github.com/cloudbase/juju-core@v0.0.0-20140504232958-a7271ac7912f/state/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  	"launchpad.net/juju-core/state/api/base"
    10  	"launchpad.net/juju-core/state/api/params"
    11  	"launchpad.net/juju-core/state/api/watcher"
    12  )
    13  
    14  // State provides access to an logger worker's view of the state.
    15  type State struct {
    16  	caller base.Caller
    17  }
    18  
    19  // NewState returns a version of the state that provides functionality
    20  // required by the logger worker.
    21  func NewState(caller base.Caller) *State {
    22  	return &State{caller}
    23  }
    24  
    25  // LoggingConfig returns the loggo configuration string for the agent
    26  // specified by agentTag.
    27  func (st *State) LoggingConfig(agentTag string) (string, error) {
    28  	var results params.StringResults
    29  	args := params.Entities{
    30  		Entities: []params.Entity{{Tag: agentTag}},
    31  	}
    32  	err := st.caller.Call("Logger", "", "LoggingConfig", args, &results)
    33  	if err != nil {
    34  		// TODO: Not directly tested
    35  		return "", err
    36  	}
    37  	if len(results.Results) != 1 {
    38  		// TODO: Not directly tested
    39  		return "", fmt.Errorf("expected one result, got %d", len(results.Results))
    40  	}
    41  	result := results.Results[0]
    42  	if err := result.Error; err != nil {
    43  		return "", err
    44  	}
    45  	return result.Result, nil
    46  }
    47  
    48  // WatchLoggingConfig returns a notify watcher that looks for changes in the
    49  // logging-config for the agent specifed by agentTag.
    50  func (st *State) WatchLoggingConfig(agentTag string) (watcher.NotifyWatcher, error) {
    51  	var results params.NotifyWatchResults
    52  	args := params.Entities{
    53  		Entities: []params.Entity{{Tag: agentTag}},
    54  	}
    55  	err := st.caller.Call("Logger", "", "WatchLoggingConfig", args, &results)
    56  	if err != nil {
    57  		// TODO: Not directly tested
    58  		return nil, err
    59  	}
    60  	if len(results.Results) != 1 {
    61  		// TODO: Not directly tested
    62  		return nil, fmt.Errorf("expected one result, got %d", len(results.Results))
    63  	}
    64  	result := results.Results[0]
    65  	if result.Error != nil {
    66  		//  TODO: Not directly tested
    67  		return nil, result.Error
    68  	}
    69  	w := watcher.NewNotifyWatcher(st.caller, result)
    70  	return w, nil
    71  }