refactor: Add registry pkg registry scanner (#933)

Signed-off-by: Ishita Sequeira <ishiseq29@gmail.com>

1 files changed, 139 insertions, 0 deletions

diff --git a/registry-scanner/pkg/registry/config.go b/registry-scanner/pkg/registry/config.go
new file mode 100644
index 0000000..641c598
--- /dev/null
+++ b/registry-scanner/pkg/registry/config.go
@@ -0,0 +1,139 @@
+package registry
+
+import (
+	"fmt"
+	"os"
+	"time"
+
+	"github.com/argoproj-labs/argocd-image-updater/registry-scanner/pkg/log"
+
+	"gopkg.in/yaml.v2"
+)
+
+// RegistryConfiguration represents a single repository configuration for being
+// unmarshaled from YAML.
+type RegistryConfiguration struct {
+	Name        string        `yaml:"name"`
+	ApiURL      string        `yaml:"api_url"`
+	Ping        bool          `yaml:"ping,omitempty"`
+	Credentials string        `yaml:"credentials,omitempty"`
+	CredsExpire time.Duration `yaml:"credsexpire,omitempty"`
+	TagSortMode string        `yaml:"tagsortmode,omitempty"`
+	Prefix      string        `yaml:"prefix,omitempty"`
+	Insecure    bool          `yaml:"insecure,omitempty"`
+	DefaultNS   string        `yaml:"defaultns,omitempty"`
+	Limit       int           `yaml:"limit,omitempty"`
+	IsDefault   bool          `yaml:"default,omitempty"`
+}
+
+// RegistryList contains multiple RegistryConfiguration items
+type RegistryList struct {
+	Items []RegistryConfiguration `yaml:"registries"`
+}
+
+func clearRegistries() {
+	registryLock.Lock()
+	registries = make(map[string]*RegistryEndpoint)
+	registryLock.Unlock()
+}
+
+// LoadRegistryConfiguration loads a YAML-formatted registry configuration from
+// a given file at path.
+func LoadRegistryConfiguration(path string, clear bool) error {
+	registryBytes, err := os.ReadFile(path)
+	if err != nil {
+		return err
+	}
+	registryList, err := ParseRegistryConfiguration(string(registryBytes))
+	if err != nil {
+		return err
+	}
+
+	if clear {
+		clearRegistries()
+	}
+
+	haveDefault := false
+
+	for _, reg := range registryList.Items {
+		tagSortMode := TagListSortFromString(reg.TagSortMode)
+		if tagSortMode != TagListSortUnsorted {
+			log.Warnf("Registry %s has tag sort mode set to %s, meta data retrieval will be disabled for this registry.", reg.ApiURL, tagSortMode)
+		}
+		ep := NewRegistryEndpoint(reg.Prefix, reg.Name, reg.ApiURL, reg.Credentials, reg.DefaultNS, reg.Insecure, tagSortMode, reg.Limit, reg.CredsExpire)
+		if reg.IsDefault {
+			if haveDefault {
+				dep := GetDefaultRegistry()
+				if dep == nil {
+					panic("unexpected: default registry should be set, but is not")
+				}
+				return fmt.Errorf("cannot set registry %s as default - only one default registry allowed, currently set to %s", ep.RegistryPrefix, dep.RegistryPrefix)
+			}
+		}
+
+		if err := AddRegistryEndpoint(ep); err != nil {
+			return err
+		}
+
+		if reg.IsDefault {
+			SetDefaultRegistry(ep)
+			haveDefault = true
+		}
+	}
+
+	log.Infof("Loaded %d registry configurations from %s", len(registryList.Items), path)
+	return nil
+}
+
+// Parses a registry configuration from a YAML input string and returns a list
+// of registries.
+func ParseRegistryConfiguration(yamlSource string) (RegistryList, error) {
+	var regList RegistryList
+	var defaultPrefixFound = ""
+	err := yaml.UnmarshalStrict([]byte(yamlSource), &regList)
+	if err != nil {
+		return RegistryList{}, err
+	}
+
+	// validate the parsed list
+	for _, registry := range regList.Items {
+		if registry.Name == "" {
+			err = fmt.Errorf("registry name is missing for entry %v", registry)
+		} else if registry.ApiURL == "" {
+			err = fmt.Errorf("API URL must be specified for registry %s", registry.Name)
+		} else if registry.Prefix == "" {
+			if defaultPrefixFound != "" {
+				err = fmt.Errorf("there must be only one default registry (already is %s), %s needs a prefix", defaultPrefixFound, registry.Name)
+			} else {
+				defaultPrefixFound = registry.Name
+			}
+		}
+
+		if err == nil {
+			if tls := TagListSortFromString(registry.TagSortMode); tls == TagListSortUnknown {
+				err = fmt.Errorf("unknown tag sort mode for registry %s: %s", registry.Name, registry.TagSortMode)
+			}
+		}
+	}
+
+	if err != nil {
+		return RegistryList{}, err
+	}
+
+	return regList, nil
+}
+
+// RestRestoreDefaultRegistryConfiguration restores the registry configuration
+// to the default values.
+func RestoreDefaultRegistryConfiguration() {
+	registryLock.Lock()
+	defer registryLock.Unlock()
+	defaultRegistry = nil
+	registries = make(map[string]*RegistryEndpoint)
+	for k, v := range registryTweaks {
+		registries[k] = v.DeepCopy()
+		if v.IsDefault {
+			SetDefaultRegistry(registries[k])
+		}
+	}
+}