appvm/generate.go

110 lines
2.0 KiB
Go

package main
import (
"fmt"
"io/ioutil"
"log"
"os"
"os/exec"
"strings"
"github.com/digitalocean/go-libvirt"
)
var template = `
{pkgs, ...}:
{
imports = [
<nixpkgs/nixos/modules/virtualisation/qemu-vm.nix>
<nix/base.nix>
];
services.xserver.displayManager.sessionCommands =
"while [ 1 ]; do ${pkgs.%s}/bin/%s; done &";
}
`
func isPackageExists(name string) bool {
cmd := exec.Command("nix-env", "-iA", name)
cmd.Stdout = os.Stdout
cmd.Stderr = os.Stderr
err := cmd.Run()
return err == nil
}
func nixPath(name string) (path string, err error) {
command := exec.Command("nix", "path-info", name)
bytes, err := command.Output()
if err != nil {
return
}
path = string(bytes)
return
}
func generate(l *libvirt.Libvirt, name, bin, vmname string) {
if !isPackageExists(name) {
log.Println("Package pkgs."+name, "does not exists")
return
}
path, err := nixPath(name)
if err != nil {
log.Println("Cannot find nix path")
return
}
path = strings.TrimSpace(path)
files, err := ioutil.ReadDir(path + "/bin/")
if err != nil {
log.Println(err)
return
}
if bin == "" && len(files) != 1 {
fmt.Println("There's more than one binary in */bin, " +
"you should specify one of them explicitly")
fmt.Println("Files in", path+"/bin/:")
for _, f := range files {
fmt.Println("\t", f.Name())
}
return
}
if bin != "" {
var found bool = false
for _, f := range files {
if bin == f.Name() {
found = true
}
}
if !found {
log.Println("There's no such file in */bin")
return
}
} else {
bin = files[0].Name()
}
realName := strings.Split(name, ".")[1]
var appFilename string
if vmname != "" {
appFilename = configDir + "/nix/" + vmname + ".nix"
} else {
appFilename = configDir + "/nix/" + realName + ".nix"
}
appNixConfig := fmt.Sprintf(template, realName, bin)
err = ioutil.WriteFile(appFilename, []byte(appNixConfig), 0600)
if err != nil {
log.Println(err)
return
}
fmt.Print(appNixConfig + "\n")
log.Println("Configuration file is saved to", appFilename)
}