internal/outcome: rename from app

This is less ambiguous, and more accurately describes the purpose of the package.

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

internal/outcome/spaccount.go

@@ -0,0 +1,56 @@
+package outcome
+
+import (
+	"encoding/gob"
+	"fmt"
+	"syscall"
+
+	"hakurei.app/container/fhs"
+	"hakurei.app/internal/validate"
+)
+
+func init() { gob.Register(spAccountOp{}) }
+
+// spAccountOp sets up user account emulation inside the container.
+type spAccountOp struct{}
+
+func (s spAccountOp) toSystem(state *outcomeStateSys) error {
+	// do checks here to fail before fork/exec
+	if state.Container == nil || state.Container.Home == nil || state.Container.Shell == nil {
+		// unreachable
+		return syscall.ENOTRECOVERABLE
+	}
+
+	// default is applied in toContainer
+	if state.Container.Username != "" && !validate.IsValidUsername(state.Container.Username) {
+		return newWithMessage(fmt.Sprintf("invalid user name %q", state.Container.Username))
+	}
+	return nil
+}
+
+func (s spAccountOp) toContainer(state *outcomeStateParams) error {
+	const fallbackUsername = "chronos"
+
+	username := state.Container.Username
+	if username == "" {
+		username = fallbackUsername
+	}
+
+	state.params.Dir = state.Container.Home
+	state.env["HOME"] = state.Container.Home.String()
+	state.env["USER"] = username
+	state.env["SHELL"] = state.Container.Shell.String()
+
+	state.params.
+		Place(fhs.AbsEtc.Append("passwd"),
+			[]byte(username+":x:"+
+				state.mapuid.String()+":"+
+				state.mapgid.String()+
+				":Hakurei:"+
+				state.Container.Home.String()+":"+
+				state.Container.Shell.String()+"\n")).
+		Place(fhs.AbsEtc.Append("group"),
+			[]byte("hakurei:x:"+state.mapgid.String()+":\n"))
+
+	return nil
+}