docker
Volume targets with trailing slashes fail
Description
The Docker daemon produces a misleading error message when a service uses a shared/top-level/named
volume and the target: includes a trailing slash. Paths with trailing slashes are valid absolute paths so Docker should accept and handle them correctly. That this causes a failure indicates that the # dockerd daemon may not be using a proper filesystem path library when handling volume target paths and it seems like it should.
Reproduce
-
Create the following compose project:
# mkdir -pv /tmp/foo mkdir: created directory '/tmp/foo' # cat /tmp/foo/docker-compose.yml volumes: foo_volume: name: "foo_volume" driver: "local" driver_opts: type: "none" o: "bind" device: "/tmp/foo/" services: bar_service: image: "ubuntu" command: "ls -alR /tmp/foo/" volumes: - type: "volume" source: "foo_volume" target: "/tmp/foo" -
Note the resulting error when run:
# docker volume rm "foo_volume" ; docker compose up foo_volume [+] Running 1/0 ✔ Volume "foo_volume" Created 0.0s ⠋ Container foo-bar_service-1 Creating 0.0s Error response from daemon: invalid mount config for type "bind": invalid mount path: 'foo_volume' mount path must be absolute -
Remove the trailing slash from
target::# diff -u "/tmp/foo/docker-compose.yml~" "/tmp/foo/docker-compose.yml" --- /tmp/foo/docker-compose.yml~ 2024-05-31 07:56:50.783871106 -0700 +++ /tmp/foo/docker-compose.yml 2024-05-31 08:00:40.833869402 -0700 @@ -16,4 +16,4 @@ volumes: - type: "volume" source: "foo_volume" - target: "/tmp/foo/" + target: "/tmp/foo" -
Note that the container now runs as expected:
# docker volume rm "foo_volume" ; docker compose up foo_volume [+] Running 2/2 ✔ Volume "foo_volume" Created 0.0s ✔ Container foo-bar_service-1 Created 0.6s Attaching to bar_service-1 bar_service-1 | /tmp/foo/: bar_service-1 | total 12 bar_service-1 | drwxrwxr-x 2 root root 80 May 31 15:00 . bar_service-1 | drwxrwxrwt 1 root root 4096 May 31 15:00 .. bar_service-1 | -rw-r--r-- 1 root root 317 May 31 15:00 docker-compose.yml bar_service-1 | -rw-r--r-- 1 root root 318 May 31 14:56 docker-compose.yml~ bar_service-1 exited with code 0
Expected behavior
Docker should accept valid absolute paths as volume target: paths.
docker version
# docker version
Client: Docker Engine - Community
Version: 26.1.3
API version: 1.45
Go version: go1.21.10
Git commit: b72abbb
Built: Thu May 16 08:33:29 2024
OS/Arch: linux/amd64
Context: default
Server: Docker Engine - Community
Engine:
Version: 26.1.3
API version: 1.45 (minimum version 1.24)
Go version: go1.21.10
Git commit: 8e96db1
Built: Thu May 16 08:33:29 2024
OS/Arch: linux/amd64
Experimental: false
containerd:
Version: 1.6.32
GitCommit: 8b3b7ca2e5ce38e8f31a34f35b2b68ceb8470d89
runc:
Version: 1.1.12
GitCommit: v1.1.12-0-g51d5e94
docker-init:
Version: 0.19.0
GitCommit: de40ad0
docker info
# docker info >./docker-info.log
WARNING: No blkio throttle.read_bps_device support
WARNING: No blkio throttle.write_bps_device support
WARNING: No blkio throttle.read_iops_device support
WARNING: No blkio throttle.write_iops_device support
# cat ./docker-info.log
Client: Docker Engine - Community
Version: 26.1.3
Context: default
Debug Mode: false
Plugins:
buildx: Docker Buildx (Docker Inc.)
Version: v0.14.0
Path: /usr/libexec/docker/cli-plugins/docker-buildx
compose: Docker Compose (Docker Inc.)
Version: v2.27.0
Path: /usr/libexec/docker/cli-plugins/docker-compose
Server:
Containers: 34
Running: 33
Paused: 0
Stopped: 1
Images: 38
Server Version: 26.1.3
Storage Driver: overlay2
Backing Filesystem: extfs
Supports d_type: true
Using metacopy: false
Native Overlay Diff: true
userxattr: false
Logging Driver: json-file
Cgroup Driver: cgroupfs
Cgroup Version: 1
Plugins:
Volume: local
Network: bridge host ipvlan macvlan null overlay
Log: awslogs fluentd gcplogs gelf journald json-file local splunk syslog
Swarm: inactive
Runtimes: io.containerd.runc.v2 nvidia runc
Default Runtime: runc
Init Binary: docker-init
containerd version: 8b3b7ca2e5ce38e8f31a34f35b2b68ceb8470d89
runc version: v1.1.12-0-g51d5e94
init version: de40ad0
Security Options:
seccomp
Profile: builtin
Kernel Version: 5.15.153.1-microsoft-standard-WSL2
Operating System: Pop!_OS 22.04 LTS
OSType: linux
Architecture: x86_64
CPUs: 8
Total Memory: 31.31GiB
Name: library.moodysalonnet
ID: 930e1cc3-4d06-44a2-828b-b203b25ad7a9
Docker Root Dir: /var/lib/docker
Debug Mode: false
Experimental: false
Insecure Registries:
127.0.0.0/8
Live Restore Enabled: false
Diagnostics ID
N/A
Additional Info
No *diagnose* tool is available from this installation:
# aptitude search -F '%p' ~i~ndocker
docker-buildx-plugin
docker-ce
docker-ce-cli
docker-ce-rootless-extras
docker-compose-plugin
nvidia-docker2
# aptitude search -F '%p' '~i~ndocker' | xargs -d '\n' -- dpkg -L | grep 'diagnose'
A related thought, it seems like the error message could also be improved. It could clearly indicate whether the error is from creating the volume or using it in a container and it could indicate whether the path error is for the source/device or the target.
I have just stumbled across the same issue. Is there anything we can do to move forward with this?
