From 114272486dd81a3804c33fa8a574b9c455c93ef1 Mon Sep 17 00:00:00 2001
From: Patryk Matuszak <305846+pmtk@users.noreply.github.com>
Date: Thu, 22 Jun 2023 15:20:00 +0200
Subject: [PATCH] simple list of blocked upgrades

---
 pkg/admin/prerun/upgrade_blocking.go      | 59 +++++++++++++++++
 pkg/admin/prerun/upgrade_blocking_test.go | 77 +++++++++++++++++++++++
 pkg/admin/prerun/version.go               |  2 +-
 3 files changed, 137 insertions(+), 1 deletion(-)
 create mode 100644 pkg/admin/prerun/upgrade_blocking.go
 create mode 100644 pkg/admin/prerun/upgrade_blocking_test.go

diff --git a/pkg/admin/prerun/upgrade_blocking.go b/pkg/admin/prerun/upgrade_blocking.go
new file mode 100644
index 0000000000..696b4cee88
--- /dev/null
+++ b/pkg/admin/prerun/upgrade_blocking.go
@@ -0,0 +1,59 @@
+package prerun
+
+import (
+	"encoding/json"
+	"errors"
+	"fmt"
+	"io/fs"
+
+	embedded "github.com/openshift/microshift/assets"
+	"k8s.io/klog/v2"
+)
+
+func IsUpgradeBlocked(execVersion versionMetadata, dataVersion versionMetadata) (bool, error) {
+	buf, err := getBlockedUpgradesAsset()
+	if err != nil {
+		if errors.Is(err, fs.ErrNotExist) {
+			return false, nil
+		}
+		return false, fmt.Errorf("failed to load embedded blocked upgrades asset: %w", err)
+	}
+
+	m, err := unmarshalBlockedUpgrades(buf)
+	if err != nil {
+		return false, err
+	}
+
+	return isBlocked(m, execVersion.String(), dataVersion.String()), nil
+}
+
+func getBlockedUpgradesAsset() ([]byte, error) {
+	return embedded.Asset("release/upgrade-blocks.json")
+}
+
+func unmarshalBlockedUpgrades(data []byte) (map[string][]string, error) {
+	var blockedEdges map[string][]string
+	err := json.Unmarshal(data, &blockedEdges)
+	if err != nil {
+		return nil, fmt.Errorf("failed to unmarshal %q: %w", string(data), err)
+	}
+	return blockedEdges, nil
+}
+
+func isBlocked(blockedUpgrades map[string][]string, execVersion, dataVersion string) bool {
+	klog.InfoS("Checking if upgrade is allowed", "existing-data-version", dataVersion, "new-binary-version", execVersion, "blocked-upgrades", blockedUpgrades)
+
+	for targetVersion, fromVersions := range blockedUpgrades {
+		if targetVersion == execVersion {
+			for _, from := range fromVersions {
+				if from == dataVersion {
+					klog.ErrorS(nil, "Detected an attempt of unsupported upgrade", "existing-data-version", dataVersion, "new-binary-version", execVersion)
+					return true
+				}
+			}
+		}
+	}
+
+	klog.InfoS("Upgrade is allowed", "existing-data-version", dataVersion, "new-binary-version", execVersion)
+	return false
+}
diff --git a/pkg/admin/prerun/upgrade_blocking_test.go b/pkg/admin/prerun/upgrade_blocking_test.go
new file mode 100644
index 0000000000..e9a0ced5b9
--- /dev/null
+++ b/pkg/admin/prerun/upgrade_blocking_test.go
@@ -0,0 +1,77 @@
+package prerun
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func Test_UnmarshalBlockedUpgrades(t *testing.T) {
+	testData := []struct {
+		input          string
+		expectedOutput map[string][]string
+	}{
+		{
+			input:          `{"4.14.10": ["4.14.5", "4.14.4"]}`,
+			expectedOutput: map[string][]string{"4.14.10": {"4.14.5", "4.14.4"}},
+		},
+		{
+			input:          `{}`,
+			expectedOutput: make(map[string][]string),
+		},
+	}
+
+	for _, td := range testData {
+		result, err := unmarshalBlockedUpgrades([]byte(td.input))
+		assert.NoError(t, err)
+		assert.Equal(t, td.expectedOutput, result)
+	}
+}
+
+func Test_IsBlocked(t *testing.T) {
+	edges := map[string][]string{
+		"4.14.10": {"4.14.5", "4.14.6"},
+		"4.15.5":  {"4.15.2"},
+	}
+
+	testData := []struct {
+		dataVersion    string
+		execVersion    string
+		expectedResult bool
+	}{
+		{
+			dataVersion:    "4.14.4",
+			execVersion:    "4.14.10",
+			expectedResult: false,
+		},
+		{
+			dataVersion:    "4.14.5",
+			execVersion:    "4.14.10",
+			expectedResult: true,
+		},
+		{
+			dataVersion:    "4.14.6",
+			execVersion:    "4.14.10",
+			expectedResult: true,
+		},
+		{
+			dataVersion:    "4.14.7",
+			execVersion:    "4.14.10",
+			expectedResult: false,
+		},
+		{
+			dataVersion:    "4.14.7",
+			execVersion:    "4.15.0",
+			expectedResult: false,
+		},
+		{
+			dataVersion:    "4.15.2",
+			execVersion:    "4.15.5",
+			expectedResult: true,
+		},
+	}
+
+	for _, td := range testData {
+		assert.Equal(t, td.expectedResult, isBlocked(edges, td.execVersion, td.dataVersion))
+	}
+}
diff --git a/pkg/admin/prerun/version.go b/pkg/admin/prerun/version.go
index 7b9dffdf1a..bc14dae3cb 100644
--- a/pkg/admin/prerun/version.go
+++ b/pkg/admin/prerun/version.go
@@ -133,5 +133,5 @@ func checkVersionDiff(execVer, dataVer versionMetadata) (bool, error) {
 		}
 	}
 
-	return false, nil
+	return IsUpgradeBlocked(execVer, dataVer)
 }