最初のDockerexecでファイルが欠落しているのに、2番目のexecで使用できるのはなぜですか？
これは非常に奇妙な状況です。 TravisCIでAlpineベースのDockerコンテナを実行します。次に、次のようにlsを実行します。
docker exec $CONTAINER_NAME ls -la specific/directory
docker exec $CONTAINER_NAME ls -la specific/directory
最初のコマンドはファイルのリストを表示しますが、そこにあるはずのいくつかのファイルがありません（ビルドされたイメージの一部であり、他のプラットフォームで調査したときにイメージ内に存在します）。
出力例：file_#の番号に注意してください
total 108
-rw-rw-r-- 1 nginx nginx 2069 Oct 21 06:08 2018_01_10_101010_file_1_here.php
-rw-rw-r-- 1 nginx nginx 1586 Oct 21 06:08 2018_01_12_101010_file_3_here.php
-rw-rw-r-- 1 nginx nginx 1649 Oct 21 06:08 2018_01_13_101010_file_4_here.php
-rw-rw-r-- 1 nginx nginx 1490 Oct 21 06:08 2018_01_14_101010_file_5_here.php
-rw-rw-r-- 1 nginx nginx 946 Oct 21 06:08 2018_01_15_101010_file_6_here.php
-rw-rw-r-- 1 nginx nginx 2379 Oct 21 06:08 2018_01_16_101010_file_7_here.php
2番目のコマンドは、期待どおりにファイルの完全なリストを表示します。
total 192
drwxrwxr-x 1 nginx nginx 4096 Oct 21 06:08 .
drwxrwxr-x 1 nginx nginx 4096 Oct 21 06:08 ..
-rw-rw-r-- 1 nginx nginx 2069 Oct 21 06:08 2018_01_10_101010_file_1_here.php
-rw-rw-r-- 1 nginx nginx 1758 Oct 21 06:08 2018_01_11_101010_file_2_here.php
-rw-rw-r-- 1 nginx nginx 1586 Oct 21 06:08 2018_01_12_101010_file_3_here.php
-rw-rw-r-- 1 nginx nginx 1649 Oct 21 06:08 2018_01_13_101010_file_4_here.php
-rw-rw-r-- 1 nginx nginx 1490 Oct 21 06:08 2018_01_14_101010_file_5_here.php
-rw-rw-r-- 1 nginx nginx 946 Oct 21 06:08 2018_01_15_101010_file_6_here.php
-rw-rw-r-- 1 nginx nginx 2379 Oct 21 06:08 2018_01_16_101010_file_7_here.php
-rw-rw-r-- 1 nginx nginx 1583 Oct 21 06:08 2018_01_17_101010_file_8_here.php
-rw-rw-r-- 1 nginx nginx 920 Oct 21 06:08 2018_01_18_101010_file_9_here.php
また、最初のコマンドで.および..ディレクトリが表示されないことにも気付きました。
なぜそれが起こるのですか？そしてそれを回避する方法は？
ところで：それはlsだけで起こるわけではありません。アプリケーションコードが初めてファイルを一覧表示しようとすると、縮小リストが表示されます。しかし、それらを再度リストすると、完全なリストが表示されます！
以下は、@ DanilaKiverと@ClemensKasererによって要求されたその他のデバッグコマンドです。
docker infoの出力：
Containers: 4
Running: 4
Paused: 0
Stopped: 0
Images: 30
Server Version: 18.06.0-ce
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 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: d64c661f1d51c48782c9cec8fda7604785f93587
runc version: 69663f0bd4b60df09991c08812a60108003fa340
init version: fec3683
Security Options:
seccomp
Profile: default
Kernel Version: 4.15.0-1028-gcp
Operating System: Ubuntu 16.04.6 LTS
OSType: linux
Architecture: x86_64
CPUs: 2
Total Memory: 7.298GiB
Name: travis-job-8895eb3f-fd49-4241-af47-47daddf7beb5
ID: AVP5:DERI:ZI6V:ZTOR:KAAL:SPUS:ZQHT:NOOK:6IFE:VCFZ:CHL4:3QAK
Docker Root Dir: /var/lib/docker
Debug Mode (client): false
Debug Mode (server): false
Registry: https://index.docker.io/v1/
Labels:
Experimental: false
Insecure Registries:
127.0.0.0/8
Registry Mirrors:
https://mirror.gcr.io/
Live Restore Enabled: false
以下を実行します。
dmesg | grep ovl
docker exec $CONTAINER_NAME sync & ls -la specific/directory
docker exec $CONTAINER_NAME ls -la specific/directory
docker exec $CONTAINER_NAME ls -la specific/directory
dmesg | grep ovl
docker exec $CONTAINER_NAME dmesg | grep ovl
与える：
# dmesg | grep ovl
[ 178.665709] WARNING: CPU: 1 PID: 8854 at /build/linux-gcp-yd4gNt/linux-gcp-4.15.0/fs/overlayfs/readdir.c:417 ovl_iterate+0x25d/0x270 [overlay]
[ 178.665761] RIP: 0010:ovl_iterate+0x25d/0x270 [overlay]
[ 178.730507] WARNING: CPU: 0 PID: 9214 at /build/linux-gcp-yd4gNt/linux-gcp-4.15.0/fs/overlayfs/readdir.c:417 ovl_iterate+0x25d/0x270 [overlay]
[ 178.730554] RIP: 0010:ovl_iterate+0x25d/0x270 [overlay]
[ 178.777656] WARNING: CPU: 0 PID: 9214 at /build/linux-gcp-yd4gNt/linux-gcp-4.15.0/fs/overlayfs/readdir.c:417 ovl_iterate+0x25d/0x270 [overlay]
[ 178.777707] RIP: 0010:ovl_iterate+0x25d/0x270 [overlay]
# docker exec $CONTAINER_NAME sync & ls -la specific/directory
total 184
drwxrwxr-x 2 travis travis 4096 Oct 21 11:38 .
drwxrwxr-x 5 travis travis 4096 Oct 21 11:38 ..
-rw-rw-r-- 1 travis travis 1156 Oct 21 11:38 2018_04_18_000001_file_01_here.php
-rw-rw-r-- 1 travis travis 1758 Oct 21 11:38 2018_04_18_000001_file_02_here.php
-rw-rw-r-- 1 travis travis 1598 Oct 21 11:38 2018_04_18_000001_file_03_here.php
-rw-rw-r-- 1 travis travis 1661 Oct 21 11:38 2018_04_18_000001_file_04_here.php
-rw-rw-r-- 1 travis travis 1502 Oct 21 11:38 2018_04_18_000001_file_05_here.php
-rw-rw-r-- 1 travis travis 958 Oct 21 11:38 2018_04_18_000001_file_06_here.php
-rw-rw-r-- 1 travis travis 2391 Oct 21 11:38 2018_04_18_000001_file_07_here.php
-rw-rw-r-- 1 travis travis 1583 Oct 21 11:38 2018_04_18_000001_file_08_here.php
-rw-rw-r-- 1 travis travis 932 Oct 21 11:38 2018_04_18_000001_file_09_here.php
-rw-rw-r-- 1 travis travis 1947 Oct 21 11:38 2018_04_18_000001_file_10_here.php
-rw-rw-r-- 1 travis travis 1484 Oct 21 11:38 2018_04_18_000001_file_11_here.php
-rw-rw-r-- 1 travis travis 1026 Oct 21 11:38 2018_04_18_000001_file_12_here.php
-rw-rw-r-- 1 travis travis 2170 Oct 21 11:38 2018_04_18_000001_file_13_here.php
-rw-rw-r-- 1 travis travis 1683 Oct 21 11:38 2018_04_18_000001_file_14_here.php
-rw-rw-r-- 1 travis travis 999 Oct 21 11:38 2018_04_18_000001_file_15_here.php
-rw-rw-r-- 1 travis travis 1477 Oct 21 11:38 2018_04_18_000001_file_16_here.php
-rw-rw-r-- 1 travis travis 1687 Oct 21 11:38 2018_04_18_000001_file_17_here.php
-rw-rw-r-- 1 travis travis 1619 Oct 21 11:38 2018_04_18_000001_file_18_here.php
-rw-rw-r-- 1 travis travis 1954 Oct 21 11:38 2018_04_18_000001_file_19_here.php
-rw-rw-r-- 1 travis travis 1203 Oct 21 11:38 2018_04_18_000001_file_20_here.php
-rw-rw-r-- 1 travis travis 1024 Oct 21 11:38 2018_04_18_000001_file_21_here.php
-rw-rw-r-- 1 travis travis 1290 Oct 21 11:38 2018_04_18_000001_file_22_here.php
-rw-rw-r-- 1 travis travis 1675 Oct 21 11:38 2018_04_18_000001_file_23_here.php
-rw-rw-r-- 1 travis travis 1411 Oct 21 11:38 2018_04_18_000001_file_24_here.php
-rw-rw-r-- 1 travis travis 1566 Oct 21 11:38 2018_04_18_000001_file_25_here.php
-rw-rw-r-- 1 travis travis 958 Oct 21 11:38 2018_04_18_000001_file_26_here.php
-rw-rw-r-- 1 travis travis 1122 Oct 21 11:38 2018_04_18_000001_file_27_here.php
-rw-rw-r-- 1 travis travis 1131 Oct 21 11:38 2018_04_18_000001_file_28_here.php
-rw-rw-r-- 1 travis travis 3034 Oct 21 11:38 2018_04_18_000001_file_29_here.php
-rw-rw-r-- 1 travis travis 1866 Oct 21 11:38 2018_04_18_000001_file_30_here.php
-rw-rw-r-- 1 travis travis 2068 Oct 21 11:38 2018_04_18_000001_file_31_here.php
-rw-rw-r-- 1 travis travis 991 Oct 21 11:38 2018_04_18_000001_file_32_here.php
-rw-rw-r-- 1 travis travis 995 Oct 21 11:38 2018_04_18_000001_file_33_here.php
-rw-rw-r-- 1 travis travis 933 Oct 21 11:38 2018_04_18_000001_file_34_here.php
-rw-rw-r-- 1 travis travis 2238 Oct 21 11:38 2018_04_18_000001_file_35_here.php
-rw-rw-r-- 1 travis travis 943 Oct 21 11:38 2018_04_18_000001_file_36_here.php
-rw-rw-r-- 1 travis travis 1765 Oct 21 11:38 2018_04_18_000001_file_37_here.php
-rw-rw-r-- 1 travis travis 2895 Oct 21 11:38 2018_04_18_000001_file_38_here.php
-rw-rw-r-- 1 travis travis 1501 Oct 21 11:38 2018_04_18_000001_file_39_here.php
-rw-rw-r-- 1 travis travis 1444 Oct 21 11:38 2018_04_18_000001_file_40_here.php
-rw-rw-r-- 1 travis travis 1722 Oct 21 11:38 2018_04_18_000001_file_41_here.php
-rw-rw-r-- 1 travis travis 1404 Oct 21 11:38 2018_04_18_000001_file_42_here.php
-rw-rw-r-- 1 travis travis 941 Oct 21 11:38 2018_04_18_000001_file_43_here.php
-rw-rw-r-- 1 travis travis 919 Oct 21 11:38 2018_04_18_000001_file_44_here.php
# docker exec $CONTAINER_NAME ls -la specific/directory
total 140
-rw-rw-r-- 1 nginx nginx 1758 Oct 21 11:38 2018_04_18_000001_file_02_here.php
-rw-rw-r-- 1 nginx nginx 1598 Oct 21 11:38 2018_04_18_000001_file_03_here.php
-rw-rw-r-- 1 nginx nginx 1661 Oct 21 11:38 2018_04_18_000001_file_04_here.php
-rw-rw-r-- 1 nginx nginx 1502 Oct 21 11:38 2018_04_18_000001_file_05_here.php
-rw-rw-r-- 1 nginx nginx 958 Oct 21 11:38 2018_04_18_000001_file_06_here.php
-rw-rw-r-- 1 nginx nginx 2391 Oct 21 11:38 2018_04_18_000001_file_07_here.php
-rw-rw-r-- 1 nginx nginx 1583 Oct 21 11:38 2018_04_18_000001_file_08_here.php
-rw-rw-r-- 1 nginx nginx 1484 Oct 21 11:38 2018_04_18_000001_file_11_here.php
-rw-rw-r-- 1 nginx nginx 1026 Oct 21 11:38 2018_04_18_000001_file_12_here.php
-rw-rw-r-- 1 nginx nginx 2170 Oct 21 11:38 2018_04_18_000001_file_13_here.php
-rw-rw-r-- 1 nginx nginx 1683 Oct 21 11:38 2018_04_18_000001_file_14_here.php
-rw-rw-r-- 1 nginx nginx 1477 Oct 21 11:38 2018_04_18_000001_file_16_here.php
-rw-rw-r-- 1 nginx nginx 1687 Oct 21 11:38 2018_04_18_000001_file_17_here.php
-rw-rw-r-- 1 nginx nginx 1954 Oct 21 11:38 2018_04_18_000001_file_19_here.php
-rw-rw-r-- 1 nginx nginx 1203 Oct 21 11:38 2018_04_18_000001_file_20_here.php
-rw-rw-r-- 1 nginx nginx 1024 Oct 21 11:38 2018_04_18_000001_file_21_here.php
-rw-rw-r-- 1 nginx nginx 1290 Oct 21 11:38 2018_04_18_000001_file_22_here.php
-rw-rw-r-- 1 nginx nginx 1675 Oct 21 11:38 2018_04_18_000001_file_23_here.php
-rw-rw-r-- 1 nginx nginx 1411 Oct 21 11:38 2018_04_18_000001_file_24_here.php
-rw-rw-r-- 1 nginx nginx 1566 Oct 21 11:38 2018_04_18_000001_file_25_here.php
-rw-rw-r-- 1 nginx nginx 958 Oct 21 11:38 2018_04_18_000001_file_26_here.php
-rw-rw-r-- 1 nginx nginx 1122 Oct 21 11:38 2018_04_18_000001_file_27_here.php
-rw-rw-r-- 1 nginx nginx 1131 Oct 21 11:38 2018_04_18_000001_file_28_here.php
-rw-rw-r-- 1 nginx nginx 2068 Oct 21 11:38 2018_04_18_000001_file_31_here.php
-rw-rw-r-- 1 nginx nginx 991 Oct 21 11:38 2018_04_18_000001_file_32_here.php
-rw-rw-r-- 1 nginx nginx 995 Oct 21 11:38 2018_04_18_000001_file_33_here.php
-rw-rw-r-- 1 nginx nginx 933 Oct 21 11:38 2018_04_18_000001_file_34_here.php
-rw-rw-r-- 1 nginx nginx 2238 Oct 21 11:38 2018_04_18_000001_file_35_here.php
-rw-rw-r-- 1 nginx nginx 943 Oct 21 11:38 2018_04_18_000001_file_36_here.php
-rw-rw-r-- 1 nginx nginx 2895 Oct 21 11:38 2018_04_18_000001_file_38_here.php
-rw-rw-r-- 1 nginx nginx 1501 Oct 21 11:38 2018_04_18_000001_file_39_here.php
-rw-rw-r-- 1 nginx nginx 1444 Oct 21 11:38 2018_04_18_000001_file_40_here.php
-rw-rw-r-- 1 nginx nginx 1722 Oct 21 11:38 2018_04_18_000001_file_41_here.php
-rw-rw-r-- 1 nginx nginx 1404 Oct 21 11:38 2018_04_18_000001_file_42_here.php
-rw-rw-r-- 1 nginx nginx 941 Oct 21 11:38 2018_04_18_000001_file_43_here.php
# docker exec $CONTAINER_NAME ls -la specific/directory
total 192
drwxrwxr-x 1 nginx nginx 4096 Oct 21 11:38 .
drwxrwxr-x 1 nginx nginx 4096 Oct 21 11:38 ..
-rw-rw-r-- 1 nginx nginx 1156 Oct 21 11:38 2018_04_18_000001_file_01_here.php
-rw-rw-r-- 1 nginx nginx 1758 Oct 21 11:38 2018_04_18_000001_file_02_here.php
-rw-rw-r-- 1 nginx nginx 1598 Oct 21 11:38 2018_04_18_000001_file_03_here.php
-rw-rw-r-- 1 nginx nginx 1661 Oct 21 11:38 2018_04_18_000001_file_04_here.php
-rw-rw-r-- 1 nginx nginx 1502 Oct 21 11:38 2018_04_18_000001_file_05_here.php
-rw-rw-r-- 1 nginx nginx 958 Oct 21 11:38 2018_04_18_000001_file_06_here.php
-rw-rw-r-- 1 nginx nginx 2391 Oct 21 11:38 2018_04_18_000001_file_07_here.php
-rw-rw-r-- 1 nginx nginx 1583 Oct 21 11:38 2018_04_18_000001_file_08_here.php
-rw-rw-r-- 1 nginx nginx 932 Oct 21 11:38 2018_04_18_000001_file_09_here.php
-rw-rw-r-- 1 nginx nginx 1947 Oct 21 11:38 2018_04_18_000001_file_10_here.php
-rw-rw-r-- 1 nginx nginx 1484 Oct 21 11:38 2018_04_18_000001_file_11_here.php
-rw-rw-r-- 1 nginx nginx 1026 Oct 21 11:38 2018_04_18_000001_file_12_here.php
-rw-rw-r-- 1 nginx nginx 2170 Oct 21 11:38 2018_04_18_000001_file_13_here.php
-rw-rw-r-- 1 nginx nginx 1683 Oct 21 11:38 2018_04_18_000001_file_14_here.php
-rw-rw-r-- 1 nginx nginx 999 Oct 21 11:38 2018_04_18_000001_file_15_here.php
-rw-rw-r-- 1 nginx nginx 1477 Oct 21 11:38 2018_04_18_000001_file_16_here.php
-rw-rw-r-- 1 nginx nginx 1687 Oct 21 11:38 2018_04_18_000001_file_17_here.php
-rw-rw-r-- 1 nginx nginx 1619 Oct 21 11:38 2018_04_18_000001_file_18_here.php
-rw-rw-r-- 1 nginx nginx 1954 Oct 21 11:38 2018_04_18_000001_file_19_here.php
-rw-rw-r-- 1 nginx nginx 1203 Oct 21 11:38 2018_04_18_000001_file_20_here.php
-rw-rw-r-- 1 nginx nginx 1024 Oct 21 11:38 2018_04_18_000001_file_21_here.php
-rw-rw-r-- 1 nginx nginx 1290 Oct 21 11:38 2018_04_18_000001_file_22_here.php
-rw-rw-r-- 1 nginx nginx 1675 Oct 21 11:38 2018_04_18_000001_file_23_here.php
-rw-rw-r-- 1 nginx nginx 1411 Oct 21 11:38 2018_04_18_000001_file_24_here.php
-rw-rw-r-- 1 nginx nginx 1566 Oct 21 11:38 2018_04_18_000001_file_25_here.php
-rw-rw-r-- 1 nginx nginx 958 Oct 21 11:38 2018_04_18_000001_file_26_here.php
-rw-rw-r-- 1 nginx nginx 1122 Oct 21 11:38 2018_04_18_000001_file_27_here.php
-rw-rw-r-- 1 nginx nginx 1131 Oct 21 11:38 2018_04_18_000001_file_28_here.php
-rw-rw-r-- 1 nginx nginx 3034 Oct 21 11:38 2018_04_18_000001_file_29_here.php
-rw-rw-r-- 1 nginx nginx 1866 Oct 21 11:38 2018_04_18_000001_file_30_here.php
-rw-rw-r-- 1 nginx nginx 2068 Oct 21 11:38 2018_04_18_000001_file_31_here.php
-rw-rw-r-- 1 nginx nginx 991 Oct 21 11:38 2018_04_18_000001_file_32_here.php
-rw-rw-r-- 1 nginx nginx 995 Oct 21 11:38 2018_04_18_000001_file_33_here.php
-rw-rw-r-- 1 nginx nginx 933 Oct 21 11:38 2018_04_18_000001_file_34_here.php
-rw-rw-r-- 1 nginx nginx 2238 Oct 21 11:38 2018_04_18_000001_file_35_here.php
-rw-rw-r-- 1 nginx nginx 943 Oct 21 11:38 2018_04_18_000001_file_36_here.php
-rw-rw-r-- 1 nginx nginx 1765 Oct 21 11:38 2018_04_18_000001_file_37_here.php
-rw-rw-r-- 1 nginx nginx 2895 Oct 21 11:38 2018_04_18_000001_file_38_here.php
-rw-rw-r-- 1 nginx nginx 1501 Oct 21 11:38 2018_04_18_000001_file_39_here.php
-rw-rw-r-- 1 nginx nginx 1444 Oct 21 11:38 2018_04_18_000001_file_40_here.php
-rw-rw-r-- 1 nginx nginx 1722 Oct 21 11:38 2018_04_18_000001_file_41_here.php
-rw-rw-r-- 1 nginx nginx 1404 Oct 21 11:38 2018_04_18_000001_file_42_here.php
-rw-rw-r-- 1 nginx nginx 941 Oct 21 11:38 2018_04_18_000001_file_43_here.php
-rw-rw-r-- 1 nginx nginx 919 Oct 21 11:38 2018_04_18_000001_file_44_here.php
# dmesg | grep ovl
[ 178.665709] WARNING: CPU: 1 PID: 8854 at /build/linux-gcp-yd4gNt/linux-gcp-4.15.0/fs/overlayfs/readdir.c:417 ovl_iterate+0x25d/0x270 [overlay]
[ 178.665761] RIP: 0010:ovl_iterate+0x25d/0x270 [overlay]
[ 178.730507] WARNING: CPU: 0 PID: 9214 at /build/linux-gcp-yd4gNt/linux-gcp-4.15.0/fs/overlayfs/readdir.c:417 ovl_iterate+0x25d/0x270 [overlay]
[ 178.730554] RIP: 0010:ovl_iterate+0x25d/0x270 [overlay]
[ 178.777656] WARNING: CPU: 0 PID: 9214 at /build/linux-gcp-yd4gNt/linux-gcp-4.15.0/fs/overlayfs/readdir.c:417 ovl_iterate+0x25d/0x270 [overlay]
[ 178.777707] RIP: 0010:ovl_iterate+0x25d/0x270 [overlay]
[ 213.441060] WARNING: CPU: 1 PID: 9378 at /build/linux-gcp-yd4gNt/linux-gcp-4.15.0/fs/overlayfs/readdir.c:417 ovl_iterate+0x25d/0x270 [overlay]
[ 213.441107] RIP: 0010:ovl_iterate+0x25d/0x270 [overlay]
# docker exec $CONTAINER_NAME dmesg | grep ovl
[ 178.665709] WARNING: CPU: 1 PID: 8854 at /build/linux-gcp-yd4gNt/linux-gcp-4.15.0/fs/overlayfs/readdir.c:417 ovl_iterate+0x25d/0x270 [overlay]
[ 178.665761] RIP: 0010:ovl_iterate+0x25d/0x270 [overlay]
[ 178.730507] WARNING: CPU: 0 PID: 9214 at /build/linux-gcp-yd4gNt/linux-gcp-4.15.0/fs/overlayfs/readdir.c:417 ovl_iterate+0x25d/0x270 [overlay]
[ 178.730554] RIP: 0010:ovl_iterate+0x25d/0x270 [overlay]
[ 178.777656] WARNING: CPU: 0 PID: 9214 at /build/linux-gcp-yd4gNt/linux-gcp-4.15.0/fs/overlayfs/readdir.c:417 ovl_iterate+0x25d/0x270 [overlay]
[ 178.777707] RIP: 0010:ovl_iterate+0x25d/0x270 [overlay]
[ 213.441060] WARNING: CPU: 1 PID: 9378 at /build/linux-gcp-yd4gNt/linux-gcp-4.15.0/fs/overlayfs/readdir.c:417 ovl_iterate+0x25d/0x270 [overlay]
[ 213.441107] RIP: 0010:ovl_iterate+0x25d/0x270 [overlay]
更新：
この問題はUbuntuXenial 16.04で発生しますが、Ubuntu Bionic18.04では発生しません。そのため、カーネルのバグのようで、後のバージョンで解決されました。
この問題はUbuntuXenial 16.04で発生しますが、Ubuntu Bionic18.04では発生しません。そのため、カーネルのバグのようで、後のバージョンで解決されました。
@DanilaKiverは この修正コミット も参照しました。これは同じ問題に関連している可能性があります。