Fix issue in integration about smartctl and return error code 4

[gthvn1]

Some device doesn't support SMART capability and getting information from such device returns an error code 4. As it happens in CI we remove the check of the return code.

[gthvn1]

I can also be a little bit more restrictive and check that return code from run_command is either 0 or 4 and failed if it is not the case.

[benjamreis]

I can also be a little bit more restrictive and check that return code from run_command is either 0 or 4 and failed if it is not the case.

I'd be more confortable with that yeah.

[stormi]

Does smartctl always output JSON, even when there's an error? And what about stderr in case the command failed?

[stormi]

I still would have checked the return code, and whenever the return code differs from 0 and 4, replace result[disk] with something which contains the return code, raw stdout and stderr (but just for the affected disks). That's why I'd also check with XO so that we know how they would handle this case. Do they display the JSON, uninterpreted? Do they look for specific pieces of information?

[gthvn1]

but we are already returning stdout that contains the error.

[gthvn1]

they just display the raw json (and we see the error code in it)

[stormi]

Ok, this, the man page and a test I made gives me all I wanted to know: it wraps the call to "regular" smartctl and apparently always puts the result inside JSON, even when there are non-recoverable errors (unless there's an error generating the JSON itself, I guess).

See this example where I gave it a non recognised argument:

smartctl -j -a --wrongarg /dev/sdb
{
  "json_format_version": [
    1,
    0
  ],
  "smartctl": {
    "version": [
      7,
      0
    ],
    "svn_revision": "4883",
    "platform_info": "x86_64-linux-4.19.0+1",
    "build_info": "(local build)",
    "argv": [
      "smartctl",
      "-j",
      "-a",
      "--wrongarg",
      "/dev/sdb"
    ],
    "messages": [
      {
        "string": "=======> UNRECOGNIZED OPTION: wrongarg",
        "severity": "error"
      }
    ],
    "exit_status": 1
  }
}

So LGTM.

[gthvn1]

[stormi]

Nitpick: "Some device doesn't support SMART capability" => "Some devices don't support SMART capability(ies?)", in the commit message.

[gthvn1]

I followed the error message reported by smartctl:
SMART support is: Unavailable - device lacks SMART capability.
I can modify it no pbs

[gthvn1]

But I think that SMART is the capability of monitoring and reporting disks status