feat: add hold file for chart upgrade

Signed-off-by: Richard Gee <[email protected]>

.gitignore

@@ -8,4 +8,4 @@ mc
 /arkade-*
 /faas-cli*
 test.out
-docker-compose.yaml
+docker-compose.yaml*

README.md

@@ -325,8 +325,8 @@ The directory that contains the Helm chart should be a Git repository. If the fl
 
 There are two commands built into arkade designed for software vendors and open source maintainers.
 
-* `arkade helm chart upgrade` - run this command to scan for container images and update them automatically by querying a remote registry. 
-* `arkade helm chart verify` - after changing the contents of a values.yaml or docker-compose.yaml file, this command will check each image exists on a remote registry
+* `arkade chart upgrade` - run this command to scan for container images and update them automatically by querying a remote registry. 
+* `arkade chart verify` - after changing the contents of a values.yaml or docker-compose.yaml file, this command will check each image exists on a remote registry
 
 Whilst end-users may use a GitOps-style tool to deploy charts and update their versions, maintainers need to make conscious decisions about when and which images to change within a Helm chart or compose file.
 
@@ -376,6 +376,45 @@ arkade chart upgrade -f \
   --write
 ```
 
+### Holding image versions within a Helm chart
+
+With the command `arkade chart upgrade` you can add a `.hold` associated with a `values.yaml` file, e.g. `values.yaml.hold` to exclude the specified images from the version update.
+
+Original YAML file:
+
+```yaml
+stan:
+  # Image used for nats deployment when using async with NATS-Streaming.
+  image: nats-streaming:0.24.6
+
+db:
+  image: postgres:16
+```
+
+Associated hold file:
+
+```
+postgres:16
+```
+
+```bash
+arkade chart upgrade -f \
+  ~/go/src/github.com/openfaas/faas-netes/chart/openfaas/values.yaml \
+  --verbose
+
+2023/01/03 10:12:47 Verifying images in: /home/alex/go/src/github.com/openfaas/faas-netes/chart/openfaas/values.yaml
+2023/01/03 10:12:47 Found 18 images
+2023/01/03 10:12:47 Found 1 image to hold/ignore in values.yaml.hold
+2023/01/03 10:12:47 Processing 17 images
+2023/01/03 10:12:48 [natsio/prometheus-nats-exporter] 0.8.0 => 0.10.1
+2023/01/03 10:12:50 [nats-streaming] 0.24.6 => 0.25.2
+2023/01/03 10:12:52 [prom/prometheus] v2.38.0 => 2.41.0
+2023/01/03 10:12:54 [prom/alertmanager] v0.24.0 => 0.25.0
+2023/01/03 10:12:54 [nats] 2.9.2 => 2.9.10
+```
+
+Within the uprgade activity `postgres:16` is no longer included.
+
 Supported:
 
 * `image:` - at the top level

cmd/chart/upgrade.go

@@ -1,6 +1,7 @@
 package chart
 
 import (
+	"bufio"
 	"errors"
 	"fmt"
 	"log"
@@ -24,6 +25,8 @@ type tagAttributes struct {
 	original  string
 }
 
+const holdFileExt = "hold"
+
 func (c *tagAttributes) attributesMatch(n tagAttributes) bool {
 	return c.hasMajor == n.hasMajor &&
 		c.hasMinor == n.hasMinor &&
@@ -96,9 +99,22 @@ Otherwise, it returns a non-zero exit code and the updated values.yaml file.`,
 		}
 
 		if verbose {
-			if len(filtered) > 0 {
-				log.Printf("Found %d images\n", len(filtered))
-			}
+			log.Printf("Found %d image%s\n", len(filtered), pluralise(len(filtered)))
+		}
+
+		holdfile := fmt.Sprintf("%s.%s", file, holdFileExt)
+		imagesToHold, err := readFileLines(holdfile)
+		if err != nil {
+			return err
+		}
+
+		if verbose {
+			log.Printf("Found %d image%s to hold/ignore in %s", len(imagesToHold), pluralise(len(imagesToHold)), holdfile)
+		}
+
+		filtered = removeHoldImages(filtered, imagesToHold)
+		if verbose {
+			log.Printf("Processing %d image%s\n", len(filtered), pluralise(len(filtered)))
 		}
 
 		wg := sync.WaitGroup{}
@@ -155,7 +171,7 @@ Otherwise, it returns a non-zero exit code and the updated values.yaml file.`,
 			if err := os.WriteFile(file, []byte(rawValues), 0600); err != nil {
 				return err
 			}
-			log.Printf("Wrote %d updates to: %s", len(updatedImages), file)
+			log.Printf("Wrote %d update%s to: %s", len(updatedImages), pluralise(len(updatedImages)), file)
 		}
 
 		return nil
@@ -252,3 +268,49 @@ func getTagAttributes(t string) tagAttributes {
 		original:  t,
 	}
 }
+
+func readFileLines(filename string) ([]string, error) {
+
+	if _, err := os.Stat(filename); os.IsNotExist(err) {
+		return nil, nil
+	}
+
+	file, err := os.Open(filename)
+	if err != nil {
+		return nil, fmt.Errorf("failed to open file: %w", err)
+	}
+	defer file.Close()
+
+	var lines []string
+	scanner := bufio.NewScanner(file)
+	for scanner.Scan() {
+		lines = append(lines, scanner.Text())
+	}
+
+	if err := scanner.Err(); err != nil {
+		return nil, fmt.Errorf("error reading file: %w", err)
+	}
+
+	return lines, nil
+}
+
+func removeHoldImages(fullset map[string]string, held []string) map[string]string {
+
+	for _, h := range held {
+		for k := range fullset {
+			if strings.EqualFold(h, k[len(k)-len(h):]) {
+				delete(fullset, k)
+			}
+		}
+	}
+
+	return fullset
+}
+
+func pluralise(count int) string {
+
+	if count == 1 {
+		return ""
+	}
+	return "s"
+}

cmd/chart/upgrade_test.go

@@ -1,6 +1,7 @@
 package chart
 
 import (
+	"reflect"
 	"testing"
 )
 
@@ -372,3 +373,175 @@ func TestGetTagAttributes(t *testing.T) {
 		})
 	}
 }
+
+func TestRemoveHoldImages(t *testing.T) {
+	tests := []struct {
+		name     string
+		fullset  map[string]string
+		held     []string
+		expected map[string]string
+	}{
+		{
+			name: "Basic exclusion",
+			fullset: map[string]string{
+				"registry/img1:16": "going",
+				"registry/img1:17": "staying",
+				"registry/img1:18": "staying",
+			},
+			held: []string{
+				"img1:16",
+			},
+			expected: map[string]string{
+				"registry/img1:17": "staying",
+				"registry/img1:18": "staying",
+			},
+		},
+		{
+			name: "Basic exclusion / muli-match",
+			fullset: map[string]string{
+				"registry/img1:16": "going",
+				"registry/img1:17": "going",
+				"registry/img1:18": "staying",
+			},
+			held: []string{
+				"img1:16",
+				"img1:17",
+			},
+			expected: map[string]string{
+				"registry/img1:18": "staying",
+			},
+		},
+		{
+			name: "No match",
+			fullset: map[string]string{
+				"registry/img1:17": "staying",
+				"registry/img1:18": "staying",
+				"registry/img1:19": "staying",
+			},
+			held: []string{
+				"img1:16",
+			},
+			expected: map[string]string{
+				"registry/img1:17": "staying",
+				"registry/img1:18": "staying",
+				"registry/img1:19": "staying",
+			},
+		},
+		{
+			name: "Different Repos images match",
+			fullset: map[string]string{
+				"registry/repo/img1:16":  "going",
+				"registry/repo2/img1:16": "going",
+				"registry/repo3/img1:18": "staying",
+			},
+			held: []string{
+				"img1:16",
+			},
+			expected: map[string]string{
+				"registry/repo3/img1:18": "staying",
+			},
+		},
+		{
+			name: "Different Repos images match / full path exclude",
+			fullset: map[string]string{
+				"registry/repo/img1:16":  "going",
+				"registry/repo2/img1:16": "staying",
+				"registry/repo3/img1:18": "staying",
+			},
+			held: []string{
+				"registry/repo/img1:16",
+			},
+			expected: map[string]string{
+				"registry/repo2/img1:16": "staying",
+				"registry/repo3/img1:18": "staying",
+			},
+		},
+		{
+			name: "Different Repos images match / two exclude",
+			fullset: map[string]string{
+				"registry/repo/img1:16":  "going",
+				"registry/repo2/img1:16": "going",
+				"registry/repo3/img1:18": "staying",
+			},
+			held: []string{
+				"registry/repo/img1:16",
+				"img1:16",
+			},
+			expected: map[string]string{
+				"registry/repo3/img1:18": "staying",
+			},
+		},
+		{
+			name:    "Empty fullset",
+			fullset: map[string]string{},
+			held: []string{
+				"hold",
+			},
+			expected: map[string]string{},
+		},
+	}
+
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			result := removeHoldImages(tc.fullset, tc.held)
+			if !reflect.DeepEqual(result, tc.expected) {
+				t.Errorf("\n%s \n  got = %v\n want = %v", tc.name, result, tc.expected)
+			}
+		})
+	}
+}
+
+func TestPluralise(t *testing.T) {
+	tests := []struct {
+		name     string
+		count    int
+		expected string
+		failTest bool
+	}{
+		{
+			name:     "Singular (1)",
+			count:    1,
+			expected: "",
+			failTest: false,
+		},
+		{
+			name:     "Plural (2)",
+			count:    2,
+			expected: "s",
+			failTest: false,
+		},
+		{
+			name:     "Zero",
+			count:    0,
+			expected: "s",
+			failTest: false,
+		},
+		{
+			name:     "Negative count",
+			count:    -1,
+			expected: "s",
+			failTest: false,
+		},
+		{
+			name:     "Large plural",
+			count:    100,
+			expected: "s",
+			failTest: false,
+		},
+		{
+			name:     "Large plural wrong expected",
+			count:    100,
+			expected: "",
+			failTest: true,
+		},
+	}
+
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			result := pluralise(tc.count)
+			if result != tc.expected && !tc.failTest {
+				t.Errorf("\n%s \n  got = %v\n want = %v", tc.name, result, tc.expected)
+			}
+		})
+	}
+}