consul/command/event.go
Frank Schroeder a49711b8bf config: refactor commands to print help for flags (#3536)
This patch refactors the commands that use the mitchellh/cli library to
populate the command line flag set in both the Run() and the Help()
method. Earlier versions of the mitchellh/cli library relied on the
Run() method to populuate the flagset for generating the usage screen.
This has changed in later versions and was previously solved with a
small monkey patch to the library to restore the old behavior.

However, this makes upgrading the library difficult since the patch has
to be restored every time.

This patch addresses this by moving the command line flags into an
initFlags() method where appropriate and also moving all variables for
the flags from the Run() method into the command itself.

Fixes #3536
2017-10-18 00:08:45 +02:00

135 lines
3.0 KiB
Go

package command
import (
"fmt"
"regexp"
consulapi "github.com/hashicorp/consul/api"
)
// EventCommand is a Command implementation that is used to
// fire new events
type EventCommand struct {
BaseCommand
// flags
name string
node string
service string
tag string
}
func (c *EventCommand) initFlags() {
c.InitFlagSet()
c.FlagSet.StringVar(&c.name, "name", "",
"Name of the event.")
c.FlagSet.StringVar(&c.node, "node", "",
"Regular expression to filter on node names.")
c.FlagSet.StringVar(&c.service, "service", "",
"Regular expression to filter on service instances.")
c.FlagSet.StringVar(&c.tag, "tag", "",
"Regular expression to filter on service tags. Must be used with -service.")
}
func (c *EventCommand) Run(args []string) int {
c.initFlags()
if err := c.FlagSet.Parse(args); err != nil {
return 1
}
// Check for a name
if c.name == "" {
c.UI.Error("Event name must be specified")
c.UI.Error("")
c.UI.Error(c.Help())
return 1
}
// Validate the filters
if c.node != "" {
if _, err := regexp.Compile(c.node); err != nil {
c.UI.Error(fmt.Sprintf("Failed to compile node filter regexp: %v", err))
return 1
}
}
if c.service != "" {
if _, err := regexp.Compile(c.service); err != nil {
c.UI.Error(fmt.Sprintf("Failed to compile service filter regexp: %v", err))
return 1
}
}
if c.tag != "" {
if _, err := regexp.Compile(c.tag); err != nil {
c.UI.Error(fmt.Sprintf("Failed to compile tag filter regexp: %v", err))
return 1
}
}
if c.tag != "" && c.service == "" {
c.UI.Error("Cannot provide tag filter without service filter.")
return 1
}
// Check for a payload
var payload []byte
args = c.FlagSet.Args()
switch len(args) {
case 0:
case 1:
payload = []byte(args[0])
default:
c.UI.Error("Too many command line arguments.")
c.UI.Error("")
c.UI.Error(c.Help())
return 1
}
// Create and test the HTTP client
client, err := c.HTTPClient()
if err != nil {
c.UI.Error(fmt.Sprintf("Error connecting to Consul agent: %s", err))
return 1
}
_, err = client.Agent().NodeName()
if err != nil {
c.UI.Error(fmt.Sprintf("Error querying Consul agent: %s", err))
return 1
}
// Prepare the request
event := client.Event()
params := &consulapi.UserEvent{
Name: c.name,
Payload: payload,
NodeFilter: c.node,
ServiceFilter: c.service,
TagFilter: c.tag,
}
// Fire the event
id, _, err := event.Fire(params, nil)
if err != nil {
c.UI.Error(fmt.Sprintf("Error firing event: %s", err))
return 1
}
// Write out the ID
c.UI.Output(fmt.Sprintf("Event ID: %s", id))
return 0
}
func (c *EventCommand) Help() string {
c.initFlags()
return c.HelpCommand(`
Usage: consul event [options] [payload]
Dispatches a custom user event across a datacenter. An event must provide
a name, but a payload is optional. Events support filtering using
regular expressions on node name, service, and tag definitions.
`)
}
func (c *EventCommand) Synopsis() string {
return "Fire a new event"
}