code clean for pkg/utils.go IsValidMACAddress

[yanggangtony]

Signed-off-by: yanggang gang.yang@daocloud.io

/kind cleanup

for _, invalidMACAddress := range invalidMACAddresses {
			if bytes.Equal(addr, invalidMACAddress) {
				valid = false
				break
			}
		}

the code will reduce the loop cost , when it is first found to be false . just break and skip next process.

And

if err != nil || linkObj.Attrs() == nil {
		return fmt.Errorf("failed to get netlink device with name %q: %v", ifName, err)
	}

will fix the potential panic, when linkObj.Attrs() is nil..

[coveralls]

Pull Request Test Coverage Report for Build 3919189276

Warning: This coverage report may be inaccurate.

This pull request's base commit is no longer the HEAD commit of its target branch. This means it includes changes from outside the original pull request, including, potentially, unrelated coverage changes.

• For more information on this, see Tracking coverage changes with pull request builds.
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• For a quick fix, rebase this PR at GitHub. Your next report should be accurate.

Details

• 0 of 1 (0.0%) changed or added relevant line in 1 file are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage remained the same at 38.027%

---

Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
pkg/utils/utils.go	0	1	0.0%

Totals
Change from base Build 3540793813:	0.0%
Covered Lines:	424
Relevant Lines:	1115

---

💛 - Coveralls

[SchSeba]

/lgtm

thanks for the contribution!

[yanggangtony]

thanks for review.
@SchSeba

[wizhaoredhat]

/lgtm

[adrianchiris]

is there really a case where netlink LinkByName completes successfully but returned Attr() is nil ?

I think not, and if there is, i think we should panic as it would be an un-expected behaviour of netlink (or any other impl of the interface)

IMO this additional condition should be removed.

[yanggangtony]

@adrianchiris
thanks for review.
i read the netlink LinkByName code again.

func (h *Handle) linkByNameDump(name string) (Link, error) {
	links, err := h.LinkList()
	if err != nil {
		return nil, err
	}

	for _, link := range links {
		if link.Attrs().Name == name {
			return link, nil
		}
	}
	return nil, LinkNotFoundError{fmt.Errorf("Link %s not found", name)}
}

the lib also not judge the link.Attrs()==nil , So we may relay on it .
and delete the case for nil

[SchSeba]

/lgtm