The Anatomy of Docker Containers

You must be curious about what goes in and out of the running Docker containers. Debugging a normal Linux system processes is very much similar to debugging a containerized application. There are various utilities like docker top, pstree  and docker ps command to peep into what’s actually going on inside the container.

Displaying overall processes running inside Docker container
root@dell-virtual-machine:/home/dell# pstree -p `pidof docker`
init(1)─┬─ModemManager(602)─┬─{ModemManager}(613)
│                   └─{ModemManager}(616)
├─NetworkManager(669)─┬─dhclient(967)
│                     ├─dnsmasq(1126)
│                     ├─{NetworkManager}(695)
│                     ├─{NetworkManager}(707)
│                     └─{NetworkManager}(708)
├─accounts-daemon(1015)─┬─{accounts-daemon}(1017)
│                       └─{accounts-daemon}(1018)
├─acpid(884)
├─avahi-daemon(455)───avahi-daemon(456)
├─bluetoothd(433)
├─colord(1442)─┬─{colord}(1444)
│              └─{colord}(1445)
├─cron(885)
├─cups-browsed(986)
├─cupsd(32540)───dbus(32543)
├─dbus-daemon(392)
├─docker.io(10531)─┬─bash(1057)
│                  ├─bash(12674)
│                  ├─bash(12734)
│                  ├─gunicorn(11864)─┬─gunicorn(11899)
│                  │                 ├─gunicorn(11900)
│                  │                 ├─gunicorn(11901)
│                  │                 └─gunicorn(11902)
│                  ├─sh(11931)───start-apache.sh(11957)───apache2ctl(11988)───apache2(11990)─┬─apache+
│                  │                                                                         └─apache+
│                  ├─sh(12070)───start-apache.sh(12099)───apache2ctl(12130)───apache2(12132)─┬─apache+
│                  │                                                                         └─apache+
│                  ├─{docker.io}(10533)
│                  ├─{docker.io}(10534)
│                  ├─{docker.io}(10535)
│                  ├─{docker.io}(10536)
│                  ├─{docker.io}(10537)
│                  ├─{docker.io}(10538)
│                  ├─{docker.io}(11869)
│                  ├─{docker.io}(11880)
│                  ├─{docker.io}(11928)
│                  ├─{docker.io}(11933)
│                  ├─{docker.io}(11935)
│                  ├─{docker.io}(12076)
│                  ├─{docker.io}(12078)
│                  ├─{docker.io}(12082)
│                  ├─{docker.io}(12269)
│                  ├─{docker.io}(12568)
│                  ├─{docker.io}(12572)
│                  ├─{docker.io}(12743)
│                  ├─{docker.io}(1058)
│                  ├─{docker.io}(1075)
│                  └─{docker.io}(1105)
├─getty(823)
├─getty(827)
├─getty(834)
├─getty(835)
├─getty(839)
├─getty(975)
├─gnome-keyring-d(1485)─┬─{gnome-keyring-d}(1486)
│                       ├─{gnome-keyring-d}(1606)
│                       ├─{gnome-keyring-d}(1607)
│                       ├─{gnome-keyring-d}(1609)
│                       ├─{gnome-keyring-d}(1907)
│                       └─{gnome-keyring-d}(2092)
├─kerneloops(901)
├─lightdm(1000)─┬─Xorg(1012)
│               ├─lightdm(1083)─┬─init(1487)─┬─at-spi-bus-laun(1629)─┬─dbus-daemon(1641)
│               │               │            │                       ├─{at-spi-bus-laun}(1631)
│               │               │            │                       ├─{at-spi-bus-laun}(1637)
│               │               │            │                       └─{at-spi-bus-laun}(1643)
│               │               │            ├─at-spi2-registr(1648)───{at-spi2-registr}(1649)
│               │               │            ├─bamfdaemon(1619)─┬─{bamfdaemon}(1650)
│               │               │            │                  ├─{bamfdaemon}(1652)
│               │               │            │                  └─{bamfdaemon}(1659)
│               │               │            ├─dbus-daemon(1578)
│               │               │            ├─dconf-service(1669)─┬─{dconf-service}(1671)
│               │               │            │                     └─{dconf-service}(1673)
│               │               │            ├─evolution-calen(1975)─┬─{evolution-calen}(1996)
│               │               │            │                       ├─{evolution-calen}(2002)
│               │               │            │                       ├─{evolution-calen}(2003)
│               │               │            │                       └─{evolution-calen}(2005)
│               │               │            ├─evolution-sourc(1903)─┬─{evolution-sourc}(1930)
│               │               │            │                       └─{evolution-sourc}(1956)
│               │               │            ├─gconfd-2(1720)
│               │               │            ├─gnome-session(1776)─┬─compiz(1945)─┬─{compiz}(1946)
│               │               │            │                     │              ├─{compiz}(1948)
│               │               │            │                     │              ├─{compiz}(1949)
│               │               │            │                     │              └─{compiz}(3916)
│               │               │            │                     ├─deja-dup-monito(2267)─┬─{deja-du+
│               │               │            │                     │                       ├─{deja-du+
│               │               │            │                     │                       └─{deja-du+
│               │               │            │                     ├─nautilus(1973)─┬─{nautilus}(1987+
│               │               │            │                     │                ├─{nautilus}(1989+
│               │               │            │                     │                └─{nautilus}(2022+
│               │               │            │                     ├─nm-applet(1971)─┬─{nm-applet}(19+
│               │               │            │                     │                 └─{nm-applet}(19+
│               │               │            │                     ├─polkit-gnome-au(1970)─┬─{polkit-+
│               │               │            │                     │                       └─{polkit-+
│               │               │            │                     ├─telepathy-indic(2160)─┬─{telepat+
│               │               │            │                     │                       └─{telepat+
│               │               │            │                     ├─unity-fallback-(1966)─┬─{unity-f+
│               │               │            │                     │                       └─{unity-f+
│               │               │            │                     ├─update-notifier(2249)─┬─{update-+
│               │               │            │                     │                       ├─{update-+
│               │               │            │                     │                       └─{update-+
│               │               │            │                     ├─{gnome-session}(1807)
│               │               │            │                     ├─{gnome-session}(1820)
│               │               │            │                     └─{gnome-session}(1895)
│               │               │            ├─gnome-terminal(2202)─┬─bash(2209)───sudo(2227)───su(22+
│               │               │            │                      ├─gnome-pty-helpe(2208)
│               │               │            │                      ├─{gnome-terminal}(2204)
│               │               │            │                      ├─{gnome-terminal}(2205)
│               │               │            │                      └─{gnome-terminal}(2207)
│               │               │            ├─gvfs-afc-volume(2017)─┬─{gvfs-afc-volume}(2018)
│               │               │            │                       └─{gvfs-afc-volume}(2023)
│               │               │            ├─gvfs-gphoto2-vo(2025)───{gvfs-gphoto2-vo}(2027)
│               │               │            ├─gvfs-mtp-volume(2029)───{gvfs-mtp-volume}(2031)
│               │               │            ├─gvfs-udisks2-vo(1992)─┬─{gvfs-udisks2-vo}(1993)
│               │               │            │                       └─{gvfs-udisks2-vo}(2008)
│               │               │            ├─gvfsd(1654)───{gvfsd}(1655)
│               │               │            ├─gvfsd-burn(2043)─┬─{gvfsd-burn}(2044)
│               │               │            │                  └─{gvfsd-burn}(2046)
│               │               │            ├─gvfsd-fuse(1661)─┬─{gvfsd-fuse}(1670)
│               │               │            │                  ├─{gvfsd-fuse}(1672)
│               │               │            │                  ├─{gvfsd-fuse}(1674)
│               │               │            │                  └─{gvfsd-fuse}(1676)
│               │               │            ├─gvfsd-metadata(2016)───{gvfsd-metadata}(2020)
│               │               │            ├─gvfsd-trash(2034)─┬─{gvfsd-trash}(2035)
│               │               │            │                   ├─{gvfsd-trash}(2037)
│               │               │            │                   ├─{gvfsd-trash}(2039)
│               │               │            │                   └─{gvfsd-trash}(2040)
│               │               │            ├─hud-service(1772)─┬─{hud-service}(1822)
│               │               │            │                   ├─{hud-service}(1828)
│               │               │            │                   └─{hud-service}(1850)
│               │               │            ├─ibus-daemon(1633)─┬─ibus-dconf(1690)─┬─{ibus-dconf}(16+
│               │               │            │                   │                  ├─{ibus-dconf}(16+
│               │               │            │                   │                  └─{ibus-dconf}(17+
│               │               │            │                   ├─ibus-engine-sim(1718)─┬─{ibus-engi+
│               │               │            │                   │                       └─{ibus-engi+
│               │               │            │                   ├─ibus-ui-gtk3(1691)─┬─{ibus-ui-gtk3+
│               │               │            │                   │                    ├─{ibus-ui-gtk3+
│               │               │            │                   │                    └─{ibus-ui-gtk3+
│               │               │            │                   ├─{ibus-daemon}(1687)
│               │               │            │                   └─{ibus-daemon}(1688)
│               │               │            ├─ibus-x11(1694)─┬─{ibus-x11}(1716)
│               │               │            │                ├─{ibus-x11}(1717)
│               │               │            │                └─{ibus-x11}(1721)
│               │               │            ├─indicator-appli(1883)───{indicator-appli}(1900)
│               │               │            ├─indicator-bluet(1861)─┬─{indicator-bluet}(1862)
│               │               │            │                       └─{indicator-bluet}(1872)
│               │               │            ├─indicator-datet(1865)─┬─{indicator-datet}(1881)
│               │               │            │                       ├─{indicator-datet}(1894)
│               │               │            │                       ├─{indicator-datet}(1899)
│               │               │            │                       ├─{indicator-datet}(1931)
│               │               │            │                       └─{indicator-datet}(1972)
│               │               │            ├─indicator-keybo(1857)─┬─{indicator-keybo}(1934)
│               │               │            │                       ├─{indicator-keybo}(1944)
│               │               │            │                       └─{indicator-keybo}(1960)
│               │               │            ├─indicator-messa(1859)─┬─{indicator-messa}(1866)
│               │               │            │                       ├─{indicator-messa}(1867)
│               │               │            │                       └─{indicator-messa}(1876)
│               │               │            ├─indicator-power(1863)─┬─{indicator-power}(1868)
│               │               │            │                       └─{indicator-power}(1874)
│               │               │            ├─indicator-print(1871)─┬─{indicator-print}(1902)
│               │               │            │                       └─{indicator-print}(1913)
│               │               │            ├─indicator-sessi(1875)─┬─{indicator-sessi}(1879)
│               │               │            │                       └─{indicator-sessi}(1898)
│               │               │            ├─indicator-sound(1869)─┬─{indicator-sound}(1877)
│               │               │            │                       ├─{indicator-sound}(1896)
│               │               │            │                       └─{indicator-sound}(1969)
│               │               │            ├─mission-control(2168)─┬─{mission-control}(2170)
│               │               │            │                       └─{mission-control}(2172)
│               │               │            ├─notify-osd(1942)─┬─{notify-osd}(1954)
│               │               │            │                  └─{notify-osd}(1955)
│               │               │            ├─pulseaudio(1906)───{pulseaudio}(1921)
│               │               │            ├─unity-files-dae(2107)─┬─{unity-files-dae}(2109)
│               │               │            │                       ├─{unity-files-dae}(2111)
│               │               │            │                       ├─{unity-files-dae}(2125)
│               │               │            │                       └─{unity-files-dae}(2126)
│               │               │            ├─unity-music-dae(2149)─┬─{unity-music-dae}(2150)
│               │               │            │                       └─{unity-music-dae}(2151)
│               │               │            ├─unity-panel-ser(1782)─┬─{unity-panel-ser}(1806)
│               │               │            │                       └─{unity-panel-ser}(1814)
│               │               │            ├─unity-panel-ser(3917)─┬─{unity-panel-ser}(3918)
│               │               │            │                       └─{unity-panel-ser}(3919)
│               │               │            ├─unity-scope-hom(2087)─┬─{unity-scope-hom}(2088)
│               │               │            │                       ├─{unity-scope-hom}(2089)
│               │               │            │                       └─{unity-scope-hom}(1087)
│               │               │            ├─unity-scope-loa(2105)─┬─{unity-scope-loa}(2108)
│               │               │            │                       ├─{unity-scope-loa}(2110)
│               │               │            │                       └─{unity-scope-loa}(2141)
│               │               │            ├─unity-settings-(1768)─┬─{unity-settings-}(1788)
│               │               │            │                       ├─{unity-settings-}(1795)
│               │               │            │                       └─{unity-settings-}(1848)
│               │               │            ├─upstart-dbus-br(1613)
│               │               │            ├─upstart-dbus-br(1615)
│               │               │            ├─upstart-event-b(1590)
│               │               │            ├─upstart-file-br(1617)
│               │               │            ├─window-stack-br(1601)
│               │               │            ├─zeitgeist-daemo(2114)───{zeitgeist-daemo}(2117)
│               │               │            ├─zeitgeist-datah(2124)─┬─{zeitgeist-datah}(2130)
│               │               │            │                       ├─{zeitgeist-datah}(2132)
│               │               │            │                       └─{zeitgeist-datah}(2136)
│               │               │            └─zeitgeist-fts(2123)─┬─cat(2131)
│               │               │                                  ├─{zeitgeist-fts}(2127)
│               │               │                                  └─{zeitgeist-fts}(2138)
│               │               └─{lightdm}(1475)
│               ├─{lightdm}(1008)
│               └─{lightdm}(1013)
├─polkitd(710)─┬─{polkitd}(717)
│              └─{polkitd}(719)
├─rsyslogd(443)─┬─{rsyslogd}(444)
│               ├─{rsyslogd}(445)
│               └─{rsyslogd}(446)
├─rtkit-daemon(1173)─┬─{rtkit-daemon}(1200)
│                    └─{rtkit-daemon}(1201)
├─sshd(3262)───sshd(932)───sshd(996)───bash(997)───sudo(1019)───su(1020)───bash(1021)───pstree(1110)
├─systemd-logind(432)
├─systemd-udevd(290)
├─thermald(828)───{thermald}(836)
├─udisksd(1995)─┬─{udisksd}(1998)
│               ├─{udisksd}(2000)
│               ├─{udisksd}(2001)
│               └─{udisksd}(2004)
├─upowerd(1112)─┬─{upowerd}(1122)
│               └─{upowerd}(1127)
├─upstart-file-br(467)
├─upstart-socket-(722)
├─upstart-udev-br(279)
└─whoopsie(919)─┬─{whoopsie}(947)
├─{whoopsie}(95

As you see above, this output provides us with a very good look at all the processes attached to Docker and what they are running.

Displaying the Open Files and Sockets for a process

Let’s dig into open files and sockers used by docker.io:
root@dell-virtual-machine:/home/dell# lsof -p 10531
lsof: WARNING: can’t stat() fuse.gvfsd-fuse file system /run/user/1000/gvfs
Output information may be incomplete.
COMMAND     PID USER   FD   TYPE             DEVICE SIZE/OFF    NODE NAME
docker.io 10531 root  cwd    DIR                8,1     4096       2 /
docker.io 10531 root  rtd    DIR                8,1     4096       2 /
docker.io 10531 root  txt    REG                8,1 15240483  282457 /usr/bin/docker
docker.io 10531 root  mem    REG                8,1    31792 1839620 /lib/x86_64-linux-gnu/librt-2.19.so
docker.io 10531 root  mem    REG                8,1   281552 1839506 /lib/x86_64-linux-gnu/libdbus-1.so.3.7.6
docker.io 10531 root  mem    REG                8,1    38920 1839554 /lib/x86_64-linux-gnu/libnih-dbus.so.1.0.0
docker.io 10531 root  mem    REG                8,1    96280 1839556 /lib/x86_64-linux-gnu/libnih.so.1.0.0
docker.io 10531 root  mem    REG                8,1   108480 1839497 /lib/x86_64-linux-gnu/libcgmanager.so.0.0.0
docker.io 10531 root  mem    REG                8,1   252032 1839595 /lib/x86_64-linux-gnu/libpcre.so.3.13.1
docker.io 10531 root  mem    REG                8,1    14664 1839509 /lib/x86_64-linux-gnu/libdl-2.19.so
docker.io 10531 root  mem    REG                8,1    67600 1839640 /lib/x86_64-linux-gnu/libudev.so.1.3.5
docker.io 10531 root  mem    REG                8,1   134296 1839622 /lib/x86_64-linux-gnu/libselinux.so.1
docker.io 10531 root  mem    REG                8,1  1840928 1839492 /lib/x86_64-linux-gnu/libc-2.19.so
docker.io 10531 root  mem    REG                8,1   754880  272238 /usr/lib/x86_64-linux-gnu/libsqlite3.so.0.8.6
docker.io 10531 root  mem    REG                8,1   228992 1839508 /lib/x86_64-linux-gnu/libdevmapper.so.1.02.1
docker.io 10531 root  mem    REG                8,1   141574 1839612 /lib/x86_64-linux-gnu/libpthread-2.19.so
docker.io 10531 root  mem    REG                8,1    47984  271408 /usr/lib/x86_64-linux-gnu/libapparmor.so.1.1.0
docker.io 10531 root  mem    REG                8,1   149120 1839468 /lib/x86_64-linux-gnu/ld-2.19.so
docker.io 10531 root    0u   CHR                1,3      0t0    6678 /dev/null
docker.io 10531 root    1u   CHR              136,4      0t0       7 /dev/pts/4
docker.io 10531 root    2u   CHR              136,4      0t0       7 /dev/pts/4
docker.io 10531 root    3r   CHR                1,9      0t0    6683 /dev/urandom
docker.io 10531 root    4u  unix 0xffff88000f4a4000      0t0  322086 /var/run/docker.sock
docker.io 10531 root    5u   REG                8,1    15360  534918 /var/lib/docker/linkgraph.db
docker.io 10531 root    6u  0000               0,10        0    6631 anon_inode
docker.io 10531 root    7u   REG                8,1    15360  534918 /var/lib/docker/linkgraph.db
docker.io 10531 root   10u  IPv6             330046      0t0     TCP *:5000 (LISTEN)
docker.io 10531 root   11u   REG                8,1     3678 1721437 /var/lib/docker/containers/eb3732c180e354745feadc2252ff5bf6c5168ba395c24d1677b10377061d1e4d/eb3732c180e354745feadc2252ff5bf6c5168ba395c24d1677b10377061d1e4d-json.log
docker.io 10531 root   12u   REG                8,1     3678 1721437 /var/lib/docker/containers/eb3732c180e354745feadc2252ff5bf6c5168ba395c24d1677b10377061d1e4d/eb3732c180e354745feadc2252ff5bf6c5168ba395c24d1677b10377061d1e4d-json.log
docker.io 10531 root   13u  IPv6             330372      0t0     TCP *:http (LISTEN)
docker.io 10531 root   14u   REG                8,1     1068 1721443 /var/lib/docker/containers/9ec2db16d06d166771be698f6ee62c10cb5350fba423b6fd0182641223133edc/9ec2db16d06d166771be698f6ee62c10cb5350fba423b6fd0182641223133edc-json.log
docker.io 10531 root   15u   REG                8,1     1068 1721443 /var/lib/docker/containers/9ec2db16d06d166771be698f6ee62c10cb5350fba423b6fd0182641223133edc/9ec2db16d06d166771be698f6ee62c10cb5350fba423b6fd0182641223133edc-json.log
docker.io 10531 root   16r  FIFO                0,9      0t0  330049 pipe
docker.io 10531 root   17u  IPv6             330755      0t0     TCP *:http-alt (LISTEN)
docker.io 10531 root   18r  FIFO                0,9      0t0  330050 pipe
docker.io 10531 root   19u   REG                8,1     1068 1721449 /var/lib/docker/containers/67c8d8388e81aab843117ab2f2ceddb723dad460cf7d80de41d514292b70ab2c/67c8d8388e81aab843117ab2f2ceddb723dad460cf7d80de41d514292b70ab2c-json.log
docker.io 10531 root   20u   REG                8,1     1068 1721449 /var/lib/docker/containers/67c8d8388e81aab843117ab2f2ceddb723dad460cf7d80de41d514292b70ab2c/67c8d8388e81aab843117ab2f2ceddb723dad460cf7d80de41d514292b70ab2c-json.log
docker.io 10531 root   21r  FIFO                0,9      0t0  330375 pipe
docker.io 10531 root   23r  FIFO                0,9      0t0  330376 pipe
docker.io 10531 root   24u   REG                8,1   301692 1721467 /var/lib/docker/containers/db385f3de590e7a4841c2009522e390a04f4ff09748a6bfa72c1d575483e6683/db385f3de590e7a4841c2009522e390a04f4ff09748a6bfa72c1d575483e6683-json.log
docker.io 10531 root   25u   REG                8,1   301692 1721467 /var/lib/docker/containers/db385f3de590e7a4841c2009522e390a04f4ff09748a6bfa72c1d575483e6683/db385f3de590e7a4841c2009522e390a04f4ff09748a6bfa72c1d575483e6683-json.log
docker.io 10531 root   26r  FIFO                0,9      0t0  330758 pipe
docker.io 10531 root   27u   REG                8,1      397 1721461 /var/lib/docker/containers/c838cb61247de7553c87d57d9583f259ee836371a4951e7d8cdbee5d5acf349b/c838cb61247de7553c87d57d9583f259ee836371a4951e7d8cdbee5d5acf349b-json.log
docker.io 10531 root   28r  FIFO                0,9      0t0  330759 pipe
docker.io 10531 root   29u   REG                8,1      397 1721461 /var/lib/docker/containers/c838cb61247de7553c87d57d9583f259ee836371a4951e7d8cdbee5d5acf349b/c838cb61247de7553c87d57d9583f259ee836371a4951e7d8cdbee5d5acf349b-json.log
docker.io 10531 root   30u   REG                8,1      767 1721473 /var/lib/docker/containers/de989d3c05594f3938e8c0d13251468f11f8b16dfb87d1376a39334645cf3fce/de989d3c05594f3938e8c0d13251468f11f8b16dfb87d1376a39334645cf3fce-json.log
docker.io 10531 root   31u   REG                8,1      767 1721473 /var/lib/docker/containers/de989d3c05594f3938e8c0d13251468f11f8b16dfb87d1376a39334645cf3fce/de989d3c05594f3938e8c0d13251468f11f8b16dfb87d1376a39334645cf3fce-json.log
docker.io 10531 root   32u   CHR                5,2      0t0    7730 /dev/ptmx
docker.io 10531 root   33u   CHR                5,2      0t0    7730 /dev/ptmx
docker.io 10531 root   36u   CHR                5,2      0t0    7730 /dev/ptmx

Inspecting the Docker Containers:

Let’s pick up Docker bash(1057) and try to inspect it. Say, I have two terminal open – one where I am going to run Docker  related command and one to inspect through strace utility:

Terminal:1

root@dell-virtual-machine:/home/dell# strace -p 1057
Process 1057 attached
read(0,

Keep this terminal open. Now open the new terminal and try the following command:

Terminal:2

docker attach de989
bash-4.1#

Terminal:1

You will see the series of messages being displayed:

root@dell-virtual-machine:/home/dell# strace -p 1057
Process 1057 attached
read(0, 0x7fffb03cb85f, 1)              = ? ERESTARTSYS (To be restarted if SA_RESTART is set)
— SIGWINCH {si_signo=SIGWINCH, si_code=SI_KERNEL} —
ioctl(0, TIOCGWINSZ, {ws_row=20, ws_col=88, ws_xpixel=0, ws_ypixel=0}) = 0
rt_sigprocmask(SIG_BLOCK, [INT], [WINCH], 8) = 0
write(2, “\r\33[Kbash-4.1# “, 14)       = 14
rt_sigprocmask(SIG_SETMASK, [WINCH], NULL, 8) = 0
rt_sigreturn()                          = 0
read(0,

octl(0, TIOCGWINSZ, {ws_row=20, ws_col=88, ws_xpixel=0, ws_ypixel=0}) = 0
ioctl(0, SNDRV_TIMER_IOCTL_STATUS or TIOCSWINSZ, {ws_row=20, ws_col=88, ws_xpixel=0, ws_ypixel=0}) = 0
ioctl(0, SNDCTL_TMR_TIMEBASE or SNDRV_TIMER_IOCTL_NEXT_DEVICE or TCGETS, {B38400 opost isig icanon echo …}) = 0
ioctl(0, SNDCTL_TMR_STOP or SNDRV_TIMER_IOCTL_GINFO or TCSETSW, {B38400 opost isig -icanon -echo …}) = 0
rt_sigprocmask(SIG_SETMASK, [], NULL, 8) = 0
rt_sigprocmask(SIG_BLOCK, [INT QUIT ALRM TERM TSTP TTIN TTOU], [], 8) = 0
rt_sigaction(SIGINT, {0x4954d0, [], SA_RESTORER, 0x7efc839289a0}, {0x452590, [], SA_RESTORER, 0x7efc839289a0}, 8) = 0
rt_sigaction(SIGTERM, {0x4954d0, [], SA_RESTORER, 0x7efc839289a0}, {SIG_IGN, [], SA_RESTORER, 0x7efc839289a0}, 8) = 0
rt_sigaction(SIGTERM, {SIG_IGN, [], SA_RESTORER, 0x7efc839289a0}, {0x4954d0, [], SA_RESTORER, 0x7efc839289a0}, 8) = 0
rt_sigaction(SIGQUIT, {0x4954d0, [], SA_RESTORER, 0x7efc839289a0}, {SIG_IGN, [], SA_RESTORER, 0x7efc839289a0}, 8) = 0
rt_sigaction(SIGQUIT, {SIG_IGN, [], SA_RESTORER, 0x7efc839289a0}, {0x4954d0, [], SA_RESTORER, 0x7efc839289a0}, 8) = 0
rt_sigaction(SIGALRM, {0x4954d0, [], SA_RESTORER, 0x7efc839289a0}, {0x452300, [HUP INT ILL TRAP ABRT BUS FPE USR1 SEGV USR2 PIPE ALRM TERM XCPU XFSZ VTALRM SYS], SA_RESTORER, 0x7efc839289a0}, 8) = 0
rt_sigaction(SIGTSTP, {0x4954d0, [], SA_RESTORER, 0x7efc839289a0}, {SIG_IGN, [], SA_RESTORER, 0x7efc839289a0}, 8) = 0
rt_sigaction(SIGTSTP, {SIG_IGN, [], SA_RESTORER, 0x7efc839289a0}, {0x4954d0, [], SA_RESTORER, 0x7efc839289a0}, 8) = 0
rt_sigaction(SIGTTOU, {0x4954d0, [], SA_RESTORER, 0x7efc839289a0}, {SIG_IGN, [], SA_RESTORER, 0x7efc839289a0}, 8) = 0
rt_sigaction(SIGTTOU, {SIG_IGN, [], SA_RESTORER, 0x7efc839289a0}, {0x4954d0, [], SA_RESTORER, 0x7efc839289a0}, 8) = 0
rt_sigaction(SIGTTIN, {0x4954d0, [], SA_RESTORER, 0x7efc839289a0}, {SIG_IGN, [], SA_RESTORER, 0x7efc839289a0}, 8) = 0
rt_sigaction(SIGTTIN, {SIG_IGN, [], SA_RESTORER, 0x7efc839289a0}, {0x4954d0, [], SA_RESTORER, 0x7efc839289a0}, 8) = 0
rt_sigprocmask(SIG_SETMASK, [], NULL, 8) = 0
rt_sigaction(SIGWINCH, {0x4953d0, [], SA_RESTORER|SA_RESTART, 0x7efc839289a0}, {0x452120, [], SA_RESTORER, 0x7efc839289a0}, 8) = 0
rt_sigprocmask(SIG_BLOCK, [INT], [], 8) = 0
write(2, “bash-4.1# “, 10)              = 10
rt_sigprocmask(SIG_SETMASK, [], NULL, 8) = 0
rt_sigprocmask(SIG_BLOCK, NULL, [], 8)  = 0

2 thoughts on “The Anatomy of Docker Containers

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