Files
mgmt/lang/funcs/core/sys/hostname_fact.go
James Shubin b134c4b778 lang: interfaces, funcs: Port Func API to new Stream signature
This removes the `Close() error` and replaces it with a more modern
Stream API that takes a context. This removes boilerplate and makes
integration with concurrent code easier. The only downside is that there
isn't an explicit cleanup step, but only one function was even using
that and it was possible to switch it to a defer in Stream.

This also renames the functions from polyfunc to just func which we
determine by API not naming.
2023-08-08 21:33:06 -04:00

81 lines
2.4 KiB
Go

// Mgmt
// Copyright (C) 2013-2023+ James Shubin and the project contributors
// Written by James Shubin <james@shubin.ca> and the project contributors
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program. If not, see <http://www.gnu.org/licenses/>.
package coresys
import (
"context"
"github.com/purpleidea/mgmt/lang/funcs/facts"
"github.com/purpleidea/mgmt/lang/types"
)
const (
// HostnameFuncName is the name this fact is registered as. It's still a
// Func Name because this is the name space the fact is actually using.
HostnameFuncName = "hostname"
)
func init() {
facts.ModuleRegister(ModuleName, HostnameFuncName, func() facts.Fact { return &HostnameFact{} }) // must register the fact and name
}
// HostnameFact is a function that returns the hostname.
// TODO: support hostnames that change in the future.
type HostnameFact struct {
init *facts.Init
}
// String returns a simple name for this fact. This is needed so this struct can
// satisfy the pgraph.Vertex interface.
func (obj *HostnameFact) String() string {
return HostnameFuncName
}
// Validate makes sure we've built our struct properly. It is usually unused for
// normal facts that users can use directly.
//func (obj *HostnameFact) Validate() error {
// return nil
//}
// Info returns some static info about itself.
func (obj *HostnameFact) Info() *facts.Info {
return &facts.Info{
Output: types.NewType("str"),
}
}
// Init runs some startup code for this fact.
func (obj *HostnameFact) Init(init *facts.Init) error {
obj.init = init
return nil
}
// Stream returns the single value that this fact has, and then closes.
func (obj *HostnameFact) Stream(ctx context.Context) error {
select {
case obj.init.Output <- &types.StrValue{
V: obj.init.Hostname,
}:
// pass
case <-ctx.Done():
return nil
}
close(obj.init.Output) // signal that we're done sending
return nil
}