Cannot use Docker Secrets for TLS files

[ChrisSamo632]

It would be better if one was able to use Docker Secrets to make TLS certificate files available to the instance (it would need to not "fix" the file permissions on startup), e.g. allow the optional specification of a TLS_CERTS_DIR or such, which would be '/run/secrets':

version: '3.7'

services:
  ldap:
    image: osixia/openldap:1.2.3
    hostname: ldap
    ...

  phpldapadmin:
    image: osixia/phpldapadmin:0.7.2
    environment:
      PHPLDAPADMIN_LDAP_HOSTS: "#PYTHON2BASH:[
  {'ldap':[
    {'server': [
      {'tls': True},
      {'port': 389}
     ]
    }
   ]
  }
  ]"
      # secure user connections
      PHPLDAPADMIN_HTTPS: "true"
      # TODO: this _CERTS_DIR variable doesn't exist
      PHPLDAPADMIN_HTTPS_CERTS_DIR: /run/secrets
      PHPLDAPADMIN_HTTPS_CRT_FILENAME: php_ldap_admin_pem
      PHPLDAPADMIN_HTTPS_KEY_FILENAME: php_ldap_admin_key
      PHPLDAPADMIN_HTTPS_CA_CRT_FILENAME: ca_pem
      # secure ldap connections
      PHPLDAPADMIN_LDAP_CLIENT_TLS: "true"
      # TODO: this _CERTS_DIR variable doesn't exist
      PHPLDAPADMIN_LDAP_CLIENT_TLS_CERTS_DIR: /run/secrets
      PHPLDAPADMIN_LDAP_CLIENT_TLS_CRT_FILENAME: php_ldap_admin_pem
      PHPLDAPADMIN_LDAP_CLIENT_TLS_KEY_FILENAME: php_ldap_admin_key
      PHPLDAPADMIN_LDAP_CLIENT_TLS_CA_CRT_FILENAME: ca_pem
    ports:
      - target: 443
        published: 6443
        protocol: tcp
        mode: ingress
    volumes:
      - phpldapadmin-data:/var/www/phpldapadmin
    secrets:
      - ca_pem
      - php_ldap_admin_pem
      - php_ldap_admin_key

volumes:
  phpldapadmin-data:

secrets:
  ca_pem:
    file: ${PWD}/certs/ca.pem
...

An alternative is probably to have a more generic "SWARM_MODE: 'true'" flag that can change startup/config logic specific for Swarm vs. Compose (use of Secrets probably not the only example)?