Making ratchet compatible with tekton by adding tekton parser (#72)

Added a tekton parser and a check to see if current image uses a tag, if
so, keep that tag and and the updated sha ref

Signed-off-by: Arif Ashogbon <[email protected]>

README.md

@@ -11,6 +11,7 @@ Cargo, Go modules, NPM, Pip, or Yarn, but for CI/CD workflows. Ratchet supports:
 -   GitLab CI
 -   Google Cloud Build
 -   Harness Drone
+-   Tekton
 
 **⚠️ Warning!** The README corresponds to the `main` branch of ratchet's
 development, and it may contain unreleased features.
@@ -85,9 +86,13 @@ ratchet pin -parser drone drone.yml
 # pin a gitlab file
 ratchet pin -parser gitlabci gitlabci.yml
 
+# output to a tekton file
+ratchet pin -out -parser tekton tekton.yml
+
 # output to a different path
 ratchet pin -out workflow-compiled.yml workflow.yml
 ```
+```
 
 #### Unpin
 

parser/parser.go

@@ -32,6 +32,7 @@ var parserFactory = map[string]func() Parser{
 	"cloudbuild": func() Parser { return new(CloudBuild) },
 	"drone":      func() Parser { return new(Drone) },
 	"gitlabci":   func() Parser { return new(GitLabCI) },
+	"tekton":     func() Parser { return new(Tekton) },
 }
 
 // For returns the parser that corresponds to the given name.

parser/tekton.go

@@ -0,0 +1,73 @@
+package parser
+
+import (
+	"fmt"
+
+	// Using banydonk/yaml instead of the default yaml pkg because the default
+	// pkg incorrectly escapes unicode. https://github.com/go-yaml/yaml/issues/737
+	"github.com/braydonk/yaml"
+	"github.com/sethvargo/ratchet/resolver"
+)
+
+type Tekton struct{}
+
+// Parse pulls the Tekton Ci refs from the documents.
+func (d *Tekton) Parse(nodes []*yaml.Node) (*RefsList, error) {
+	var refs RefsList
+	for i, node := range nodes {
+		if err := d.parseOne(&refs, node); err != nil {
+			return nil, fmt.Errorf("failed to parse node %d: %w", i, err)
+		}
+	}
+
+	return &refs, nil
+}
+
+func (d *Tekton) parseOne(refs *RefsList, node *yaml.Node) error {
+	if node == nil {
+		return nil
+	}
+
+	if node.Kind != yaml.DocumentNode {
+		return fmt.Errorf("expected document node, got %v", node.Kind)
+	}
+
+	for _, docMap := range node.Content {
+		if docMap.Kind != yaml.MappingNode {
+			continue
+		}
+
+		// Confirm it's a tekton file then proceed to look for image keyword
+		for _, stepsMap := range docMap.Content {
+			if stepsMap.Value == "apiVersion" {
+				d.findSpecs(refs, docMap)
+				break
+			}
+		}
+	}
+
+	return nil
+}
+func (d *Tekton) findSpecs(refs *RefsList, node *yaml.Node) error {
+	for i, specsMap := range node.Content {
+		if specsMap.Value == "spec" {
+			specs := node.Content[i+1]
+			d.findImages(refs, specs)
+		}
+	}
+	return nil
+}
+
+func (d *Tekton) findImages(refs *RefsList, node *yaml.Node) error {
+	for i, property := range node.Content {
+		if property.Value == "image" {
+			image := node.Content[i+1]
+			ref := resolver.NormalizeContainerRef(image.Value)
+			refs.Add(ref, image)
+			break
+		} else {
+			d.findImages(refs, property)
+		}
+	}
+	return nil
+}

parser/tekton_test.go

@@ -0,0 +1,64 @@
+package parser
+
+import (
+	"reflect"
+	"testing"
+
+	"github.com/braydonk/yaml"
+)
+
+func TestTekton_Parse(t *testing.T) {
+	t.Parallel()
+
+	cases := []struct {
+		name string
+		in   string
+		exp  []string
+	}{
+		{
+			name: "mostly_empty_file",
+			in: `
+jobs:
+`,
+			exp: []string{},
+		},
+		{
+			name: "steps",
+			in: `
+apiVersion: tekton.dev/v1beta1
+kind: Task
+metadata:
+   name: testData
+spec:
+    params:
+    - name: username
+      type: string
+    steps:
+      - name: git
+        image: alpine/git
+`,
+			exp: []string{
+				"container://alpine/git",
+			},
+		},
+	}
+
+	for _, tc := range cases {
+		tc := tc
+
+		t.Run(tc.name, func(t *testing.T) {
+			t.Parallel()
+
+			m := helperStringToYAML(t, tc.in)
+
+			refs, err := new(Tekton).Parse([]*yaml.Node{m})
+			if err != nil {
+				t.Fatal(err)
+			}
+
+			if got, want := refs.Refs(), tc.exp; !reflect.DeepEqual(got, want) {
+				t.Errorf("expected %q to be %q", got, want)
+			}
+		})
+	}
+}

resolver/container.go

@@ -44,6 +44,9 @@ func (g *Container) Resolve(ctx context.Context, value string) (string, error) {
 	if err != nil {
 		return "", fmt.Errorf("failed to lookup container ref: %w", err)
 	}
+	if value == ref.Name() {
+		return fmt.Sprintf("%s@%s", ref.Name(), resp.Digest.String()), nil
+	}
 
 	return fmt.Sprintf("%s@%s", ref.Context().Name(), resp.Digest.String()), nil
 }

testdata/tekton.yml

@@ -0,0 +1,11 @@
+apiVersion: tekton.dev/v1beta1
+kind: Task
+metadata:
+  name: testData
+spec:
+  params:
+    - name: username
+      type: string
+  steps:
+    - name: build
+      image: golang:1.12