terraform/command/output.go

93 lines
2.1 KiB
Go

package command
import (
"flag"
"fmt"
"os"
"strings"
"github.com/hashicorp/terraform/terraform"
)
// OutputCommand is a Command implementation that reads an output
// from a Terraform state and prints it.
type OutputCommand struct {
Meta
}
func (c *OutputCommand) Run(args []string) int {
var statePath string
args = c.Meta.process(args)
cmdFlags := flag.NewFlagSet("output", flag.ContinueOnError)
cmdFlags.StringVar(&statePath, "state", DefaultStateFilename, "path")
cmdFlags.Usage = func() { c.Ui.Error(c.Help()) }
if err := cmdFlags.Parse(args); err != nil {
return 1
}
args = cmdFlags.Args()
if len(args) != 1 {
c.Ui.Error(
"The output command expects exactly one argument with the name\n" +
"of an output variable.\n")
cmdFlags.Usage()
return 1
}
name := args[0]
f, err := os.Open(statePath)
if err != nil {
c.Ui.Error(fmt.Sprintf("Error loading file: %s", err))
return 1
}
state, err := terraform.ReadState(f)
f.Close()
if err != nil {
c.Ui.Error(fmt.Sprintf("Error reading state: %s", err))
return 1
}
if len(state.Outputs) == 0 {
c.Ui.Error(fmt.Sprintf(
"The state file has no outputs defined. Define an output\n" +
"in your configuration with the `output` directive and re-run\n" +
"`terraform apply` for it to become available."))
return 1
}
v, ok := state.Outputs[name]
if !ok {
c.Ui.Error(fmt.Sprintf(
"The output variable requested could not be found in the state\n" +
"file. If you recently added this to your configuration, be\n" +
"sure to run `terraform apply`, since the state won't be updated\n" +
"with new output variables until that command is run."))
return 1
}
c.Ui.Output(v)
return 0
}
func (c *OutputCommand) Help() string {
helpText := `
Usage: terraform output [options] NAME
Reads an output variable from a Terraform state file and prints
the value.
Options:
-state=path Path to the state file to read. Defaults to
"terraform.tfstate".
`
return strings.TrimSpace(helpText)
}
func (c *OutputCommand) Synopsis() string {
return "Read an output from a state file"
}