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Table of Contents Expand all

play_arrow Overview
- play_arrow Junos Automation Scripts Overview
- play_arrow Junos XML Management Protocol and Junos XML API Overview
play_arrow Automation Scripting Using XSLT
- play_arrow XSLT Overview
- play_arrow Standard XPath and XSLT Functions Used in Automation Scripts
- play_arrow Standard XSLT Elements and Attributes Used in Automation Scripts
play_arrow Automation Scripting Using SLAX
- play_arrow SLAX Overview
- play_arrow SLAX Statements
- play_arrow The libslax Distribution for Automation Scripting
play_arrow Automation Scripting Using Python
- play_arrow Python Overview
play_arrow Automation Script Input
- play_arrow Global Parameters in Automation Scripts
  - Global Parameters and Variables in Junos OS Automation Scripts
play_arrow Extension Functions and Named Templates for Automation Scripts
play_arrow Manage Automation Scripts
- play_arrow Store and Enable Scripts
- play_arrow Configure a Remote Source for Scripts
- play_arrow Configure the Session Protocol for Scripts
  - Understanding the Session Protocol in Automation Scripts
  - Example: Specify the Session Protocol for a Connection within Scripts
- play_arrow Control Execution of Scripts
- play_arrow Synchronize Scripts Between Routing Engines
- play_arrow Convert Scripts Between SLAX and XSLT
  - Convert Scripts Between SLAX and XSLT
play_arrow Commit Scripts
- play_arrow Commit Scripts Overview
  - Commit Script Overview
  - How Commit Scripts Work
- play_arrow Create and Execute Commit Scripts
- play_arrow Generate a Custom Warning, Error, or System Log Message Using Commit Scripts
- play_arrow Generate Persistent or Transient Configuration Changes Using Commit Scripts
- play_arrow Create Custom Configuration Syntax with Commit Script Macros
- play_arrow Commit Script Examples
- play_arrow Junos XML and XSLT Tag Elements Used in Commit Scripts
- play_arrow Troubleshoot Commit Scripts
play_arrow Op Scripts
- play_arrow Op Scripts Overview
  - Op Script Overview
  - How Op Scripts Work
- play_arrow Create and Execute Op Scripts
- play_arrow Op Script Examples
- play_arrow Provision Services Using Service Template Automation
  - Service Template Automation Overview
  - Example: Configure Service Template Automation
- play_arrow Troubleshoot Op Scripts
  - Trace Op Script Processing on Devices Running Junos OS
  - Trace Script Processing on Devices Running Junos OS Evolved
play_arrow Event Policies and Event Scripts
play_arrow SNMP Scripts
- play_arrow SNMP Scripts Overview
  - SNMP Scripts Overview
- play_arrow Create and Execute SNMP Scripts
- play_arrow SNMP Script Example
  - Example: Process Unsupported OIDs with an SNMP Script
- play_arrow Troubleshoot SNMP Scripts
  - Trace SNMP Script Processing on Devices Running Junos OS
  - Trace Script Processing on Devices Running Junos OS Evolved
play_arrow Configuration Statements and Operational Commands
- Junos CLI Reference Overview

list Table of Contents

English

Example: Generate a Custom Error Message

date_range 19-Nov-24

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Junos OS commit scripts can generate custom error messages during a commit operation to alert you when the configuration violates custom configuration rules. Emitting an error message causes the commit to fail. This example creates a commit script that generates a custom error message when a specific statement is not included in the device configuration, thereby halting the commit operation.

Requirements

Junos OS Release 16.1R3 or later release when using a Python script.

Overview and Commit Script

Using a commit script, write a custom error message that appears when the description statement is not included at the [edit interfaces t1-fpc/pic/port] hierarchy level:

The script is shown in XSLT, SLAX, and Python.

XSLT Syntax

content_copy zoom_out_map
<?xml version="1.0" standalone="yes"?>
<xsl:stylesheet version="1.0"
    xmlns:xsl="http://www.w3.org/1999/XSL/Transform" 
    xmlns:junos="http://xml.juniper.net/junos/*/junos" 
    xmlns:xnm="http://xml.juniper.net/xnm/1.1/xnm" 
    xmlns:jcs="http://xml.juniper.net/junos/commit-scripts/1.0">
    <xsl:import href="../import/junos.xsl"/>
 
    <xsl:template match="configuration">
        <xsl:variable name="interface" select="interfaces/interface"/>
        <xsl:for-each select="$interface[starts-with(name, 't1-')]"> 
            <xsl:variable name="ifname" select="."/>
            <xsl:if test="not(description)">
                <xnm:error>
                    <xsl:call-template name="jcs:edit-path"/>
                    <xsl:call-template name="jcs:statement"/>
                    <message>Missing a description for this T1 interface.</message>
                </xnm:error>
            </xsl:if>
        </xsl:for-each>
    </xsl:template>
</xsl:stylesheet>

SLAX Syntax

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version 1.2;
ns junos = "http://xml.juniper.net/junos/*/junos";
ns xnm = "http://xml.juniper.net/xnm/1.1/xnm";
ns jcs = "http://xml.juniper.net/junos/commit-scripts/1.0";
import "../import/junos.xsl";
 
match configuration {
    var $interface = interfaces/interface;
    for-each ($interface[starts-with(name, 't1-')]) {
        var $ifname = .;
        if (not(description)) {
            <xnm:error> {
                call jcs:edit-path();
                call jcs:statement();
                <message> "Missing a description for this T1 interface.";
            }
        }
    }
}

Python Syntax

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from junos import Junos_Configuration
import jcs

def main():
    root = Junos_Configuration
    for element in root.xpath(
        "./interfaces/interface[starts-with(name,'t1-')]"):
        # Missing description
        if element.find('description') is None:
            # Emit error message to console
            jcs.emit_error("Missing a description for this T1 interface: " 
                + element.find('name').text)

if __name__ == '__main__':
    main()

Configuration

Procedure

Step-by-Step Procedure

Download, enable, and test the script: To test that a commit script generates an error message correctly, make sure that the candidate configuration contains the condition that elicits the error. For this example, ensure that the configuration for a T1 interface does not include the description statement.

To test the example in this topic:

Copy the script into a text file, name the file description.xsl, description.slax, or description.py as appropriate, and copy it to the /var/db/scripts/commit/ directory on the device.

Note:
Unsigned Python scripts must be owned by either root or a user in the Junos OS super-user login class, and only the file owner can have write permission for the file.
In configuration mode, configure the file statement and the script filename at the [edit system scripts commit] hierarchy level.
```
[edit]
user@host# set system scripts commit file description.xsl
```
If the script is written in Python, enable the execution of unsigned Python scripts.
```
[edit]
user@host# set system scripts language python
```
Note:
Configure the language python3 statement to use Python 3 to execute Python scripts, or configure the language python statement to use Python 2.7 to execute Python scripts. For more information, see language.
If the configuration for every T1 interface includes the description statement, delete the description for an existing T1 interface for testing purposes.
```
[edit]
user@host# delete interfaces t1–0/0/1 description
```
Issue the commit command to commit the configuration.
```
user@host# commit
```

Verification

Purpose

Verify the error message generated by the commit script.

Action

Review the output of the commit command. The commit script generates an error message for each T1 interface that does not include a description statement. Any error causes the commit process to fail.

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[edit]
user@host# commit
[edit interfaces interface t1-0/0/1]
    'description'
        Missing a description for this T1 interface.
[edit interfaces interface t1-0/0/2]
    'description'
        Missing a description for this T1 interface.
error: 2 errors reported by commit scripts
error: commit script failure

To display the XML-formatted version of the error message, issue the commit check | display xml command.

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[edit interfaces t1-0/0/1]
user@host# commit check | display xml
<rpc-reply xmlns:junos="http://xml.juniper.net/junos/10.0R1/junos">
    <commit-results>
        <routing-engine junos:style="normal">
            <name>re0</name>
            <xnm:error>
                <edit-path>
                    [edit interfaces interface t1-0/0/1]
                </edit-path>
                <statement>
                    description
                </statement>
                <message>
                    Missing a description for this T1 interface.
                </message>
            </xnm:error>
            <xnm:error>
                <edit-path>
                    [edit interfaces interface t1-0/0/2]
                </edit-path>
                <statement>
                    description
                </statement>
                <message>
                    Missing a description for this T1 interface.
                </message>
            </xnm:error>
            <xnm:error xmlns="http://xml.juniper.net/xnm/1.1/xnm"
                     xmlns:xnm="http://xml.juniper.net/xnm/1.1/xnm">
                <message>
                    2 errors reported by commit scripts
                </message>
            </xnm:error>
            <xnm:error xmlns="http://xml.juniper.net/xnm/1.1/xnm" 
					        xmlns:xnm="http://xml.juniper.net/xnm/1.1/xnm">
                <message>
                    commit script failure
                </message>
            </xnm:error>
        </routing-engine>
    </commit-results>
    <cli>
        <banner>[edit interfaces]</banner>
    </cli>
</rpc-reply>

To display a detailed trace of commit script processing, issue the commit check | display detail command.

content_copy zoom_out_map
[edit interfaces t1-0/0/1]
user@host# commit check | display detail
2009-06-15 15:56:09 PDT: reading commit script configuration
2009-06-15 15:56:09 PDT: testing commit script configuration
2009-06-15 15:56:09 PDT: opening commit script '/var/db/scripts/commit/error.xsl'
2009-06-15 15:56:09 PDT: reading commit script 'error.xsl'
2009-06-15 15:56:09 PDT: running commit script 'error.xsl'
2009-06-15 15:56:09 PDT: processing commit script 'error.xsl'
[edit interfaces interface t1-0/0/1]
    'description'
        Missing a description for this T1 interface.
[edit interfaces interface t1-0/0/2]
    'description'
    Missing a description for this T1 interface.
2009-06-15 15:56:09 PDT: 2 errors from script 'error.xsl'
error: 2 errors reported by commit scripts
error: commit script failure

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Automation Scripting User Guide

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Example: Generate a Custom Error Message

Requirements

Overview and Commit Script

Configuration

Procedure

Step-by-Step Procedure

Verification

Verifying Script Execution

Purpose

Action

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Automation Scripting User Guide

ON THIS PAGE

Example: Generate a Custom Error Message

Requirements

Overview and Commit Script

Configuration

Procedure

Step-by-Step Procedure

Verification

Verifying Script Execution

Purpose

Action

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