github.com/wallyworld/juju@v0.0.0-20161013125918-6cf1bc9d917a/worker/uniter/runner/jujuc/add-metric.go (about)

     1  // Copyright 2012-2014 Canonical Ltd.
     2  // Licensed under the AGPLv3, see LICENCE file for details.
     3  
     4  package jujuc
     5  
     6  import (
     7  	"fmt"
     8  	"time"
     9  
    10  	"github.com/juju/cmd"
    11  	"github.com/juju/errors"
    12  	"github.com/juju/utils/keyvalues"
    13  	"gopkg.in/juju/charm.v6-unstable"
    14  )
    15  
    16  // Metric represents a single metric set by the charm.
    17  type Metric struct {
    18  	Key   string
    19  	Value string
    20  	Time  time.Time
    21  }
    22  
    23  // AddMetricCommand implements the add-metric command.
    24  type AddMetricCommand struct {
    25  	cmd.CommandBase
    26  	ctx     Context
    27  	Metrics []Metric
    28  }
    29  
    30  // NewAddMetricCommand generates a new AddMetricCommand.
    31  func NewAddMetricCommand(ctx Context) (cmd.Command, error) {
    32  	return &AddMetricCommand{ctx: ctx}, nil
    33  }
    34  
    35  // Info returns the command infor structure for the add-metric command.
    36  func (c *AddMetricCommand) Info() *cmd.Info {
    37  	return &cmd.Info{
    38  		Name:    "add-metric",
    39  		Args:    "key1=value1 [key2=value2 ...]",
    40  		Purpose: "add metrics",
    41  	}
    42  }
    43  
    44  // Init parses the command's parameters.
    45  func (c *AddMetricCommand) Init(args []string) error {
    46  	// TODO(fwereade): 2016-03-17 lp:1558657
    47  	now := time.Now()
    48  	if len(args) == 0 {
    49  		return fmt.Errorf("no metrics specified")
    50  	}
    51  	options, err := keyvalues.Parse(args, false)
    52  	if err != nil {
    53  		return err
    54  	}
    55  	for key, value := range options {
    56  		c.Metrics = append(c.Metrics, Metric{key, value, now})
    57  	}
    58  	return nil
    59  }
    60  
    61  // Run adds metrics to the hook context.
    62  func (c *AddMetricCommand) Run(ctx *cmd.Context) (err error) {
    63  	for _, metric := range c.Metrics {
    64  		if charm.IsBuiltinMetric(metric.Key) {
    65  			return errors.Errorf("%v uses a reserved prefix", metric.Key)
    66  		}
    67  		err := c.ctx.AddMetric(metric.Key, metric.Value, metric.Time)
    68  		if err != nil {
    69  			return errors.Annotate(err, "cannot record metric")
    70  		}
    71  	}
    72  	return nil
    73  }