refactor(builder): change output of version subcommand. (#8994)

With this change, running `builder version` on binaries installed with
`go install` will output the version specified at the suffix.

If it's under development, the following output will be obtained.
```
$ GO111MODULE=on CGO_ENABLED=0 go run . version
ocb version (devel)
```

**Link to tracking Issue:** #8770

---------

Co-authored-by: Bogdan Drutu <[email protected]>

.chloggen/output_version_of_binary.yaml

@@ -0,0 +1,12 @@
+
+change_type: enhancement
+
+component: cmd/builder
+
+note: "running builder version on binaries installed with `go install` will output the version specified at the suffix."
+
+issues: [8770]
+
+subtext:
+
+change_logs: [user]

cmd/builder/internal/version.go

@@ -5,22 +5,42 @@ package internal // import "go.opentelemetry.io/collector/cmd/builder/internal"
 
 import (
  "fmt"
+ "runtime/debug"
 
  "github.com/spf13/cobra"
 )
 
 var (
- version = "dev"
+ version = ""
  date = "unknown"
 )
 
+// binVersion returns the version of the binary.
+// If the version is not set, it attempts to read the build information.
+// Returns an error if the build information cannot be read.
+func binVersion() (string, error) {
+ if version != "" {
+ return version, nil
+ }
+ info, ok := debug.ReadBuildInfo()
+ if !ok {
+ return "", fmt.Errorf("failed to read build info")
+ }
+ return info.Main.Version, nil
+}
+
 func versionCommand() *cobra.Command {
  return &cobra.Command{
  Use: "version",
  Short: "Version of ocb",
  Long: "Prints the version of the ocb binary",
- Run: func(cmd *cobra.Command, args []string) {
+ RunE: func(cmd *cobra.Command, args []string) error {
+ version, err := binVersion()
+ if err != nil {
+ return err
+ }
  cmd.Println(fmt.Sprintf("%s version %s", cmd.Parent().Name(), version))
+ return nil
  },
  }
 }