debugging

Signed-off-by: Jess Frazelle <jess@mesosphere.com>
This commit is contained in:
Jess Frazelle 2016-04-16 16:05:09 -07:00
parent 0ae930df26
commit b92f1bdae4
8 changed files with 51 additions and 14 deletions

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@ -49,7 +49,7 @@ image.tar:
docker export $(shell docker create $(DOCKER_ROOTFS_IMAGE) sh) > $@
rootfs.go: image.tar
go generate
GOMAXPROCS=1 go generate
fmt:
@echo "+ $@"
@ -76,6 +76,7 @@ clean: clean-rootfs
@$(RM) *.tar
@$(RM) rootfs.go
@$(RM) -r $(BINDIR)
-@docker rm $(shell docker ps -aq) /dev/null 2>&1
install:
@echo "+ $@"

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@ -8,13 +8,19 @@ This is based off a crazy idea from [@crosbymichael](https://github.com/crosbymi
**NOTE**
You may have noticed you can't file an issue. That's because this is using a crazy
person's (aka my) fork of libcontainer
and until I get the patches into upstream there's no
way in hell I'm fielding issues from whoever is crazy
enough to try this.
person's (aka my) fork of libcontainer and until I get the patches into upstream
there's no way in hell I'm fielding issues from whoever is crazy enough to try this.
### Building
This uses the new Golang vendoring so you need go 1.6 or
`GO15VENDOREXPERIMENT=1` in your env.
You will also need `libapparmor-dev` and `libseccomp-dev`.
Most importantly you need userns in your kernel (`CONFIG_USER_NS=y`)
or else this won't even work.
```console
$ make static
Static container created at: ./bin/alpine
@ -100,6 +106,12 @@ The binary spawned does NOT need to oversee the container process if you
run in detached mode with a PID file. You can have it watched by the user mode
systemd so that this binary is really just the launcher :)
## Example
Nginx running with my user "jessie".
![nginx.png](nginx.png)
## Caveats
**Caps the binary needs to unpack and set

13
main.go
View file

@ -12,6 +12,7 @@ import (
aaprofile "github.com/docker/docker/profiles/apparmor"
"github.com/opencontainers/runc/libcontainer"
"github.com/opencontainers/runc/libcontainer/apparmor"
"github.com/opencontainers/runc/libcontainer/user"
"github.com/opencontainers/runtime-spec/specs-go"
)
@ -180,13 +181,21 @@ func main() {
// install the default apparmor profile
if apparmor.IsEnabled() {
if err := aaprofile.InstallDefault(defaultApparmorProfile); err != nil {
logrus.Warnf("AppArmor is enabled on the the system, but the profile (%s) could not be loaded", defaultApparmorProfile)
// check if we have the docker-default apparmor profile loaded
if err := aaprofile.IsLoaded(defaultApparmorProfile); err != nil {
logrus.Warnf("AppArmor enabled on system but the %s profile is not loaded. apparmor_parser needs root to load a profile so we can't do it for you.", defaultApparmorProfile)
} else {
spec.Process.ApparmorProfile = defaultApparmorProfile
}
}
// set the CgroupsPath as this user
user, err := user.CurrentUser()
if err != nil {
logrus.Fatal(err)
}
spec.Linux.CgroupsPath = sPtr(user.Name)
if err := unpackRootfs(spec); err != nil {
logrus.Fatal(err)
}

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@ -111,11 +111,14 @@ func (m *Manager) Apply(pid int) (err error) {
var c = m.Cgroups
logrus.Debugf("pre get cgroups data: %#v", c)
d, err := getCgroupData(m.Cgroups, pid)
if err != nil {
return err
}
logrus.Debugf("cgroups data: %#v, config: %#v", d, d.config)
if c.Paths != nil {
paths := make(map[string]string)
for name, path := range c.Paths {
@ -129,6 +132,7 @@ func (m *Manager) Apply(pid int) (err error) {
paths[name] = path
}
m.Paths = paths
logrus.Debugf("cgroups apply paths: %#v", m.Paths)
return cgroups.EnterPid(m.Paths, pid)
}
@ -136,6 +140,7 @@ func (m *Manager) Apply(pid int) (err error) {
defer m.mu.Unlock()
paths := make(map[string]string)
for _, sys := range subsystems {
logrus.Debugf("applying cgroups to subsystem %#v", sys)
if err := sys.Apply(d); err != nil {
return err
}
@ -353,23 +358,25 @@ func writeFile(dir, file, data string) error {
if dir == "" {
return fmt.Errorf("no such directory for %s", file)
}
// get the current user
u, err := user.CurrentUser()
if err != nil {
return err
}
if err := os.Chown(dir, u.Uid, u.Gid); err != nil {
return fmt.Errorf("failed to chown %s to %d:%d -> %v", dir, u.Uid, u.Gid, err)
if err := os.Lchown(dir, u.Uid, u.Gid); err != nil {
return fmt.Errorf("failed to chown to %d:%d -> %v", u.Uid, u.Gid, err)
}
logrus.Debugf("chown dir %s to %d:%d", dir, u.Uid, u.Gid)
if err := os.Chown(filepath.Join(dir, "tasks"), u.Uid, u.Gid); err != nil {
return fmt.Errorf("failed to chown %s/tasks to %d:%d -> %v", dir, u.Uid, u.Gid, err)
if err := os.Lchown(filepath.Join(dir, file), u.Uid, u.Gid); err != nil {
return fmt.Errorf("failed to chown to %d:%d -> %v", u.Uid, u.Gid, err)
}
logrus.Debugf("chown %s to %d:%d", filepath.Join(dir, file), u.Uid, u.Gid)
if err := ioutil.WriteFile(filepath.Join(dir, file), []byte(data), 0700); err != nil {
logrus.Debugf("failed to write %v to %v: %v", data, file, err)
//return err
}
return nil
}

View file

@ -10,6 +10,7 @@ import (
"path/filepath"
"strconv"
"github.com/Sirupsen/logrus"
"github.com/opencontainers/runc/libcontainer/cgroups"
"github.com/opencontainers/runc/libcontainer/configs"
libcontainerUtils "github.com/opencontainers/runc/libcontainer/utils"
@ -27,6 +28,7 @@ func (s *CpusetGroup) Apply(d *cgroupData) error {
if err != nil && !cgroups.IsNotFound(err) {
return err
}
logrus.Debugf("apply cpuset dir is %s", dir)
return s.ApplyDir(dir, d.config, d.pid)
}

View file

@ -171,6 +171,7 @@ func (c *linuxContainer) Set(config configs.Config) error {
c.m.Lock()
defer c.m.Unlock()
c.config = &config
logrus.Debugf("setting cgroups")
return c.cgroupManager.Set(c.config)
}
@ -741,6 +742,7 @@ func (c *linuxContainer) Restore(process *Process, criuOpts *CriuOpts) error {
}
func (c *linuxContainer) criuApplyCgroups(pid int, req *criurpc.CriuReq) error {
logrus.Debugf("criu apply cgroups")
if err := c.cgroupManager.Apply(pid); err != nil {
return err
}

View file

@ -13,6 +13,7 @@ import (
"strconv"
"syscall"
"github.com/Sirupsen/logrus"
"github.com/opencontainers/runc/libcontainer/cgroups"
"github.com/opencontainers/runc/libcontainer/configs"
"github.com/opencontainers/runc/libcontainer/system"
@ -247,6 +248,9 @@ func (p *initProcess) start() error {
return newSystemError(err)
}
p.setExternalDescriptors(fds)
logrus.Debugf("starting process apply cgroups")
// Do this before syncing with child so that no children
// can escape the cgroup
if err := p.manager.Apply(p.pid()); err != nil {