github.com/mhilton/juju-juju@v0.0.0-20150901100907-a94dd2c73455/worker/uniter/runner/jujuc/relation-get.go (about)

     1  // Copyright 2012, 2013 Canonical Ltd.
     2  // Licensed under the AGPLv3, see LICENCE file for details.
     3  
     4  package jujuc
     5  
     6  import (
     7  	"fmt"
     8  
     9  	"github.com/juju/cmd"
    10  	"launchpad.net/gnuflag"
    11  
    12  	"github.com/juju/juju/apiserver/params"
    13  )
    14  
    15  // RelationGetCommand implements the relation-get command.
    16  type RelationGetCommand struct {
    17  	cmd.CommandBase
    18  	ctx        Context
    19  	RelationId int
    20  	Key        string
    21  	UnitName   string
    22  	out        cmd.Output
    23  }
    24  
    25  func NewRelationGetCommand(ctx Context) cmd.Command {
    26  	return &RelationGetCommand{ctx: ctx}
    27  }
    28  
    29  func (c *RelationGetCommand) Info() *cmd.Info {
    30  	args := "<key> <unit id>"
    31  	doc := `
    32  relation-get prints the value of a unit's relation setting, specified by key.
    33  If no key is given, or if the key is "-", all keys and values will be printed.
    34  `
    35  	if name, found := c.ctx.RemoteUnitName(); found {
    36  		args = "[<key> [<unit id>]]"
    37  		doc += fmt.Sprintf("Current default unit id is %q.", name)
    38  	}
    39  	return &cmd.Info{
    40  		Name:    "relation-get",
    41  		Args:    args,
    42  		Purpose: "get relation settings",
    43  		Doc:     doc,
    44  	}
    45  }
    46  
    47  func (c *RelationGetCommand) SetFlags(f *gnuflag.FlagSet) {
    48  	rV := newRelationIdValue(c.ctx, &c.RelationId)
    49  
    50  	c.out.AddFlags(f, "smart", cmd.DefaultFormatters)
    51  	f.Var(rV, "r", "specify a relation by id")
    52  	f.Var(rV, "relation", "")
    53  }
    54  
    55  func (c *RelationGetCommand) Init(args []string) error {
    56  	if c.RelationId == -1 {
    57  		return fmt.Errorf("no relation id specified")
    58  	}
    59  	c.Key = ""
    60  	if len(args) > 0 {
    61  		if c.Key = args[0]; c.Key == "-" {
    62  			c.Key = ""
    63  		}
    64  		args = args[1:]
    65  	}
    66  	if name, found := c.ctx.RemoteUnitName(); found {
    67  		c.UnitName = name
    68  	}
    69  	if len(args) > 0 {
    70  		c.UnitName = args[0]
    71  		args = args[1:]
    72  	}
    73  	if c.UnitName == "" {
    74  		return fmt.Errorf("no unit id specified")
    75  	}
    76  	return cmd.CheckEmpty(args)
    77  }
    78  
    79  func (c *RelationGetCommand) Run(ctx *cmd.Context) error {
    80  	r, found := c.ctx.Relation(c.RelationId)
    81  	if !found {
    82  		return fmt.Errorf("unknown relation id")
    83  	}
    84  	var settings params.Settings
    85  	if c.UnitName == c.ctx.UnitName() {
    86  		node, err := r.Settings()
    87  		if err != nil {
    88  			return err
    89  		}
    90  		settings = node.Map()
    91  	} else {
    92  		var err error
    93  		settings, err = r.ReadSettings(c.UnitName)
    94  		if err != nil {
    95  			return err
    96  		}
    97  	}
    98  	if c.Key == "" {
    99  		return c.out.Write(ctx, settings)
   100  	}
   101  	if value, ok := settings[c.Key]; ok {
   102  		return c.out.Write(ctx, value)
   103  	}
   104  	return c.out.Write(ctx, nil)
   105  }