ",
  "url" : ""

As this file contains security information, it is recommended to change the permissions on this file, so only you can read or write to it:

$ chmod 600 credentials.yml

Now every time hammr is launched, you no longer need to provide the authentication information as part of the command-line. Hammr will automatically use the information contained in this file.


The key acceptAutoSigned is to accept or not self-signed SSL certificates. Default value is false.

Using Supervisor Mode

UForge allows you to access UForge as another user if you have supervisor access. Supervisor access rights are assigned by the UForge administrator.


Users with Supervisor Access will be able to log in as ANY of the users in the organization without entering a password. This right should be limited to support or managed services. Users with Supervisor Role needs to respect the privacy of the user data, according to current legislation.

To use hammr in supervisor mode you will need to enter your user name (UserA) as well as the user name of the account you want to access (UserB). For example:

$ hammr os list --url -u "UserA\UserB" -p password