refactor! remove pkg directory (#145)

* refactor!: remove pkg directory

* chore: include breaking changes in draft

config/config.go

@@ -0,0 +1,77 @@
+package config
+
+import (
+	"fmt"
+	"os"
+	"path/filepath"
+	"regexp"
+
+	"github.com/docker/attest/tuf"
+	"sigs.k8s.io/yaml"
+)
+
+const (
+	MappingFilename = "mapping.yaml"
+)
+
+func LoadLocalMappings(configDir string) (*PolicyMappings, error) {
+	if configDir == "" {
+		return nil, nil
+	}
+	mappings := &policyMappingsFile{}
+	path := filepath.Join(configDir, MappingFilename)
+	mappingFile, err := os.ReadFile(path)
+	if err != nil {
+		return nil, fmt.Errorf("failed to read local policy mapping file %s: %w", path, err)
+	}
+	err = yaml.Unmarshal(mappingFile, mappings)
+	if err != nil {
+		return nil, fmt.Errorf("failed to unmarshal policy mapping file %s: %w", path, err)
+	}
+	return expandMappingFile(mappings)
+}
+
+func LoadTUFMappings(tufClient tuf.Downloader, localTargetsDir string) (*PolicyMappings, error) {
+	if tufClient == nil {
+		return nil, fmt.Errorf("tuf client not set")
+	}
+	filename := MappingFilename
+	file, err := tufClient.DownloadTarget(filename, filepath.Join(localTargetsDir, filename))
+	if err != nil {
+		return nil, fmt.Errorf("failed to download policy mapping file %s: %w", filename, err)
+	}
+	mappings := &policyMappingsFile{}
+
+	err = yaml.Unmarshal(file.Data, mappings)
+	if err != nil {
+		return nil, fmt.Errorf("failed to unmarshal policy mapping file %s: %w", filename, err)
+	}
+	return expandMappingFile(mappings)
+}
+
+func expandMappingFile(mappingFile *policyMappingsFile) (*PolicyMappings, error) {
+	policies := make(map[string]*PolicyMapping)
+	for _, policy := range mappingFile.Policies {
+		policies[policy.ID] = policy
+	}
+
+	var rules []*PolicyRule
+	for _, rule := range mappingFile.Rules {
+		r, err := regexp.Compile(rule.Pattern)
+		if err != nil {
+			return nil, err
+		}
+		rules = append(rules, &PolicyRule{
+			Pattern:     r,
+			PolicyID:    rule.PolicyID,
+			Replacement: rule.Replacement,
+		})
+	}
+
+	return &PolicyMappings{
+		Version:  mappingFile.Version,
+		Kind:     mappingFile.Kind,
+		Policies: policies,
+		Rules:    rules,
+	}, nil
+}

config/types.go

@@ -0,0 +1,54 @@
+package config
+
+import (
+	"regexp"
+)
+
+type policyMappingsFile struct {
+	Version  string            `json:"version"`
+	Kind     string            `json:"kind"`
+	Policies []*PolicyMapping  `json:"policies"`
+	Rules    []*policyRuleFile `json:"rules"`
+}
+
+type policyRuleFile struct {
+	Pattern     string `json:"pattern"`
+	PolicyID    string `json:"policy-id"`
+	Replacement string `json:"rewrite"`
+}
+
+type PolicyMappings struct {
+	Version  string
+	Kind     string
+	Policies map[string]*PolicyMapping
+	Rules    []*PolicyRule
+}
+
+type AttestationStyle string
+
+const (
+	AttestationStyleAttached  AttestationStyle = "attached"
+	AttestationStyleReferrers AttestationStyle = "referrers"
+)
+
+type PolicyMapping struct {
+	ID           string              `json:"id"`
+	Description  string              `json:"description"`
+	Files        []PolicyMappingFile `json:"files"`
+	Attestations *AttestationConfig  `json:"attestations"`
+}
+
+type AttestationConfig struct {
+	Style AttestationStyle `json:"style"`
+	Repo  string           `json:"repo"`
+}
+
+type PolicyMappingFile struct {
+	Path string `json:"path"`
+}
+
+type PolicyRule struct {
+	Pattern     *regexp.Regexp
+	PolicyID    string
+	Replacement string
+}