[sonic-netns-exec]: use "$@" to reflects all positional parameters as they were set initially

[SuvarnaMeenakshi]

Signed-off-by: SuvarnaMeenakshi sumeenak@microsoft.com

fixes #4367
- What I did
Issue:
sonic-netns-exec fails to execute below command in swss.sh:

_function clean_up_tables()_
{
    sonic-netns-exec "$NET_NS" sonic-db-cli $1 EVAL "
    local tables = {$2}
    for i = 1, table.getn(tables) do
        local matches = redis.call('KEYS', tables[i])
        for j,name in ipairs(matches) do
            redis.call('DEL', name)
        end
    end" 0
}

This command fails with error " redis.exceptions.ResponseError: value is not an integer or out of range" .

Root cause:

When sonic-netns-exec executes the above function, argument passed to sonic-db-cli is NOT executed as a single script.

The argument is passed as separate keywords to sonic-db-cli, as below:

['EVAL', 'local', 'tables', '=', "{'PORT_TABLE*'}", 'for', 'i', '=', '1,', 'table.getn(tables)', 'do', 'local', 'matches', '=', "redis.call('KEYS',", 'tables[i])', 'for', 'j,name', 'in', 'ipairs(matches)', 'do', "redis.call('DEL',", 'name)', 'end', 'end', '0']

- How I did it
To make sure that the parameters are passed as they were set initially, fix sonic-netns-exec to use double quoted "$@", where "$@" is "$1" "$2" "$3" ... "${N}"

After fix, the argument passed to sonic-db-cli is as below:

Argument passed to sonic-db-cli:

['EVAL', "\n    local tables = {'PORT_TABLE*'}\n    for i = 1, table.getn(tables) do\n        local matches = redis.call('KEYS', tables[i])\n        for j,name in ipairs(matches) do\n            redis.call('DEL', name)\n        end\n    end", '0']

- How to verify it
Load VS image and create vs testbed with T0 topology.
Do a config reload -y
Run test_announce_routes.py - this was failing before fix as vlan1000 interface was down, after fix this passes.
- Description for the changelog

- A picture of a cute animal (not mandatory but encouraged)

[lguohan]

the focus of the description should be why you need to quote here, why the command does not work without quote.

[lguohan]

btw, which command in swss.sh is the offending command?

[SuvarnaMeenakshi]

btw, which command in swss.sh is the offending command?

in swss.sh clean_up_tables():
sonic-netns-exec "$NET_NS" sonic-db-cli $1 EVAL "
local tables = {$2}
for i = 1, table.getn(tables) do <… >

[SuvarnaMeenakshi]

the focus of the description should be why you need to quote here, why the command does not work without quote.

Updated description and fix.

[lguohan]

@SuvarnaMeenakshi , can you use markdown format to format you description? it is really difficult to read and understand.

[SuvarnaMeenakshi]

@SuvarnaMeenakshi , can you use markdown format to format you description? it is really difficult to read and understand.

Updated description.

[abdosi]

btw, which command in swss.sh is the offending command?

in swss.sh clean_up_tables():
sonic-netns-exec "$NET_NS" sonic-db-cli $1 EVAL "
local tables = {$2}
for i = 1, table.getn(tables) do <… >

@lguohan: Instead of passing script as string may be using using lua script file will be cleaner here. We can pass file name instead of string.

[qiluo-msft]

The first line of the code in PR description looks weird.