Ovaj članak će govoriti o tome kako to funkcionira
O uobičajenim problemima s Dockerom i njihovim rješenjima već
Ključne karakteristike
- Rad sa odvojenim jezgrom, čime se obezbjeđuje mrežna, memorijska i I/O izolacija, moguće je nametnuti korištenje hardverske izolacije zasnovane na proširenjima virtuelizacije
- Podrška za industrijske standarde uključujući OCI (format kontejnera), Kubernetes CRI
- Dosljedne performanse regularnih Linux kontejnera, povećana izolacija bez troškova performansi regularnih VM-ova
- Eliminišite potrebu za pokretanjem kontejnera unutar punopravnih virtuelnih mašina, generički interfejsi pojednostavljuju integraciju i pokretanje
postavljanje
Postoje
važno: Rad Kata kontejnera je podržan samo na hardveru, virtuelizirano prosljeđivanje također ne radi uvijek potrebna je podrška za sse4.1 od procesora.
Instalacija Kata kontejnera je prilično jednostavna:
Instalirajte uslužne programe za rad sa spremištima:
# yum -y install yum-utils
Onemogućite Selinux (ispravnije je konfigurirati, ali radi jednostavnosti isključim ga):
# setenforce 0
# sed -i 's/^SELINUX=enforcing$/SELINUX=permissive/' /etc/selinux/config
Povezujemo spremište i izvodimo instalaciju
# source /etc/os-release
# ARCH=$(arch)
# BRANCH="${BRANCH:-stable-1.10}"
# yum-config-manager --add-repo "http://download.opensuse.org/repositories/home:/katacontainers:/releases:/${ARCH}:/${BRANCH}/CentOS_${VERSION_ID}/home:katacontainers:releases:${ARCH}:${BRANCH}.repo"
# yum -y install kata-runtime kata-proxy kata-shim
podešavanje
Postavit ću se za rad sa dockerom, njegova instalacija je tipična, neću to detaljnije opisivati:
# rpm -qa | grep docker
docker-ce-cli-19.03.6-3.el7.x86_64
docker-ce-19.03.6-3.el7.x86_64
# docker -v
Docker version 19.03.6, build 369ce74a3c
Unosimo promjene u daemon.json:
# cat <<EOF > /etc/docker/daemon.json
{
"default-runtime": "kata-runtime",
"runtimes": {
"kata-runtime": {
"path": "/usr/bin/kata-runtime"
}
}
}
EOF
Ponovo pokrenite docker:
# service docker restart
Funkcionalno testiranje
Ako pokrenete kontejner prije ponovnog pokretanja docker-a, možete vidjeti da će uname dati verziju kernela koja radi na glavnom sistemu:
# docker run busybox uname -a
Linux 19efd7188d06 3.10.0-1062.12.1.el7.x86_64 #1 SMP Tue Feb 4 23:02:59 UTC 2020 x86_64 GNU/Linux
Nakon ponovnog pokretanja, verzija kernela izgleda ovako:
# docker run busybox uname -a
Linux 9dd1f30fe9d4 4.19.86-5.container #1 SMP Sat Feb 22 01:53:14 UTC 2020 x86_64 GNU/Linux
Više timova!
# time docker run busybox mount
kataShared on / type 9p (rw,dirsync,nodev,relatime,mmap,access=client,trans=virtio)
proc on /proc type proc (rw,nosuid,nodev,noexec,relatime)
tmpfs on /dev type tmpfs (rw,nosuid,size=65536k,mode=755)
devpts on /dev/pts type devpts (rw,nosuid,noexec,relatime,gid=5,mode=620,ptmxmode=666)
sysfs on /sys type sysfs (ro,nosuid,nodev,noexec,relatime)
tmpfs on /sys/fs/cgroup type tmpfs (ro,nosuid,nodev,noexec,relatime,mode=755)
cgroup on /sys/fs/cgroup/systemd type cgroup (ro,nosuid,nodev,noexec,relatime,xattr,name=systemd)
cgroup on /sys/fs/cgroup/cpu,cpuacct type cgroup (ro,nosuid,nodev,noexec,relatime,cpu,cpuacct)
cgroup on /sys/fs/cgroup/blkio type cgroup (ro,nosuid,nodev,noexec,relatime,blkio)
cgroup on /sys/fs/cgroup/memory type cgroup (ro,nosuid,nodev,noexec,relatime,memory)
cgroup on /sys/fs/cgroup/devices type cgroup (ro,nosuid,nodev,noexec,relatime,devices)
cgroup on /sys/fs/cgroup/perf_event type cgroup (ro,nosuid,nodev,noexec,relatime,perf_event)
cgroup on /sys/fs/cgroup/net_cls,net_prio type cgroup (ro,nosuid,nodev,noexec,relatime,net_cls,net_prio)
cgroup on /sys/fs/cgroup/freezer type cgroup (ro,nosuid,nodev,noexec,relatime,freezer)
cgroup on /sys/fs/cgroup/pids type cgroup (ro,nosuid,nodev,noexec,relatime,pids)
cgroup on /sys/fs/cgroup/cpuset type cgroup (ro,nosuid,nodev,noexec,relatime,cpuset)
mqueue on /dev/mqueue type mqueue (rw,nosuid,nodev,noexec,relatime)
shm on /dev/shm type tmpfs (rw,nosuid,nodev,noexec,relatime,size=65536k)
kataShared on /etc/resolv.conf type 9p (rw,dirsync,nodev,relatime,mmap,access=client,trans=virtio)
kataShared on /etc/hostname type 9p (rw,dirsync,nodev,relatime,mmap,access=client,trans=virtio)
kataShared on /etc/hosts type 9p (rw,dirsync,nodev,relatime,mmap,access=client,trans=virtio)
proc on /proc/bus type proc (ro,relatime)
proc on /proc/fs type proc (ro,relatime)
proc on /proc/irq type proc (ro,relatime)
proc on /proc/sys type proc (ro,relatime)
tmpfs on /proc/acpi type tmpfs (ro,relatime)
tmpfs on /proc/timer_list type tmpfs (rw,nosuid,size=65536k,mode=755)
tmpfs on /sys/firmware type tmpfs (ro,relatime)
real 0m2.381s
user 0m0.066s
sys 0m0.039s
# time docker run busybox free -m
total used free shared buff/cache available
Mem: 1993 30 1962 0 1 1946
Swap: 0 0 0
real 0m3.297s
user 0m0.086s
sys 0m0.050s
Brzo testiranje opterećenja
Za procjenu gubitaka od virtuelizacije - pokrećem sysbench, kao glavni primjer
Pokretanje sysbench-a koristeći Docker+containerd
Test procesora
sysbench 1.0: multi-threaded system evaluation benchmark
Running the test with following options:
Number of threads: 1
Initializing random number generator from current time
Prime numbers limit: 20000
Initializing worker threads...
Threads started!
General statistics:
total time: 36.7335s
total number of events: 10000
total time taken by event execution: 36.7173s
response time:
min: 3.43ms
avg: 3.67ms
max: 8.34ms
approx. 95 percentile: 3.79ms
Threads fairness:
events (avg/stddev): 10000.0000/0.00
execution time (avg/stddev): 36.7173/0.00
RAM test
sysbench 1.0: multi-threaded system evaluation benchmark
Running the test with following options:
Number of threads: 1
Initializing random number generator from current time
Initializing worker threads...
Threads started!
Operations performed: 104857600 (2172673.64 ops/sec)
102400.00 MiB transferred (2121.75 MiB/sec)
General statistics:
total time: 48.2620s
total number of events: 104857600
total time taken by event execution: 17.4161s
response time:
min: 0.00ms
avg: 0.00ms
max: 0.17ms
approx. 95 percentile: 0.00ms
Threads fairness:
events (avg/stddev): 104857600.0000/0.00
execution time (avg/stddev): 17.4161/0.00
Pokretanje sysbench-a pomoću Docker+Kata kontejnera
Test procesora
sysbench 1.0: multi-threaded system evaluation benchmark
Running the test with following options:
Number of threads: 1
Initializing random number generator from current time
Prime numbers limit: 20000
Initializing worker threads...
Threads started!
General statistics:
total time: 36.5747s
total number of events: 10000
total time taken by event execution: 36.5594s
response time:
min: 3.43ms
avg: 3.66ms
max: 4.93ms
approx. 95 percentile: 3.77ms
Threads fairness:
events (avg/stddev): 10000.0000/0.00
execution time (avg/stddev): 36.5594/0.00
RAM test
sysbench 1.0: multi-threaded system evaluation benchmark
Running the test with following options:
Number of threads: 1
Initializing random number generator from current time
Initializing worker threads...
Threads started!
Operations performed: 104857600 (2450366.94 ops/sec)
102400.00 MiB transferred (2392.94 MiB/sec)
General statistics:
total time: 42.7926s
total number of events: 104857600
total time taken by event execution: 16.1512s
response time:
min: 0.00ms
avg: 0.00ms
max: 0.43ms
approx. 95 percentile: 0.00ms
Threads fairness:
events (avg/stddev): 104857600.0000/0.00
execution time (avg/stddev): 16.1512/0.00
U principu, situacija je već jasna, ali je optimalnije pokrenuti testove nekoliko puta, uklanjajući vanjske vrijednosti i usrednjavajući rezultate, tako da još ne radim više testova.
nalazi
Unatoč činjenici da je takvim kontejnerima potrebno oko pet do deset puta duže da se pokrenu (uobičajeno vrijeme za pokretanje sličnih naredbi kada se koristi containerd je manje od trećine sekunde), oni i dalje rade prilično brzo ako uzmemo apsolutno vrijeme početka ( gore su primjeri, komande se izvode u prosjeku za tri sekunde). Pa, rezultati brzog testiranja CPU-a i RAM-a pokazuju gotovo iste rezultate, što ne može a da ne raduje, posebno u svjetlu činjenice da je izolacija osigurana pomoću tako dobro pokrenutog mehanizma kao što je kvm.
Najava
Članak je pregled, ali vam daje priliku da osjetite alternativno vrijeme izvođenja. Mnoga područja primjene nisu pokrivena, na primjer, stranica opisuje mogućnost pokretanja Kubernetesa iznad Kata kontejnera. Osim toga, možete pokrenuti i niz testova usmjerenih na pronalaženje sigurnosnih problema, postavljanje ograničenja i druge zanimljive stvari.
Molim sve one koji su ovdje pročitali i premotali da se uključe u anketu o kojoj će ovisiti buduća izdanja na ovu temu.
Samo registrovani korisnici mogu učestvovati u anketi.
Da li da nastavim da objavljujem članke o Kata kontejnerima?
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80,0%Da, pišite više!28
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20,0%Ne, nemoj…7
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izvor: www.habr.com