Dan,
Thanks for coming back to me on this.
If I use an NFS store (with Read & Write) as Podman’s storage, do you anticipate any race conditions when multiple podman processes reading and writing at the same time? Do I need implement any locking mechanisms like what they do in relational
databases.
Yum and DNF should not be a bigger issue as we don’t build them every day and we use distroless for the Go microservices and Java s built on a custom base image with all deps already included.
Thanks again.
Puvi Ganeshar | @pg925u
Principal, Platform Engineer
CICD - Pipeline Express | Toronto
From:
Daniel Walsh <dwalsh@redhat.com>
Date: Wednesday, October 23, 2024 at 11:10 AM
To: podman@lists.podman.io <podman@lists.podman.io>
Subject: [Podman] Re: Speeding up podman by using cache
On 10/22/24 11:04, Ganeshar, Puvi wrote:
Hello Podman team,
I am about explore this option so just wanted to check with you all before as I might be wasting my time.
I am in Platform Engineering team at DirecTV, and we run Go and Java pipelines on Jenkins using Amazon EKS as the workers. So, the process is that when a Jenkins build runs, it asks the EKS for a worker (Kubernetes pod) and the cluster would spawn one and the new pod would communicate back to the Jenkins controller. We use the Jenkins Kubernetes pod template to configure the communication. We are currently running the latest LTS of podman, v5.2.2, however still using cgroups-v1 for now, planning to migrate early 2025 by upgrading the cluster to use Amazon Linux 2023 which uses cgroups-v2 as default. Here’s the podman configuration details that we use:
host:
arch: arm64
buildahVersion: 1.37.2
cgroupControllers:
- cpuset
- cpu
- cpuacct
- blkio
- memory
- devices
- freezer
- net_cls
- perf_event
- net_prio
- hugetlb
- pids
cgroupManager: cgroupfs
cgroupVersion: v1
conmon:
package: conmon-2.1.12-1.el9.aarch64
path: /usr/bin/conmon
version: 'conmon version 2.1.12, commit: f174c390e4760883511ab6b5c146dcb244aeb647'
cpuUtilization:
idlePercent: 99.22
systemPercent: 0.37
userPercent: 0.41
cpus: 16
databaseBackend: sqlite
distribution:
distribution: centos
version: "9"
eventLogger: file
freeLocks: 2048
hostname: podmanv5-arm
idMappings:
gidmap: null
uidmap: null
kernel: 5.10.225-213.878.amzn2.aarch64
linkmode: dynamic
logDriver: k8s-file
memFree: 8531066880
memTotal: 33023348736
networkBackend: netavark
networkBackendInfo:
backend: netavark
dns:
package: aardvark-dns-1.12.1-1.el9.aarch64
path: /usr/libexec/podman/aardvark-dns
version: aardvark-dns 1.12.1
package: netavark-1.12.2-1.el9.aarch64
path: /usr/libexec/podman/netavark
version: netavark 1.12.2
ociRuntime:
name: crun
package: crun-1.16.1-1.el9.aarch64
path: /usr/bin/crun
version: |-
crun version 1.16.1
commit: afa829ca0122bd5e1d67f1f38e6cc348027e3c32
rundir: /run/crun
spec: 1.0.0
+SYSTEMD +SELINUX +APPARMOR +CAP +SECCOMP +EBPF +CRIU +YAJL
os: linux
pasta:
executable: /usr/bin/pasta
package: passt-0^20240806.gee36266-2.el9.aarch64
version: |
pasta 0^20240806.gee36266-2.el9.aarch64-pasta
Copyright Red Hat
GNU General Public License, version 2 or later
https://www.gnu.org/licenses/old-licenses/gpl-2.0.html
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.
remoteSocket:
exists: false
path: /run/podman/podman.sock
rootlessNetworkCmd: pasta
security:
apparmorEnabled: false
capabilities: CAP_CHOWN,CAP_DAC_OVERRIDE,CAP_FOWNER,CAP_FSETID,CAP_KILL,CAP_NET_BIND_SERVICE,CAP_SETFCAP,CAP_SETGID,CAP_SETPCAP,CAP_SETUID,CAP_SYS_CHROOT
rootless: false
seccompEnabled: true
seccompProfilePath: /usr/share/containers/seccomp.json
selinuxEnabled: false
serviceIsRemote: false
slirp4netns:
executable: /usr/bin/slirp4netns
package: slirp4netns-1.3.1-1.el9.aarch64
version: |-
slirp4netns version 1.3.1
commit: e5e368c4f5db6ae75c2fce786e31eef9da6bf236
libslirp: 4.4.0
SLIRP_CONFIG_VERSION_MAX: 3
libseccomp: 2.5.2
swapFree: 0
swapTotal: 0
uptime: 144h 6m 15.00s (Approximately 6.00 days)
variant: v8
plugins:
authorization: null
log:
- k8s-file
- none
- passthrough
- journald
network:
- bridge
- macvlan
- ipvlan
volume:
- local
registries:
search:
- registry.access.redhat.com
- registry.redhat.io
- docker.io
store:
configFile: /etc/containers/storage.conf
containerStore:
number: 0
paused: 0
running: 0
stopped: 0
graphDriverName: overlay
graphOptions:
overlay.mountopt: nodev,metacopy=on
graphRoot: /var/lib/containers/storage
graphRootAllocated: 107352141824
graphRootUsed: 23986397184
graphStatus:
Backing Filesystem: xfs
Native Overlay Diff: "false"
Supports d_type: "true"
Supports shifting: "true"
Supports volatile: "true"
Using metacopy: "false"
imageCopyTmpDir: /var/tmp
imageStore:
number: 1
runRoot: /run/containers/storage
transientStore: false
volumePath: /var/lib/containers/storage/volumes
version:
APIVersion: 5.2.2
Built: 1724331496
BuiltTime: Thu Aug 22 12:58:16 2024
GitCommit: ""
GoVersion: go1.22.5 (Red Hat 1.22.5-2.el9)
Os: linux
OsArch: linux/arm64
Version: 5.2.2
We migrated to podman when Kubernetes deprecated docker and have been using podman for the last two years or so. Its working well, however since we run over 500 builds a day, I am trying to explore whether I can speed up the podman build process by using image caching. I wanted to see if I use an NFS file system (Amazon FSX) as the storage for podman (overlay-fs) would it improve podman performance by the builds completing much faster as of the already downloaded images on the NFS. Currently, podman in each pod on the EKS cluster would download all the required images every time so not taking advantage of the cached images.
These are my concerns:
- Any race conditions, a podman processes colliding with each other during read and write.
- Performance of I/O operations as NFS communication will be over the network.
Have any of you tried this method before? If so, can you share any pitfalls that you’ve faced?
Any comments / advice would be beneficial as I need to weigh up pros and cons before spending time on this. Also, if it causes outage due to storage failures it would block all our developers; so, I will have to design this in a way where we can recover quickly.
Thanks very much in advance and have a great day.
Puvi Ganeshar | @pg925u
Principal, Platform Engineer
CICD - Pipeline Express | Toronto
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You can setup an additional store which is preloaded with Images on an NFS share, which should work fine.
Whether this improves performance or not is probably something you need to discover.
If you are dealing with YUM and DNF, you might also want to play with sharing of the rpm database with the build system.