Allow for variables in the configuration parser filename

server/config_parser.go

@@ -3,11 +3,33 @@ package server
 import (
  "runtime"
 
- "github.com/gammazero/workerpool"
+ "fmt"
+ "strings"
 
+ "github.com/gammazero/workerpool"
  "github.com/pelican-dev/wings/internal/ufs"
 )
 
+// Helper function to replace variables in the file path of the configuration parser
+func replaceParserConfigPathVariables(filename string, envvars map[string]interface{}) string {
+ // Check if filename contains at least one '{' and one '}'
+ // This is here for performance as 99% of the eggs configuration parsers do not have variables in its path
+ if !strings.Contains(filename, "{") || !strings.Contains(filename, "}") {
+ return filename
+ }
+
+ // Replace "{{" with "${" and "}}" with "}"
+ filename = strings.ReplaceAll(filename, "{{", "${")
+ filename = strings.ReplaceAll(filename, "}}", "}")
+
+ // replaces ${varname} with varval
+ for varname, varval := range envvars {
+ filename = strings.ReplaceAll(filename, fmt.Sprintf("${%s}", varname), fmt.Sprint(varval))
+ }
+
+ return filename
+}
+
 // UpdateConfigurationFiles updates all the defined configuration files for
 // a server automatically to ensure that they always use the specified values.
 func (s *Server) UpdateConfigurationFiles() {
@@ -20,7 +42,8 @@ func (s *Server) UpdateConfigurationFiles() {
  f := cf
 
  pool.Submit(func() {
- file, err := s.Filesystem().UnixFS().Touch(f.FileName, ufs.O_RDWR|ufs.O_CREATE, 0o644)
+ filename := replaceParserConfigPathVariables(f.FileName, s.Config().EnvVars)
+ file, err := s.Filesystem().UnixFS().Touch(filename, ufs.O_RDWR|ufs.O_CREATE, 0o644)
  if err != nil {
  s.Log().WithField("file_name", f.FileName).WithField("error", err).Error("failed to open file for configuration")
  return