podman/libpod/oci_util.go
Juan Antonio Osorio Robles 020abbfeab Expose security attribute errors with their own messages
This creates error objects for runtime errors that might come from the
runtime. Thus, indicating to users that the place to debug should be in
the security attributes of the container.

When creating a container with a SELinux label that doesn't exist, we
get a fairly cryptic error message:

```
$ podman run --security-opt label=type:my_container.process -it fedora bash
Error: OCI runtime error: write file `/proc/thread-self/attr/exec`: Invalid argument
```

This instead handles any errors coming from LSM's `/proc` API and
enhances the error message with a relevant indicator that it's related
to the container's security attributes.

A sample run looks as follows:

```
$ bin/podman run --security-opt label=type:my_container.process -it fedora bash
Error: `/proc/thread-self/attr/exec`: OCI runtime error: unable to assign security attribute
```

With `debug` log level enabled it would be:

```
Error: write file `/proc/thread-self/attr/exec`: Invalid argument: OCI runtime error: unable to assign security attribute
```

Note that these errors wrap ErrOCIRuntime, so it's still possible to to
compare these errors with `errors.Is/errors.As`.

One advantage of this approach is that we could start handling these
errors in a more efficient manner in the future.

e.g. If a SELinux label doesn't exist (yet), we could retry until it
becomes available.

Signed-off-by: Juan Antonio Osorio Robles <jaosorior@redhat.com>
2021-01-12 16:10:17 +02:00

143 lines
3.9 KiB
Go

package libpod
import (
"fmt"
"net"
"os"
"regexp"
"strings"
"time"
"github.com/containers/podman/v2/libpod/define"
"github.com/cri-o/ocicni/pkg/ocicni"
"github.com/pkg/errors"
"github.com/sirupsen/logrus"
)
// Timeout before declaring that runtime has failed to kill a given
// container
const killContainerTimeout = 5 * time.Second
// ociError is used to parse the OCI runtime JSON log. It is not part of the
// OCI runtime specifications, it follows what runc does
type ociError struct {
Level string `json:"level,omitempty"`
Time string `json:"time,omitempty"`
Msg string `json:"msg,omitempty"`
}
// Create systemd unit name for cgroup scopes
func createUnitName(prefix string, name string) string {
return fmt.Sprintf("%s-%s.scope", prefix, name)
}
// Bind ports to keep them closed on the host
func bindPorts(ports []ocicni.PortMapping) ([]*os.File, error) {
var files []*os.File
notifySCTP := false
for _, i := range ports {
isV6 := net.ParseIP(i.HostIP).To4() == nil
if i.HostIP == "" {
isV6 = false
}
switch i.Protocol {
case "udp":
var (
addr *net.UDPAddr
err error
)
if isV6 {
addr, err = net.ResolveUDPAddr("udp6", fmt.Sprintf("[%s]:%d", i.HostIP, i.HostPort))
} else {
addr, err = net.ResolveUDPAddr("udp4", fmt.Sprintf("%s:%d", i.HostIP, i.HostPort))
}
if err != nil {
return nil, errors.Wrapf(err, "cannot resolve the UDP address")
}
proto := "udp4"
if isV6 {
proto = "udp6"
}
server, err := net.ListenUDP(proto, addr)
if err != nil {
return nil, errors.Wrapf(err, "cannot listen on the UDP port")
}
f, err := server.File()
if err != nil {
return nil, errors.Wrapf(err, "cannot get file for UDP socket")
}
files = append(files, f)
case "tcp":
var (
addr *net.TCPAddr
err error
)
if isV6 {
addr, err = net.ResolveTCPAddr("tcp6", fmt.Sprintf("[%s]:%d", i.HostIP, i.HostPort))
} else {
addr, err = net.ResolveTCPAddr("tcp4", fmt.Sprintf("%s:%d", i.HostIP, i.HostPort))
}
if err != nil {
return nil, errors.Wrapf(err, "cannot resolve the TCP address")
}
proto := "tcp4"
if isV6 {
proto = "tcp6"
}
server, err := net.ListenTCP(proto, addr)
if err != nil {
return nil, errors.Wrapf(err, "cannot listen on the TCP port")
}
f, err := server.File()
if err != nil {
return nil, errors.Wrapf(err, "cannot get file for TCP socket")
}
files = append(files, f)
case "sctp":
if !notifySCTP {
notifySCTP = true
logrus.Warnf("port reservation for SCTP is not supported")
}
default:
return nil, fmt.Errorf("unknown protocol %s", i.Protocol)
}
}
return files, nil
}
func getOCIRuntimeError(runtimeMsg string) error {
includeFullOutput := logrus.GetLevel() == logrus.DebugLevel
if match := regexp.MustCompile("(?i).*permission denied.*|.*operation not permitted.*").FindString(runtimeMsg); match != "" {
errStr := match
if includeFullOutput {
errStr = runtimeMsg
}
return errors.Wrapf(define.ErrOCIRuntimePermissionDenied, "%s", strings.Trim(errStr, "\n"))
}
if match := regexp.MustCompile("(?i).*executable file not found in.*|.*no such file or directory.*").FindString(runtimeMsg); match != "" {
errStr := match
if includeFullOutput {
errStr = runtimeMsg
}
return errors.Wrapf(define.ErrOCIRuntimeNotFound, "%s", strings.Trim(errStr, "\n"))
}
if match := regexp.MustCompile("`/proc/[a-z0-9-].+/attr.*`").FindString(runtimeMsg); match != "" {
errStr := match
if includeFullOutput {
errStr = runtimeMsg
}
if strings.HasSuffix(match, "/exec`") {
return errors.Wrapf(define.ErrSetSecurityAttribute, "%s", strings.Trim(errStr, "\n"))
} else if strings.HasSuffix(match, "/current`") {
return errors.Wrapf(define.ErrGetSecurityAttribute, "%s", strings.Trim(errStr, "\n"))
}
return errors.Wrapf(define.ErrSecurityAttribute, "%s", strings.Trim(errStr, "\n"))
}
return errors.Wrapf(define.ErrOCIRuntime, "%s", strings.Trim(runtimeMsg, "\n"))
}