[sonic-py-common] porting sonic_db_dump_load.py from sonic-py-swsssdk to sonic-py-common (sonic-net#12185)

Porting sonic_db_dump_load.py from sonic-py-swsssdk to sonic-py-common.

#### Why I did it
sonic-py-swsssdk will be deprecate, so porting sonic_db_dump_load.py to sonic-py-common.

#### How I did it
Copy sonic_db_dump_load.py to sonic-py-common, and fix minor API different.

#### How to verify it
Pass all E2E test.
The platform_tests/test_advanced_reboot.py::test_warm_reboot will cover this script.

#### Which release branch to backport (provide reason below if selected)

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- Note we only backport fixes to a release branch, *not* features!
- Please also provide a reason for the backporting below.
- e.g.
- [x] 202006
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- [ ] 201811
- [ ] 201911
- [ ] 202006
- [ ] 202012
- [ ] 202106
- [ ] 202111
- [ ] 202205

#### Description for the changelog
Porting sonic_db_dump_load.py from sonic-py-swsssdk to sonic-py-common.

#### Ensure to add label/tag for the feature raised. example - [PR#2174](sonic-net/sonic-utilities#2174) where, Generic Config and Update feature has been labelled as GCU.

#### Link to config_db schema for YANG module changes
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Link should point to correct section on https://github.com/Azure/sonic-buildimage/blob/master/src/sonic-yang-models/doc/Configuration.md
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#### A picture of a cute animal (not mandatory but encouraged)

Author: liuh-80

src/sonic-py-common/setup.py

@@ -27,6 +27,12 @@
         'pytest',
         'mock==3.0.5' # For python 2. Version >=4.0.0 drops support for py2
     ],
+    entry_points={
+        'console_scripts': [
+            'sonic-db-load = sonic_py_common.sonic_db_dump_load:sonic_db_dump_load',
+            'sonic-db-dump = sonic_py_common.sonic_db_dump_load:sonic_db_dump_load',
+        ],
+    },
     classifiers=[
         'Intended Audience :: Developers',
         'Operating System :: Linux',

src/sonic-py-common/sonic_py_common/sonic_db_dump_load.py

@@ -0,0 +1,139 @@
+## ref: https://github.com/p/redis-dump-load/blob/7bbdb1eaea0a51ed4758d3ce6ca01d497a4e7429/redisdl.py
+
+def sonic_db_dump_load():
+    import optparse
+    import os.path
+    import re
+    import sys
+    from redisdl import dump, load
+    from swsscommon.swsscommon import SonicDBConfig
+
+    DUMP = 1
+    LOAD = 2
+
+    def options_to_kwargs(options):
+        args = {}
+        if options.password:
+            args['password'] = options.password
+        if options.encoding:
+            args['encoding'] = options.encoding
+        # dump only
+        if hasattr(options, 'pretty') and options.pretty:
+            args['pretty'] = True
+        if hasattr(options, 'keys') and options.keys:
+            args['keys'] = options.keys
+        # load only
+        if hasattr(options, 'use_expireat') and options.use_expireat:
+            args['use_expireat'] = True
+        if hasattr(options, 'empty') and options.empty:
+            args['empty'] = True
+        if hasattr(options, 'backend') and options.backend:
+            args['streaming_backend'] = options.backend
+        if hasattr(options, 'dbname') and options.dbname:
+            if options.conntype == 'tcp':
+                args['host'] = SonicDBConfig.getDbHostname(options.dbname)
+                args['port'] = SonicDBConfig.getDbPort(options.dbname)
+                args['db'] = SonicDBConfig.getDbId(options.dbname)
+                args['unix_socket_path'] = None
+            elif options.conntype == "unix_socket":
+                args['host'] = None
+                args['port'] = None
+                args['db'] = SonicDBConfig.getDbId(options.dbname)
+                args['unix_socket_path'] = SonicDBConfig.getDbSock(options.dbname)
+            else:
+                raise TypeError('redis connection type is tcp or unix_socket')
+
+        return args
+
+    def do_dump(options):
+        if options.output:
+            output = open(options.output, 'w')
+        else:
+            output = sys.stdout
+
+        kwargs = options_to_kwargs(options)
+        dump(output, **kwargs)
+
+        if options.output:
+            output.close()
+
+    def do_load(options, args):
+        if len(args) > 0:
+            input = open(args[0], 'rb')
+        else:
+            input = sys.stdin
+
+        kwargs = options_to_kwargs(options)
+        load(input, **kwargs)
+
+        if len(args) > 0:
+            input.close()
+
+    script_name = os.path.basename(sys.argv[0])
+    if re.search(r'load(?:$|\.)', script_name):
+        action = help = LOAD
+    elif re.search(r'dump(?:$|\.)', script_name):
+        action = help = DUMP
+    else:
+        # default is dump, however if dump is specifically requested
+        # we don't show help text for toggling between dumping and loading
+        action = DUMP
+        help = None
+
+    if help == LOAD:
+        usage = "Usage: %prog [options] [FILE]"
+        usage += "\n\nLoad data from FILE (which must be a JSON dump previously created"
+        usage += "\nby redisdl) into specified or default redis."
+        usage += "\n\nIf FILE is omitted standard input is read."
+    elif help == DUMP:
+        usage = "Usage: %prog [options]"
+        usage += "\n\nDump data from specified or default redis."
+        usage += "\n\nIf no output file is specified, dump to standard output."
+    else:
+        usage = "Usage: %prog [options]"
+        usage += "\n       %prog -l [options] [FILE]"
+        usage += "\n\nDump data from redis or load data into redis."
+        usage += "\n\nIf input or output file is specified, dump to standard output and load"
+        usage += "\nfrom standard input."
+    parser = optparse.OptionParser(usage=usage)
+    parser.add_option('-w', '--password', help='connect with PASSWORD')
+    if help == DUMP:
+        parser.add_option('-n', '--dbname', help='dump DATABASE (APPL_DB/ASIC_DB...)')
+        parser.add_option('-t', '--conntype', help='indicate redis connection type (tcp[default] or unix_socket)', default='tcp')
+        parser.add_option('-k', '--keys', help='dump only keys matching specified glob-style pattern')
+        parser.add_option('-o', '--output', help='write to OUTPUT instead of stdout')
+        parser.add_option('-y', '--pretty', help='split output on multiple lines and indent it', action='store_true')
+        parser.add_option('-E', '--encoding', help='set encoding to use while decoding data from redis', default='utf-8')
+    elif help == LOAD:
+        parser.add_option('-n', '--dbname', help='dump DATABASE (APPL_DB/ASIC_DB...)')
+        parser.add_option('-t', '--conntype', help='indicate redis connection type (tcp[default] or unix_socket)', default='tcp')
+        parser.add_option('-e', '--empty', help='delete all keys in destination db prior to loading', action='store_true')
+        parser.add_option('-E', '--encoding', help='set encoding to use while encoding data to redis', default='utf-8')
+        parser.add_option('-B', '--backend', help='use specified streaming backend')
+        parser.add_option('-A', '--use-expireat', help='use EXPIREAT rather than TTL/EXPIRE', action='store_true')
+    else:
+        parser.add_option('-l', '--load', help='load data into redis (default is to dump data from redis)', action='store_true')
+        parser.add_option('-n', '--dbname', help='dump DATABASE (APPL_DB/ASIC_DB/COUNTERS_DB/LOGLEVEL_DB/CONFIG_DB...)')
+        parser.add_option('-t', '--conntype', help='indicate redis connection type (tcp[default] or unix_socket)', default='tcp')
+        parser.add_option('-k', '--keys', help='dump only keys matching specified glob-style pattern')
+        parser.add_option('-o', '--output', help='write to OUTPUT instead of stdout (dump mode only)')
+        parser.add_option('-y', '--pretty', help='split output on multiple lines and indent it (dump mode only)', action='store_true')
+        parser.add_option('-e', '--empty', help='delete all keys in destination db prior to loading (load mode only)', action='store_true')
+        parser.add_option('-E', '--encoding', help='set encoding to use while decoding data from redis', default='utf-8')
+        parser.add_option('-A', '--use-expireat', help='use EXPIREAT rather than TTL/EXPIRE', action='store_true')
+        parser.add_option('-B', '--backend', help='use specified streaming backend (load mode only)')
+    options, args = parser.parse_args()
+
+    if hasattr(options, 'load') and options.load:
+        action = LOAD
+
+    if action == DUMP:
+        if len(args) > 0:
+            parser.print_help()
+            exit(4)
+        do_dump(options)
+    else:
+        if len(args) > 1:
+            parser.print_help()
+            exit(4)
+        do_load(options, args)