cmd/mbf: poison open via environment

This enables use of non-cache cmd/mbf utils as root.

Signed-off-by: Ophestra <cat@gensokyo.uk>

2 files changed, 9 insertions, 1 deletions

diff --git a/cmd/mbf/cache.go b/cmd/mbf/cache.go
index 0e20ca99..166e1c45 100644
--- a/cmd/mbf/cache.go
+++ b/cmd/mbf/cache.go
@@ -2,6 +2,7 @@ package main
 
 import (
 	"context"
+	"errors"
 	"net/http"
 	"os"
 	"path/filepath"
@@ -14,6 +15,9 @@ import (
 	"hakurei.app/pkg"
 )
 
+// poisonOpen is whether cache.open is poisoned. This enables running as root.
+var _, poisonOpen = os.LookupEnv("MBF_POISON_OPEN")
+
 // cache refers to an instance of [pkg.Cache] that might be open.
 type cache struct {
 	ctx context.Context
@@ -49,6 +53,10 @@ func writeTitle(msg message.Msg, s string) {
 
 // open opens the underlying [pkg.Cache].
 func (cache *cache) open() (err error) {
+	if poisonOpen {
+		return errors.New("attempting to open cache")
+	}
+
 	if cache.c != nil {
 		return os.ErrInvalid
 	}
diff --git a/cmd/mbf/main.go b/cmd/mbf/main.go
index 014a7f47..5dd4e8a0 100644
--- a/cmd/mbf/main.go
+++ b/cmd/mbf/main.go
@@ -71,7 +71,7 @@ func main() {
 	log.SetPrefix("mbf: ")
 	msg := message.New(log.Default())
 
-	if os.Geteuid() == 0 {
+	if !poisonOpen && os.Geteuid() == 0 {
 		log.Fatal("this program must not run as root")
 	}