From 1e3e99f2fe95c8679f8962b8175038bd7d0558f2 Mon Sep 17 00:00:00 2001 From: Matthew Heon Date: Mon, 8 Jul 2019 18:37:40 -0400 Subject: Move the HostConfig portion of Inspect inside libpod When we first began writing Podman, we ran into a major issue when implementing Inspect. Libpod deliberately does not tie its internal data structures to Docker, and stores most information about containers encoded within the OCI spec. However, Podman must present a CLI compatible with Docker, which means it must expose all the information in 'docker inspect' - most of which is not contained in the OCI spec or libpod's Config struct. Our solution at the time was the create artifact. We JSON'd the complete CreateConfig (a parsed form of the CLI arguments to 'podman run') and stored it with the container, restoring it when we needed to run commands that required the extra info. Over the past month, I've been looking more at Inspect, and refactored large portions of it into Libpod - generating them from what we know about the OCI config and libpod's (now much expanded, versus previously) container configuration. This path comes close to completing the process, moving the last part of inspect into libpod and removing the need for the create artifact. This improves libpod's compatability with non-Podman containers. We no longer require an arbitrarily-formatted JSON blob to be present to run inspect. Fixes: #3500 Signed-off-by: Matthew Heon --- pkg/util/utils_linux.go | 43 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 43 insertions(+) (limited to 'pkg/util/utils_linux.go') diff --git a/pkg/util/utils_linux.go b/pkg/util/utils_linux.go index 47fa1031f..318bd2b1b 100644 --- a/pkg/util/utils_linux.go +++ b/pkg/util/utils_linux.go @@ -1,7 +1,14 @@ package util import ( + "fmt" + "os" + "path/filepath" + "syscall" + "github.com/containers/psgo" + "github.com/pkg/errors" + "github.com/sirupsen/logrus" ) // GetContainerPidInformationDescriptors returns a string slice of all supported @@ -9,3 +16,39 @@ import ( func GetContainerPidInformationDescriptors() ([]string, error) { return psgo.ListDescriptors(), nil } + +// FindDeviceNodes parses /dev/ into a set of major:minor -> path, where +// [major:minor] is the device's major and minor numbers formatted as, for +// example, 2:0 and path is the path to the device node. +// Symlinks to nodes are ignored. +func FindDeviceNodes() (map[string]string, error) { + nodes := make(map[string]string) + err := filepath.Walk("/dev", func(path string, info os.FileInfo, err error) error { + if err != nil { + logrus.Warnf("Error descending into path %s: %v", path, err) + return filepath.SkipDir + } + + // If we aren't a device node, do nothing. + if info.Mode()&(os.ModeDevice|os.ModeCharDevice) == 0 { + return nil + } + + // We are a device node. Get major/minor. + sysstat, ok := info.Sys().(*syscall.Stat_t) + if !ok { + return errors.Errorf("Could not convert stat output for use") + } + major := uint64(sysstat.Rdev / 256) + minor := uint64(sysstat.Rdev % 256) + + nodes[fmt.Sprintf("%d:%d", major, minor)] = path + + return nil + }) + if err != nil { + return nil, err + } + + return nodes, nil +} -- cgit v1.2.3-54-g00ecf