config

Documentation

Overview

Package config simplifies the declaration of configuration options. Right now the implementation maps them directly to command line flags. When combined with test/e2e/framework/viperconfig in a test suite, those flags then can also be read from a config file.

The command line flags all get stored in a private flag set. The developer of the E2E test suite decides how they are exposed. Options include:

• exposing as normal flags in the actual command line: CopyFlags(Flags, flag.CommandLine)
• populate via test/e2e/framework/viperconfig: viperconfig.ViperizeFlags("my-config.yaml", "", Flags)
• a combination of both: CopyFlags(Flags, flag.CommandLine) viperconfig.ViperizeFlags("my-config.yaml", "", flag.CommandLine)

Instead of defining flags one-by-one, test developers annotate a structure with tags and then call a single function. This is the same approach as in https://godoc.org/github.com/jessevdk/go-flags, but implemented so that a test suite can continue to use the normal "flag" package.

For example, a file storage/csi.go might define:

var scaling struct {
        NumNodes int  `default:"1" description:"number of nodes to run on"`
        Master string
}
_ = config.AddOptions(&scaling, "storage.csi.scaling")

This defines the following command line flags:

-storage.csi.scaling.numNodes=<int>  - number of nodes to run on (default: 1)
-storage.csi.scaling.master=<string>

All fields in the structure must be exported and have one of the following types (same as in the `flag` package): - bool - time.Duration - float64 - string - int - int64 - uint - uint64 - and/or nested or embedded structures containing those basic types.

Each basic entry may have a tag with these optional keys:

usage:   additional explanation of the option
default: the default value, in the same format as it would
         be given on the command line and true/false for
         a boolean

The names of the final configuration options are a combination of an optional common prefix for all options in the structure and the name of the fields, concatenated with a dot. To get names that are consistent with the command line flags defined by `ginkgo`, the initial character of each field name is converted to lower case.

There is currently no support for aliases, so renaming the fields or the common prefix will be visible to users of the test suite and may breaks scripts which use the old names.

The variable will be filled with the actual values by the test suite before running tests. Beware that the code which registers Ginkgo tests cannot use those config options, because registering tests and options both run before the E2E test suite handles parameters.

Index

• Variables
• func AddOptions(options interface{}, prefix string) bool
• func AddOptionsToSet(flags *flag.FlagSet, options interface{}, prefix string) bool
• func CopyFlags(source *flag.FlagSet, target *flag.FlagSet)

Variables

var Flags = flag.NewFlagSet("", flag.ContinueOnError)

Flags is the flag set that AddOptions adds to. Test authors should also use it instead of directly adding to the global command line.

Functions

func AddOptions

func AddOptions(options interface{}, prefix string) bool

AddOptions analyzes the options value and creates the necessary flags to populate it.

The prefix can be used to root the options deeper in the overall set of options, with a dot separating different levels.

The function always returns true, to enable this simplified registration of options: _ = AddOptions(...)

It panics when it encounters an error, like unsupported types or option name conflicts.

func AddOptionsToSet

func AddOptionsToSet(flags *flag.FlagSet, options interface{}, prefix string) bool

AddOptionsToSet is the same as AddOption, except that it allows choosing the flag set.

func CopyFlags

func CopyFlags(source *flag.FlagSet, target *flag.FlagSet)

CopyFlags ensures that all flags that are defined in the source flag set appear in the target flag set as if they had been defined there directly. From the flag package it inherits the behavior that there is a panic if the target already contains a flag from the source.