Buildah fails on OpenShift with anyuid disabled

[ghost]

Description

On my MiniShift containers start with radmon uid, and thus there are no entries for such a user in /etc/passwd and /etc/group. As a result buildah complains about a non existing user. I fixed that in an entrypoint of an image. It's based on centos:7:

FROM centos:7
ENV BUILDAH_ISOLATION=chroot
USER root
ENV HOME=/root
RUN curl -o /etc/yum.repos.d/vbatts-shadow-utils-newxidmap-epel-7.repo https://copr.fedorainfracloud.org/coprs/vbatts/shadow-utils-newxidmap/repo/epel-7/vbatts-shadow-utils-newxidmap-epel-7.repo && \
  yum install -y buildah shadow-utils46-newxidmap slirp4netns

When I am in a running container, this is my user:

[user@workspace8ac858kqvzlvikzp demo-operator]$ id -u
1000160000
[user@workspace8ac858kqvzlvikzp demo-operator]$ id -g
0
[user@workspace8ac858kqvzlvikzp demo-operator]$ whoami
user

However, /etc/subuid and /etc/subgid are empty.

[user@workspace8ac858kqvzlvikzp demo-operator]$ cat /etc/subuid
[user@workspace8ac858kqvzlvikzp demo-operator]$ cat /etc/subgid

Consequently, buildah complains:

ERRO[0000] error reading allowed ID mappings: error reading subuid mappings for user "user" and subgid mappings for group "user": No subuid ranges found for user "user" in /etc/subuid

I wonder what range should I put in those files.

I tried user:100000:1000160000 but then buildah fails with exit status 1.

Output of rpm -q buildah or apt list buildah:

buildah-1.5-2.gite94b4f9.el7.centos.x86_64

Output of buildah version:

Version:         1.5
Go Version:      go1.10.3
Image Spec:      1.0.0
Runtime Spec:    1.0.0
CNI Spec:        0.4.0
libcni Version:  v0.7.0-alpha1
Git Commit:      e94b4f9
Built:           Wed Feb 13 16:54:55 2019
OS/Arch:         linux/amd64

Output of cat /etc/*release:

NAME="CentOS Linux"
VERSION="7 (Core)"
ID="centos"
ID_LIKE="rhel fedora"
VERSION_ID="7"
PRETTY_NAME="CentOS Linux 7 (Core)"
ANSI_COLOR="0;31"
CPE_NAME="cpe:/o:centos:centos:7"
HOME_URL="https://www.centos.org/"
BUG_REPORT_URL="https://bugs.centos.org/"

CENTOS_MANTISBT_PROJECT="CentOS-7"
CENTOS_MANTISBT_PROJECT_VERSION="7"
REDHAT_SUPPORT_PRODUCT="centos"
REDHAT_SUPPORT_PRODUCT_VERSION="7"

Output of uname -a:

Linux workspace8ac858kqvzlvikzp.dev-6f5676f485-kpjvv 3.10.0-957.5.1.el7.x86_64 #1 SMP Fri Feb 1 14:54:57 UTC 2019 x86_64 x86_64 x86_64 GNU/Linux

Output of cat /etc/containers/storage.conf:

[user@workspace8ac858kqvzlvikzp demo-operator]$ cat /etc/containers/storage.conf
# storage.conf is the configuration file for all tools
# that share the containers/storage libraries
# See man 5 containers-storage.conf for more information
# The "container storage" table contains all of the server options.
[storage]

# Default Storage Driver
driver = "overlay"

# Temporary storage location
runroot = "/var/run/containers/storage"

# Primary Read/Write location of container storage
graphroot = "/var/lib/containers/storage"

[storage.options]
# Storage options to be passed to underlying storage drivers

# AdditionalImageStores is used to pass paths to additional Read/Only image stores
# Must be comma separated list.
additionalimagestores = [
]

# Size is used to set a maximum size of the container image.  Only supported by
# certain container storage drivers.
size = ""

# OverrideKernelCheck tells the driver to ignore kernel checks based on kernel version
override_kernel_check = "true"

# Remap-UIDs/GIDs is the mapping from UIDs/GIDs as they should appear inside of
# a container, to UIDs/GIDs as they should appear outside of the container, and
# the length of the range of UIDs/GIDs.  Additional mapped sets can be listed
# and will be heeded by libraries, but there are limits to the number of
# mappings which the kernel will allow when you later attempt to run a
# container.
#
# remap-uids = 0:1668442479:65536
# remap-gids = 0:1668442479:65536

# Remap-User/Group is a name which can be used to look up one or more UID/GID
# ranges in the /etc/subuid or /etc/subgid file.  Mappings are set up starting
# with an in-container ID of 0 and the a host-level ID taken from the lowest
# range that matches the specified name, and using the length of that range.
# Additional ranges are then assigned, using the ranges which specify the
# lowest host-level IDs first, to the lowest not-yet-mapped container-level ID,
# until all of the entries have been used for maps.
#
# remap-user = "storage"
# remap-group = "storage"

[storage.options.thinpool]
# Storage Options for thinpool

# autoextend_percent determines the amount by which pool needs to be
# grown. This is specified in terms of % of pool size. So a value of 20 means
# that when threshold is hit, pool will be grown by 20% of existing
# pool size.
# autoextend_percent = "20"

# autoextend_threshold determines the pool extension threshold in terms
# of percentage of pool size. For example, if threshold is 60, that means when
# pool is 60% full, threshold has been hit.
# autoextend_threshold = "80"

# basesize specifies the size to use when creating the base device, which
# limits the size of images and containers.
# basesize = "10G"

# blocksize specifies a custom blocksize to use for the thin pool.
# blocksize="64k"

# directlvm_device specifies a custom block storage device to use for the
# thin pool. Required if you setup devicemapper
# directlvm_device = ""

# directlvm_device_force wipes device even if device already has a filesystem
# directlvm_device_force = "True"

# fs specifies the filesystem type to use for the base device.
# fs="xfs"

# log_level sets the log level of devicemapper.
# 0: LogLevelSuppress 0 (Default)
# 2: LogLevelFatal
# 3: LogLevelErr
# 4: LogLevelWarn
# 5: LogLevelNotice
# 6: LogLevelInfo
# 7: LogLevelDebug
# log_level = "7"

# min_free_space specifies the min free space percent in a thin pool require for
# new device creation to succeed. Valid values are from 0% - 99%.
# Value 0% disables
# min_free_space = "10%"

# mkfsarg specifies extra mkfs arguments to be used when creating the base
# device.
# mkfsarg = ""

# mountopt specifies extra mount options used when mounting the thin devices.
# mountopt = ""

# use_deferred_removal Marking device for deferred removal
# use_deferred_removal = "True"

# use_deferred_deletion Marking device for deferred deletion
# use_deferred_deletion = "True"

# xfs_nospace_max_retries specifies the maximum number of retries XFS should
# attempt to complete IO when ENOSPC (no space) error is returned by
# underlying storage device.
# xfs_nospace_max_retries = "0"

[rhatdan]

@eivantsov Could you test this against master? We have much newer versions of buildah available.
Reopen if this is not fixed.