coredns/directives_generate.go
Grant Spence 0ed689e2d0
Generate zplugin.go correctly with third-party plugins (#6692)
Previously, the generation of zplugin.go would not separate
third-party external plugins from CoreDNS plugins in the go
import block. This leads to the TestImportOrdering unit test
failing, as it requires that third-party imports paths to be
in a separate import block.

While this issue does not affect the main CoreDNS repo, it can cause
unit test failures in forks of CoreDNS that include external third-party
plugins.

Signed-off-by: Grant Spence <gspence@redhat.com>
2024-05-29 15:41:09 -04:00

127 lines
2.6 KiB
Go

//go:build ignore
package main
import (
"bufio"
"go/format"
"log"
"os"
"strings"
)
func main() {
mi := make(map[string]string, 0)
md := []string{}
file, err := os.Open(pluginFile)
if err != nil {
log.Fatalf("Failed to open %s: %q", pluginFile, err)
}
defer file.Close()
scanner := bufio.NewScanner(file)
for scanner.Scan() {
line := scanner.Text()
if strings.HasPrefix(line, "#") {
continue
}
items := strings.Split(line, ":")
if len(items) != 2 {
// ignore empty lines
continue
}
name, repo := items[0], items[1]
if _, ok := mi[name]; ok {
log.Fatalf("Duplicate entry %q", name)
}
md = append(md, name)
mi[name] = pluginPath + repo // Default, unless overridden by 3rd arg
if _, err := os.Stat(pluginFSPath + repo); err != nil { // External package has been given
mi[name] = repo
}
}
genImports("core/plugin/zplugin.go", "plugin", mi)
genDirectives("core/dnsserver/zdirectives.go", "dnsserver", md)
}
func genImports(file, pack string, mi map[string]string) {
outs := header + "package " + pack + "\n\n" + "import ("
if len(mi) > 0 {
outs += "\n"
}
coreDnsImports := ""
thirdPartyImports := ""
outs += "// Include all plugins.\n"
for _, v := range mi {
if strings.HasPrefix(v, githubOrg) {
coreDnsImports += `_ "` + v + `"` + "\n"
} else {
thirdPartyImports += `_ "` + v + `"` + "\n"
}
}
outs += coreDnsImports
if thirdPartyImports != "" {
outs += "\n" + thirdPartyImports
}
outs += ")\n"
if err := formatAndWrite(file, outs); err != nil {
log.Fatalf("Failed to format and write: %q", err)
}
}
func genDirectives(file, pack string, md []string) {
outs := header + "package " + pack + "\n\n"
outs += `
// Directives are registered in the order they should be
// executed.
//
// Ordering is VERY important. Every plugin will
// feel the effects of all other plugin below
// (after) them during a request, but they must not
// care what plugin above them are doing.
var Directives = []string{
`
for i := range md {
outs += `"` + md[i] + `",` + "\n"
}
outs += "}\n"
if err := formatAndWrite(file, outs); err != nil {
log.Fatalf("Failed to format and write: %q", err)
}
}
func formatAndWrite(file string, data string) error {
res, err := format.Source([]byte(data))
if err != nil {
return err
}
if err = os.WriteFile(file, res, 0644); err != nil {
return err
}
return nil
}
const (
githubOrg = "github.com/coredns"
pluginPath = githubOrg + "/coredns/plugin/"
pluginFile = "plugin.cfg"
pluginFSPath = "plugin/" // Where the plugins are located on the file system
header = "// generated by directives_generate.go; DO NOT EDIT\n\n"
)