Couldn't render template "mkdir /app/var/tmp: Permission denied

[oalders]

After docker compose build and docker compose up web-server I see this in the output:

web-server-1  | [2024/10/28 11:09:56] [ERROR] [/healthcheck] Couldn't render template "mkdir /app/var/tmp: Permission denied at /app/local/lib/perl5/x86_64-linux-gnu/Text/Xslate.pm line 419.
web-server-1  | "
web-server-1  | [2024/10/28 11:09:56] [ERROR] [/healthcheck] Couldn't render template "mkdir /app/var/tmp: Permission denied at /app/local/lib/perl5/x86_64-linux-gnu/Text/Xslate.pm line 419.

I can make it go away via:

diff --git a/docker-compose.yml b/docker-compose.yml
index 726e9c9d..09e323a1 100644
--- a/docker-compose.yml
+++ b/docker-compose.yml
@@ -15,8 +15,9 @@ services:
       - './:/app/'
       - 'assets:/app/root/assets/'
       - '/app/local'
+      - '/app/var'

In the container I then see:

$ find var/tmp/
var/tmp/
var/tmp/templates
var/tmp/templates/%2Fapp%2Froot
var/tmp/templates/%2Fapp%2Froot/healthcheck.txc
var/tmp/templates/%2Fapp%2Froot/base.txc
var/tmp/templates/%2Fapp%2Froot/home.txc
var/tmp/templates/%2Fapp%2Froot/inc
var/tmp/templates/%2Fapp%2Froot/inc/no_sidebar.txc
var/tmp/templates/%2Fapp%2Froot/inc/opengraph.txc
var/tmp/templates/%2Fapp%2Froot/inc/keyboard_shortcuts.txc