diff --git a/cmd/podman/common/specgen.go b/cmd/podman/common/specgen.go index 7716fc1505..2333f2f7e4 100644 --- a/cmd/podman/common/specgen.go +++ b/cmd/podman/common/specgen.go @@ -260,6 +260,8 @@ func FillOutSpecGen(s *specgen.SpecGenerator, c *ContainerCLIOpts, args []string // If some mappings are specified, assume a private user namespace if userNS.IsDefaultValue() && (!s.IDMappings.HostUIDMapping || !s.IDMappings.HostGIDMapping) { s.UserNS.NSMode = specgen.Private + } else { + s.UserNS.NSMode = specgen.NamespaceMode(userNS) } s.Terminal = c.TTY diff --git a/libpod/container.go b/libpod/container.go index 6a87ad3a9b..9ad938a5c1 100644 --- a/libpod/container.go +++ b/libpod/container.go @@ -277,6 +277,9 @@ type ContainerConfig struct { User string `json:"user,omitempty"` // Additional groups to add Groups []string `json:"groups,omitempty"` + // AddCurrentUserPasswdEntry indicates that the current user passwd entry + // should be added to the /etc/passwd within the container + AddCurrentUserPasswdEntry bool `json:"addCurrentUserPasswdEntry,omitempty"` // Namespace Config // IDs of container to share namespaces with @@ -774,7 +777,10 @@ func (c *Container) Hostname() string { // WorkingDir returns the containers working dir func (c *Container) WorkingDir() string { - return c.config.Spec.Process.Cwd + if c.config.Spec.Process != nil { + return c.config.Spec.Process.Cwd + } + return "/" } // State Accessors diff --git a/libpod/container_internal_linux.go b/libpod/container_internal_linux.go index cfcf9b8233..f86903fd1b 100644 --- a/libpod/container_internal_linux.go +++ b/libpod/container_internal_linux.go @@ -9,6 +9,7 @@ import ( "io/ioutil" "net" "os" + "os/user" "path" "path/filepath" "strconv" @@ -33,7 +34,7 @@ import ( "github.com/containers/libpod/v2/pkg/util" "github.com/containers/storage/pkg/archive" securejoin "github.com/cyphar/filepath-securejoin" - "github.com/opencontainers/runc/libcontainer/user" + User "github.com/opencontainers/runc/libcontainer/user" spec "github.com/opencontainers/runtime-spec/specs-go" "github.com/opencontainers/runtime-tools/generate" "github.com/opencontainers/selinux/go-selinux/label" @@ -1420,9 +1421,23 @@ func (c *Container) getHosts() string { return hosts } -// generatePasswd generates a container specific passwd file, -// iff g.config.User is a number -func (c *Container) generatePasswd() (string, error) { +// generateCurrentUserPasswdEntry generates an /etc/passwd entry for the user +// running the container engine +func (c *Container) generateCurrentUserPasswdEntry() (string, error) { + uid := rootless.GetRootlessUID() + if uid == 0 { + return "", nil + } + u, err := user.LookupId(strconv.Itoa(rootless.GetRootlessUID())) + if err != nil { + return "", errors.Wrapf(err, "failed to get current user") + } + return fmt.Sprintf("%s:x:%s:%s:%s:%s:/bin/sh\n", u.Username, u.Uid, u.Gid, u.Username, c.WorkingDir()), nil +} + +// generateUserPasswdEntry generates an /etc/passwd entry for the container user +// to run in the container. +func (c *Container) generateUserPasswdEntry() (string, error) { var ( groupspec string gid int @@ -1440,14 +1455,16 @@ func (c *Container) generatePasswd() (string, error) { if err != nil { return "", nil } + // Lookup the user to see if it exists in the container image _, err = lookup.GetUser(c.state.Mountpoint, userspec) - if err != nil && err != user.ErrNoPasswdEntries { + if err != nil && err != User.ErrNoPasswdEntries { return "", err } if err == nil { return "", nil } + if groupspec != "" { ugid, err := strconv.ParseUint(groupspec, 10, 32) if err == nil { @@ -1460,14 +1477,39 @@ func (c *Container) generatePasswd() (string, error) { gid = group.Gid } } + return fmt.Sprintf("%d:x:%d:%d:container user:%s:/bin/sh\n", uid, uid, gid, c.WorkingDir()), nil +} + +// generatePasswd generates a container specific passwd file, +// iff g.config.User is a number +func (c *Container) generatePasswd() (string, error) { + if !c.config.AddCurrentUserPasswdEntry && c.config.User == "" { + return "", nil + } + pwd := "" + if c.config.User != "" { + entry, err := c.generateUserPasswdEntry() + if err != nil { + return "", err + } + pwd += entry + } + if c.config.AddCurrentUserPasswdEntry { + entry, err := c.generateCurrentUserPasswdEntry() + if err != nil { + return "", err + } + pwd += entry + } + if pwd == "" { + return "", nil + } originPasswdFile := filepath.Join(c.state.Mountpoint, "/etc/passwd") orig, err := ioutil.ReadFile(originPasswdFile) if err != nil && !os.IsNotExist(err) { return "", errors.Wrapf(err, "unable to read passwd file %s", originPasswdFile) } - - pwd := fmt.Sprintf("%s%d:x:%d:%d:container user:%s:/bin/sh\n", orig, uid, uid, gid, c.WorkingDir()) - passwdFile, err := c.writeStringToRundir("passwd", pwd) + passwdFile, err := c.writeStringToRundir("passwd", string(orig)+pwd) if err != nil { return "", errors.Wrapf(err, "failed to create temporary passwd file") } diff --git a/libpod/container_internal_linux_test.go b/libpod/container_internal_linux_test.go new file mode 100644 index 0000000000..078cc53a73 --- /dev/null +++ b/libpod/container_internal_linux_test.go @@ -0,0 +1,42 @@ +// +build linux + +package libpod + +import ( + "io/ioutil" + "os" + "testing" + + spec "github.com/opencontainers/runtime-spec/specs-go" + "github.com/stretchr/testify/assert" +) + +func TestGenerateUserPasswdEntry(t *testing.T) { + dir, err := ioutil.TempDir("", "libpod_test_") + if err != nil { + t.Fatal(err) + } + defer os.RemoveAll(dir) + + c := Container{ + config: &ContainerConfig{ + User: "123:456", + Spec: &spec.Spec{}, + }, + state: &ContainerState{ + Mountpoint: "/does/not/exist/tmp/", + }, + } + user, err := c.generateUserPasswdEntry() + if err != nil { + t.Fatal(err) + } + assert.Equal(t, user, "123:x:123:456:container user:/:/bin/sh\n") + + c.config.User = "567" + user, err = c.generateUserPasswdEntry() + if err != nil { + t.Fatal(err) + } + assert.Equal(t, user, "567:x:567:0:container user:/:/bin/sh\n") +} diff --git a/libpod/options.go b/libpod/options.go index bff3f3c185..560b406e29 100644 --- a/libpod/options.go +++ b/libpod/options.go @@ -844,6 +844,20 @@ func WithPIDNSFrom(nsCtr *Container) CtrCreateOption { } } +// WithAddCurrentUserPasswdEntry indicates that container should add current +// user entry to /etc/passwd, since the UID will be mapped into the container, +// via user namespace +func WithAddCurrentUserPasswdEntry() CtrCreateOption { + return func(ctr *Container) error { + if ctr.valid { + return define.ErrCtrFinalized + } + + ctr.config.AddCurrentUserPasswdEntry = true + return nil + } +} + // WithUserNSFrom indicates the the container should join the user namespace of // the given container. // If the container has joined a pod, it can only join the namespaces of diff --git a/pkg/specgen/generate/namespaces.go b/pkg/specgen/generate/namespaces.go index 39a45398d1..22670ca615 100644 --- a/pkg/specgen/generate/namespaces.go +++ b/pkg/specgen/generate/namespaces.go @@ -153,7 +153,9 @@ func namespaceOptions(ctx context.Context, s *specgen.SpecGenerator, rt *libpod. // User switch s.UserNS.NSMode { case specgen.KeepID: - if !rootless.IsRootless() { + if rootless.IsRootless() { + toReturn = append(toReturn, libpod.WithAddCurrentUserPasswdEntry()) + } else { // keep-id as root doesn't need a user namespace s.UserNS.NSMode = specgen.Host } diff --git a/test/e2e/run_userns_test.go b/test/e2e/run_userns_test.go index c0d98f7b15..24d3e42eb2 100644 --- a/test/e2e/run_userns_test.go +++ b/test/e2e/run_userns_test.go @@ -89,6 +89,16 @@ var _ = Describe("Podman UserNS support", func() { Expect(ok).To(BeTrue()) }) + It("podman --userns=keep-id check passwd", func() { + session := podmanTest.Podman([]string{"run", "--userns=keep-id", "alpine", "id", "-un"}) + session.WaitWithDefaultTimeout() + Expect(session.ExitCode()).To(Equal(0)) + u, err := user.Current() + Expect(err).To(BeNil()) + ok, _ := session.GrepString(u.Name) + Expect(ok).To(BeTrue()) + }) + It("podman --userns=keep-id root owns /usr", func() { session := podmanTest.Podman([]string{"run", "--userns=keep-id", "alpine", "stat", "-c%u", "/usr"}) session.WaitWithDefaultTimeout()