Refactors configuration parser, removes Registry level from config file

Most conditional parsing code has been moved into UnmarshalYAML
functions for simplicity

Uses the BrianBland fork of goyaml in configuration.go temporarily until
fix https://github.com/go-yaml/yaml/pull/52 is merged in
This commit is contained in:
Brian Bland 2014-11-04 09:41:32 -08:00
parent 2b51a8ab43
commit 96d26842f8
3 changed files with 250 additions and 237 deletions

View file

@ -13,12 +13,10 @@ The version is specified as a string of the form `MajorVersion.MinorVersion`, wh
File Structure (as of Version 0.1)
------------------------------------
The configuration structure is defined in `configuration.go`, and is best described by the following two examples:
The configuration structure is defined by the `Configuration` struct in `configuration.go`, and is best described by the following two examples:
```yaml
version: 0.1
registry:
loglevel: info
storage:
s3:
@ -35,8 +33,6 @@ registry:
```yaml
version: 0.1
registry:
loglevel: debug
storage: inmemory
```
@ -44,10 +40,7 @@ registry:
### version
The version is expected to remain a top-level field, as to allow for a consistent version check before parsing the remainder of the configuration file.
### registry
The registry configuration consists of two fields: `loglevel` and `storage`
#### loglevel
### loglevel
This specifies the log level of the registry.
Supported values:
@ -56,7 +49,7 @@ Supported values:
* `info`
* `debug`
#### storage
### storage
This specifies the storage driver, and may be provided either as a string (only the driver type) or as a driver name with a parameters map, as seen in the first example above.
The parameters map will be passed into the factory constructor of the given storage driver type.
@ -70,7 +63,7 @@ Environment Variables
To support the workflow of running a docker registry from a standard container without having to modify configuration files, the registry configuration also supports environment variables for overriding fields.
Any field that is a descendent of `registry` can be replaced by providing an environment variable of the following form: `REGISTRY_<uppercase key>[_<uppercase key>]...`.
Any configuration field other than version can be replaced by providing an environment variable of the following form: `REGISTRY_<uppercase key>[_<uppercase key>]...`.
For example, to change the loglevel to `error`, one can provide `REGISTRY_LOGLEVEL=error`, and to change the s3 storage driver's region parameter to `us-west-1`, one can provide `REGISTRY_STORAGE_S3_LOGLEVEL=us-west-1`.

View file

@ -7,99 +7,182 @@ import (
"strconv"
"strings"
"gopkg.in/yaml.v2"
"gopkg.in/BrianBland/yaml.v2"
)
// CurrentVersion is the most recent Version that can be parsed
var CurrentVersion = Version{Major: 0, Minor: 1}
// Configuration is a versioned system configuration
// When marshaled into yaml, this produces a document matching the current version's format
// Configuration is a versioned registry configuration, intended to be provided by a yaml file, and
// optionally modified by environment variables
type Configuration struct {
// Version is the version which defines the format of the rest of the configuration
Version Version `yaml:"version"`
Registry Registry `yaml:"registry"`
// Loglevel is the level at which registry operations are logged
Loglevel Loglevel `yaml:"loglevel"`
// Storage is the configuration for the registry's storage driver
Storage Storage `yaml:"storage"`
}
// Version is a major/minor version pair
// Minor version upgrades should be strictly additive
// v_0_1_Configuration is a Version 0.1 Configuration struct
// This is currently aliased to Configuration, as it is the current version
type v_0_1_Configuration Configuration
// Version is a major/minor version pair of the form Major.Minor
// Major version upgrades indicate structure or type changes
type Version struct {
Major uint
Minor uint
// Minor version upgrades should be strictly additive
type Version string
// MajorMinorVersion constructs a Version from its Major and Minor components
func MajorMinorVersion(major, minor uint) Version {
return Version(fmt.Sprintf("%d.%d", major, minor))
}
func (version Version) String() string {
return fmt.Sprintf("%d.%d", version.Major, version.Minor)
func (version Version) major() (uint, error) {
majorPart := strings.Split(string(version), ".")[0]
major, err := strconv.ParseUint(majorPart, 10, 0)
return uint(major), err
}
// MarshalYAML is implemented to serialize the Version into a string format
func (version Version) MarshalYAML() (interface{}, error) {
return version.String(), nil
// Major returns the major version portion of a Version
func (version Version) Major() uint {
major, _ := version.major()
return major
}
// Registry defines the configuration for a registry
type Registry struct {
// LogLevel specifies the level at which the registry will be logged
LogLevel string
func (version Version) minor() (uint, error) {
minorPart := strings.Split(string(version), ".")[1]
minor, err := strconv.ParseUint(minorPart, 10, 0)
return uint(minor), err
}
// Storage specifies the configuration of the registry's object storage
Storage Storage
// Minor returns the minor version portion of a Version
func (version Version) Minor() uint {
minor, _ := version.minor()
return minor
}
// UnmarshalYAML implements the yaml.Unmarshaler interface
// Unmarshals a string of the form X.Y into a Version, validating that X and Y can represent uints
func (version *Version) UnmarshalYAML(unmarshal func(interface{}) error) error {
var versionString string
err := unmarshal(&versionString)
if err != nil {
return err
}
newVersion := Version(versionString)
if _, err := newVersion.major(); err != nil {
return err
}
if _, err := newVersion.minor(); err != nil {
return err
}
*version = newVersion
return nil
}
// CurrentVersion is the most recent Version that can be parsed
var CurrentVersion = MajorMinorVersion(0, 1)
// Loglevel is the level at which operations are logged
// This can be error, warn, info, or debug
type Loglevel string
// UnmarshalYAML implements the yaml.Umarshaler interface
// Unmarshals a string into a Loglevel, lowercasing the string and validating that it represents a
// valid loglevel
func (loglevel *Loglevel) UnmarshalYAML(unmarshal func(interface{}) error) error {
var loglevelString string
err := unmarshal(&loglevelString)
if err != nil {
return err
}
loglevelString = strings.ToLower(loglevelString)
switch loglevelString {
case "error", "warn", "info", "debug":
default:
return fmt.Errorf("Invalid loglevel %s Must be one of [error, warn, info, debug]", loglevelString)
}
*loglevel = Loglevel(loglevelString)
return nil
}
// Storage defines the configuration for registry object storage
type Storage struct {
// Type specifies the storage driver type (examples: inmemory, filesystem, s3, ...)
Type string
type Storage map[string]Parameters
// Parameters specifies the key/value parameters map passed to the storage driver constructor
Parameters map[string]string
// Type returns the storage driver type, such as filesystem or s3
func (storage Storage) Type() string {
// Return only key in this map
for k := range storage {
return k
}
return ""
}
// Parameters returns the Parameters map for a Storage configuration
func (storage Storage) Parameters() Parameters {
return storage[storage.Type()]
}
// setParameter changes the parameter at the provided key to the new value
func (storage Storage) setParameter(key, value string) {
storage[storage.Type()][key] = value
}
// UnmarshalYAML implements the yaml.Unmarshaler interface
// Unmarshals a single item map into a Storage or a string into a Storage type with no parameters
func (storage *Storage) UnmarshalYAML(unmarshal func(interface{}) error) error {
var storageMap map[string]Parameters
err := unmarshal(&storageMap)
if err == nil {
if len(storageMap) > 1 {
types := make([]string, 0, len(storageMap))
for k := range storageMap {
types = append(types, k)
}
return fmt.Errorf("Must provide exactly one storage type. Provided: %v", types)
}
*storage = storageMap
return nil
}
var storageType string
err = unmarshal(&storageType)
if err == nil {
*storage = Storage{storageType: Parameters{}}
return nil
}
return err
}
// MarshalYAML implements the yaml.Marshaler interface
func (storage Storage) MarshalYAML() (interface{}, error) {
return yaml.MapSlice{yaml.MapItem{storage.Type, storage.Parameters}}, nil
if storage.Parameters == nil {
return storage.Type, nil
}
return map[string]Parameters(storage), nil
}
// untypedConfiguration is the unmarshalable configuration struct that only assumes the existence of
// a version string parameter
// This is done to parse the configuration version, then parse the remainder with a version-specific
// parser
type untypedConfiguration struct {
// Version is the version string defined in a configuration yaml
// This can safely parse versions defined as float types in yaml
Version string `yaml:"version"`
// Registry is an untyped placeholder for the Registry configuration, which can later be parsed
// into a current Registry struct
Registry interface{} `yaml:"registry"`
}
// V_0_1_RegistryConfiguration is the unmarshalable Registry configuration struct specific to
// Version{0, 1}
type V_0_1_RegistryConfiguration struct {
// LogLevel is the level at which the registry will log
// The loglevel can be overridden with the environment variable REGISTRY_LOGLEVEL, for example:
// REGISTRY_LOGLEVEL=info
LogLevel string `yaml:"loglevel"`
// Storage is an untyped placeholder for the Storage configuration, which can later be parsed as
// a Storage struct
// The storage type can be overridden with the environment variable REGISTRY_STORAGE, for
// example: REGISTRY_STORAGE=s3
// Note: If REGISTRY_STORAGE changes the storage type, all included parameters will be ignored
// The storage parameters can be overridden with any environment variable of the format:
// REGISTRY_STORAGE_<storage driver type>_<parameter name>, for example:
// REGISTRY_STORAGE_S3_BUCKET=my-bucket
Storage interface{} `yaml:"storage"`
}
// Parameters defines a key-value parameters mapping
type Parameters map[string]string
// Parse parses an input configuration yaml document into a Configuration struct
// This should be capable of handling old configuration format versions
// This should generally be capable of handling old configuration format versions
//
// Environment variables may be used to override configuration parameters other than version, which
// may be defined on a per-version basis. See V_0_1_RegistryConfiguration for more details
// Environment variables may be used to override configuration parameters other than version,
// following the scheme below:
// Configuration.Abc may be replaced by the value of REGISTRY_ABC,
// Configuration.Abc.Xyz may be replaced by the value of REGISTRY_ABC_XYZ, and so forth
func Parse(in []byte) (*Configuration, error) {
var untypedConfig untypedConfiguration
var config Configuration
var untypedConfig struct {
Version Version
}
var config *Configuration
err := yaml.Unmarshal(in, &untypedConfig)
if err != nil {
@ -109,128 +192,70 @@ func Parse(in []byte) (*Configuration, error) {
return nil, fmt.Errorf("Please specify a configuration version. Current version is %s", CurrentVersion)
}
// Convert the version string from X.Y to Version{X, Y}
versionParts := strings.Split(untypedConfig.Version, ".")
if len(versionParts) != 2 {
return nil, fmt.Errorf("Invalid version: %s Expected format: X.Y", untypedConfig.Version)
}
majorVersion, err := strconv.ParseUint(versionParts[0], 10, 0)
if err != nil {
return nil, fmt.Errorf("Major version must be of type uint, received %v", versionParts[0])
}
minorVersion, err := strconv.ParseUint(versionParts[1], 10, 0)
if err != nil {
return nil, fmt.Errorf("Minor version must be of type uint, received %v", versionParts[1])
}
config.Version = Version{Major: uint(majorVersion), Minor: uint(minorVersion)}
// Parse the remainder of the configuration depending on the provided version
switch config.Version {
case Version{0, 1}:
registry, err := parseV_0_1_Registry(untypedConfig.Registry)
switch untypedConfig.Version {
case "0.1":
config, err = parseV_0_1_Registry(in)
if err != nil {
return nil, err
}
config.Registry = *registry
default:
return nil, fmt.Errorf("Unsupported configuration version %s Current version is %s", config.Version, CurrentVersion)
return nil, fmt.Errorf("Unsupported configuration version %s Current version is %s", untypedConfig.Version, CurrentVersion)
}
switch config.Registry.LogLevel {
case "error", "warn", "info", "debug":
default:
return nil, fmt.Errorf("Invalid loglevel %s Must be one of [error, warn, info, debug]", config.Registry.LogLevel)
return config, nil
}
return &config, nil
}
// parseV_0_1_Registry parses a Registry configuration for Version{0, 1}
func parseV_0_1_Registry(registry interface{}) (*Registry, error) {
// parseV_0_1_Registry parses a registry Configuration for Version 0.1
func parseV_0_1_Registry(in []byte) (*Configuration, error) {
envMap := getEnvMap()
registryBytes, err := yaml.Marshal(registry)
if err != nil {
return nil, err
}
var v_0_1 V_0_1_RegistryConfiguration
err = yaml.Unmarshal(registryBytes, &v_0_1)
var config v_0_1_Configuration
err := yaml.Unmarshal(in, &config)
if err != nil {
return nil, err
}
if logLevel, ok := envMap["REGISTRY_LOGLEVEL"]; ok {
v_0_1.LogLevel = logLevel
// Override config.Loglevel if environment variable is provided
if loglevel, ok := envMap["REGISTRY_LOGLEVEL"]; ok {
var newLoglevel Loglevel
err := yaml.Unmarshal([]byte(loglevel), &newLoglevel)
if err != nil {
return nil, err
}
v_0_1.LogLevel = strings.ToLower(v_0_1.LogLevel)
var storage Storage
storage.Parameters = make(map[string]string)
switch v_0_1.Storage.(type) {
case string:
// Storage is provided only by type
storage.Type = v_0_1.Storage.(string)
case map[interface{}]interface{}:
// Storage is provided as a {type: parameters} map
storageMap := v_0_1.Storage.(map[interface{}]interface{})
if len(storageMap) > 1 {
keys := make([]string, 0, len(storageMap))
for key := range storageMap {
keys = append(keys, toString(key))
}
return nil, fmt.Errorf("Must provide exactly one storage type. Provided: %v", keys)
}
var params map[interface{}]interface{}
// There will only be one key-value pair at this point
for k, v := range storageMap {
// Parameters may be parsed as numerical or boolean values, so just convert these to
// strings
storage.Type = toString(k)
paramsMap, ok := v.(map[interface{}]interface{})
if !ok {
return nil, fmt.Errorf("Must provide parameters as a map[string]string. Provided: %#v", v)
}
params = paramsMap
}
for k, v := range params {
storage.Parameters[toString(k)] = toString(v)
}
case interface{}:
// Bad type for storage
return nil, fmt.Errorf("Registry storage must be provided by name, optionally with parameters. Provided: %v", v_0_1.Storage)
config.Loglevel = newLoglevel
}
// Override config.Storage if environment variable is provided
if storageType, ok := envMap["REGISTRY_STORAGE"]; ok {
if storageType != storage.Type {
storage.Type = storageType
if storageType != config.Storage.Type() {
// Reset the storage parameters because we're using a different storage type
storage.Parameters = make(map[string]string)
config.Storage = Storage{storageType: Parameters{}}
}
}
if storage.Type == "" {
return nil, fmt.Errorf("Must provide exactly one storage type, optionally with parameters. Provided: %v", v_0_1.Storage)
if config.Storage.Type() == "" {
return nil, fmt.Errorf("Must provide exactly one storage type, optionally with parameters. Provided: %v", config.Storage)
}
// Find all environment variables of the format:
// Override storage parameters with all environment variables of the format:
// REGISTRY_STORAGE_<storage driver type>_<parameter name>
storageParamsRegexp, err := regexp.Compile(fmt.Sprintf("^REGISTRY_STORAGE_%s_([A-Z0-9]+)$", strings.ToUpper(storage.Type)))
storageParamsRegexp, err := regexp.Compile(fmt.Sprintf("^REGISTRY_STORAGE_%s_([A-Z0-9]+)$", strings.ToUpper(config.Storage.Type())))
if err != nil {
return nil, err
}
for k, v := range envMap {
if submatches := storageParamsRegexp.FindStringSubmatch(k); submatches != nil {
storage.Parameters[strings.ToLower(submatches[1])] = v
config.Storage.setParameter(strings.ToLower(submatches[1]), v)
}
}
return &Registry{LogLevel: v_0_1.LogLevel, Storage: storage}, nil
return (*Configuration)(&config), nil
}
// getEnvMap reads the current environment variables and converts these into a key/value map
// This is used to distinguish between empty strings returned by os.GetEnv(key) because of undefined
// environment variables and explicitly empty ones
func getEnvMap() map[string]string {
envMap := make(map[string]string)
for _, env := range os.Environ() {
@ -239,11 +264,3 @@ func getEnvMap() map[string]string {
}
return envMap
}
// toString converts reasonable objects into strings that may be used for configuration parameters
func toString(v interface{}) string {
if v == nil {
return ""
}
return fmt.Sprint(v)
}

View file

@ -14,15 +14,10 @@ func Test(t *testing.T) { TestingT(t) }
// configStruct is a canonical example configuration, which should map to configYamlV_0_1
var configStruct = Configuration{
Version: Version{
Major: 0,
Minor: 1,
},
Registry: Registry{
LogLevel: "info",
Version: "0.1",
Loglevel: "info",
Storage: Storage{
Type: "s3",
Parameters: map[string]string{
"s3": Parameters{
"region": "us-east-1",
"bucket": "my-bucket",
"rootpath": "/registry",
@ -34,14 +29,11 @@ var configStruct = Configuration{
"port": "",
},
},
},
}
// configYamlV_0_1 is a Version{0, 1} yaml document representing configStruct
// configYamlV_0_1 is a Version 0.1 yaml document representing configStruct
var configYamlV_0_1 = `
version: 0.1
registry:
loglevel: info
storage:
s3:
@ -56,6 +48,14 @@ registry:
port: ~
`
// inmemoryConfigYamlV_0_1 is a Version 0.1 yaml document specifying an inmemory storage driver with
// no parameters
var inmemoryConfigYamlV_0_1 = `
version: 0.1
loglevel: info
storage: inmemory
`
type ConfigSuite struct {
expectedConfig *Configuration
}
@ -84,6 +84,16 @@ func (suite *ConfigSuite) TestParseSimple(c *C) {
c.Assert(config, DeepEquals, suite.expectedConfig)
}
// TestParseInmemory validates that configuration yaml with storage provided as a string can be
// parsed into a Configuration struct with no storage parameters
func (suite *ConfigSuite) TestParseInmemory(c *C) {
suite.expectedConfig.Storage = Storage{"inmemory": Parameters{}}
config, err := Parse([]byte(inmemoryConfigYamlV_0_1))
c.Assert(err, IsNil)
c.Assert(config, DeepEquals, suite.expectedConfig)
}
// TestParseWithSameEnvStorage validates that providing environment variables that match the given
// storage type and parameters will not alter the parsed Configuration struct
func (suite *ConfigSuite) TestParseWithSameEnvStorage(c *C) {
@ -99,9 +109,9 @@ func (suite *ConfigSuite) TestParseWithSameEnvStorage(c *C) {
// and add to the given storage parameters will change and add parameters to the parsed
// Configuration struct
func (suite *ConfigSuite) TestParseWithDifferentEnvStorageParams(c *C) {
suite.expectedConfig.Registry.Storage.Parameters["region"] = "us-west-1"
suite.expectedConfig.Registry.Storage.Parameters["secure"] = "true"
suite.expectedConfig.Registry.Storage.Parameters["newparam"] = "some Value"
suite.expectedConfig.Storage.setParameter("region", "us-west-1")
suite.expectedConfig.Storage.setParameter("secure", "true")
suite.expectedConfig.Storage.setParameter("newparam", "some Value")
os.Setenv("REGISTRY_STORAGE_S3_REGION", "us-west-1")
os.Setenv("REGISTRY_STORAGE_S3_SECURE", "true")
@ -115,7 +125,7 @@ func (suite *ConfigSuite) TestParseWithDifferentEnvStorageParams(c *C) {
// TestParseWithDifferentEnvStorageType validates that providing an environment variable that
// changes the storage type will be reflected in the parsed Configuration struct
func (suite *ConfigSuite) TestParseWithDifferentEnvStorageType(c *C) {
suite.expectedConfig.Registry.Storage = Storage{Type: "inmemory", Parameters: map[string]string{}}
suite.expectedConfig.Storage = Storage{"inmemory": Parameters{}}
os.Setenv("REGISTRY_STORAGE", "inmemory")
@ -128,8 +138,8 @@ func (suite *ConfigSuite) TestParseWithDifferentEnvStorageType(c *C) {
// that changes the storage type will be reflected in the parsed Configuration struct and that
// environment storage parameters will also be included
func (suite *ConfigSuite) TestParseWithDifferentEnvStorageTypeAndParams(c *C) {
suite.expectedConfig.Registry.Storage = Storage{Type: "filesystem", Parameters: map[string]string{}}
suite.expectedConfig.Registry.Storage.Parameters["rootdirectory"] = "/tmp/testroot"
suite.expectedConfig.Storage = Storage{"filesystem": Parameters{}}
suite.expectedConfig.Storage.setParameter("rootdirectory", "/tmp/testroot")
os.Setenv("REGISTRY_STORAGE", "filesystem")
os.Setenv("REGISTRY_STORAGE_FILESYSTEM_ROOTDIRECTORY", "/tmp/testroot")
@ -152,7 +162,7 @@ func (suite *ConfigSuite) TestParseWithSameEnvLoglevel(c *C) {
// TestParseWithDifferentEnvLoglevel validates that providing an environment variable defining the
// log level will override the value provided in the yaml document
func (suite *ConfigSuite) TestParseWithDifferentEnvLoglevel(c *C) {
suite.expectedConfig.Registry.LogLevel = "error"
suite.expectedConfig.Loglevel = "error"
os.Setenv("REGISTRY_LOGLEVEL", "error")
@ -164,7 +174,7 @@ func (suite *ConfigSuite) TestParseWithDifferentEnvLoglevel(c *C) {
// TestParseInvalidVersion validates that the parser will fail to parse a newer configuration
// version than the CurrentVersion
func (suite *ConfigSuite) TestParseInvalidVersion(c *C) {
suite.expectedConfig.Version = Version{Major: CurrentVersion.Major, Minor: CurrentVersion.Minor + 1}
suite.expectedConfig.Version = MajorMinorVersion(CurrentVersion.Major(), CurrentVersion.Minor()+1)
configBytes, err := yaml.Marshal(suite.expectedConfig)
c.Assert(err, IsNil)
_, err = Parse(configBytes)
@ -174,18 +184,11 @@ func (suite *ConfigSuite) TestParseInvalidVersion(c *C) {
func copyConfig(config Configuration) *Configuration {
configCopy := new(Configuration)
configCopy.Version = *new(Version)
configCopy.Version.Major = config.Version.Major
configCopy.Version.Minor = config.Version.Minor
configCopy.Registry = *new(Registry)
configCopy.Registry.LogLevel = config.Registry.LogLevel
configCopy.Registry.Storage = *new(Storage)
configCopy.Registry.Storage.Type = config.Registry.Storage.Type
configCopy.Registry.Storage.Parameters = make(map[string]string)
for k, v := range config.Registry.Storage.Parameters {
configCopy.Registry.Storage.Parameters[k] = v
configCopy.Version = MajorMinorVersion(config.Version.Major(), config.Version.Minor())
configCopy.Loglevel = config.Loglevel
configCopy.Storage = Storage{config.Storage.Type(): Parameters{}}
for k, v := range config.Storage.Parameters() {
configCopy.Storage.setParameter(k, v)
}
return configCopy