Introduction

This reproduction sample shows a problem with mounting secret directories (as file mounting is not available for Windows containers) when using Docker Compose v2.

Reproduction

This shows the respective outputs when running the reproduction sample Docker Compose v1/v2.

The problem could be reproduced on:

• Docker Desktop 4.6.1 (with the included Docker Compose version)
• Docker Desktop 4.8.2 (with the included Docker Compose version)
• Docker Desktop 4.8.2 with Docker Compose 2.6.1
• Mirantis Container Runtime 20.10.9 with Docker Compose 2.6.1 on Windows Server 2019

Docker Compose v1

When running docker-compose up (aka Docker Compose v1) in the directory the following output is shown:

PS C:\Development\DockerComposeSecretRepro> docker-compose up
WARNING: Service "service" uses an undefined secret file "C:\Development\DockerComposeSecretRepro\Secrets", the following file should be created "C:\Development\DockerComposeSecretRepro\Secrets"
Creating network "dockercomposesecretrepro_default" with the default driver
Creating dockercomposesecretrepro_service_1 ... done
Attaching to dockercomposesecretrepro_service_1
service_1  | SUPER_SECRET
dockercomposesecretrepro_service_1 exited with code 0

Docker Compose v2

When running docker compose up (aka Docker Compose v2) in the directory the following output is shown:

PS C:\Development\DockerComposeSecretRepro> docker compose up
[+] Running 1/2
- Network dockercomposesecretrepro_default      Created                                                           0.3s
- Container dockercomposesecretrepro-service-1  Creating                                                          0.0s
Error response from daemon: invalid mount config for type "bind": invalid mount path: '/run/secrets/C:\Secrets\'

This shows that secrets directories do not seem to work with Docker Compose v2.

This result can be reproduced at least with the following versions of Docker Composes:

• 2.5.1
• 2.6.1