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This removes some boilerplate from the libpod package, so we can focus on container stuff there. And it gives us a tidy sub-package for focusing on ctime extraction, so we can focus on unit testing and portability of the extraction utility there. For the unsupported implementation, I'm falling back to Go's ModTime [1]. That's obviously not the creation time, but it's likely to be closer than the uninitialized Time structure from cc6f0e85 (more changes to compile darwin, 2018-07-04, #1047). Especially for our use case in libpod/oci, where we're looking at write-once exit files. The test is more complicated than I initially expected, because on Linux filesystem timestamps come from a truncated clock without interpolation [2] (and network filesystems can be completely decoupled [3]). So even for local disks, creation times can be up to a jiffie earlier than 'before'. This test ensures at least monotonicity by creating two files and ensuring the reported creation time for the second is greater than or equal to the reported creation time for the first. It also checks that both creation times are within the window from one second earlier than 'before' through 'after'. That should be enough of a window for local disks, even if the kernel for those systems has an abnormally large jiffie. It might be ok on network filesystems, although it will not be very resilient to network clock lagging behind the local system clock. [1]: https://golang.org/pkg/os/#FileInfo [2]: https://groups.google.com/d/msg/linux.kernel/mdeXx2TBYZA/_4eJEuJoAQAJ Subject: Re: Apparent backward time travel in timestamps on file creation Date: Thu, 30 Mar 2017 20:20:02 +0200 Message-ID: <tqMPU-1Sb-21@gated-at.bofh.it> [3]: https://groups.google.com/d/msg/linux.kernel/mdeXx2TBYZA/cTKj4OBuAQAJ Subject: Re: Apparent backward time travel in timestamps on file creation Date: Thu, 30 Mar 2017 22:10:01 +0200 Message-ID: <tqOyl-36A-1@gated-at.bofh.it> Signed-off-by: W. Trevor King <wking@tremily.us> Closes: #1050 Approved by: mheon
libpod - library for running OCI-based containers in Pods
Status: Active Development
What is the scope of this project?
libpod provides a library for applications looking to use the Container Pod concept popularized by Kubernetes. libpod also contains a tool called podman for managing Pods, Containers, and Container Images.
At a high level, the scope of libpod and podman is the following:
- Support multiple image formats including the existing Docker/OCI image formats.
- Support for multiple means to download images including trust & image verification.
- Container image management (managing image layers, overlay filesystems, etc).
- Full management of container lifecycle
- Support for pods to manage groups of containers together
- Resource isolation of containers and pods.
What is not in scope for this project?
- Signing and pushing images to various image storages. See Skopeo.
- Container Runtimes daemons for working with Kubernetes CRIs. See CRI-O. We are working to integrate libpod into CRI-O to share containers and backend code with Podman.
OCI Projects Plans
The plan is to use OCI projects and best of breed libraries for different aspects:
- Runtime: runc (or any OCI compliant runtime) and oci runtime tools to generate the spec
- Images: Image management using containers/image
- Storage: Container and image storage is managed by containers/storage
- Networking: Networking support through use of CNI
- Builds: Builds are supported via Buildah.
- Conmon: Conmon is a tool for monitoring OCI runtimes. It is part of the CRI-O package
Podman Information for Developers
Installation notes Information on how to install Podman in your environment.
OCI Hooks Support Information on how Podman configures OCI Hooks to run when launching a container.
Podman API Documentation on the Podman API using Varlink.
Podman Commands A list of the Podman commands with links to their man pages and in many cases videos showing the commands in use.
Podman Troubleshooting Guide A list of common issues and solutions for Podman.
Podman Usage Transfer Useful information for ops and dev transfer as it relates to infrastructure that utilizes Podman. This page includes tables showing Docker commands and their Podman equivalent commands.
Tutorials Tutorials on using Podman.
Contributing Information about contributing to this project.
Current Roadmap
- Varlink API for Podman
- Integrate libpod into CRI-O to replace its existing container management backend
- Pod commands for Podman
- Rootless containers
- Support for cleaning up containers via post-run hooks