[sonic-yang-mgmt]: sonic-yang-mgmt package for configuration validation.

[praveen-li]

This package includes python yang libraries which will be used with sonic utilities
package to validate the config. This python libraries are written on top of libyang
and also provides functionality to translate the config from SONiC ConfigDB to SONiC
YANG and vice-versa.

NOTE: This PR Depends on PR 3730

This PR has changes done under PR 3874 and 3891 as well. So those can be closed once this is merged.

Signed-off-by: Praveen Chaudhary pchaudhary@linkedin.com
Signed-off-by: Ping Mao pmao@linkedin.com

- What I did

wheel package Makefiles

• wheel package Makefiles for sonic-yang-mgmt package.

libyang Python APIs:

• python APIs based on libyang
• functions to load/merge yang models and Yang data files
• function to validate data trees based on Yang models
• functions to merge yang data files/trees
• add/set/delete node in schema and data trees
• find data/schema nodes from xpath from the Yang data/schema tree in memory
• find dependencies
• dump the data tree in json/xml

Extension of libyang Python APIs:

-- Cropping input config based on Yang Model.
-- Translate input config based on Yang Model.
-- rev Translate input config based on Yang Model.
-- Find xpath of port, portleaf and a yang list.
-- Find if node is key of a list while deletion if yes, then delete the parent.

- How I did it

wheel package Makefiles

• Added steps to build sonic-yang-mgmt python wheel package with sonic build.
• Also to install it by default on sonic image.

libyang Python APIs:

• based on libyang python2 modules which is built by libyang
• add functions to load/validate Yang models and Yang data trees
• Add functions to

Extension of libyang Python APIs:

From the json format of yang models, a map is created from config DB tables
to container in yang model. Input Config is cropped on based of this map.
Input Config is also translated based of this map.
Similarly from yang data tree, output is reverse translated to config DB.

This PR also includes:
-- Find xpath of port, portleaf and a yang list.
-- Find if node is key of a list while deletion if yes, then delete the parent.

Yang model can be represented in JSON as below:

{
  "module": {
    "@name": "sonic-vlan", 
    "@xmlns": "urn:ietf:params:xml:ns:yang:yin:1", 
    "@xmlns:vlan": "http://github.com/Azure/sonic-vlan", 
    "@xmlns:yang": "urn:ietf:params:xml:ns:yang:ietf-yang-types", 
    "@xmlns:inet": "urn:ietf:params:xml:ns:yang:ietf-inet-types", 
    "@xmlns:head": "http://sonic-head", 
    "@xmlns:port": "http://github.com/Azure/sonic-port", 
    "namespace": {
      "@uri": "http://github.com/Azure/sonic-vlan"
    }, 
    "prefix": {
      "@value": "vlan"
    }, 
    "import": [
      {
        "@module": "ietf-yang-types", 
        "prefix": {
          "@value": "yang"
        }
      }, 
      {
        "@module": "ietf-inet-types", 
        "prefix": {
          "@value": "inet"
        }
      }, 
      {
        "@module": "sonic-head", 
        "prefix": {
          "@value": "head"
        }, 
        "revision-date": {
          "@date": "2019-07-01"
        }
      }, 
      {
        "@module": "sonic-port", 
        "prefix": {
          "@value": "port"
        }, 
        "revision-date": {
          "@date": "2019-07-01"
        }
      }
    ], 
    "organization": {
      "text": "Linkedin Corporation"
    }, 
    "contact": {
      "text": "lnos_coders@linkedin.com"
    }, 
    "description": {
      "text": "VLAN yang Module for SONiC OS"
    }, 
    "revision": {
      "@date": "2019-07-01", 
      "description": {
        "text": "First Revision"
      }
    },
    "container": {
      "@name": "sonic-vlan", 
      "container": [
        {
          "@name": "VLAN_INTERFACE", 
          "description": {
            "text": "VLAN_INTERFACE part of config_db.json"
          }, 
          "list": {
            "@name": "VLAN_INTERFACE_LIST", 
            "key": {
              "@value": "vlanid ip-prefix"
            }, 
            "leaf": [
              {
                "@name": "vlanid", 
                "type": {
                  "@name": "leafref", 
                  "path": {
                    "@value": "../../../VLAN/VLAN_LIST/vlanid"
                  }
                }
              }, 
              {
                "@name": "ip-prefix", 
                "type": {
                  "@name": "inet:ip-prefix"
                }, 
                "mandatory": {
                  "@value": "true"
                }
              }, 

This is used to create a map between Config DB Table and YANG Model Container.
Note: As per guideline https://github.com/Azure/SONiC/blob/master/doc/mgmt/SONiC_YANG_Model_Guidelines.md. Table maps to only container in YANG.

- How to verify it

wheel package Makefiles

Built this package separately.

pchaudha@be1e6e58be56:/sonic$ make -f slave.mk target/python-wheels/sonic_yang_mgmt-1.0-py-none-any.whl
SONiC Build System

Build Configuration
"CONFIGURED_PLATFORM"             : "broadcom"
"CONFIGURED_ARCH"                 : "amd64"
"SONIC_CONFIG_PRINT_DEPENDENCIES" : ""
"SONIC_BUILD_JOBS"                : "1"
"SONIC_CONFIG_MAKE_JOBS"          : "24"
"SONIC_USE_DOCKER_BUILDKIT"       : ""
"USERNAME"                        : "admin"
"PASSWORD"                        : "YourPaSsWoRd"
"ENABLE_DHCP_GRAPH_SERVICE"       : ""
"SHUTDOWN_BGP_ON_START"           : ""
"ENABLE_PFCWD_ON_START"           : ""
"INSTALL_DEBUG_TOOLS"             : ""
"ROUTING_STACK"                   : "frr"
"FRR_USER_UID"                    : "300"
"FRR_USER_GID"                    : "300"
"ENABLE_SYNCD_RPC"                : ""
"ENABLE_ORGANIZATION_EXTENSIONS"  : "y"
"HTTP_PROXY"                      : ""
"HTTPS_PROXY"                     : ""
"ENABLE_SYSTEM_TELEMETRY"         : "y"
"ENABLE_RESTAPI"                  : "n"
"ENABLE_ZTP"                      : ""
"SONIC_DEBUGGING_ON"              : ""
"SONIC_PROFILING_ON"              : ""
"KERNEL_PROCURE_METHOD"           : "build"
"BUILD_TIMESTAMP"                 : ""
"BLDENV"                          : ""
"VS_PREPARE_MEM"                  : "yes"
"ENABLE_SFLOW"                    : "y"


pchaudha@be1e6e58be56:/sonic$ ls target/python-wheels/sonic_yang_mgmt-1.0-py-none-any.whl
target/python-wheels/sonic_yang_mgmt-1.0-py-none-any.whl
pchaudha@be1e6e58be56:/sonic$

libyang Python APIs:

• pytests while build sonic-yang-mgmt python wheel package
• create sample Yang models for sonic ACL/interface/port/clan
• sample Yang data files
• test file with test cases, it includes categories to test, xpath and expected results for testing Yang data/schema tree wrapper functions

pytests while build target/python-wheels/sonic_yang_mgmt-1.0-py-none-any.whl:

============================= test session starts ==============================
platform linux2 -- Python 2.7.13, pytest-3.0.6, py-1.4.32, pluggy-0.4.0
rootdir: /sonic/src/sonic-yang-mgmt, inifile:
plugins: cov-2.4.0
collected 18 items

tests/test_sonic_yang_mgmt.py .
tests/libyang-python-tests/test_sonic_yang.py .................

========================== 18 passed in 0.21 seconds ===========================

Extension of libyang Python APIs:

Added PyTest:

    def test_xlate_rev_xlate(self):
        # In this test, xlation and revXlation is tested with latest Sonic
        # YANG model.

        yang_dir = "/sonic/src/sonic-yang-models/yang-models/"
        yang_test_file = "/sonic/src/sonic-yang-models/tests/yang_model_tests/yangTest.json"
        jIn = self.readIjsonInput(yang_test_file, 'SAMPLE_CONFIG_DB_JSON')
        # load yang models
        syc = sy.sonic_yang(yang_dir)

        syc.loadYangModel()

        syc.load_data(json.loads(jIn))

        syc.get_data()

        if syc.jIn and syc.jIn == syc.revXlateJson:
            print("Xlate and Rev Xlate Passed")
        else:
            print("Xlate and Rev Xlate failed")
            # make it fail
            assert False == True

        return

- Description for the changelog
This package includes python yang libraries which will be used with sonic utilities
pacakge to validate the config. This python libraries are written on top of libyang
and also provides functionality to translate the config from SONiC ConfigDB to SONiC
YANG and vice-versa.

- A picture of a cute animal (not mandatory but encouraged)
I can put Microsoft logo :). Thx

[praveen-li]

retest this please

[renukamanavalan]

This is where the SONiC Yang files are to be checked in.
Curious, why there is none,

[praveen-li]

This is where the SONiC Yang files are to be checked in.
Curious, why there is none,

@renuka

This PR has basic build steps, Code and YANG files comes with PR 3730, 3784 & 3891.

[svc-acs]

Build started for merge commit.

[praveen-li]

+ Renuka Yes, I think, I need to do that. I made it to PY on review comments from Renuka. But pip doesn't let it installed on the sonic switch, if it doesn't have a proper version number. I will give a try to PY3 first, But due to the version of sonic utilities as PY2 I may have to fall back on the PY2. Thanks, Regards Praveen

________________________________ From: vishnushetty <notifications@github.com> Sent: Thursday, April 2, 2020 5:52 PM To: Azure/sonic-buildimage <sonic-buildimage@noreply.github.com> Cc: Praveen Chaudhary <pchaudhary@linkedin.com>; Mention <mention@noreply.github.com> Subject: Re: [Azure/sonic-buildimage] [sonic-yang-mgmt]: a.)Dev code, b.) build time test code and c.) wheel package Makefiles for sonic-yang-mgmt package. (#3861) @vishnushetty commented on this pull request.

________________________________ In rules/sonic-yang-mgmt-py2.mk<https://nam06.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgh.neting.cc%2FAzure%2Fsonic-buildimage%2Fpull%2F3861%23discussion_r402677562&data=02%7C01%7Cpchaudhary%40linkedin.com%7Cd413e8ca48014edb347408d7d7693f5a%7C72f988bf86f141af91ab2d7cd011db47%7C1%7C0%7C637214719344268742&sdata=zdFfJPslxZvt1fEf6crPolWRKOKECOOdtlbfc0nz%2FUk%3D&reserved=0>:

@@ -0,0 +1,8 @@

+# sonic-yang-mgmt python wheel + +SONIC_YANG_MGMT_PY = sonic_yang_mgmt-1.0-py-none-any.whl do you want to change PY(py) -> PY2(py2) to be consistent with version — You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub<https://nam06.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgh.neting.cc%2FAzure%2Fsonic-buildimage%2Fpull%2F3861%23pullrequestreview-386872556&data=02%7C01%7Cpchaudhary%40linkedin.com%7Cd413e8ca48014edb347408d7d7693f5a%7C72f988bf86f141af91ab2d7cd011db47%7C1%7C0%7C637214719344268742&sdata=FQsw1yzLzHRUNmrOc5NP241Z%2BAHd8TeZjXU2BF15Sik%3D&reserved=0>, or unsubscribe<https://nam06.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgh.neting.cc%2Fnotifications%2Funsubscribe-auth%2FAJHZHPPXPWTTYCWOYXQBHZTRKUXLTANCNFSM4JYRKTEQ&data=02%7C01%7Cpchaudhary%40linkedin.com%7Cd413e8ca48014edb347408d7d7693f5a%7C72f988bf86f141af91ab2d7cd011db47%7C1%7C0%7C637214719344278738&sdata=%2B%2Bl%2FW32ML0DCZnQduyyDlkqhBXVNqAdcNScwNg%2FGZek%3D&reserved=0>.

[lgtm-com]

This pull request introduces 17 alerts when merging 2eaba1c8fd2fd70e93f5dccac20572cc12d43acf into 711445c - view on LGTM.com

new alerts:

• 7 for Unused local variable
• 5 for Unused import
• 2 for Illegal raise
• 1 for Testing equality to None
• 1 for 'import *' may pollute namespace
• 1 for Module is imported with 'import' and 'import from'

[lgtm-com]

This pull request introduces 17 alerts when merging 1246ce4e7d24a070b8b7a9c7df7ff34753d9fb25 into de5a04a - view on LGTM.com

new alerts:

• 7 for Unused local variable
• 5 for Unused import
• 2 for Illegal raise
• 1 for Testing equality to None
• 1 for 'import *' may pollute namespace
• 1 for Module is imported with 'import' and 'import from'

[lgtm-com]

This pull request introduces 1 alert when merging a065d2a6c5a05557a79f049ce5737909bd4a47cb into 7405f8c - view on LGTM.com

new alerts:

• 1 for Illegal raise

[lgtm-com]

This pull request introduces 1 alert when merging 1b8977d910f60ff561179b511e8a5a62cb3e71b6 into 7405f8c - view on LGTM.com

new alerts:

• 1 for Illegal raise

[praveen-li]

retest vsimage please

[praveen-li]

retest vsimage please

[praveen-li]

05/11/2020 Review:
AI:Make the function private and only the function which are called from outside should be public.

[praveen-li]

@renukamanavalan, @lguohan, @zhenggen-xu

Latest commit to address below review comments:

    [sonic_yang.py]: Categories public and private functions.

    Changes:

    1.) Categories public and private functions.
    2.) Minor spaces related changes.
    3.) Defining class SonicYangException and using it in all public functions.
    4.) Changing Class names to PascalCase.
    5.) Keeping functions, which deals with Libyang, in lower_underscore_case, rest functions names are in camelCase.

Kindly let me know if any other concerns. Thanks a lot for the review.

[lgtm-com]

This pull request introduces 1 alert when merging d450aec234ab6f47b30b3b4e61b23e3448f1d9e8 into 0542afb - view on LGTM.com

new alerts:

• 1 for Unused import

[lgtm-com]

This pull request introduces 1 alert when merging 0466e8272b0a3ab853e4b8d8484499a8dc8e4f5c into 0542afb - view on LGTM.com

new alerts:

• 1 for Unused import

[praveen-li]

retest vsimage please

[praveen-li]

@renukamanavalan, @lguohan, @zhenggen-xu

All tests passed, Kindly review. Thanks a lot.

[renukamanavalan]

Overall concern -- based on our discussion on this PR.

This PR adds additional validation for load & reload. With neither update, nor save guarded by the same validation, there is a good probable window to get a saved .JSON, which can't be loaded back.

This can lead to inconsistent state and difficulties ahead.

As we have SWSS sdk, as the center point for all updates, we have a single point for validation.

Request: Please make this as a priority to address in future PRs, ASAP.

[praveen-li]

Overall concern -- based on our discussion on this PR.

This PR adds additional validation for load & reload. With neither update, nor save guarded by the same validation, there is a good probable window to get a saved .JSON, which can't be loaded back.

This can lead to inconsistent state and difficulties ahead.

As we have SWSS sdk, as the center point for all updates, we have a single point for validation.

Request: Please make this as a priority to address in future PRs, ASAP.

@renukamanavalan @lguohan @zhenggen-xu
Sure, That will be my next target. At SWSS SDK level, I need to find whether the user is trying to update the config or trying to add an entire new config. The rest should be doable. And The testing effort will be huge.

Note: As of now, I had to remove config validation while config load\reload, because I notice multiple ASIC files change. So I would like to know first, whether we need validation for each file or not ?, Please let me know if you can help me here.