Consider allowing more linters

[mtrmac]

#1522 has disabled 5 out of the 7 default golangci-lint linters. That seems excessive.

For the record, currently:

% golangci-lint version              
golangci-lint has version 1.52.2 built with go1.20.2 from da04413a on 2023-03-25T18:11:28Z
% golangci-lint run --no-config ./...
pkg/chunked/compressor/compressor.go:331:21: SA1019: hdr.Xattrs is deprecated: Use PAXRecords instead. (staticcheck)
		for k, v := range hdr.Xattrs {
		                  ^
check.go:289:14: Error return value of `io.Copy` is not checked (errcheck)
						io.Copy(io.Discard, diffReader)
						       ^
check.go:883:54: SA1019: tar.TypeRegA has been deprecated since Go 1.11 and an alternative has been available since Go 1.1: Use TypeReg instead. (staticcheck)
		if hdr.Typeflag == tar.TypeLink || hdr.Typeflag == tar.TypeRegA {
		                                                   ^
check.go:902:45: SA1019: tar.TypeRegA has been deprecated since Go 1.11 and an alternative has been available since Go 1.1: Use TypeReg instead. (staticcheck)
	if typeflag == tar.TypeLink || typeflag == tar.TypeRegA {
	                                           ^
lockfile_compat.go:8:15: SA1019: lockfile.Locker is deprecated: Refer directly to *LockFile, the provided implementation, instead. (staticcheck)
type Locker = lockfile.Locker //lint:ignore SA1019 // lockfile.Locker is deprecated
              ^
pkg/regexp/regexp.go:26:9: copylocks: return copies lock value: github.com/containers/storage/pkg/regexp.Regexp contains sync.Once contains sync.Mutex (govet)
	return re
	       ^
pkg/ioutils/fswriters.go:153:18: Error return value of `w.closeTempFile` is not checked (errcheck)
		w.closeTempFile()
		               ^
pkg/ioutils/readers_test.go:82:7: lostcancel: the cancel function returned by context.WithTimeout should be called, not discarded, to avoid a context leak (govet)
	ctx, _ := context.WithTimeout(context.Background(), 100*time.Millisecond)
	     ^
pkg/archive/archive.go:402:5: SA1019: hdr.Xattrs has been deprecated since Go 1.10: Use PAXRecords instead. (staticcheck)
	if hdr.Xattrs == nil {
	   ^
pkg/archive/archive.go:403:3: SA1019: hdr.Xattrs has been deprecated since Go 1.10: Use PAXRecords instead. (staticcheck)
		hdr.Xattrs = make(map[string]string)
		^
pkg/archive/archive.go:411:4: SA1019: hdr.Xattrs has been deprecated since Go 1.10: Use PAXRecords instead. (staticcheck)
			hdr.Xattrs[xattr] = string(capability)
			^
pkg/archive/archive.go:646:20: SA1019: tar.TypeRegA has been deprecated since Go 1.11 and an alternative has been available since Go 1.1: Use TypeReg instead. (staticcheck)
	case tar.TypeReg, tar.TypeRegA:
	                  ^
drivers/chown.go:63:12: SA1019: pwalk.Walk is deprecated: use [github.com/opencontainers/selinux/pkg/pwalkdir.Walk] (staticcheck)
	if err := pwalk.Walk(".", chown); err != nil {
	          ^
drivers/vfs/driver.go:186:21: Error return value of `label.SetFileLabel` is not checked (errcheck)
		label.SetFileLabel(dir, mountLabel)
		                  ^
types/utils.go:210:25: Error return value is not checked (errcheck)
	ReloadConfigurationFile(configFile, storeOptions)

At least the “error return”, “return copies lock value”, “the cancel function returned by context.WithTimeout should be called” parts seem relevant and valuable.

[mtrmac]

I’m sorry, that attribution is incorrect; those linters have been disabled for years, and I don’t now care to track what was the default at which time.

My primary point is that we are now very much diverging from the current default, which seems unintuitive — linter developers probably don’t care about utility / comprehensive coverage of our chosen set of linters, and per the examples above, quite likely to be suboptimal for this project.

[rhatdan]

What are the list of linters, you believe we should enable?

[mtrmac]

I have no expertise in that at all; that’s partly why this is an issue and not a PR.

At this point my recommendation would be to either just switch to the default set (if we don’t have any opinion at all), or to at least enable the default set (because it’s likely enough to be useful, and if we want to be more strict, sure, why not).

[rhatdan]

I agree, I think we need to start turning on more of the linters and starting with the default set would be great. Getting to the point that podman, buildah, common, image and storage supported the same set should be the goal.

[mtrmac]

This was changed in #1615 , but the configuration still disables 4/7 default linters.