Release Announcement: NSO 6.6 is here!
Check out the release highlights to see what's new
NSO DevCenterTry NSO

README v1.2.6 2025-01-07

Table of contents

1. General
   1.1 Extract the NED package
   1.2 Install the NED package
       1.2.1 Local install
       1.2.2 System install
   1.3 Configure the NED in NSO
2. Optional debug and trace setup
3. Dependencies
4. Sample device configuration
5. Built in live-status actions
6. Built in live-status show
7. Limitations
8. How to report NED issues and feature requests
9. How to rebuild a NED
10. Configure the NED to use ssh multi factor authentication

1. General

This document describes the redhat-dir389 NED.

General info and considerations.

  • REDHAT-DIR389: This NED addresses Redhat Dir389 deployments

    • We will reffer to them throughout this document simply as "the device" or "the Redhat-DIR389 device".

  • The devices are expected to run RedHat, Fedora or derived Linux systems. Interaction with the device is done via CLI using SSH session encrypted with strong secure ciphers. Telnet is not supported.

  • Since the underlying OS is a Linux based system, unless otherwise requested, live status commands or RPCs are limited/not implemented.

  • Please make sure you have the right ned-settings configured as below at section 1.3.1 or refer to section 8 from NedSettings readme.

Additional README files bundled with this NED package

Common NED Features

Verified target systems

1.1 Extract the NED package

It is assumed the NED package ncs-<NSO version>-redhat-dir389-<NED version>.signed.bin has already been downloaded from software.cisco.com.

In this instruction the following example settings will be used:

  • NSO version: 6.0

  • NED version: 1.0.1

  • NED package downloaded to: /tmp/ned-package-store

  1. Extract the NED package and verify its signature:

  2. In case the signature can not be verified (for instance if no internet connection), do as below instead:

  3. The result of the extraction shall be a tar.gz file with the same name as the .bin file:

1.2 Install the NED package

There are two alternative ways to install this NED package. Which one to use depends on how NSO itself is setup.

In the instructions below the following example settings will be used:

  • NSO version: 6.0

  • NED version: 1.0.1

  • NED download directory: /tmp/ned-package-store

  • NSO run time directory: ~/nso-lab-rundir

A prerequisite is to set the environment variable NSO_RUNDIR to point at the NSO run time directory:

1.2.1 Local install

This section describes how to install a NED package on a locally installed NSO (see "NSO Local Install" in the NSO Installation guide).

It is assumed the NED package has been been unpacked to a tar.gz file as described in 1.1.

  1. Untar the tar.gz file. This creates a new sub-directory named:redhat-dir389-<NED major digit>.<NED minor digit>:

  2. Install the NED into NSO, using the ncs-setup tool:

  3. Open a NSO CLI session and load the new NED package like below:

Alternatively the tar.gz file can be installed directly into NSO. Then skip steps 1 and 2 and do like below instead:

Set the environment variable NED_ROOT_DIR to point at the NSO NED package:

1.2.2 System install

This section describes how to install a NED package on a system installed NSO (see "NSO System Install" in the NSO Installation Guide).

It is assumed the NED package has been been unpacked to a tar.gz file as described in 1.1.

  1. Do a NSO backup before installing the new NED package:

  2. Start a NSO CLI session and fetch the NED package:

  3. Install the NED package (add the argument replace-existing if a previous version has been loaded):

  4. Load the NED package

1.3 Configure the NED in NSO

This section describes the steps for configuring a device instance using the newly installed NED package.

  • Start a NSO CLI session:

  • Enter configuration mode:

  • Configure a new authentication group (my-group) to be used for this device:

  • Configure a new device instance (example: dev-1):

  • If configured protocol is ssh, do fetch the host keys now:

1.3.1 <MANDATORY!> Configure/define LDAP-SETTINGS:

1.3.2 From redhat-dir389 v1.2.0 onwards, additional options are available:

1.3.3 Example of ned-settings configuration with tls enabled:

1.3.4 Example of ned-settings configuration with tls disabled:

1.3.5 VERY IMPORTANT! Define managed-dn-list BASE DN or full DN to be managed by the NED.

  • path: <device-name>/ned-settings/redhat-dir389/ldap-settings/managed-dn-list *

    • Define the dn ldap entries the NED is authorized to manage

    • PLEASE NOTE THAT THE NED WILL TRY TO MANAGE ONLY THE DEFINED LDAP ENTRIES WITH DN FORMATTED AS FOLLOWS:

      • [Important UPDATE]: base_dn can be used starting with NED v 1.1

      • if the base dn is provided, all entries returned by ldapsearch will be stored in /config/ldap-entries list accordingly.

      • Multiple "dn" formats accepted as inputs, i.e.:

        • ou=ouName,o=oName

        • ou=ouName,o=oName,dc=dcValue

        • ou=ouName,o=oName,dc=dcValue1,dc=dcValue2

        • ou=ouName,o=oName1,o=oName2

        • ou=ouName,o=oName1,o=oName2,dc=dcValue

        • ou=ouName,o=oName1,o=oName2,dc=dcValue1,dc=dcValue2

        • cn=abc-def.com,ou=ouName,o=oName

        • cn=abc-def.com,ou=ouName,o=oName,dc=dcValue

        • cn=abc-def.com,ou=ouName,o=oName,o=oName2

        • cn=abc-def.com,ou=ouName,o=oName,o=oName2,dc=dcValue

        • cn=abc-def.com,ou=ouName,o=oName,dc=dcValue1,dc=dcValue2

        • cn=abc-def.com,ou=ouName,o=oName,o=oName2,dc=dcValue1,dc=dcValue2

        • uid=12345,cn=abc-def.com,ou=ouName,o=oName

        • uid=12345,cn=abc-def.com,ou=ouName,o=oName,o=oName2

        • uid=12345,cn=abc-def.com,ou=ouName,o=oName,dc=dcValue

        • uid=12345,cn=abc-def.com,ou=ouName,o=oName,dc=dcValue1,dc=dcValue2

        • uid=12345,cn=abc-def.com,ou=ouName,o=oName,o=oName2,dc=dcValue1

        • uid=12345,cn=abc-def.com,ou=ouName,o=oName,o=oName2,dc=dcValue1,dc=dcValue2

      • MANDATORY RDN parameters requested are :

        • ou Managed Organizational Unit Name to run ldap search on (ldapsearch 'ou' param)

        • o Managed Organization to run ldap search on (ldapsearch 'o' param)

      • OPTIONAL parameters:

        • uid Managed uid to run ldapsearch on (ldapsearch 'uid' param)

        • cn Managed cn to run ldap search on (ldapsearch 'cn' param)

        • dc Managed dc to run ldap search on (ldapsearch 'dc' param)

  • Finally commit the configuration

  • Verify configuration, using a sync-from.

If the sync-from was not successful, check the NED configuration again.

2. Optional debug and trace setup

It is often desirable to see details from when and how the NED interacts with the device(Example: troubleshooting)

This can be achieved by configuring NSO to generate a trace file for the NED. A trace file contains information about all interactions with the device. Messages sent and received as well as debug printouts, depending on the log level configured.

NSO creates one separate trace file for each device instance with tracing enabled. Stored in the following location:

$NSO_RUNDIR/logs/ned-redhat-dir389-cli-1.0-<device name>.trace

Do as follows to enable tracing in one specific device instance in NSO:

  1. Start a NSO CLI session:

  2. Enter configuration mode:

  3. Enable trace raw:

    Alternatively, tracing can be enabled globally affecting all configured device instances:

  4. Configure the log level for printouts to the trace file:

    Alternatively the log level can be set globally affecting all configured device instances using this NED package.

The log level 'info' is used by default and the 'debug' level is the most verbose.

IMPORTANT: Tracing shall be used with caution. This feature does increase the number of IPC messages sent between the NED and NSO. In some cases this can affect the performance in NSO. Hence, tracing should normally be disabled in production systems.

An alternative method for generating printouts from the NED is to enable the Java logging mechanism. This makes the NED print log messages to common NSO Java log file.

$NSO_RUNDIR/logs/ncs-java-vm.log

Do as follows to enable Java logging in the NED

  1. Start a NSO CLI session:

  2. Enter configuration mode:

  3. Enable Java logging with level all from the NED package:

  4. Configure the NED to log to the Java logger

    Alternatively Java logging can be enabled globally affecting all configured device instances using this NED package.

IMPORTANT: Java logging does not use any IPC messages sent to NSO. Consequently, NSO performance is not affected. However, all log printouts from all log enabled devices are saved in one single file. This means that the usability is limited. Typically single device use cases etc.

3. Dependencies

This NED has the following host environment dependencies:

  • Java 1.8 (NSO version < 6.2)

  • Java 17 (NSO version >= 6.2)

  • Gnu Sed

Dependencies for NED recompile:

  • Apache Ant

  • Bash

  • Gnu Sort

  • Gnu awk

  • Grep

  • Python3 (with packages: re, sys, getopt, subprocess, argparse, os, glob)

4. Sample device configuration

NED USAGE EXAMPLE

LDAP entries are managed under ldap-entries list

/ldap-entries list has 4 keys requested to work around the unique dn name combination, as defined in ned settings too:

After the key is provided, all the attributes available will be visible:

Attributes list can contain quoted LDIF ready <attribute: value> pairs, quoted if the cli doesn't otherwise accept them.

4.1 VERY IMPORTANT: Ldap Entries usage and management

RedHat Dir389 default configuration seems to allow very relaxed combinations of Ldap Entries attributes name : values.

RedHat directory 389 allows above behavior, and since we don't have any detailed yang design to limit this behavior, it will be allowed in the NED too.

  • Example - see parameters objectClass, password below:

4.2 Initial config, sample

4.3 Create new Ldap Entry:

  • Show NSO cli dry run output:

TO fix above exception, update ned settings with the dn parameters, commit, run a connect/sync-from and retry.

4.4 Delete existing ldap entry

4.5 Modify existing ldap entry - replacing existing attribute value

VERY IMPORTANT !:

To update existing attributes entry, if you wish to just replace the value of a given attribute, you must:

<1> delete existing attribute first,

<2> and then add the new attribute

* Example: update password attribute

  • Show NSO cli dry run output:

  • Show NSO cli dry run NATIVE output:

  • commit

5. Built in live-status actions

NONE

6. Built in live-status show

NONE

7. Limitations

NONE

8. How to report NED issues and feature requests

Issues like bugs and errors shall always be reported to the Cisco NSO NED team through the Cisco Support channel:

The following information is required for the Cisco NSO NED team to be able to investigate an issue:

Do as follows to gather the necessary information needed for your device, here named 'dev-1':

  1. Enable full debug logging in the NED

  2. Configure the NSO to generate a raw trace file from the NED

  3. If the NED already had trace enabled, clear it in order to submit only relevant information

    Do as follows for NSO 6.4 or newer:

    Do as follows for older NSO versions:

  4. Run a compare-config to populate the trace with initial device config

  5. Reproduce the found issue using ncs_cli or your NSO service. Write down each necessary step in a reproduction report.

    In addition to this, it helps if you can show how it should work by manually logging into the device using SSH/TELNET and type the relevant commands showing a successful operation.

  6. Gather the reproduction report and a copy of the raw trace file containing data recorded when the issue happened.

  7. Contact the Cisco support and request to open a case. Provide the gathered files together with access details for a device that can be used by the Cisco NSO NED when investigating the issue.

Requests for new features and extensions of the NED are handled by the Cisco NSO NED team when applicable. Such requests shall also go through the Cisco support channel.

The following information is required for feature requests and extensions:

  1. Set the config on the real device including all existing dependent config and run sync-from to show it in the trace.

  2. Run sync-from # devices device dev-1 sync-from

  3. Attach the raw trace to the ticket

  4. List the config you want implemented in the same syntax as shown on the device

  5. SSH/TELNET access to a device that can be used by the Cisco NSO NED team for testing and verification of the new feature. This usually means that both read and write permissions are required. Pseudo access via tools like Webex, Zoom etc is not acceptable. However, it is ok with access through VPNs, jump servers etc as long as we can connect to the NED via SSH/TELNET.

9. How to rebuild a NED

To rebuild the NED do as follows:

When the NED has been successfully rebuilt, it is necessary to reload the package into NSO.

10. Configure the NED to use ssh multi factor authentication

This NED supports multi factor authentication (MFA) using the ssh authentication method 'keyboard-interactive'.

Some additional steps are required to enable the MFA support:

  1. Verify that your NSO version supports MFA. This is configurable as additional settings in the authentication group used by the device instance.

    Enter a NSO CLI and enter the following and do tab completion:

    If 'mfa' is displayed in the output like above, NSO has MFA support enabled. In case MFA is not supported it is necessary to upgrade NSO before proceeding.

  2. Implement the authenticator executable. The MFA feature relies on an external executable to take care of the client part of the multi factor authentication. The NED will automatically call this executable for each challenge presented by the ssh server and expects to get a proper response in return.

    The executable can be a simple shell script or a program implemented in any programming language.

    The required behaviour is like this:

    • read one line from stdin The line passed from the NED will be a semi colon separated string containing the following info:

      The elements for device name, user, password and opaque corresponds to what has been configured in NSO. The ssh server name, instruction and prompt are given by the ssh server during the authentication step.

      Each individual element in the semi colon separated list is Base64 encoded.

    • Extract the challenge based on the contents above.

    • Print a response matching the challenge to stdout and exit with code 0

    • In case a matching response can not be given do exit with code 2

    Below is a simple example of an MFA authenticator implemented in Python3:

  3. Configure the authentication group used by the device instance to enable MFA. There are two configurables available:

    • executable The path to the external multi factor authentication executable (mandatory).

    • opaque Opaque data that will passed as a cookie element to the executable (optional).

  4. Try connecting to the device.

10.1 Trouble shooting

In case of connection problems the following steps can help for debugging:

Enable the NED trace in debug level:

Try connect again

Inspect the generated trace file.

Verify that the ssh client is using the external authenticator executable:

Verify that the executable is called with the challenges presented by the ssh server:

Check for any errors reported by the NED when calling the executable

PreviousREADME-ned-settingsNextredhat-openshift-k8s

Last updated

Was this helpful?