Documentation
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Overview ¶
SPDX-FileCopyrightText: 2017 Comcast Cable Communications Management, LLC SPDX-License-Identifier: Apache-2.0
SPDX-FileCopyrightText: 2017 Comcast Cable Communications Management, LLC SPDX-License-Identifier: Apache-2.0 Package config supplies a simple workflow for initializing an uber/fx App instance with spf13/pflag, spf13/viper, and any other components that need to be initialized prior to any uber/fx providers running. Additionally, this package provides simpler providers for use by applications that do not need this more complex workflow.
SPDX-FileCopyrightText: 2017 Comcast Cable Communications Management, LLC SPDX-License-Identifier: Apache-2.0
SPDX-FileCopyrightText: 2017 Comcast Cable Communications Management, LLC SPDX-License-Identifier: Apache-2.0
Index ¶
Constants ¶
This section is empty.
Variables ¶
This section is empty.
Functions ¶
func ProvideViper ¶
func ProvideViper(builders ...ViperBuilder) func(ViperIn) (ViperOut, error)
ProvideViper produces components for the viper environment. Each builder is invoked in sequence, and any error will short-circuit construction. This provider function does not itself read any configuration or otherwise modify the viper instance it creates. At least one builder function must read configuration.
Types ¶
type ApplicationName ¶ added in v0.0.3
type ApplicationName string
ApplicationName is the type of component that identifies the executable or application name.
func DefaultApplicationName ¶ added in v0.0.3
func DefaultApplicationName() ApplicationName
DefaultApplicationName simply returns os.Arg[0]
type CommandLine ¶ added in v0.0.3
type CommandLine struct {
// Name is the executable or application name. If unset, os.Args[0] is used.
Name string
// Arguments are the command-line arguments to parse. If nil, os.Args[1:] is used. Note that
// if this slice is explicitly set to an empty slice, then an empty slice of arguments will be parsed.
Arguments []string
// ErrorHandling is the pflag error handling mode. Defaults to ContinueOnError.
ErrorHandling pflag.ErrorHandling
// DisableParse controls whether Provide will parse the command line after building the flagset.
// Setting this to true allows upstream providers or invoke functions to handle the parsing.
DisableParse bool
}
CommandLine describes how to provide a *pflag.FlagSet to an uber/fx container. The zero value for this type is valid and will parse the executable's command line defined by os.Args. Examples include:
CommandLine{}.Provide(parseCommandLine)
CommandLine{Name: "custom"}.Provide(builder1, builder2)
CommandLine{DisableParse: true}.Provide(parseIt)
func (CommandLine) Provide ¶ added in v0.0.3
func (cl CommandLine) Provide(builders ...FlagSetBuilder) fx.Option
Provide is an uber/fx provide function that creates a *pflag.FlagSet. Zero or more builders may be passed to configure flagset, which includes adding command-line arguments. If none of the builders parse the command line, and if DisableParse is false, this function will parse the arguments prior to returning the flagset.
This provider will short-circuit application startup using fx.Error if any command-line parsing error occurs.
type CommandLineOut ¶ added in v0.0.3
type CommandLineOut struct {
fx.Out
// Name is the application (or, executable) name determined by CommandLine.Provide.
// It defaults to os.Args[0]. This component will always be supplied regardless of
// the CommandLine settings.
Name ApplicationName
// FlagSet is the command line flags and configuration. This will be parsed by default.
FlagSet *pflag.FlagSet
}
CommandLineOut defines the components provided by CommandLine.Provide
type FlagSetBuilder ¶ added in v0.0.3
FlagSetBuilder is a builder strategy for tailoring a flagset. Most commonly, this involves setting up any command line flags.
type KeyUnmarshaller ¶
type KeyUnmarshaller interface {
// IsSet checks if a configuration key is present, either in the source or as a default.
// See https://godoc.org/github.com/spf13/viper#IsSet
IsSet(string) bool
// UnmarshalKey unmarshals an object, normally a pointer to struct, from a given configuration key.
// No attempt is made to verify the existence of the configuration key. If no such key exists,
// unmarshalling will still happen against a default set of options.
// See https://godoc.org/github.com/spf13/viper#UnmarshalKey
UnmarshalKey(string, interface{}) error
}
KeyUnmarshaller is a strategy for unmarshalling objects from hierarchial configuration sources.
type MissingKeyError ¶
MissingKeyError is returned when a required key was not found in the configuration
func NewMissingKeyError ¶
func NewMissingKeyError(k string) MissingKeyError
NewMissingKeyError creates an error that indicates the given configuration key is not present in the underlying configuration source
type Unmarshaller ¶
type Unmarshaller interface {
KeyUnmarshaller
Unmarshal(interface{}) error
}
Unmarshaller is a strategy for unmarshalling configuration, mostly in the form of structs.
type ViperBuilder ¶ added in v0.0.3
ViperBuilder is a builder strategy for tailoring a viper instance. The ViperIn set of dependencies will always have the Name field set, either as a component or by defaulting to DefaultApplicationName.
func Json ¶ added in v0.0.3
func Json(data string) ViperBuilder
Json uses ReadConfig to read configuration from an in-memory JSON string.
func ReadConfig ¶ added in v0.0.3
func ReadConfig(format string, data io.Reader) ViperBuilder
ReadConfig returns a ViperBuilder that reads in a configuration file from an arbitrary io.Reader.
func Yaml ¶ added in v0.0.3
func Yaml(data string) ViperBuilder
Yaml uses ReadConfig to read configuration from an in-memory YAML string.
type ViperIn ¶ added in v0.0.3
type ViperIn struct {
fx.In
// Name is the application (or, executable) name. This component will be supplied if using
// CommandLine.Provide. If unset, DefaultApplicationName is used. The instance of this struct
// passed to builders will always have this field set.
//
// This name is frequently used to determine names of or paths to configuration files. It is
// passed to each builder function in Viper.Provide.
Name ApplicationName `optional:"true"`
// FlagSet is the optional spf13 FlagSet component. It is passed to each builder function.
// If supplied, this component can be used to tailor the viper instance using command-line arguments.
FlagSet *pflag.FlagSet `optional:"true"`
// DecoderOptions is an optional component that is a slice of spf13/viper decoder options for unmarshalling.
// If supplied, this slice is used to create the Unmarshaller component.
//
// Note that spf13/viper provides a default set of options. See https://godoc.org/github.com/spf13/viper#DecoderConfigOption
DecoderOptions []viper.DecoderConfigOption `optional:"true"`
}
ViperIn describes the dependencies for creating an spf13 Viper instance
type ViperOut ¶
type ViperOut struct {
fx.Out
Viper *viper.Viper
Unmarshaller Unmarshaller
}
ViperOut lists the components emitted for a Viper instance
type ViperUnmarshaller ¶
type ViperUnmarshaller struct {
// Viper is the required viper instance
Viper *viper.Viper
// Options are passed to viper for each unmarshal operation. This field is optional.
Options []viper.DecoderConfigOption
}
ViperUnmarshaller is an Unmarshaller backed by Viper.
func (ViperUnmarshaller) IsSet ¶
func (vu ViperUnmarshaller) IsSet(k string) bool
func (ViperUnmarshaller) Unmarshal ¶
func (vu ViperUnmarshaller) Unmarshal(v interface{}) error
func (ViperUnmarshaller) UnmarshalKey ¶
func (vu ViperUnmarshaller) UnmarshalKey(k string, v interface{}) error
Source Files