From e64e6500d3a3bdbb2d3c9faa5e2d9d845f120b17 Mon Sep 17 00:00:00 2001 From: Aditya Rajan Date: Tue, 28 Dec 2021 16:02:25 +0530 Subject: volume: add support for non-volatile upperdir,workdir for overlay volumes Often users want their overlayed volumes to be `non-volatile` in nature that means that same `upper` dir can be re-used by one or more containers but overall of nature of volumes still have to be `overlay` so work done is still on a overlay not on the actual volume. Following PR adds support for more advanced options i.e custom `workdir` and `upperdir` for overlayed volumes. So that users can re-use `workdir` and `upperdir` across new containers as well. Usage ```console $ podman run -it -v myvol:/data:O,upperdir=/path/persistant/upper,workdir=/path/persistant/work alpine sh ``` Signed-off-by: Aditya R --- libpod/container_internal_linux.go | 36 +++++++++++++++++++++++++++++++++++- 1 file changed, 35 insertions(+), 1 deletion(-) (limited to 'libpod') diff --git a/libpod/container_internal_linux.go b/libpod/container_internal_linux.go index 84293ccb2..5cc2a78fc 100644 --- a/libpod/container_internal_linux.go +++ b/libpod/container_internal_linux.go @@ -391,18 +391,52 @@ func (c *Container) generateSpec(ctx context.Context) (*spec.Spec, error) { } overlayFlag := false + upperDir := "" + workDir := "" for _, o := range namedVol.Options { if o == "O" { overlayFlag = true } + if overlayFlag && strings.Contains(o, "upperdir") { + splitOpt := strings.SplitN(o, "=", 2) + if len(splitOpt) > 1 { + upperDir = splitOpt[1] + if upperDir == "" { + return nil, errors.New("cannot accept empty value for upperdir") + } + } + } + if overlayFlag && strings.Contains(o, "workdir") { + splitOpt := strings.SplitN(o, "=", 2) + if len(splitOpt) > 1 { + workDir = splitOpt[1] + if workDir == "" { + return nil, errors.New("cannot accept empty value for workdir") + } + } + } } if overlayFlag { + var overlayMount spec.Mount + var overlayOpts *overlay.Options contentDir, err := overlay.TempDir(c.config.StaticDir, c.RootUID(), c.RootGID()) if err != nil { return nil, err } - overlayMount, err := overlay.Mount(contentDir, mountPoint, namedVol.Dest, c.RootUID(), c.RootGID(), c.runtime.store.GraphOptions()) + + if (upperDir != "" && workDir == "") || (upperDir == "" && workDir != "") { + return nil, errors.Wrapf(err, "must specify both upperdir and workdir") + } + + overlayOpts = &overlay.Options{RootUID: c.RootUID(), + RootGID: c.RootGID(), + UpperDirOptionFragment: upperDir, + WorkDirOptionFragment: workDir, + GraphOpts: c.runtime.store.GraphOptions(), + } + + overlayMount, err = overlay.MountWithOptions(contentDir, mountPoint, namedVol.Dest, overlayOpts) if err != nil { return nil, errors.Wrapf(err, "mounting overlay failed %q", mountPoint) } -- cgit v1.2.3-54-g00ecf