open-nomad/command/node_pool_init.go
Tim Gross c1a01697c8
node pools: implement node pool init command (#17479)
Implement a `nomad node pool init` command that generates an example spec file
in either HCL or JSON format.
2023-06-13 14:51:29 -04:00

129 lines
3 KiB
Go

// Copyright (c) HashiCorp, Inc.
// SPDX-License-Identifier: MPL-2.0
package command
import (
"errors"
"fmt"
"io/fs"
"os"
"strings"
"github.com/hashicorp/nomad/command/asset"
"github.com/posener/complete"
)
const (
// DefaultHclNodePoolInitName is the default name we use when initializing
// the example node pool spec file in HCL format
DefaultHclNodePoolInitName = "pool.nomad.hcl"
// DefaultJsonNodePoolInitName is the default name we use when initializing
// the example node pool spec in JSON format
DefaultJsonNodePoolInitName = "pool.nomad.json"
)
// NodePoolInitCommand generates a new variable specification
type NodePoolInitCommand struct {
Meta
}
func (c *NodePoolInitCommand) Help() string {
helpText := `
Usage: nomad node pool init <filename>
Creates an example node pool specification file that can be used as a starting
point to customize further. When no filename is supplied, a default filename
of "pool.nomad.hcl" or "pool.nomad.json" will be used depending on the output
format.
Init Options:
-out (hcl | json)
Format of generated node pool specification. Defaults to "hcl".
-quiet
Do not print success message.
`
return strings.TrimSpace(helpText)
}
func (c *NodePoolInitCommand) Synopsis() string {
return "Create an example node pool specification file"
}
func (c *NodePoolInitCommand) AutocompleteFlags() complete.Flags {
return complete.Flags{
"-out": complete.PredictSet("hcl", "json"),
"-quiet": complete.PredictNothing,
}
}
func (c *NodePoolInitCommand) AutocompleteArgs() complete.Predictor {
return complete.PredictNothing
}
func (c *NodePoolInitCommand) Name() string { return "node pool init" }
func (c *NodePoolInitCommand) Run(args []string) int {
var outFmt string
var quiet bool
flags := c.Meta.FlagSet(c.Name(), FlagSetClient)
flags.Usage = func() { c.Ui.Output(c.Help()) }
flags.StringVar(&outFmt, "out", "hcl", "")
flags.BoolVar(&quiet, "quiet", false, "")
if err := flags.Parse(args); err != nil {
return 1
}
// Check that we get no arguments
args = flags.Args()
if l := len(args); l > 1 {
c.Ui.Error("This command takes no arguments or one: <filename>")
c.Ui.Error(commandErrorText(c))
return 1
}
var fileName string
var fileContent []byte
switch outFmt {
case "hcl":
fileName = DefaultHclNodePoolInitName
fileContent = asset.NodePoolSpec
case "json":
fileName = DefaultJsonNodePoolInitName
fileContent = asset.NodePoolSpecJSON
}
if len(args) == 1 {
fileName = args[0]
}
// Check if the file already exists
_, err := os.Stat(fileName)
if err == nil {
c.Ui.Error(fmt.Sprintf("File %q already exists", fileName))
return 1
}
if err != nil && !errors.Is(err, fs.ErrNotExist) {
c.Ui.Error(fmt.Sprintf("Failed to stat %q: %v", fileName, err))
return 1
}
// Write out the example
err = os.WriteFile(fileName, fileContent, 0660)
if err != nil {
c.Ui.Error(fmt.Sprintf("Failed to write %q: %v", fileName, err))
return 1
}
// Success
if !quiet {
c.Ui.Output(fmt.Sprintf("Example node pool specification written to %s", fileName))
}
return 0
}