github.com/wallyworld/juju@v0.0.0-20161013125918-6cf1bc9d917a/api/logger/logger.go (about)

     1  // Copyright 2013 Canonical Ltd.
     2  // Licensed under the AGPLv3, see LICENCE file for details.
     3  
     4  package logger
     5  
     6  import (
     7  	"fmt"
     8  
     9  	"gopkg.in/juju/names.v2"
    10  
    11  	"github.com/juju/juju/api/base"
    12  	apiwatcher "github.com/juju/juju/api/watcher"
    13  	"github.com/juju/juju/apiserver/params"
    14  	"github.com/juju/juju/watcher"
    15  )
    16  
    17  // State provides access to an logger worker's view of the state.
    18  type State struct {
    19  	facade base.FacadeCaller
    20  }
    21  
    22  // NewState returns a version of the state that provides functionality
    23  // required by the logger worker.
    24  func NewState(caller base.APICaller) *State {
    25  	return &State{base.NewFacadeCaller(caller, "Logger")}
    26  }
    27  
    28  // LoggingConfig returns the loggo configuration string for the agent
    29  // specified by agentTag.
    30  func (st *State) LoggingConfig(agentTag names.Tag) (string, error) {
    31  	var results params.StringResults
    32  	args := params.Entities{
    33  		Entities: []params.Entity{{Tag: agentTag.String()}},
    34  	}
    35  	err := st.facade.FacadeCall("LoggingConfig", args, &results)
    36  	if err != nil {
    37  		// TODO: Not directly tested
    38  		return "", err
    39  	}
    40  	if len(results.Results) != 1 {
    41  		// TODO: Not directly tested
    42  		return "", fmt.Errorf("expected 1 result, got %d", len(results.Results))
    43  	}
    44  	result := results.Results[0]
    45  	if err := result.Error; err != nil {
    46  		return "", err
    47  	}
    48  	return result.Result, nil
    49  }
    50  
    51  // WatchLoggingConfig returns a notify watcher that looks for changes in the
    52  // logging-config for the agent specified by agentTag.
    53  func (st *State) WatchLoggingConfig(agentTag names.Tag) (watcher.NotifyWatcher, error) {
    54  	var results params.NotifyWatchResults
    55  	args := params.Entities{
    56  		Entities: []params.Entity{{Tag: agentTag.String()}},
    57  	}
    58  	err := st.facade.FacadeCall("WatchLoggingConfig", args, &results)
    59  	if err != nil {
    60  		// TODO: Not directly tested
    61  		return nil, err
    62  	}
    63  	if len(results.Results) != 1 {
    64  		// TODO: Not directly tested
    65  		return nil, fmt.Errorf("expected 1 result, got %d", len(results.Results))
    66  	}
    67  	result := results.Results[0]
    68  	if result.Error != nil {
    69  		//  TODO: Not directly tested
    70  		return nil, result.Error
    71  	}
    72  	w := apiwatcher.NewNotifyWatcher(st.facade.RawAPICaller(), result)
    73  	return w, nil
    74  }