diff options
Diffstat (limited to 'vendor/github.com/projectatomic/buildah/unshare/unshare.go')
| -rw-r--r-- | vendor/github.com/projectatomic/buildah/unshare/unshare.go | 273 |
1 files changed, 0 insertions, 273 deletions
diff --git a/vendor/github.com/projectatomic/buildah/unshare/unshare.go b/vendor/github.com/projectatomic/buildah/unshare/unshare.go deleted file mode 100644 index 4eea74956..000000000 --- a/vendor/github.com/projectatomic/buildah/unshare/unshare.go +++ /dev/null @@ -1,273 +0,0 @@ -// +build linux - -package unshare - -import ( - "bytes" - "fmt" - "io" - "os" - "os/exec" - "runtime" - "strconv" - "strings" - "syscall" - - "github.com/containers/storage/pkg/reexec" - "github.com/opencontainers/runtime-spec/specs-go" - "github.com/pkg/errors" - "github.com/projectatomic/buildah/util" -) - -// Cmd wraps an exec.Cmd created by the reexec package in unshare(), and -// handles setting ID maps and other related settings by triggering -// initialization code in the child. -type Cmd struct { - *exec.Cmd - UnshareFlags int - UseNewuidmap bool - UidMappings []specs.LinuxIDMapping - UseNewgidmap bool - GidMappings []specs.LinuxIDMapping - GidMappingsEnableSetgroups bool - Setsid bool - Setpgrp bool - Ctty *os.File - OOMScoreAdj *int - Hook func(pid int) error -} - -// Command creates a new Cmd which can be customized. -func Command(args ...string) *Cmd { - cmd := reexec.Command(args...) - return &Cmd{ - Cmd: cmd, - } -} - -func (c *Cmd) Start() error { - runtime.LockOSThread() - defer runtime.UnlockOSThread() - - // Set an environment variable to tell the child to synchronize its startup. - if c.Env == nil { - c.Env = os.Environ() - } - c.Env = append(c.Env, fmt.Sprintf("_Buildah-unshare=%d", c.UnshareFlags)) - - // Create the pipe for reading the child's PID. - pidRead, pidWrite, err := os.Pipe() - if err != nil { - return errors.Wrapf(err, "error creating pid pipe") - } - c.Env = append(c.Env, fmt.Sprintf("_Buildah-pid-pipe=%d", len(c.ExtraFiles)+3)) - c.ExtraFiles = append(c.ExtraFiles, pidWrite) - - // Create the pipe for letting the child know to proceed. - continueRead, continueWrite, err := os.Pipe() - if err != nil { - pidRead.Close() - pidWrite.Close() - return errors.Wrapf(err, "error creating pid pipe") - } - c.Env = append(c.Env, fmt.Sprintf("_Buildah-continue-pipe=%d", len(c.ExtraFiles)+3)) - c.ExtraFiles = append(c.ExtraFiles, continueRead) - - // Pass along other instructions. - if c.Setsid { - c.Env = append(c.Env, "_Buildah-setsid=1") - } - if c.Setpgrp { - c.Env = append(c.Env, "_Buildah-setpgrp=1") - } - if c.Ctty != nil { - c.Env = append(c.Env, fmt.Sprintf("_Buildah-ctty=%d", len(c.ExtraFiles)+3)) - c.ExtraFiles = append(c.ExtraFiles, c.Ctty) - } - if c.GidMappingsEnableSetgroups { - c.Env = append(c.Env, "_Buildah-allow-setgroups=1") - } else { - c.Env = append(c.Env, "_Buildah-allow-setgroups=0") - } - - // Make sure we clean up our pipes. - defer func() { - if pidRead != nil { - pidRead.Close() - } - if pidWrite != nil { - pidWrite.Close() - } - if continueRead != nil { - continueRead.Close() - } - if continueWrite != nil { - continueWrite.Close() - } - }() - - // Start the new process. - err = c.Cmd.Start() - if err != nil { - return err - } - - // Close the ends of the pipes that the parent doesn't need. - continueRead.Close() - continueRead = nil - pidWrite.Close() - pidWrite = nil - - // Read the child's PID from the pipe. - pidString := "" - b := new(bytes.Buffer) - io.Copy(b, pidRead) - pidString = b.String() - pid, err := strconv.Atoi(pidString) - if err != nil { - fmt.Fprintf(continueWrite, "error parsing PID %q: %v", pidString, err) - return errors.Wrapf(err, "error parsing PID %q", pidString) - } - pidString = fmt.Sprintf("%d", pid) - - // If we created a new user namespace, set any specified mappings. - if c.UnshareFlags&syscall.CLONE_NEWUSER != 0 { - // Always set "setgroups". - setgroups, err := os.OpenFile(fmt.Sprintf("/proc/%s/setgroups", pidString), os.O_TRUNC|os.O_WRONLY, 0) - if err != nil { - fmt.Fprintf(continueWrite, "error opening setgroups: %v", err) - return errors.Wrapf(err, "error opening /proc/%s/setgroups", pidString) - } - defer setgroups.Close() - if c.GidMappingsEnableSetgroups { - if _, err := fmt.Fprintf(setgroups, "allow"); err != nil { - fmt.Fprintf(continueWrite, "error writing \"allow\" to setgroups: %v", err) - return errors.Wrapf(err, "error opening \"allow\" to /proc/%s/setgroups", pidString) - } - } else { - if _, err := fmt.Fprintf(setgroups, "deny"); err != nil { - fmt.Fprintf(continueWrite, "error writing \"deny\" to setgroups: %v", err) - return errors.Wrapf(err, "error writing \"deny\" to /proc/%s/setgroups", pidString) - } - } - - if len(c.UidMappings) == 0 || len(c.GidMappings) == 0 { - uidmap, gidmap, err := util.GetHostIDMappings("") - if err != nil { - fmt.Fprintf(continueWrite, "error reading ID mappings in parent: %v", err) - return errors.Wrapf(err, "error reading ID mappings in parent") - } - if len(c.UidMappings) == 0 { - c.UidMappings = uidmap - for i := range c.UidMappings { - c.UidMappings[i].HostID = c.UidMappings[i].ContainerID - } - } - if len(c.GidMappings) == 0 { - c.GidMappings = gidmap - for i := range c.GidMappings { - c.GidMappings[i].HostID = c.GidMappings[i].ContainerID - } - } - } - - if len(c.GidMappings) > 0 { - // Build the GID map, since writing to the proc file has to be done all at once. - g := new(bytes.Buffer) - for _, m := range c.GidMappings { - fmt.Fprintf(g, "%d %d %d\n", m.ContainerID, m.HostID, m.Size) - } - // Set the GID map. - if c.UseNewgidmap { - cmd := exec.Command("newgidmap", append([]string{pidString}, strings.Fields(strings.Replace(g.String(), "\n", " ", -1))...)...) - g.Reset() - cmd.Stdout = g - cmd.Stderr = g - err := cmd.Run() - if err != nil { - fmt.Fprintf(continueWrite, "error running newgidmap: %v: %s", err, g.String()) - return errors.Wrapf(err, "error running newgidmap: %s", g.String()) - } - } else { - gidmap, err := os.OpenFile(fmt.Sprintf("/proc/%s/gid_map", pidString), os.O_TRUNC|os.O_WRONLY, 0) - if err != nil { - fmt.Fprintf(continueWrite, "error opening /proc/%s/gid_map: %v", pidString, err) - return errors.Wrapf(err, "error opening /proc/%s/gid_map", pidString) - } - defer gidmap.Close() - if _, err := fmt.Fprintf(gidmap, "%s", g.String()); err != nil { - fmt.Fprintf(continueWrite, "error writing /proc/%s/gid_map: %v", pidString, err) - return errors.Wrapf(err, "error writing /proc/%s/gid_map", pidString) - } - } - } - - if len(c.UidMappings) > 0 { - // Build the UID map, since writing to the proc file has to be done all at once. - u := new(bytes.Buffer) - for _, m := range c.UidMappings { - fmt.Fprintf(u, "%d %d %d\n", m.ContainerID, m.HostID, m.Size) - } - // Set the GID map. - if c.UseNewuidmap { - cmd := exec.Command("newuidmap", append([]string{pidString}, strings.Fields(strings.Replace(u.String(), "\n", " ", -1))...)...) - u.Reset() - cmd.Stdout = u - cmd.Stderr = u - err := cmd.Run() - if err != nil { - fmt.Fprintf(continueWrite, "error running newuidmap: %v: %s", err, u.String()) - return errors.Wrapf(err, "error running newuidmap: %s", u.String()) - } - } else { - uidmap, err := os.OpenFile(fmt.Sprintf("/proc/%s/uid_map", pidString), os.O_TRUNC|os.O_WRONLY, 0) - if err != nil { - fmt.Fprintf(continueWrite, "error opening /proc/%s/uid_map: %v", pidString, err) - return errors.Wrapf(err, "error opening /proc/%s/uid_map", pidString) - } - defer uidmap.Close() - if _, err := fmt.Fprintf(uidmap, "%s", u.String()); err != nil { - fmt.Fprintf(continueWrite, "error writing /proc/%s/uid_map: %v", pidString, err) - return errors.Wrapf(err, "error writing /proc/%s/uid_map", pidString) - } - } - } - } - - if c.OOMScoreAdj != nil { - oomScoreAdj, err := os.OpenFile(fmt.Sprintf("/proc/%s/oom_score_adj", pidString), os.O_TRUNC|os.O_WRONLY, 0) - if err != nil { - fmt.Fprintf(continueWrite, "error opening oom_score_adj: %v", err) - return errors.Wrapf(err, "error opening /proc/%s/oom_score_adj", pidString) - } - defer oomScoreAdj.Close() - if _, err := fmt.Fprintf(oomScoreAdj, "%d\n", *c.OOMScoreAdj); err != nil { - fmt.Fprintf(continueWrite, "error writing \"%d\" to oom_score_adj: %v", c.OOMScoreAdj, err) - return errors.Wrapf(err, "error writing \"%d\" to /proc/%s/oom_score_adj", c.OOMScoreAdj, pidString) - } - } - // Run any additional setup that we want to do before the child starts running proper. - if c.Hook != nil { - if err = c.Hook(pid); err != nil { - fmt.Fprintf(continueWrite, "hook error: %v", err) - return err - } - } - - return nil -} - -func (c *Cmd) Run() error { - if err := c.Start(); err != nil { - return err - } - return c.Wait() -} - -func (c *Cmd) CombinedOutput() ([]byte, error) { - return nil, errors.New("unshare: CombinedOutput() not implemented") -} - -func (c *Cmd) Output() ([]byte, error) { - return nil, errors.New("unshare: Output() not implemented") -} |