Cannot squash if no "real" layers #33823
Description
Description
My first attempt to reproduce #33822 was with a Dockerfile which just contained a couple of ENV statements. But the docker build --squash failed with:
error squashing image: error getting tar stream to parent: layer ID 'sha256:404361ced64e208b54937071ef96722b59d45df96dea1652d655e961625ee5bd' is not a parent of the specified layer: cannot provide diff to non-parent
Steps to reproduce the issue:
# cat iidsquash/Dockerfile
FROM alpine:3.6
ENV FOO=BAR
ENV BAZ=BAH
# docker build --squash iidsquash/
Sending build context to Docker daemon 3.072kB
Step 1/3 : FROM alpine:3.6
---> 665ffb03bfae
Step 2/3 : ENV FOO BAR
---> Using cache
---> 7320b5308144
Step 3/3 : ENV BAZ BAH
---> Using cache
---> 04519b303d0e
error squashing image: error getting tar stream to parent: layer ID 'sha256:404361ced64e208b54937071ef96722b59d45df96dea1652d655e961625ee5bd' is not a parent of the specified layer: cannot provide diff to non-parent
Describe the results you received:
The above error message, which is a little cryptic, especially since sha256:404361ced64e2... isn't once of the hashes in the preceding output.
Describe the results you expected:
Ideally a successful squash or at least a more informative message (e.g. "No layers to squash" if that is indeed the cause)
Additional information you deem important (e.g. issue happens only occasionally):
This was a dev tree at d311a3a, via make shell. I was running ./bundles/latest/binary-daemon/dockerd --log-level=debug --experimental
Output of docker version:
Client:
Version: unknown-version
API version: 1.30
Go version: go1.8.3
Git commit: unknown-commit
Built: unknown-buildtime
OS/Arch: linux/amd64
Server:
Version: 17.06.0-dev
API version: 1.31 (minimum version 1.12)
Go version: go1.8.3
Git commit: d311a3a68
Built: Mon Jun 26 11:45:35 2017
OS/Arch: linux/amd64
Experimental: true
Output of docker info:
Containers: 0
Running: 0
Paused: 0
Stopped: 0
Images: 7
Server Version: 17.06.0-dev
Storage Driver: overlay2
Backing Filesystem: extfs
Supports d_type: true
Native Overlay Diff: true
Logging Driver: json-file
Cgroup Driver: cgroupfs
Plugins:
Volume: local
Network: bridge host ipvlan macvlan null overlay
Log: awslogs fluentd gcplogs gelf journald json-file logentries splunk syslog
Swarm: inactive
Runtimes: runc
Default Runtime: runc
Init Binary: docker-init
containerd version: 3addd840653146c90a254301d6c3a663c7fd6429
runc version: 2d41c047c83e09a6d61d464906feb2a2f3c52aa4
init version: 949e6fa
Security Options:
seccomp
Profile: default
Kernel Version: 4.9.0-3-amd64
Operating System: Debian GNU/Linux 8 (jessie) (containerized)
OSType: linux
Architecture: x86_64
CPUs: 4
Total Memory: 15.53GiB
Name: e6f2dd6a12e5
ID: SMVL:I3Z2:JGZD:W7RB:L2Z7:FGWM:2N7A:IOYF:J6XR:RUX4:76JL:LI3N
Docker Root Dir: /var/lib/docker
Debug Mode (client): false
Debug Mode (server): false
Registry: https://index.docker.io/v1/
Experimental: true
Insecure Registries:
127.0.0.0/8
Live Restore Enabled: false
WARNING: No swap limit support
WARNING: bridge-nf-call-iptables is disabled
WARNING: bridge-nf-call-ip6tables is disabled
Additional environment details (AWS, VirtualBox, physical, etc.):
/cc @tonistiigi