Unable to reset entrypoint #41770
Description
Description
As reported in #41745:
I've just ran "apt-get upgrade" on my CI, which upgraded docker to "Docker version 20.10.0, build 7287ab3".
Now builds are not passing anymore ("dockerfile parse error line xxx: ENTRYPOINT requires at least one argument") when the Dockerfile attempts to reset the entrypoint from the parent image using ENTRYPOINT [].
Steps to reproduce the issue:
Below a very simplified version of my Dockerfile:
DOCKER_BUILDKIT=1 docker build -t foo -<<'EOF'
# syntax=docker/dockerfile:experimental
FROM maven:3.6.3-jdk-8-slim as javabuild
RUN --mount=type=cache,id=mvn,target=/usr/share/maven/ref/repository \
mvn version:help
FROM javabuild
RUN echo "sonar"
# Reset entrypoint from parent image
ENTRYPOINT []
EOF
Describe the results you received:
[+] Building 0.6s (4/4) FINISHED
=> [internal] load build definition from Dockerfile 0.0s
=> => transferring dockerfile: 307B 0.0s
=> [internal] load .dockerignore 0.0s
=> => transferring context: 2B 0.0s
=> resolve image config for docker.io/docker/dockerfile:experimental 0.0s
=> CACHED docker-image://docker.io/docker/dockerfile:experimental@sha256:1fbe6f83ffb91b4a9919c2bf359b22e7508f8670c1443389b01848db91ef1083 0.0s
failed to solve with frontend dockerfile.v0: failed to solve with frontend gateway.v0: rpc error: code = Unknown desc = failed to create LLB definition: dockerfile parse error line 12: ENTRYPOINT requires at least one argument
Describe the results you expected:
A successful build.
The Dockerfile has not been modified, it worked perfectly on Docker 19.03 before I ran the apt-get upgrade.
Additional tests done:
If I remove the first line (# syntax=docker/dockerfile:experimental) and mount on the RUN command, the "minimal testcase" works as expected.
But that's not something I'm willing to do on all my Dockerfiles in all projects under our CI, because the caching capabilities during builds have greatly reduced our build times (thanks to the team for this feature, btw).
Output of docker version:
Client: Docker Engine - Community
Version: 20.10.0
API version: 1.41
Go version: go1.13.15
Git commit: 7287ab3
Built: Tue Dec 8 18:59:53 2020
OS/Arch: linux/amd64
Context: default
Experimental: true
Server: Docker Engine - Community
Engine:
Version: 20.10.0
API version: 1.41 (minimum version 1.12)
Go version: go1.13.15
Git commit: eeddea2
Built: Tue Dec 8 18:57:44 2020
OS/Arch: linux/amd64
Experimental: false
containerd:
Version: 1.4.3
GitCommit: 269548fa27e0089a8b8278fc4fc781d7f65a939b
runc:
Version: 1.0.0-rc92
GitCommit: ff819c7e9184c13b7c2607fe6c30ae19403a7aff
docker-init:
Version: 0.19.0
GitCommit: de40ad0
Output of docker info:
Client:
Context: default
Debug Mode: false
Plugins:
app: Docker App (Docker Inc., v0.9.1-beta3)
buildx: Build with BuildKit (Docker Inc., v0.4.2-docker)
Server:
Containers: 0
Running: 0
Paused: 0
Stopped: 0
Images: 12
Server Version: 20.10.0
Storage Driver: overlay2
Backing Filesystem: extfs
Supports d_type: true
Native Overlay Diff: true
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 logentries splunk s yslog
Swarm: inactive
Runtimes: io.containerd.runc.v2 io.containerd.runtime.v1.linux runc
Default Runtime: runc
Init Binary: docker-init
containerd version: 269548fa27e0089a8b8278fc4fc781d7f65a939b
runc version: ff819c7e9184c13b7c2607fe6c30ae19403a7aff
init version: de40ad0
Security Options:
apparmor
seccomp
Profile: default
Kernel Version: 4.15.0-101-generic
Operating System: Ubuntu 18.04.5 LTS
OSType: linux
Architecture: x86_64
CPUs: 8
Total Memory: 15.66GiB
Name: ci-node-1
ID: JMTB:MV5N:DFIK:T6VA:BMPB:46DT:R6XZ:CLOJ:7NDD:ZVVP:BYXY:7L2F
Docker Root Dir: /var/lib/docker
Debug Mode: false
Registry: https://index.docker.io/v1/
Labels:
Experimental: false
Insecure Registries:
127.0.0.0/8
Registry Mirrors:
https://docker-nexus.mycompany.com/
Live Restore Enabled: false
WARNING: No swap limit support
Additional environment details (AWS, VirtualBox, physical, etc.):
Ubuntu VM running on VMWare vSphere.