validation: test with different test cases for hugetlb cgroups

Test if hugetlb cgroups tests work correctly, with different page size values.
Also test if the test fails with an error when creating a hugetlb cgroup
with a wrong page size like 3GB. Make it also print out correct TAP output.

Signed-off-by: Dongsu Park <[email protected]>

Author: Dongsu Park

validation/linux_cgroups_hugetlb.go

@@ -2,39 +2,103 @@ package main
 
 import (
 	"fmt"
+	"runtime"
 
 	"github.com/mndrix/tap-go"
 	rspec "github.com/opencontainers/runtime-spec/specs-go"
 	"github.com/opencontainers/runtime-tools/cgroups"
 	"github.com/opencontainers/runtime-tools/validation/util"
 )
 
-func main() {
-	page := "1GB"
-	var limit uint64 = 52985 * 1024 * 1024 * 1024 // multiple of hugepage size
-	g, err := util.GetDefaultGenerator()
-	if err != nil {
-		util.Fatal(err)
+func testHugetlbCgroups() error {
+	t := tap.New()
+	t.Header(0)
+	defer t.AutoPlan()
+
+	// limit =~ 100 * page size
+	// NOTE: on some systems, pagesize "1GB" doesn't seem to work.
+	// Ideally we should auto-detect the value.
+	cases := []struct {
+		page  string
+		limit uint64
+	}{
+		{"2MB", 100 * 2 * 1024 * 1024},
+		{"1GB", 100 * 1024 * 1024 * 1024},
+		{"2MB", 100 * 2 * 1024 * 1024},
+		{"1GB", 100 * 1024 * 1024 * 1024},
 	}
-	g.SetLinuxCgroupsPath(cgroups.AbsCgroupPath)
-	g.AddLinuxResourcesHugepageLimit(page, limit)
-	err = util.RuntimeOutsideValidate(g, nil, func(config *rspec.Spec, t *tap.T, state *rspec.State) error {
-		cg, err := cgroups.FindCgroup()
+
+	for _, c := range cases {
+		g, err := util.GetDefaultGenerator()
 		if err != nil {
 			return err
 		}
-		lhd, err := cg.GetHugepageLimitData(state.Pid, config.Linux.CgroupsPath)
+		g.SetLinuxCgroupsPath(cgroups.AbsCgroupPath)
+		g.AddLinuxResourcesHugepageLimit(c.page, c.limit)
+		err = util.RuntimeOutsideValidate(g, t, func(config *rspec.Spec, t *tap.T, state *rspec.State) error {
+			cg, err := cgroups.FindCgroup()
+			if err != nil {
+				return err
+			}
+			lhd, err := cg.GetHugepageLimitData(state.Pid, config.Linux.CgroupsPath)
+			if err != nil {
+				return err
+			}
+			for _, lhl := range lhd {
+				if lhl.Pagesize != c.page {
+					continue
+				}
+				t.Ok(lhl.Limit == c.limit, "hugepage limit is set correctly")
+				t.Diagnosticf("expect: %d, actual: %d", c.limit, lhl.Limit)
+			}
+			return nil
+		})
 		if err != nil {
 			return err
 		}
-		for _, lhl := range lhd {
-			if lhl.Pagesize == page && lhl.Limit != limit {
-				return fmt.Errorf("hugepage %s limit is not set correctly, expect: %d, actual: %d", page, limit, lhl.Limit)
-			}
-		}
+	}
+
+	return nil
+}
+
+func testWrongHugetlb() error {
+	// We deliberately set the page size to a wrong value, "3MB", to see
+	// if the container really returns an error.
+	page := "3MB"
+	var limit uint64 = 100 * 3 * 1024 * 1024
+
+	g, err := util.GetDefaultGenerator()
+	if err != nil {
+		return err
+	}
+
+	t := tap.New()
+	t.Header(0)
+	defer t.AutoPlan()
+
+	g.SetLinuxCgroupsPath(cgroups.AbsCgroupPath)
+	g.AddLinuxResourcesHugepageLimit(page, limit)
+
+	err = util.RuntimeOutsideValidate(g, t, func(config *rspec.Spec, t *tap.T, state *rspec.State) error {
 		return nil
 	})
-	if err != nil {
+	t.Ok(err != nil, "hugepage invalid pagesize results in an errror")
+	if err == nil {
+		t.Diagnosticf("expect: err != nil, actual: err == nil")
+	}
+	return err
+}
+
+func main() {
+	if "linux" != runtime.GOOS {
+		util.Fatal(fmt.Errorf("linux-specific cgroup test"))
+	}
+
+	if err := testHugetlbCgroups(); err != nil {
+		util.Fatal(err)
+	}
+
+	if err := testWrongHugetlb(); err == nil {
 		util.Fatal(err)
 	}
 }