test: Move test support files to separate dir and keep tests in /test

Signed-off-by: Jacques de Laval <jacques@de-laval.se>

test/tenv/exec.sh

@@ -0,0 +1,36 @@
+#!/bin/sh
+
+set -eu
+
+if [ "$#" -lt 2 ]; then
+    echo "Usage:"
+    echo "  $0 [target-pid] [command [arguments]]"
+    exit 1
+fi
+target="$1"
+shift
+
+TEST_DIR=$(dirname "$0"../)
+TENV_ROOT="${TENV_ROOT:-$(pwd)/${TEST_DIR}/tenv-root}"
+
+nsenter=$(command -v nsenter)
+chroot=$(command -v chroot)
+
+export PS1='\w \$ '
+export PS2='> '
+export PS3='#? '
+export PS4='+ '
+
+PATH="$TESTENV_PATH"
+export PATH
+
+"$nsenter" \
+    --preserve-credentials \
+    --user \
+    --mount \
+    --uts \
+    --ipc \
+    --net \
+    --pid \
+    -w -t "$target" \
+    "$chroot" "$TENV_ROOT" "$@"