pkg/sysregistriesv2/system_registries_v2.go
func GetRegistries(ctx *types.SystemContext) ([]Registry, error) {
	configPath := getConfigPath(ctx)

	configMutex.Lock()
	defer configMutex.Unlock()
	// if the config has already been loaded, return the cached registries
	if registries, inCache := configCache[configPath]; inCache {
		return registries, nil
	}

	// load the config
	config, err := loadRegistryConf(configPath)
	if err != nil {
		// Return an empty []Registry if we use the default config,
		// which implies that the config path of the SystemContext
		// isn't set.  Note: if ctx.SystemRegistriesConfPath points to
		// the default config, we will still return an error.
		if os.IsNotExist(err) && (ctx == nil || ctx.SystemRegistriesConfPath == "") {
			return []Registry{}, nil
		}
		return nil, err
	}

	registries := config.Registries

	// backwards compatibility for v1 configs
	v1Registries, err := getV1Registries(config)
	if err != nil {
		return nil, err
	}
	if len(v1Registries) > 0 {
		if len(registries) > 0 {
			return nil, &InvalidRegistries{s: "mixing sysregistry v1/v2 is not supported"}
		}
		registries = v1Registries
	}

	registries, err = postProcessRegistries(registries)
	if err != nil {
		return nil, err
	}

	// populate the cache
	configCache[configPath] = registries

	return registries, err
}
func GetRegistries(ctx *types.SystemContext) ([]Registry, error) {
	configPath := getConfigPath(ctx)

	configMutex.Lock()
	defer configMutex.Unlock()
	// if the config has already been loaded, return the cached registries
	if registries, inCache := configCache[configPath]; inCache {
		return registries, nil
	}

	// load the config
	config, err := loadRegistryConf(configPath)
	if err != nil {
		// Return an empty []Registry if we use the default config,
		// which implies that the config path of the SystemContext
		// isn't set.  Note: if ctx.SystemRegistriesConfPath points to
		// the default config, we will still return an error.
		if os.IsNotExist(err) && (ctx == nil || ctx.SystemRegistriesConfPath == "") {
			return []Registry{}, nil
		}
		return nil, err
	}

	registries := config.Registries

	// backwards compatibility for v1 configs
	v1Registries, err := getV1Registries(config)
	if err != nil {
		return nil, err
	}
	if len(v1Registries) > 0 {
		if len(registries) > 0 {
			return nil, &InvalidRegistries{s: "mixing sysregistry v1/v2 is not supported"}
		}
		registries = v1Registries
	}

	registries, err = postProcessRegistries(registries)
	if err != nil {
		return nil, err
	}

	// populate the cache
	configCache[configPath] = registries

	return registries, err
}
// GetRegistries loads and returns the registries specified in the config.
// Note the parsed content of registry config files is cached.  For reloading,
// use `InvalidateCache` and re-call `GetRegistries`.