feat(materials): Helm Chart material support

app/controlplane/api/workflowcontract/v1/crafting_schema.proto

@@ -83,6 +83,7 @@ message CraftingSchema {
       // Static analysis output format
       // https://github.com/microsoft/sarif-tutorials/blob/main/docs/1-Introduction.md
       SARIF = 9;
+      HELM_CHART = 10;
     }
   }
 }

go.mod

@@ -310,7 +310,7 @@ require (
 	google.golang.org/genproto/googleapis/rpc v0.0.0-20240401170217-c3f982113cda // indirect
 	gopkg.in/inf.v0 v0.9.1 // indirect
 	gopkg.in/ini.v1 v1.67.0 // indirect
-	gopkg.in/yaml.v2 v2.4.0 // indirect
+	gopkg.in/yaml.v2 v2.4.0
 	gopkg.in/yaml.v3 v3.0.1 // indirect
 	k8s.io/api v0.28.3 // indirect
 	k8s.io/apimachinery v0.28.3

internal/attestation/crafter/materials/helmchart.go

@@ -0,0 +1,132 @@
+//
+// Copyright 2024 The Chainloop Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package materials
+
+import (
+	"archive/tar"
+	"compress/gzip"
+	"context"
+	"fmt"
+	"io"
+	"os"
+	"strings"
+
+	schemaapi "github.com/chainloop-dev/chainloop/app/controlplane/api/workflowcontract/v1"
+	api "github.com/chainloop-dev/chainloop/internal/attestation/crafter/api/attestation/v1"
+	"github.com/chainloop-dev/chainloop/internal/casclient"
+	"github.com/rs/zerolog"
+	"gopkg.in/yaml.v2"
+)
+
+const (
+	// chartFileName is the name of the Chart.yaml file in the helm chart
+	chartFileName = "Chart.yaml"
+	// chartValuesYamlFileName is the name of the values.yaml file in the helm chart
+	chartValuesYamlFileName = "values.yaml"
+)
+
+type HelmChartCrafter struct {
+	backend *casclient.CASBackend
+	*crafterCommon
+}
+
+func NewHelmChartCrafter(materialSchema *schemaapi.CraftingSchema_Material, backend *casclient.CASBackend,
+	l *zerolog.Logger) (*HelmChartCrafter, error) {
+	if materialSchema.Type != schemaapi.CraftingSchema_Material_HELM_CHART {
+		return nil, fmt.Errorf("material type is not HELM_CHART format")
+	}
+
+	return &HelmChartCrafter{
+		backend:       backend,
+		crafterCommon: &crafterCommon{logger: l, input: materialSchema},
+	}, nil
+}
+
+func (c *HelmChartCrafter) Craft(ctx context.Context, filepath string) (*api.Attestation_Material, error) {
+	// Open the helm chart tar file
+	f, err := os.Open(filepath)
+	if err != nil {
+		return nil, fmt.Errorf("can't open the file: %w", err)
+	}
+	defer f.Close()
+
+	// Decompress the file if possible
+	uncompressedStream, err := gzip.NewReader(f)
+	if err != nil {
+		return nil, fmt.Errorf("can't uncompress file, unexpected material type: %w", err)
+	}
+
+	// Create a tar reader
+	tarReader := tar.NewReader(uncompressedStream)
+
+	// Flags to track whether required files are found
+	var chartFileValid, chartValuesValid bool
+
+	// Iterate through the files in the tar archive
+	for {
+		header, err := tarReader.Next()
+		if err == io.EOF {
+			// Reached the end of tar archive
+			break
+		}
+		if err != nil {
+			return nil, fmt.Errorf("error reading tar file: %w", err)
+		}
+
+		// Check if the file is a regular file
+		if header.Typeflag != tar.TypeReg {
+			continue // Skip if it's not a regular file
+		}
+
+		// Validate Chart.yaml and values.yaml files. The files will have prepended the path of the directory
+		// it was compressed from. So, we can check if the file name contains the required file names
+		// Ex: helm-chart/Chart.yaml, helm-chart/values.yaml
+		if strings.Contains(header.Name, chartFileName) {
+			if err := c.validateYamlFile(tarReader); err != nil {
+				return nil, fmt.Errorf("invalid Chart.yaml file: %w", err)
+			}
+			chartFileValid = true
+		} else if strings.Contains(header.Name, chartValuesYamlFileName) {
+			if err := c.validateYamlFile(tarReader); err != nil {
+				return nil, fmt.Errorf("invalid values.yaml file: %w", err)
+			}
+			chartValuesValid = true
+		}
+
+		// Stop iterating if both files are found
+		if chartValuesValid && chartFileValid {
+			break
+		}
+	}
+
+	// If the chart.yaml and values.yaml files are not found, return an error
+	if !chartFileValid || !chartValuesValid {
+		return nil, fmt.Errorf("missing required files in the helm chart: Chart.yaml and values.yaml")
+	}
+
+	// Upload and craft the chart
+	return uploadAndCraft(ctx, c.input, c.backend, filepath, c.logger)
+}
+
+// validateYamlFile validates the YAML file just by trying to unmarshal it
+func (c *HelmChartCrafter) validateYamlFile(r io.Reader) error {
+	v := make(map[string]interface{})
+	if err := yaml.NewDecoder(r).Decode(v); err != nil {
+		return fmt.Errorf("failed to unmarshal YAML file: %w", err)
+	}
+
+	return nil
+}