From 64d8b4eebb01c6647b0588475c785cdd075389d3 Mon Sep 17 00:00:00 2001 From: Giuseppe Scrivano Date: Fri, 24 Apr 2020 14:54:43 +0200 Subject: podman: implement userns=keep-id add missing implementation for userns=keep-id and enable the user namespaces tests. Signed-off-by: Giuseppe Scrivano --- pkg/specgen/generate/namespaces.go | 20 ++++++++ pkg/specgen/namespaces.go | 14 ++++- pkg/util/utils.go | 101 ++++++++++++++++++++----------------- 3 files changed, 86 insertions(+), 49 deletions(-) (limited to 'pkg') diff --git a/pkg/specgen/generate/namespaces.go b/pkg/specgen/generate/namespaces.go index 2aaeb9513..1fdc921ce 100644 --- a/pkg/specgen/generate/namespaces.go +++ b/pkg/specgen/generate/namespaces.go @@ -10,6 +10,7 @@ import ( "github.com/containers/libpod/pkg/cgroups" "github.com/containers/libpod/pkg/rootless" "github.com/containers/libpod/pkg/specgen" + "github.com/containers/libpod/pkg/util" spec "github.com/opencontainers/runtime-spec/specs-go" "github.com/opencontainers/runtime-tools/generate" "github.com/pkg/errors" @@ -175,6 +176,13 @@ func GenerateNamespaceOptions(s *specgen.SpecGenerator, rt *libpod.Runtime, pod // User switch s.UserNS.NSMode { + case specgen.KeepID: + if rootless.IsRootless() { + s.User = "" + } else { + // keep-id as root doesn't need a user namespace + s.UserNS.NSMode = specgen.Host + } case specgen.FromPod: if pod == nil || infraCtr == nil { return nil, errNoInfra @@ -378,6 +386,18 @@ func specConfigureNamespaces(s *specgen.SpecGenerator, g *generate.Generator, rt if err := g.RemoveLinuxNamespace(string(spec.UserNamespace)); err != nil { return err } + case specgen.KeepID: + var ( + err error + uid, gid int + ) + s.IDMappings, uid, gid, err = util.GetKeepIDMapping() + if err != nil { + return err + } + g.SetProcessUID(uint32(uid)) + g.SetProcessGID(uint32(gid)) + fallthrough case specgen.Private: if err := g.AddOrReplaceLinuxNamespace(string(spec.UserNamespace), ""); err != nil { return err diff --git a/pkg/specgen/namespaces.go b/pkg/specgen/namespaces.go index fffbd6d9e..cee49ff51 100644 --- a/pkg/specgen/namespaces.go +++ b/pkg/specgen/namespaces.go @@ -76,6 +76,17 @@ func (n *Namespace) IsPod() bool { func (n *Namespace) IsPrivate() bool { return n.NSMode == Private } + +// IsAuto indicates the namespace is auto +func (n *Namespace) IsAuto() bool { + return n.NSMode == Auto +} + +// IsKeepID indicates the namespace is KeepID +func (n *Namespace) IsKeepID() bool { + return n.NSMode == KeepID +} + func validateUserNS(n *Namespace) error { if n == nil { return nil @@ -186,12 +197,11 @@ func ParseUserNamespace(ns string) (Namespace, error) { if len(split) != 2 { return toReturn, errors.Errorf("invalid setting for auto: mode") } - toReturn.NSMode = KeepID + toReturn.NSMode = Auto toReturn.Value = split[1] return toReturn, nil case ns == "keep-id": toReturn.NSMode = KeepID - toReturn.NSMode = FromContainer return toReturn, nil } return ParseNamespace(ns) diff --git a/pkg/util/utils.go b/pkg/util/utils.go index 64331cf66..917f57742 100644 --- a/pkg/util/utils.go +++ b/pkg/util/utils.go @@ -330,6 +330,58 @@ func ParseSignal(rawSignal string) (syscall.Signal, error) { return sig, nil } +// GetKeepIDMapping returns the mappings and the user to use when keep-id is used +func GetKeepIDMapping() (*storage.IDMappingOptions, int, int, error) { + options := storage.IDMappingOptions{ + HostUIDMapping: true, + HostGIDMapping: true, + } + uid, gid := 0, 0 + if rootless.IsRootless() { + min := func(a, b int) int { + if a < b { + return a + } + return b + } + + uid = rootless.GetRootlessUID() + gid = rootless.GetRootlessGID() + + uids, gids, err := rootless.GetConfiguredMappings() + if err != nil { + return nil, -1, -1, errors.Wrapf(err, "cannot read mappings") + } + maxUID, maxGID := 0, 0 + for _, u := range uids { + maxUID += u.Size + } + for _, g := range gids { + maxGID += g.Size + } + + options.UIDMap, options.GIDMap = nil, nil + + options.UIDMap = append(options.UIDMap, idtools.IDMap{ContainerID: 0, HostID: 1, Size: min(uid, maxUID)}) + options.UIDMap = append(options.UIDMap, idtools.IDMap{ContainerID: uid, HostID: 0, Size: 1}) + if maxUID > uid { + options.UIDMap = append(options.UIDMap, idtools.IDMap{ContainerID: uid + 1, HostID: uid + 1, Size: maxUID - uid}) + } + + options.GIDMap = append(options.GIDMap, idtools.IDMap{ContainerID: 0, HostID: 1, Size: min(gid, maxGID)}) + options.GIDMap = append(options.GIDMap, idtools.IDMap{ContainerID: gid, HostID: 0, Size: 1}) + if maxGID > gid { + options.GIDMap = append(options.GIDMap, idtools.IDMap{ContainerID: gid + 1, HostID: gid + 1, Size: maxGID - gid}) + } + + options.HostUIDMapping = false + options.HostGIDMapping = false + + } + // Simply ignore the setting and do not setup an inner namespace for root as it is a no-op + return &options, uid, gid, nil +} + // ParseIDMapping takes idmappings and subuid and subgid maps and returns a storage mapping func ParseIDMapping(mode namespaces.UsernsMode, uidMapSlice, gidMapSlice []string, subUIDMap, subGIDMap string) (*storage.IDMappingOptions, error) { options := storage.IDMappingOptions{ @@ -350,53 +402,8 @@ func ParseIDMapping(mode namespaces.UsernsMode, uidMapSlice, gidMapSlice []strin return &options, nil } if mode.IsKeepID() { - if len(uidMapSlice) > 0 || len(gidMapSlice) > 0 { - return nil, errors.New("cannot specify custom mappings with --userns=keep-id") - } - if len(subUIDMap) > 0 || len(subGIDMap) > 0 { - return nil, errors.New("cannot specify subuidmap or subgidmap with --userns=keep-id") - } - if rootless.IsRootless() { - min := func(a, b int) int { - if a < b { - return a - } - return b - } - - uid := rootless.GetRootlessUID() - gid := rootless.GetRootlessGID() - - uids, gids, err := rootless.GetConfiguredMappings() - if err != nil { - return nil, errors.Wrapf(err, "cannot read mappings") - } - maxUID, maxGID := 0, 0 - for _, u := range uids { - maxUID += u.Size - } - for _, g := range gids { - maxGID += g.Size - } - - options.UIDMap, options.GIDMap = nil, nil - - options.UIDMap = append(options.UIDMap, idtools.IDMap{ContainerID: 0, HostID: 1, Size: min(uid, maxUID)}) - options.UIDMap = append(options.UIDMap, idtools.IDMap{ContainerID: uid, HostID: 0, Size: 1}) - if maxUID > uid { - options.UIDMap = append(options.UIDMap, idtools.IDMap{ContainerID: uid + 1, HostID: uid + 1, Size: maxUID - uid}) - } - - options.GIDMap = append(options.GIDMap, idtools.IDMap{ContainerID: 0, HostID: 1, Size: min(gid, maxGID)}) - options.GIDMap = append(options.GIDMap, idtools.IDMap{ContainerID: gid, HostID: 0, Size: 1}) - if maxGID > gid { - options.GIDMap = append(options.GIDMap, idtools.IDMap{ContainerID: gid + 1, HostID: gid + 1, Size: maxGID - gid}) - } - - options.HostUIDMapping = false - options.HostGIDMapping = false - } - // Simply ignore the setting and do not setup an inner namespace for root as it is a no-op + options.HostUIDMapping = false + options.HostGIDMapping = false return &options, nil } -- cgit v1.2.3-54-g00ecf From 88f1994ab9a0bf3a8df3c8f74a39cd1db27c2070 Mon Sep 17 00:00:00 2001 From: Giuseppe Scrivano Date: Fri, 24 Apr 2020 15:37:31 +0200 Subject: podman: assume user namespace if there are mappings if some mappings are specified, assume there is a private user namespace. Signed-off-by: Giuseppe Scrivano --- cmd/podman/common/specgen.go | 7 ++++++- pkg/namespaces/namespaces.go | 7 ++++++- test/e2e/run_userns_test.go | 1 - 3 files changed, 12 insertions(+), 3 deletions(-) (limited to 'pkg') diff --git a/cmd/podman/common/specgen.go b/cmd/podman/common/specgen.go index ce91e0b2e..ed45a6595 100644 --- a/cmd/podman/common/specgen.go +++ b/cmd/podman/common/specgen.go @@ -209,10 +209,15 @@ func FillOutSpecGen(s *specgen.SpecGenerator, c *ContainerCLIOpts, args []string } } - s.IDMappings, err = util.ParseIDMapping(ns.UsernsMode(c.UserNS), c.UIDMap, c.GIDMap, c.SubUIDName, c.SubGIDName) + userNS := ns.UsernsMode(c.UserNS) + s.IDMappings, err = util.ParseIDMapping(userNS, c.UIDMap, c.GIDMap, c.SubUIDName, c.SubGIDName) if err != nil { return err } + // If some mappings are specified, assume a private user namespace + if userNS.IsDefaultValue() && (!s.IDMappings.HostUIDMapping || !s.IDMappings.HostGIDMapping) { + s.UserNS.NSMode = specgen.Private + } s.Terminal = c.TTY ep, err := ExposedPorts(c.Expose, c.Net.PublishPorts, c.PublishAll, nil) diff --git a/pkg/namespaces/namespaces.go b/pkg/namespaces/namespaces.go index 2cb3c3f20..2ffbde977 100644 --- a/pkg/namespaces/namespaces.go +++ b/pkg/namespaces/namespaces.go @@ -31,7 +31,7 @@ func (n CgroupMode) IsHost() bool { // IsDefaultValue indicates whether the cgroup namespace has the default value. func (n CgroupMode) IsDefaultValue() bool { - return n == "" + return n == "" || n == defaultType } // IsNS indicates a cgroup namespace passed in by path (ns:) @@ -102,6 +102,11 @@ func (n UsernsMode) IsAuto() bool { return parts[0] == "auto" } +// IsDefaultValue indicates whether the user namespace has the default value. +func (n UsernsMode) IsDefaultValue() bool { + return n == "" || n == defaultType +} + // GetAutoOptions returns a AutoUserNsOptions with the settings to setup automatically // a user namespace. func (n UsernsMode) GetAutoOptions() (*storage.AutoUserNsOptions, error) { diff --git a/test/e2e/run_userns_test.go b/test/e2e/run_userns_test.go index d4b4f9024..25f12ec2e 100644 --- a/test/e2e/run_userns_test.go +++ b/test/e2e/run_userns_test.go @@ -218,7 +218,6 @@ var _ = Describe("Podman UserNS support", func() { }) It("podman --userns=container:CTR", func() { - Skip(v2fail) ctrName := "userns-ctr" session := podmanTest.Podman([]string{"run", "-d", "--uidmap=0:0:1", "--uidmap=1:1:4998", "--name", ctrName, "alpine", "top"}) session.WaitWithDefaultTimeout() -- cgit v1.2.3-54-g00ecf