open-nomad/command/meta.go

127 lines
3.1 KiB
Go

package command
import (
"bufio"
"flag"
"io"
"os"
"strings"
"github.com/hashicorp/nomad/api"
"github.com/mitchellh/cli"
"github.com/mitchellh/colorstring"
)
const (
// Names of environment variables used to supply various
// config options to the Nomad CLI.
EnvNomadAddress = "NOMAD_ADDR"
EnvNomadRegion = "NOMAD_REGION"
// Constants for CLI identifier length
shortId = 8
fullId = 36
)
// FlagSetFlags is an enum to define what flags are present in the
// default FlagSet returned by Meta.FlagSet.
type FlagSetFlags uint
const (
FlagSetNone FlagSetFlags = 0
FlagSetClient FlagSetFlags = 1 << iota
FlagSetDefault = FlagSetClient
)
// Meta contains the meta-options and functionality that nearly every
// Nomad command inherits.
type Meta struct {
Ui cli.Ui
// These are set by the command line flags.
flagAddress string
// Whether to not-colorize output
noColor bool
// The region to send API requests
region string
}
// FlagSet returns a FlagSet with the common flags that every
// command implements. The exact behavior of FlagSet can be configured
// using the flags as the second parameter, for example to disable
// server settings on the commands that don't talk to a server.
func (m *Meta) FlagSet(n string, fs FlagSetFlags) *flag.FlagSet {
f := flag.NewFlagSet(n, flag.ContinueOnError)
// FlagSetClient is used to enable the settings for specifying
// client connectivity options.
if fs&FlagSetClient != 0 {
f.StringVar(&m.flagAddress, "address", "", "")
f.StringVar(&m.region, "region", "", "")
f.BoolVar(&m.noColor, "no-color", false, "")
}
// Create an io.Writer that writes to our UI properly for errors.
// This is kind of a hack, but it does the job. Basically: create
// a pipe, use a scanner to break it into lines, and output each line
// to the UI. Do this forever.
errR, errW := io.Pipe()
errScanner := bufio.NewScanner(errR)
go func() {
for errScanner.Scan() {
m.Ui.Error(errScanner.Text())
}
}()
f.SetOutput(errW)
return f
}
// Client is used to initialize and return a new API client using
// the default command line arguments and env vars.
func (m *Meta) Client() (*api.Client, error) {
config := api.DefaultConfig()
if v := os.Getenv(EnvNomadAddress); v != "" {
config.Address = v
}
if m.flagAddress != "" {
config.Address = m.flagAddress
}
if v := os.Getenv(EnvNomadRegion); v != "" {
config.Region = v
}
if m.region != "" {
config.Region = m.region
}
return api.NewClient(config)
}
func (m *Meta) Colorize() *colorstring.Colorize {
return &colorstring.Colorize{
Colors: colorstring.DefaultColors,
Disable: m.noColor,
Reset: true,
}
}
// generalOptionsUsage returns the help string for the global options.
func generalOptionsUsage() string {
helpText := `
-address=<addr>
The address of the Nomad server.
Overrides the NOMAD_ADDR environment variable if set.
Default = http://127.0.0.1:4646
-region=<region>
The region of the Nomad servers to forward commands to.
Overrides the NOMAD_REGION environment variable if set.
Defaults to the Agent's local region.
-no-color
Disables colored command output.
`
return strings.TrimSpace(helpText)
}