gomod2nix/builder/symlink/symlink.go

109 lines
2.3 KiB
Go

package main
import (
"encoding/json"
"fmt"
"os"
"path/filepath"
"sort"
)
type Package struct {
GoPackagePath string `json:"-"`
Version string `json:"version"`
Hash string `json:"hash"`
ReplacedPath string `json:"replaced,omitempty"`
}
type Sources map[string]string
func populateStruct(path string, data interface{}) {
pathVal := os.Getenv(path)
if len(path) == 0 {
panic(fmt.Sprintf("env var '%s' was unset", path))
}
path = pathVal
b, err := os.ReadFile(path)
if err != nil {
panic(err)
}
err = json.Unmarshal(b, &data)
if err != nil {
panic(err)
}
}
func main() {
sources := make(Sources)
pkgs := make(map[string]*Package)
populateStruct("sourcesPath", &sources)
populateStruct("jsonPath", &pkgs)
keys := make([]string, 0, len(pkgs))
for key := range pkgs {
keys = append(keys, key)
}
sort.Strings(keys)
makeSymlinks(keys, sources)
}
func makeSymlinks(keys []string, sources Sources) {
// Iterate, in reverse order
for i := len(keys) - 1; i >= 0; i-- {
key := keys[i]
src := sources[key]
paths := []string{key}
for _, path := range paths {
vendorDir := filepath.Join("vendor", filepath.Dir(path))
if err := os.MkdirAll(vendorDir, 0o755); err != nil {
panic(err)
}
vendorPath := filepath.Join("vendor", path)
if _, err := os.Stat(vendorPath); err == nil {
populateVendorPath(vendorPath, src)
continue
}
// If the file doesn't already exist, just create a simple symlink
err := os.Symlink(src, vendorPath)
if err != nil {
panic(err)
}
}
}
}
func populateVendorPath(vendorPath string, src string) {
files, err := os.ReadDir(src)
if err != nil {
panic(err)
}
for _, f := range files {
innerSrc := filepath.Join(src, f.Name())
dst := filepath.Join(vendorPath, f.Name())
if err := os.Symlink(innerSrc, dst); err != nil {
// assume it's an existing directory, try to link the directory content instead.
// TODO should we do this recursively?
files, err := os.ReadDir(innerSrc)
if err != nil {
panic(err)
}
for _, f := range files {
srcFile := filepath.Join(innerSrc, f.Name())
dstFile := filepath.Join(dst, f.Name())
if err := os.Symlink(srcFile, dstFile); err != nil {
fmt.Println("ignoring symlink error", srcFile, dstFile)
}
}
}
}
}