github.com/m3db/m3@v1.5.0/src/x/config/configflag/example_test.go (about)

     1  // Copyright (c) 2019 Uber Technologies, Inc.
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     3  // Permission is hereby granted, free of charge, to any person obtaining a copy
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     9  //
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    11  // all copies or substantial portions of the Software.
    12  //
    13  // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
    14  // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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    16  // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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    19  // THE SOFTWARE.
    20  
    21  package configflag_test
    22  
    23  import (
    24  	"flag"
    25  	"fmt"
    26  
    27  	"github.com/m3db/m3/src/x/config"
    28  	"github.com/m3db/m3/src/x/config/configflag"
    29  )
    30  
    31  // The FlagStringSlice allows for multiple values when used as a flag variable.
    32  func ExampleFlagStringSlice() {
    33  	var configFiles configflag.FlagStringSlice
    34  	fs := flag.NewFlagSet("config", flag.PanicOnError)
    35  	fs.Var(&configFiles, "f", "config files")
    36  	noError(fs.Parse([]string{"-f", "file1.yaml", "-f", "file2.yaml", "-f", "file3.yaml"}))
    37  
    38  	fmt.Println("Config files:", configFiles.Value)
    39  	// Output:
    40  	// Config files: [file1.yaml file2.yaml file3.yaml]
    41  }
    42  
    43  // Options supports registration of config related flags, followed by config
    44  // loading.
    45  func ExampleOptionsRegister() {
    46  	var cfgOpts configflag.Options
    47  
    48  	var flags flag.FlagSet
    49  
    50  	// normal use would use Register() (default flagset)
    51  	cfgOpts.RegisterFlagSet(&flags)
    52  
    53  	noError(flags.Parse([]string{"-f", "./testdata/config1.yaml", "-f", "./testdata/config2.yaml"}))
    54  
    55  	var cfg struct {
    56  		Foo int    `yaml:"foo"`
    57  		Bar string `yaml:"bar"`
    58  	}
    59  	noError(cfgOpts.MainLoad(&cfg, config.Options{}))
    60  
    61  	fmt.Println(cfg)
    62  	// Output: {1 bar}
    63  }
    64  
    65  func noError(err error) {
    66  	if err != nil {
    67  		panic(err.Error())
    68  	}
    69  }