github.com/flavio/docker@v0.1.3-0.20170117145210-f63d1a6eec47/daemon/logger/factory.go (about)

     1  package logger
     2  
     3  import (
     4  	"fmt"
     5  	"sync"
     6  )
     7  
     8  // Creator builds a logging driver instance with given context.
     9  type Creator func(Info) (Logger, error)
    10  
    11  // LogOptValidator checks the options specific to the underlying
    12  // logging implementation.
    13  type LogOptValidator func(cfg map[string]string) error
    14  
    15  type logdriverFactory struct {
    16  	registry     map[string]Creator
    17  	optValidator map[string]LogOptValidator
    18  	m            sync.Mutex
    19  }
    20  
    21  func (lf *logdriverFactory) register(name string, c Creator) error {
    22  	if lf.driverRegistered(name) {
    23  		return fmt.Errorf("logger: log driver named '%s' is already registered", name)
    24  	}
    25  
    26  	lf.m.Lock()
    27  	lf.registry[name] = c
    28  	lf.m.Unlock()
    29  	return nil
    30  }
    31  
    32  func (lf *logdriverFactory) driverRegistered(name string) bool {
    33  	lf.m.Lock()
    34  	_, ok := lf.registry[name]
    35  	lf.m.Unlock()
    36  	return ok
    37  }
    38  
    39  func (lf *logdriverFactory) registerLogOptValidator(name string, l LogOptValidator) error {
    40  	lf.m.Lock()
    41  	defer lf.m.Unlock()
    42  
    43  	if _, ok := lf.optValidator[name]; ok {
    44  		return fmt.Errorf("logger: log validator named '%s' is already registered", name)
    45  	}
    46  	lf.optValidator[name] = l
    47  	return nil
    48  }
    49  
    50  func (lf *logdriverFactory) get(name string) (Creator, error) {
    51  	lf.m.Lock()
    52  	defer lf.m.Unlock()
    53  
    54  	c, ok := lf.registry[name]
    55  	if !ok {
    56  		return c, fmt.Errorf("logger: no log driver named '%s' is registered", name)
    57  	}
    58  	return c, nil
    59  }
    60  
    61  func (lf *logdriverFactory) getLogOptValidator(name string) LogOptValidator {
    62  	lf.m.Lock()
    63  	defer lf.m.Unlock()
    64  
    65  	c, _ := lf.optValidator[name]
    66  	return c
    67  }
    68  
    69  var factory = &logdriverFactory{registry: make(map[string]Creator), optValidator: make(map[string]LogOptValidator)} // global factory instance
    70  
    71  // RegisterLogDriver registers the given logging driver builder with given logging
    72  // driver name.
    73  func RegisterLogDriver(name string, c Creator) error {
    74  	return factory.register(name, c)
    75  }
    76  
    77  // RegisterLogOptValidator registers the logging option validator with
    78  // the given logging driver name.
    79  func RegisterLogOptValidator(name string, l LogOptValidator) error {
    80  	return factory.registerLogOptValidator(name, l)
    81  }
    82  
    83  // GetLogDriver provides the logging driver builder for a logging driver name.
    84  func GetLogDriver(name string) (Creator, error) {
    85  	return factory.get(name)
    86  }
    87  
    88  // ValidateLogOpts checks the options for the given log driver. The
    89  // options supported are specific to the LogDriver implementation.
    90  func ValidateLogOpts(name string, cfg map[string]string) error {
    91  	if name == "none" {
    92  		return nil
    93  	}
    94  
    95  	if !factory.driverRegistered(name) {
    96  		return fmt.Errorf("logger: no log driver named '%s' is registered", name)
    97  	}
    98  
    99  	validator := factory.getLogOptValidator(name)
   100  	if validator != nil {
   101  		return validator(cfg)
   102  	}
   103  	return nil
   104  }