add limited support for containerd config patch version-awareness

Author: BenTheElder

pkg/apis/config/v1alpha4/types.go

@@ -75,11 +75,14 @@ type Cluster struct {
 	// ContainerdConfigPatches are applied to every node's containerd config
 	// in the order listed.
 	// These should be toml stringsto be applied as merge patches
+	// If the version field in these patches doesn't match containerd config, it will not be a applied
+	// This way you can write configurations that work for both by supplying two patches
 	ContainerdConfigPatches []string `yaml:"containerdConfigPatches,omitempty" json:"containerdConfigPatches,omitempty"`
 
 	// ContainerdConfigPatchesJSON6902 are applied to every node's containerd config
 	// in the order listed.
 	// These should be YAML or JSON formatting RFC 6902 JSON patches
+	// NOTE: These are not currently version-aware.
 	ContainerdConfigPatchesJSON6902 []string `yaml:"containerdConfigPatchesJSON6902,omitempty" json:"containerdConfigPatchesJSON6902,omitempty"`
 }
 

pkg/build/nodeimage/containerd.go

@@ -36,7 +36,7 @@ const containerdConfigPatchSystemdCgroupFalse = `
 `
 
 func configureContainerdSystemdCgroupFalse(containerCmdr exec.Cmder, config string) error {
-	patched, err := patch.TOML(config, []string{containerdConfigPatchSystemdCgroupFalse}, []string{})
+	patched, err := patch.ContainerdTOML(config, []string{containerdConfigPatchSystemdCgroupFalse}, []string{})
 	if err != nil {
 		return errors.Wrap(err, "failed to configure containerd SystemdCgroup=false")
 	}

pkg/cluster/internal/create/actions/config/config.go

@@ -127,7 +127,7 @@ func (a *Action) Execute(ctx *actions.ActionContext) error {
 				if err := node.Command("cat", containerdConfigPath).SetStdout(&buff).Run(); err != nil {
 					return errors.Wrap(err, "failed to read containerd config from node")
 				}
-				patched, err := patch.TOML(buff.String(), ctx.Config.ContainerdConfigPatches, ctx.Config.ContainerdConfigPatchesJSON6902)
+				patched, err := patch.ContainerdTOML(buff.String(), ctx.Config.ContainerdConfigPatches, ctx.Config.ContainerdConfigPatchesJSON6902)
 				if err != nil {
 					return errors.Wrap(err, "failed to patch containerd config")
 				}

pkg/internal/patch/toml.go

@@ -29,16 +29,31 @@ import (
 	"sigs.k8s.io/kind/pkg/errors"
 )
 
-// TOML patches toPatch with the patches (should be TOML merge patches) and patches6902 (should be JSON 6902 patches)
-func TOML(toPatch string, patches []string, patches6902 []string) (string, error) {
+// ContainerdTOML patches toPatch with the patches (should be TOML merge patches) and patches6902 (should be JSON 6902 patches)
+func ContainerdTOML(toPatch string, patches []string, patches6902 []string) (string, error) {
 	// convert to JSON for patching
 	j, err := tomlToJSON([]byte(toPatch))
 	if err != nil {
 		return "", err
 	}
+	version, err := containerdConfigVersion(toPatch)
+	if err != nil {
+		return "", errors.WithStack(err)
+	}
 	// apply merge patches
 	for _, patch := range patches {
 		pj, err := tomlToJSON([]byte(patch))
+		if err != nil {
+			return "", errors.WithStack(err)
+		}
+		patchVersion, err := containerdConfigVersion(patch)
+		if err != nil {
+			return "", errors.WithStack(err)
+		}
+		// skip if patch sets version and version does not match
+		if patchVersion != 0 && patchVersion != version {
+			continue
+		}
 		if err != nil {
 			return "", err
 		}
@@ -64,6 +79,17 @@ func TOML(toPatch string, patches []string, patches6902 []string) (string, error
 	return jsonToTOMLString(j)
 }
 
+func containerdConfigVersion(configTOML string) (int, error) {
+	type version struct {
+		Version int `toml:"version,omitempty"`
+	}
+	v := version{}
+	if err := toml.Unmarshal([]byte(configTOML), &v); err != nil {
+		return 0, errors.WithStack(err)
+	}
+	return v.Version, nil
+}
+
 // tomlToJSON converts arbitrary TOML to JSON
 func tomlToJSON(t []byte) ([]byte, error) {
 	// we use github.com.pelletier/go-toml here to unmarshal arbitrary TOML to JSON

pkg/internal/patch/toml_test.go

@@ -22,7 +22,7 @@ import (
 	"sigs.k8s.io/kind/pkg/internal/assert"
 )
 
-func TestTOML(t *testing.T) {
+func TestContainerdTOML(t *testing.T) {
 	t.Parallel()
 	type testCase struct {
 		Name            string
@@ -49,6 +49,31 @@ func TestTOML(t *testing.T) {
 			ExpectError: false,
 			ExpectOutput: `disabled_plugins = ["restart"]
 
+[plugins]
+  [plugins.cri]
+    [plugins.cri.containerd]
+      [plugins.cri.containerd.runtimes]
+        [plugins.cri.containerd.runtimes.runsc]
+          runtime_type = "io.containerd.runsc.v1"
+  [plugins.linux]
+    shim_debug = true
+`,
+		},
+		{
+			Name: "Only matching patches",
+			ToPatch: `version = 2
+
+disabled_plugins = ["restart"]
+
+[plugins.linux]
+  shim_debug = true
+[plugins.cri.containerd.runtimes.runsc]
+  runtime_type = "io.containerd.runsc.v1"`,
+			Patches:     []string{"version = 3\ndisabled_plugins=[\"bar\"]", "version = 2\n disabled_plugins=[\"baz\"]"},
+			ExpectError: false,
+			ExpectOutput: `disabled_plugins = ["baz"]
+version = 2
+
 [plugins]
   [plugins.cri]
     [plugins.cri.containerd]
@@ -190,7 +215,7 @@ func TestTOML(t *testing.T) {
 		tc := tc // capture test case
 		t.Run(tc.Name, func(t *testing.T) {
 			t.Parallel()
-			out, err := TOML(tc.ToPatch, tc.Patches, tc.PatchesJSON6902)
+			out, err := ContainerdTOML(tc.ToPatch, tc.Patches, tc.PatchesJSON6902)
 			assert.ExpectError(t, tc.ExpectError, err)
 			if err == nil {
 				assert.StringEqual(t, tc.ExpectOutput, out)