Initial commit

This commit is contained in:
Mikaël Cluseau
2018-07-06 19:07:37 +11:00
commit 2de2a4d0f6
25 changed files with 2050 additions and 0 deletions

32
pkg/vars/boot.go Normal file
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@ -0,0 +1,32 @@
package vars
import (
"bytes"
"fmt"
"io/ioutil"
)
var (
bootVarPrefix = []byte("direktil.var.")
)
func BootArgs() [][]byte {
ba, err := ioutil.ReadFile("/proc/cmdline")
if err != nil {
// should not happen
panic(fmt.Errorf("failed to read /proc/cmdline: ", err))
}
return bytes.Split(ba, []byte{' '})
}
func BootArgValue(prefix, defaultValue string) string {
prefixB := []byte("direktil." + prefix + "=")
for _, ba := range BootArgs() {
if bytes.HasPrefix(ba, prefixB) {
return string(ba[len(prefixB):])
}
}
return defaultValue
}

60
pkg/vars/vars.go Normal file
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package vars
import (
"bytes"
"novit.nc/direktil/pkg/config"
)
type Var struct {
Template []byte
Value []byte
}
func Vars(cfg *config.Config) []Var {
res := make([]Var, 0)
for _, arg := range BootArgs() {
if !bytes.HasPrefix(arg, bootVarPrefix) {
continue
}
parts := bytes.SplitN(arg[len(bootVarPrefix):], []byte{'='}, 2)
res = append(res, Var{
Template: append(append([]byte("$(var:"), parts[0]...), ')'),
Value: parts[1],
})
}
configVarsLoop:
for _, v := range cfg.Vars {
t := []byte("$(var:" + v.Name + ")")
for _, prev := range res {
if bytes.Equal(prev.Template, t) {
continue configVarsLoop
}
}
res = append(res, Var{t, []byte(v.Default)})
}
return res
}
// Substitute variables in src
func Substitute(src []byte, cfg *config.Config) (dst []byte) {
dst = src
for _, bv := range Vars(cfg) {
if !bytes.Contains(dst, bv.Template) {
continue
}
v := bytes.TrimSpace(bv.Value)
dst = bytes.Replace(dst, bv.Template, v, -1)
}
return
}