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Introduction

This document describes the functionality of the JobSchedulerSSHJob and the parameters to configure the Job properly. Additionally this document provides a minimal example for a SSH Job configuration.

Mode Of Operation

Unix based operating systems provide an SSH client, while MS Windows operating systems do not. 

The JobSchedulerSSHJob allows the execution of shell commands and scripts on a remote host running a SSH server without requiring a local SSH client to be installed.

For a minimal SSH job only a limited number of parameters has to be configured as shown in the example below.

Example

A minimal SSH Job configuration

Simple SSH Job
<?xml version="1.0" encoding="ISO-8859-1"?>
<job title="Launch remote commands or executable files by SSH" stop_on_error="no">
    <description >
        <include  file="jobs/JobSchedulerSSHJob.xml"/>
    </description>
    <params >
        <param  name="host" value="HOSTNAME"/>
        <param  name="user" value="USERNAME"/>
        <param  name="password" value="PASSWORD"/>
        <param  name="auth_method" value="password"/>
        <param  name="command" value="printenv"/>
    </params>
    <script  language="java" java_class="sos.scheduler.job.SOSSSHJob2JSAdapter"/>
    <run_time />
</job>

Parameters

  • Required Parameters
    • Parameters which have to be set in the job configuration to proerly run the job
      • Example: To connect to a remote host, the  'host' parameter is always required to run the job properly.
  • Optional Parameters
    • Parameters which are not required or parameters which are technically required but are instantiated throug a default value and therefore do not have to be set in the job configuration
      • Example 1: technically required, but instantiated with default value
        • To connect to a remote host, the  'port' parameter is required. The parameter is instantiated with the default value '22' therefore the 'port' parameter does not have to be set in the job configuration.
      • Example 2: not required
        • The 'proxy_host' parameter is only used if the jobs connection has to be instantiated over a proxy, otherwise it is not needed at all

Required Parameters

host

  • default value:
    • empty
  • description:
    • This parameter specifies the hostname or IP address of the SSH server to which a connection is to be made.

user

  • default value:
    • empty
  • description:
    • This parameter specifies the user account to be used when connecting to the SSH server.

Optional Parameters

port

  • default value:
    • 22
  • description:
    •  This parameter specifies the port number of the SSH server.

auth_method

  • default value:
    • publickey
  • description:
    • This parameter specifies the authorization method for the SSH server - the publickey and password methods are supported. When the publickey authorization method is used, then the path name of the private key file must be set in the auth_file parameter. Should the private key file be secured by a password then this must be specified with the password parameter. For the password authorization method the password for each user account must be specified using the password parameter. The authorization methods which are enabled depend on the SSH server configuration. Not all SSH server configurations support the password authorization method.

password

  • default value:
    • empty
  • description:
    • This parameter specifies the user account password for authorization by the SSH server and must be specified if the password authorization method is specified in the auth_method parameter. 
      Alternatively, this parameter may specify the secret key passphrase if the publickey authorization method has been set in the auth_method parameter.

auth_file

  • default value:
    • empty
  • description:
    • This parameter specifies the path and name of a user's private key file used for registration on an SSH server. This parameter must be specified if the publickey authorization method has been specified in the auth_method parameter. 
      If the private key file is secured with a passphrase, the password parameter hat to be set with the passphrase.

command_delimiter

  • default value:
    • %%
  • description:
    • Command delimiter characters are specified using this parameter. These delimiters can then used in the command parameter to separate multiple commands. These commands are then executed in a separate SSH session.

command

  • default value:
    • empty
  • description:
    • This parameter specifies a command that is to be executed on the SSH server. Multiple commands can be separated by the command delimiter that is specified using the command_delimiter parameter.

command_script

  • default value:
    • empty
  • description:
    • This parameter can be used as an alternative to commandcommand_delimiter and command_script_file. It contains script code which will be saved to a temporary (script-)file on the remote host and executed there. The script can access task and order parameters by environment variables. The names are in upper case and have "SCHEDULER_PARAM_" as a prefix. Order parameters with the same name overwrite task parameters.

command_script_file

  • default value:
    • empty
  • description:
    • This parameter can be used as an alternative to commandcommand_delimiter and command_script. It contains the name of a local (script-)file, which will be transferred to the remote host and executed there. The script can access task and order parameters by environment variables. The names are in upper case and have "SCHEDULER_PARAM_" as a prefix. Order parameters with the same name overwrite task parameters.

proxy_host

  • default value:
    • empty
  • description
    • The value of this parameter is the host name or the IP address of a proxy used to create the connection to the SSH server. The use of a proxy is optional.

proxy_port

  • default value:
    • empty
  • description
    • This parameter specifies the port number of the proxy, should a proxy be used to create the connection to the SSH server.

proxy_user

  • default value:
    • empty
  • description
    • The value of this parameter specifies the user account for authorization by the proxy server should a proxy be used to connect to the SSH server.

proxy_password

  • default value:
    • empty
  • description
    • This parameter specifies the password for the proxy server user account, should a proxy be used to connect to the SSH server.

command_script_param

  • default value:
    • empty
  • description
    • This parameter contains a parameter string, which will be appended when calling the command_script or the command_script_file.

ignore_error

  • default value:
    • false
  • description
    • If the value true is set, then execution errors caused by commands on the SSH server are ignored. Otherwise such execution errors for jobs and orders are reported by the Job Scheduler.

ignore_exit_code

  • default value:
    • empty
  • description
    • This parameter configures one or more exit codes which will not be treated as errors. Multiple exit codes can be defined comma separated or using ranges.
  • examples:
    • 255
    • 2,3,4,100
    • 4,50-60,210-220

ignore_signal

  • default value:
    • false
  • description
    • If the value true is set, then on Unix systems all signals will be ignored that terminate the execution of a command on the SSH server - if for example a command is terminated using kill. 
      Note that by default the Job Scheduler reports errors for commands that are terminated by signals.

ignore_stderr

  • default value:
    • false
  • description
    • This job checks if any output to stderr has been created by a command that is being executed on the SSH server and reports this as an error. 
      If the value true is set, then output to stderr will not be reported as an error by the Job Scheduler.

simulate_shell

  • default value:
    • false
  • description
    • If the value true is set, then a login to a shell is simulated to execute commands. Some scripts may cause problems if no shell is present.

simulate_shell_prompt_trigger

  • default value:
    • empty
  • description
    • The expected command line prompt. Using this prompt the job tries to find out if commands may be entered or have been carried out. If no prompt can be configured, timeout parameters have to be used.

simulate_shell_login_timeout

  • default value:
    • empty
  • description
    • If no new characters are written to stdout or stderr after the given number of milliseconds, the job assumes that that the login has been carried out and the shell is waiting for commands.

simulate_shell_inactivity_timeout

  • default value:
    • empty
  • description
    • If no new characters are written to stdout or stderr after the given number of milliseconds, the job assumes that that the command has been carried out and the shell is waiting for commands.

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