% script='x1,x2,x3=xs=ARGV; xs.each {|x|FileUtils.rm_f(x)}; File.write(x1,"ok"); FileUtils.copy_file(x1,x2); FileUtils.copy_file(x2,x3); xs.each{|x|p File.read(x)}'
% docker run --rm -it -v "$PWD":/mnt ruby:2.7 ruby -rfileutils -e "$script" /mnt/1.txt /2.txt /mnt/3.txt
"ok"
"ok"
""
% docker run --rm -it -v "$PWD":/mnt ruby:2.7 ruby -rfileutils -e "$script" /mnt/1.txt /mnt/2.txt /mnt/3.txt
"ok"
"ok"
"ok"
% docker run --rm -it -v "$PWD":/mnt ruby:2.7 ruby -rfileutils -e "$script" /1.txt /2.txt /3.txt
"ok"
"ok"
"ok"% uname -a
Linux echo 5.8.12-arch1-1 #1 SMP PREEMPT Sat, 26 Sep 2020 21:42:58 +0000 x86_64 GNU/Linux
% docker version
Client:
Version: 19.03.13-ce
API version: 1.40
Go version: go1.15.2
Git commit: 4484c46d9d
Built: Sat Sep 26 12:04:46 2020
OS/Arch: linux/amd64
Experimental: false
Server:
Engine:
Version: 19.03.13-ce
API version: 1.40 (minimum version 1.12)
Go version: go1.15.2
Git commit: 4484c46d9d
Built: Sat Sep 26 12:03:35 2020
OS/Arch: linux/amd64
Experimental: false
containerd:
Version: v1.4.1.m
GitCommit: c623d1b36f09f8ef6536a057bd658b3aa8632828.m
runc:
Version: 1.0.0-rc92
GitCommit: ff819c7e9184c13b7c2607fe6c30ae19403a7aff
docker-init:
Version: 0.18.0
GitCommit: fec3683
% docker run --rm -it -v "$PWD":/mnt ruby:2.7 findmnt
TARGET SOURCE FSTYPE OPTIONS
/ overlay overlay rw,relatime
├─/proc proc proc rw,nosuid,n
│ ├─/proc/bus proc[/bus] proc ro,relatime
│ ├─/proc/fs proc[/fs] proc ro,relatime
│ ├─/proc/irq proc[/irq] proc ro,relatime
│ ├─/proc/sys proc[/sys] proc ro,relatime
│ ├─/proc/sysrq-trigger proc[/sysrq-trigger] proc ro,relatime
│ ├─/proc/asound tmpfs tmpfs ro,relatime
│ ├─/proc/acpi tmpfs tmpfs ro,relatime
│ ├─/proc/kcore tmpfs[/null] tmpfs rw,nosuid,s
│ ├─/proc/keys tmpfs[/null] tmpfs rw,nosuid,s
│ ├─/proc/latency_stats tmpfs[/null] tmpfs rw,nosuid,s
│ ├─/proc/timer_list tmpfs[/null] tmpfs rw,nosuid,s
│ ├─/proc/sched_debug tmpfs[/null] tmpfs rw,nosuid,s
│ └─/proc/scsi tmpfs tmpfs ro,relatime
├─/dev tmpfs tmpfs rw,nosuid,s
│ ├─/dev/console devpts[/0] devpts rw,nosuid,n
│ ├─/dev/pts devpts devpts rw,nosuid,n
│ ├─/dev/mqueue mqueue mqueue rw,nosuid,n
│ └─/dev/shm shm tmpfs rw,nosuid,n
├─/sys sysfs sysfs ro,nosuid,n
│ ├─/sys/firmware tmpfs tmpfs ro,relatime
│ └─/sys/fs/cgroup tmpfs tmpfs rw,nosuid,n
│ ├─/sys/fs/cgroup/systemd cgroup[/docker/bcf63a805a2feb88d6115eb09ca8dc4590d0827d4901237cdfb8ed43076914b1]
│ │ cgroup ro,nosuid,n
│ ├─/sys/fs/cgroup/blkio cgroup[/docker/bcf63a805a2feb88d6115eb09ca8dc4590d0827d4901237cdfb8ed43076914b1]
│ │ cgroup ro,nosuid,n
│ ├─/sys/fs/cgroup/freezer cgroup[/docker/bcf63a805a2feb88d6115eb09ca8dc4590d0827d4901237cdfb8ed43076914b1]
│ │ cgroup ro,nosuid,n
│ ├─/sys/fs/cgroup/cpuset cgroup[/docker/bcf63a805a2feb88d6115eb09ca8dc4590d0827d4901237cdfb8ed43076914b1]
│ │ cgroup ro,nosuid,n
│ ├─/sys/fs/cgroup/net_cls,net_prio
│ │ cgroup[/docker/bcf63a805a2feb88d6115eb09ca8dc4590d0827d4901237cdfb8ed43076914b1]
│ │ cgroup ro,nosuid,n
│ ├─/sys/fs/cgroup/hugetlb cgroup[/docker/bcf63a805a2feb88d6115eb09ca8dc4590d0827d4901237cdfb8ed43076914b1]
│ │ cgroup ro,nosuid,n
│ ├─/sys/fs/cgroup/memory cgroup[/docker/bcf63a805a2feb88d6115eb09ca8dc4590d0827d4901237cdfb8ed43076914b1]
│ │ cgroup ro,nosuid,n
│ ├─/sys/fs/cgroup/cpu,cpuacct cgroup[/docker/bcf63a805a2feb88d6115eb09ca8dc4590d0827d4901237cdfb8ed43076914b1]
│ │ cgroup ro,nosuid,n
│ ├─/sys/fs/cgroup/rdma cgroup cgroup ro,nosuid,n
│ ├─/sys/fs/cgroup/devices cgroup[/docker/bcf63a805a2feb88d6115eb09ca8dc4590d0827d4901237cdfb8ed43076914b1]
│ │ cgroup ro,nosuid,n
│ ├─/sys/fs/cgroup/pids cgroup[/docker/bcf63a805a2feb88d6115eb09ca8dc4590d0827d4901237cdfb8ed43076914b1]
│ │ cgroup ro,nosuid,n
│ └─/sys/fs/cgroup/perf_event cgroup[/docker/bcf63a805a2feb88d6115eb09ca8dc4590d0827d4901237cdfb8ed43076914b1]
│ cgroup ro,nosuid,n
├─/mnt /dev/nvme0n1p2[/home/taiki] ext4 rw,relatime
├─/etc/resolv.conf /dev/nvme0n1p2[/var/lib/docker/containers/bcf63a805a2feb88d6115eb09ca8dc4590d0827d4901237cdfb8ed43076914b1/resolv.conf]
│ ext4 rw,relatime
├─/etc/hostname /dev/nvme0n1p2[/var/lib/docker/containers/bcf63a805a2feb88d6115eb09ca8dc4590d0827d4901237cdfb8ed43076914b1/hostname]
│ ext4 rw,relatime
└─/etc/hosts /dev/nvme0n1p2[/var/lib/docker/containers/bcf63a805a2feb88d6115eb09ca8dc4590d0827d4901237cdfb8ed43076914b1/hosts]
ruby-jp の #container あたりで聞いてみようかな。