README v1.0.4 2025-02-24
Table of contents
1. General
This document describes the ciena-saos_nc NED.
IMPORTANT: This NED is delivered without any of the device YANG models bundled to the NED package.
It is required to download the YANG files separately and rebuild the NED package before the NED is fully operational. See the README-rebuild.md for further information.
In summary, the below steps are needed to have a fully functioning NED:
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>-ciena-saos_nc-<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
Extract the NED package and verify its signature:
In case the signature can not be verified (for instance if no internet connection), do as below instead:
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:
IMPORTANT:
This NED is delivered as an “empty” package, i.e without any device YANG models bundled. It must be rebuilt with the device YANG models to become operational.
The procedure to rebuild the empty NED (described in the README-rebuild.md) shall typically be done in a lab environment. For this step a “local install” of the NED shall be used. It is not suitable to use “system install” here since it is intended for production systems only.
Once this NED has been rebuilt with the device YANG and exported to one or many separate tar.gz customized NED packages, a “system installation” can be used on them.
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.
Untar the tar.gz file. This creates a new sub-directory named:
ciena-saos_nc-<NED major digit>.<NED minor digit>:Install the NED into NSO, using the ncs-setup tool:
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.
Do a NSO backup before installing the new NED package:
Start a NSO CLI session and fetch the NED package:
Install the NED package (add the argument replace-existing if a previous version has been loaded):
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):
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-ciena-saos_nc-gen-1.0-<device name>.trace
Do as follows to enable tracing in one specific device instance in NSO:
Start a NSO CLI session:
Enter configuration mode:
Enable trace raw:
Alternatively, tracing can be enabled globally affecting all configured device instances:
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
Start a NSO CLI session:
Enter configuration mode:
Enable Java logging with level all from the NED package:
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
NONE
5. Built in RPC actions
5.1. rpc add-filter-path
5.2. rpc clean-package
5.3. rpc clear-cached-capabilities
5.4. rpc clear-filter-paths
5.5. rpc compare-config
5.6. rpc compile-modules
5.7. rpc export-package
5.8. rpc get-modules
5.9. rpc import-filter-paths
5.10. rpc list-filter-paths
5.11. rpc list-module-sets
5.12. rpc list-modules
5.13. rpc list-profiles
5.14. rpc patch-modules
5.15. rpc rebuild-package
5.16. rpc remove-filter-path
5.17. rpc show-default-local-dir
5.18. rpc show-loaded-schema
5.19. rpc verify-get-config
6. Built in live-status show
NONE
7. Limitations
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':
Enable full debug logging in the NED
Configure the NSO to generate a raw trace file from the NED
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:
Run a compare-config to populate the trace with initial device config
Reproduce the found issue using ncs_cli or your NSO service. Write down each necessary step in a reproduction report.
Gather the reproduction report and a copy of the raw trace file containing data recorded when the issue happened.
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:
A detailed use case description, with details like:
Data of interest
The kind of operations to be used on the data. Like: 'read', 'create', 'update', 'delete' and the order of the operation
Device APIs involved in the operations (For example: REST URLs and payloads)
Device documentation describing the operations involved
Run sync-from # devices device dev-1 sync-from (if relevant)
Attach the raw trace to the ticket (if relevant)
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.
9. How to rebuild a NED
Check the README-rebuild.md file, chapter 1.3, for more information.
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:
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.
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:
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).
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
11. Custom XML transforms
One useful feature present in the NED package is the ability to have java code manipulate the contents of netconf XML before sent to NSO, or when applying edits, before being sent to the device. This feature is implemented as custom XML transform methods which can be referred in the yang schema, either statically at compile time, or dynamically at run-time. In the case of run-time referral, it can even be done on a per key-path level, i.e. transforms can be called for specific key-paths in data.
While the implementation of these transforms is out of scope for this document and for normal usage of the NED, the application of built-in transforms is a very powerful additional tool which can be used to overcome some issues commonly found in various devices.
To refer the transforms from yang, the custom tailf extension meta-data is used. Since editing the original yang is discouraged, the meta-data extension can be either added at compile-time through the schema customization mechanism described in section 'Advanced: repairing YANG modules' in the README-rebuild.md, or at run-time through the ned-setting 'transaction inject-meta-data' (which can take key-paths).
The built-in transforms that can be referred are listed below. Note that each transform is declared to work under certain constraints, regarding 'direction' (i.e. to or from device), what type of yang node it can operate on, and so on.
11.1 filter-exclude-config
This transform filters out config, by default in both directions, i.e. it will act the same as if an exclude filter-path is added at the given node in the schema. It can be applied on all types of nodes, for container and list nodes, all children will also be filtered out. If a meta-value argument with either value 'from-device' or 'to-device' is added, the filtering will only occur in the given direction (NOTE: this means that NSO and the device might get out-of-sync, use with care).
Since meta-data can be injected on key-path level, it's even possible to filter out a certain instance from a list in the configuration such as this:
11.2 filter-by-version
This transform acts similarly to 'filter-exclude-config', however, it always applies in both directions. It takes a mandatory meta-value whose format is described below. It is used together with the ned-setting transaction/filter-config-by-version which provides a version used for comparison, or when that ned-setting has the value 'auto', a device version which is supplied through a ned-specific implementation calling the method setDeviceVersion().
The meta-value describes a range for the version to compare to, and if valid, will let the config pass, i.e. filtering out config for which the meta-value is false. The format of the meta-value is best described using an example value:
NOTE: The version format can also be three digits, e.g. 7.3.1. The version can contain one, two or three digits, which can be freely mixed in expressions.
11.3 filter-leaf
This transform can filter out leaf values which are either invalid, or has the default value declared in the yang module. It works as a combination of the ned-settings transaction/filter-invalid-values=true and the capabilities/defaults-mode-override=trim but only for the leaf node where this meta-data is applied. The mandatory meta-value can be either of:
11.4 reorder-keys
This transform can be used where a device gives data in a non-compliant format where list keys are either out-of-order or not the first elements in the XML, i.e. where the XML needs to be re-ordered before being validated against the yang schema. It takes no meta-value and should be placed on the problematic list node(s) in the schema.
11.5 edit-full-delete
This transform can be used when a device acts in a non-compliant way, where a container needs to be deleted instead of its contents. It can be needed where a device doesn't want a reachable default value set back instead of it being deleted, which is how NSO normally 'clears' a value which is to be deleted, and which has a default value declared.
11.6 edit-op
This transform can be used to set the netconf operation to use when the node in question is to be deleted or edited. By default nodes are deleted with the operation 'delete'. With this transform, one can instead use 'remove' (or any proprietary keyword) to do the delete instead. It can also be used to reverse the effect of the ned-setting transaction/delete-with-remove is enabled, i.e. to force 'delete' for selected node(s), for a given node. Also, the edit-op can be set to 'replace' (or any proprietary keyword) to force that netconf operation whenever the node is present in edit-config (i.e. if not deleted).
11.7 hidden-config
This transform can be used if device contains config that can be set, but which is not reflected in the running configuration. It can be used on leaf and leaf-list nodes. When the annotated node is set from NSO, it is always echoed back from the NED to NSO as if the device contains the value. It works like the annotation tailf:ned-ignore-compare-config, but can also be used on leaf-list nodes. The only difference is that from NSO perspective the data looks as if it is actually present on device.
11.8 redeploy-on-edit
With this transform added on a node in the schema, the node and its children will be redeployed in full when edited (i.e. as if the whole content doesn't exist on device). This means that if the node is present in the edit-config, its contents in the edit-config will be replaced with the full content in the to-transaction. This is useful if the device has the non-compliant behaviour as if 'replace' is implied on the node, i.e. the device resets all the node's content to only include the contents in the edit-config, which results in NSO becoming out-of-sync if not all contents are redeployed in the edit.
11.9 remove-before-edit
This transform will inject a delete of the annotated node when it appears in an edit-config. This can be useful if the device has the non-compliant behaviour that the contents of a node can not be edited if not first cleared in the same edit.
This annotation can also take the meta-value argument 'delayed-commit', see 'redeploy-point' for more info on this.
11.10 redeploy-parent-on-edit + redeploy-point
The transform 'redeploy-parent-on-edit' will redeploy the parent annotated with 'redeploy-point', whenever this node is edited. The parent will also first be deleted. an edit-config. This can be useful if the device has the non-compliant behaviour that the contents of a node can not be edited if not first cleared in the same edit.
For example, if a device can't edit the pw-id and peer-ip inside the pw list within an l2vpn instance, but instead actually needs the full instance to be deleted and redeployed in the same edit, the below injects could be used in customize-schmea.schypp:
The meta-value argument 'delayed-commit' can be used in 'redeploy-point' (and in 'remove-before-edit' as mentioned above) to force a split of the edit-config, so that the delete will happen in first edit-config sent (together with the rest of the edit), after which a commit is sent. Then there will be an additional edit-config/commit containing the new config to be set. This can work in some use-cases, however, since this behaviour indicates a serious deviation from standard netconf transactionality in the device, it must be used with great care, and is not guaranteed to work.
NOTE: If using 'delayed-commit', the ned-setting 'transaction force-revert-diff' must be enabled to ensure that config is rolled back correctly to compensate for the intermediate commit done.
11.11 replace-all-leaf-list|long-obu-diff-leaf-list
In some devices it has been observed that leaf-list nodes doesn't behave according to netconf standard. Two annotations exists which can be used to mitigate two problems found.
The first is 'replace-all-leaf-list' which indicates that the semantics of the leaf-list is that all its content must re-added when edited, i.e. members not present in edit-config are reset on device (which causes NSO to be out-of-sync). Hence, editing the leaf-list always includes all members present after the transaction (i.e. no explicit delete operation is needed). This can potentially result in a very large edit-config of course, if the leaf-list has many members.
The other annotation, 'long-obu-diff-leaf-list' can be used when the leaf-list has the semantics of an 'ordered-by user' leaf-list, but is not editable as such (i.e. the normal netconf move can not be used). Instead, it will be edited by adding/deleting members, hence the resulting edit for a re-order will first remove all elements from the first inserted element, then the rest of the elements will be added in correct order, as if being added for the first time. As with 'replace-all-leaf-list', this can potentially also result in a very large edit-config.
11.12 diff-set|delete-before|after
Some devices have non-compliant behaviour such that in certain use-cases, the order of the contents in edit-config matters. In these cases this might be solved by adding re-ordering meta-data annotations. These annotations are then used to force a re-order when specific nodes appears in the edit-config.
NOTE: To be able to use these annotations, the ned-setting 'transaction enable-diff-dependencies' must be set to true.
The annotation is added to the node to be re-ordered, relative to another (target) node, when both are present. The path to the target node is given by appending ':' to the chosen re-order variant.
For example if the schema has a node 'scheduler' which needs to be set before it's sibling queue-group, present in schema in parent node /mef-egress-qos:egress-qos, the below annotation injection can be used in the customize-schema.schypp file to achieve the needed re-ordering:
This will have the effect that whenever both scheduler and queue-group are present in an edit-config, scheduler will be set before queue-group.
12. Run arbitrary commands on device
Some commands that are available to a user logged in to an interactive CLI session on the device might not be available through NETCONF. For situations like this the NED provides the feature to run arbitrary commands through an interactive SSH login to the device. This SSH session is handled internally in the NED and connected in NSO to a live-status action called 'exec any'.
There are some ned-settings to control the behaviour of this feature, see the section 'ned-settings ciena-saos_nc live-status cli' in README-ned-settings.md for details on this.
Specifically, to be able to handle the interactive session towards the device, the NED needs to know the format for the device prompt. It also assumes that pagination is turned off before reading output from command sent (i.e. that the device doesn't pause terminal output, waiting for interactive response). The ned-settings 'prompt-pattern' and 'no-pagniation-cmd' are used to control this. These might have proper default values, please check that this matches your device though before trying this feature, since if not configured correctly the NED will hang until timed out.
As an example, to run the command 'show running-config' on the device, and get the resulting output as a string from the ncs_cli, run the following:
Note that when using ncs_cli, the command-line given might need to be quoted if it contains characters that are interpreted by the ncs_cli itself.
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