Folder permissions.

[an0wak]

Hi,

I am running Docker on Debian 12.11.

Client: Docker Engine - Community
 Version:           28.3.2
 API version:       1.51
 Go version:        go1.24.5
 Git commit:        578ccf6
 Built:             Wed Jul  9 16:13:55 2025
 OS/Arch:           linux/amd64
 Context:           default

Server: Docker Engine - Community
 Engine:
  Version:          28.3.2
  API version:      1.51 (minimum version 1.24)
  Go version:       go1.24.5
  Git commit:       e77ff99
  Built:            Wed Jul  9 16:13:55 2025
  OS/Arch:          linux/amd64
  Experimental:     false
 containerd:
  Version:          1.7.27
  GitCommit:        05044ec0a9a75232cad458027ca83437aae3f4da
 runc:
  Version:          1.2.5
  GitCommit:        v1.2.5-0-g59923ef
 docker-init:
  Version:          0.19.0
  GitCommit:        de40ad0

I seem to be having permission errors on folders and cannot for the life of me work out why. I have followed previous posts without luck.

Noted the following. Also tried chmod 777

# run dnscrypt proxy server with configuration mounted from a host directory
# note that the files must be readable by world, or owned by nobody:nogroup
# note that the files in the configuration directory '/path/to/config' must be
# readable by world, or owned by nobody:nogroup, and the directory itself must be
# writeable by world, or owned by nobody:nogroup

Errors I get in logs are as follows

[2025-07-18 03:28:09] [WARNING] Couldn't write cache file [public-resolvers.md]: open sf-cu2u246of3nj7t2d.tmp: permission denied
[2025-07-18 03:28:09] [WARNING] Couldn't update cache file [public-resolvers.md]: chtimes public-resolvers.md: no such file or directory
[2025-07-18 03:28:09] [WARNING] Couldn't write cache file [public-resolvers.md]: open sf-cu2u246of3nj7t2d.tmp: permission denied
[2025-07-18 03:28:09] [WARNING] Couldn't update cache file [public-resolvers.md]: chtimes public-resolvers.md: no such file or directory

My compose.yml

  dnscrypt:
    container_name: dnscrypt-proxy
    image: klutchell/dnscrypt-proxy:latest
    hostname: dnscrypt
    networks:
      pihole_net:
        ipv4_address: 172.16.255.2
    expose:
      - "5300/udp"
      - "5300/tcp"
    environment:
      TZ: 'UTC' 
    volumes:
      - ./etc-dnscrypt-proxy:/config:rw
    restart: unless-stopped

My Folder permissions

drwsrwxr-x 2 nobody nogroup 4096 Jul 18 13:21 etc-dnscrypt-proxy

Is there something I am missing?

[klutchell]

Hey @an0wak , those are just warnings and shouldn't prevent the app from running. It's commented in the code here.

We can try to fix the permissions but I want to confirm first if the app is working, even with the warnings.

[an0wak]

The container itself seems to be working fine. Ta.

[klutchell]

@an0wak can you also share the config you are mounting? I don't see this warning with the default config.

[adam-bloom]

It all depends on the permissions of the mounted directory. The container by default runs with user and group IDs for 65532 - https://github.com/klutchell/dnscrypt-proxy-docker/blob/main/Dockerfile#L28-L29. You can pass your own in the docker compose file under the user argument.

In order to get the config folder to be writable, I:

1. created a new user on the system for dnscrypt-proxy
2. have that user own the host directory mapped into the container
3. use that UID/GID for the container as well