kola: Add --no-net flag

The Docker Hub recently decided that us pulling the `nginx` image
over and over many times a day was abusive and started rate limiting
us.

For OSTree's test suite at least, there's no good reason for us
to run podman's tests at all.  Similarly for e.g. Ignition.

And just as a general rule I think it's useful to cleanly separate
tests that can be run fully offline from those that require
Internet access.

mantle/cmd/kola/options.go

@@ -57,6 +57,7 @@ func init() {
 	ss("debug-systemd-unit", []string{}, "full-unit-name.service to enable SYSTEMD_LOG_LEVEL=debug on. Can be specified multiple times.")
 	sv(&kola.Options.IgnitionVersion, "ignition-version", "", "Ignition version override: v2, v3")
 	ssv(&kola.BlacklistedTests, "blacklist-test", []string{}, "Test pattern to blacklist. Can be specified multiple times.")
+	bv(&kola.NoNet, "no-net", false, "Don't run tests that require an Internet connection")
 	ssv(&kola.Tags, "tag", []string{}, "Test tag to run. Can be specified multiple times.")
 	bv(&kola.Options.SSHOnTestFailure, "ssh-on-test-failure", false, "SSH into a machine when tests fail")
 	sv(&kola.Options.CosaWorkdir, "workdir", "", "coreos-assembler working directory")

mantle/kola/harness.go

@@ -83,6 +83,7 @@ var (
 
 	TestParallelism int    //glue var to set test parallelism from main
 	TAPFile         string // if not "", write TAP results here
+	NoNet           bool   // Disable tests requiring Internet
 
 	BlacklistedTests []string // tests which are blacklisted
 	Tags             []string // tags to be ran
@@ -242,11 +243,22 @@ func filterTests(tests map[string]*register.Test, patterns []string, pltfrm stri
 		checkPlatforms = append(checkPlatforms, "qemu")
 	}
 
-	var blacklisted bool
 	noPattern := hasString("*", patterns)
 	for name, t := range tests {
+		var noNetFiltered bool
+		var blacklisted bool
+		for _, flag := range t.Flags {
+			if flag == register.RequiresInternetAccess && NoNet {
+				noNetFiltered = true
+				break
+			}
+		}
+		if noNetFiltered {
+			plog.Debugf("Skipping test that requires network: %s", t.Name)
+			continue
+		}
+
 		// Drop anything which is blacklisted directly or by pattern
-		blacklisted = false
 		for _, bl := range BlacklistedTests {
 			match, err := filepath.Match(bl, t.Name)
 			if err != nil {