add new noop state storage for k8s (#1731)

add new noop state and config storage for k8s

It will avoid any errors when trying to create state or config files
in a read-only filesystem in k8s

Related-to: #1638

Co-authored-by: taskbot <[email protected]>

Author: yrobla

pkg/config/config.go

@@ -140,23 +140,37 @@ func applyBackwardCompatibility(config *Config) error {
 // LoadOrCreateConfig fetches the application configuration.
 // If it does not already exist - it will create a new config file with default values.
 func LoadOrCreateConfig() (*Config, error) {
-	return LoadOrCreateConfigWithPath("")
+	provider := NewProvider()
+	return provider.LoadOrCreateConfig()
+}
+
+// LoadOrCreateConfigWithDefaultPath is the internal implementation for loading config with the default path.
+// This avoids circular dependency issues.
+func LoadOrCreateConfigWithDefaultPath() (*Config, error) {
+	configPath, err := getConfigPath()
+	if err != nil {
+		return nil, fmt.Errorf("unable to fetch config path: %w", err)
+	}
+	return LoadOrCreateConfigFromPath(configPath)
 }
 
 // LoadOrCreateConfigWithPath fetches the application configuration from a specific path.
 // If configPath is empty, it uses the default path.
 // If it does not already exist - it will create a new config file with default values.
 func LoadOrCreateConfigWithPath(configPath string) (*Config, error) {
-	var config Config
-	var err error
-
 	if configPath == "" {
-		configPath, err = getConfigPath()
-		if err != nil {
-			return nil, fmt.Errorf("unable to fetch config path: %w", err)
-		}
+		// When no path is specified, use the provider pattern to handle runtime-specific behavior
+		return LoadOrCreateConfig()
 	}
 
+	return LoadOrCreateConfigFromPath(configPath)
+}
+
+// LoadOrCreateConfigFromPath is the core implementation for loading/creating config from a specific path
+func LoadOrCreateConfigFromPath(configPath string) (*Config, error) {
+	var config Config
+	var err error
+
 	// Check to see if the config file already exists.
 	configPath = path.Clean(configPath)
 	newConfig := false
@@ -233,7 +247,8 @@ func (c *Config) saveToPath(configPath string) error {
 // UpdateConfig locks a separate lock file, reads from disk, applies the changes
 // from the anonymous function, writes to disk and unlocks the file.
 func UpdateConfig(updateFn func(*Config)) error {
-	return UpdateConfigAtPath("", updateFn)
+	provider := NewProvider()
+	return provider.UpdateConfig(updateFn)
 }
 
 // UpdateConfigAtPath locks a separate lock file, reads from disk, applies the changes

pkg/config/interface.go

@@ -1,5 +1,9 @@
 package config
 
+import (
+	"github.com/stacklok/toolhive/pkg/container/runtime"
+)
+
 // Provider defines the interface for configuration operations
 type Provider interface {
 	GetConfig() *Config
@@ -28,12 +32,12 @@ func (*DefaultProvider) GetConfig() *Config {
 
 // UpdateConfig updates the config using the default path
 func (*DefaultProvider) UpdateConfig(updateFn func(*Config)) error {
-	return UpdateConfig(updateFn)
+	return UpdateConfigAtPath("", updateFn)
 }
 
 // LoadOrCreateConfig loads or creates config using the default path
 func (*DefaultProvider) LoadOrCreateConfig() (*Config, error) {
-	return LoadOrCreateConfig()
+	return LoadOrCreateConfigWithDefaultPath()
 }
 
 // SetRegistryURL validates and sets a registry URL
@@ -106,3 +110,57 @@ func (p *PathProvider) UnsetRegistry() error {
 func (p *PathProvider) GetRegistryConfig() (url, localPath string, allowPrivateIP bool, registryType string) {
 	return getRegistryConfig(p)
 }
+
+// KubernetesProvider is a no-op implementation of Provider for Kubernetes environments.
+// In Kubernetes, configuration is managed by the cluster, not by local files.
+type KubernetesProvider struct{}
+
+// NewKubernetesProvider creates a new no-op config provider for Kubernetes environments
+func NewKubernetesProvider() *KubernetesProvider {
+	return &KubernetesProvider{}
+}
+
+// GetConfig returns a default config for Kubernetes environments
+func (*KubernetesProvider) GetConfig() *Config {
+	config := createNewConfigWithDefaults()
+	return &config
+}
+
+// UpdateConfig is a no-op for Kubernetes environments
+func (*KubernetesProvider) UpdateConfig(_ func(*Config)) error {
+	return nil
+}
+
+// LoadOrCreateConfig returns a default config for Kubernetes environments
+func (*KubernetesProvider) LoadOrCreateConfig() (*Config, error) {
+	config := createNewConfigWithDefaults()
+	return &config, nil
+}
+
+// SetRegistryURL is a no-op for Kubernetes environments
+func (*KubernetesProvider) SetRegistryURL(_ string, _ bool) error {
+	return nil
+}
+
+// SetRegistryFile is a no-op for Kubernetes environments
+func (*KubernetesProvider) SetRegistryFile(_ string) error {
+	return nil
+}
+
+// UnsetRegistry is a no-op for Kubernetes environments
+func (*KubernetesProvider) UnsetRegistry() error {
+	return nil
+}
+
+// GetRegistryConfig returns empty registry configuration for Kubernetes environments
+func (*KubernetesProvider) GetRegistryConfig() (url, localPath string, allowPrivateIP bool, registryType string) {
+	return "", "", false, ""
+}
+
+// NewProvider creates the appropriate config provider based on the runtime environment
+func NewProvider() Provider {
+	if runtime.IsKubernetesRuntime() {
+		return NewKubernetesProvider()
+	}
+	return NewDefaultProvider()
+}