JAMS Agentd for Linux/Unix

Agents Introduction

Agents allow users to define specific actions that can run locally or remotely throughout a JAMS network. By default, JAMS can only run Jobs and Sequences on the Primary Engine. Agents allow users to extend that capability to run Jobs on a variety of different environments. For example, by using JAMS Agents, a single JAMS Scheduler can execute tasks on many systems.

The JAMS Agentd is a version of the JAMS Agent that runs as a background process on Linux/Unix machines. This topic details how to install this Agent to your primary machine.

Installing the Agent

There are two ways to install the Agent:

• Install from a package (.rpm or .deb): You need to use appropriate package management tools (rpm, yum, apt-get, yast). The .rpm and .deb packages are preferred if you need to install in the standard location as root. The package can also be installed in a non-standard location, but it only handles installation as root.  It also has the advantage of allowing the package system to check for updated versions automatically. (See the notes on the system distribution specific Repo page.)
• Install from the tarball (.tgz):  The is an archive of the files necessary for the install, which needs to be manually installed by following the instructions in the README file included with the .tgz file. This is the preferred method if you need a non-root install.

Installing the Agent from a Package

1. Go to the JAMS Scheduler Repository at: JAMS Scheduler Repository.
2. Select the repository for your system.
3. Download the appropriate jams-agentd package (.rpm [Red Hat packages], .deb [Debian packages], or .rpm [SUSE packages]. For Red Hat, there are different builds for each release.
   
4. Copy the package to the target machine and become root.
5. Use the package manager to install the package.
6. It may be necessary to open the firewall for the JAMS Server to connect to the Agent.  In this case, the default port 77.
   
   For example, use the following for Red Hat rpm. You can use the --prefix PATH option to relocate the RPM package.  (This is not available for the Debian packages.)
   
           # rpm -i jams-agentd-6.5.31-1.el7.x86_64.rpm
   NOTE: JAMS AgentD must be installed as root.

The installer adds the following files:

Root Installation Directory	File Name	Description
/usr/sbin	jams-agentd	Service daemon and management command.
	jams-register	Connection security management command.
/usr/share/doc/jams-agentd	CHANGES	The list of version changes.
	COPYRIGHT	The copyright statement.
	NEWS	Additional details for the list of changes.
	README	Additional information about installation and management.
/usr/share/doc/jams-agentd/openssl	License	The OpenSSL license.
/usr/share/man/man8	jams-agentd.8.gz	The manual page for jams-agentd.
	jams-register.8.gz	The manual page for jams-register.

 The installer also creates a standard configuration, if one is not present. This includes the following certificates and directories:

Root Installation Directory	File Name	Description
/etc/init.d	jams-agentd	The service control script.
/etc/jams	agent-client.config	The Connection configuration file.
	jams-agentd.config	The Service configuration file.
/etc/jams/certs		The Secure SSL certificate storage.
/etc/pam.d	jams-agentd	The PAM authentication file for the Agent.
/var/log/jams		The JAMS related log files.
/var/run	jams-agentd.pid	The executing Agent process id file.
/var/tmp/jams		JAMS Job temporary files (Job scripts).

The jams-agentd daemon has the following built-in commands for managing the daemon service:

Command	Description
jams-agentd -E	Stop the service.
jams-agentd -F	Restart the service.
jams-agentd -G	Start the service.
jams-agentd -T	Report service status.

The jams-agentd daemon can also be managed directly, if the service interface is not being used. Use the following commands:  

Command	Description
jams-agentd -d	Start the jams-agentd daemon in the background.
jams-agentd -K	Stop the jams-agentd daemon.
jams-agentd -Q	Test if the daemon is running. Exit code 1 if not.

Avoid stopping and restarting the daemon directly because it may cause problems with the service management software.

Testing the Connection and Connecting from the JAMS Scheduler

Ensure the correct ports are open/listening on the agentd machine. Port 77 is the default port that jams-agentd uses. You will want to test this connection from the JAMS Scheduler machine by using Telnet or PowerShell.  See the example below:

telnet YourAgent 77
test-netconnection YourAgent -port 77

Creating the Agent Definition

After you verify the connection from the JAMS Scheduler machine to the agentd machine, you can create the Agent Definition in the JAMS Client. 

1. In the JAMS Client, click Agents from the Shortcut menu.
2. Click the Add (+) button to add an Agent.
3. Enter the Name, Description, Type of Agent, and Type of Platform.
4. Click OK.
   
5. On the Properties tab, enter the IP address for the Agent.
   
6. Click the State tab.
7. View the License Allocated section. The License Allocated section is blank until you execute the first Job on the Agent. The State section displays "Idle" when the JAMS AgentD is currently not executing Jobs.
8. Click OK.        

Creating a Credential

Create a Credential for a user on the Linux machine that has the ability to log in and execute the process that is defined in the JAMS Job.

1. In the JAMS Client, click Credentials from the Shortcut menu.
2. Click the Add (+) button to add a new Credential.
3. On the Add a New JAMS Credential dialog, enter the Logon As and Password fields.
4. Click OK.
   

Creating a Job Definition

1. In the JAMS Client, click Definitions from the Shortcut menu.
2. Click the Add (+) button to add a new Definition.
3. On the Add a New JAMS Job Definition dialog, select an Execution Method.
   
4. Click the Source tab.
5. Enter the following:
   

   #!/bin/bash
   ls

   
6. Click the Properties tab.
7. Under Schedule, set the Agent.
8. Under Execute, select LinuxAdmin.
9. Click OK. 

Public Key Authentication

PUBLIC-KEY is a valid user_authentication option in the config file. It uses the same public-private key in JAMS as SSH.

PAM Support

Currently, the PAM support needs to have a PAM configuration file for jams-agentd. This is expected to be in the /etc/pam.d directory. When installing jams-agentd, the installer will attempt to create this file by copying the file for sshd with certain edits.

The PAM support uses only auth and account parts. No password updates are possible and a session is not used.  This may cause problems with some types of PAM plug ins.

jams-agentD Commands

Commands

The following table lists the commands available for the jams-agentd command. 

Short Command	Long Command	Argument Optional	Valid Options	Description
-d	--daemon-mode		-c -p	Fork/exit the program to run in the background.
-h	--host-mode		-c -j	Job hosting mode, used internally to run Jobs.
-s	--shared-mode		-c -u	Shared
-C	--create-config	file name	-p -u	Create config_file with default settings or send to standard out.
-E	--stop-service			Stop jams-agentd service.
-F	--restart-service			Stop and start jams-agentd service.
-G	--start-service			Start jams-agentd service.
-I	--install-jams		-c -p -r -u	Install jams-agentd files and configurations with prompts.
-J	--install-quietly		-c -p -r -u	Install jams-agentd files and configurations without prompts.
-K	--kill-daemon	signal number		Stop jams-agentd daemon, using the optional signal.
-P	--pam-config	file name		Create standard PAM config file or send to standard out.
-Q	--query-status			Check for running daemon.
-R	--remove-service			Remove the jams-agentd service.
-S	--service-file	file name	-c -u	Create the standard Service control file or send to standard out.
-T	--service-status			Report the status of jams-agentd service.
-U	--update-config			Update the config file with latest settings (planned).
-V	--version			Report the current version and configuration locations.
-?	--help			List of commands and options.

Options

The following table lists options available for the jams-agentd command.

Short Option	Long Option	Argument	Description
-c	--config-file	file	Use an alternate configuration file.
-j	--job-id	job-id	The ID of the running Job.
-l	--log-level	log-level	Set the logging level to ERROR, WARN, INFO, DEBUG, or TRACE.
-p	--port-number	port	Listen on alternate port.
-r	--root path	install-dir	Directory to use as the root for installation.
-u	--user-name	user name	User environment.