3 files changed, 51 insertions, 135 deletions
diff --git a/libpod/container_top.go b/libpod/container_top.go
deleted file mode 100644
index f5d314d49..000000000
--- a/libpod/container_top.go
+++ /dev/null
@@ -1,135 +0,0 @@
-package libpod
-
-import (
-	"io/ioutil"
-	"path/filepath"
-	"strings"
-
-	"github.com/pkg/errors"
-	"github.com/projectatomic/libpod/pkg/util"
-	"github.com/projectatomic/libpod/utils"
-	"github.com/sirupsen/logrus"
-)
-
-// GetContainerPids reads sysfs to obtain the pids associated with the container's cgroup
-// and uses locking
-func (c *Container) GetContainerPids() ([]string, error) {
-	if !c.batched {
-		c.lock.Lock()
-		defer c.lock.Unlock()
-		if err := c.syncContainer(); err != nil {
-			return []string{}, errors.Wrapf(err, "error updating container %s state", c.ID())
-		}
-	}
-	return c.getContainerPids()
-}
-
-// Gets the pids for a container without locking.  should only be called from a func where
-// locking has already been established.
-func (c *Container) getContainerPids() ([]string, error) {
-	cgroupPath, err := c.CGroupPath()
-	if err != nil {
-		return nil, err
-	}
-
-	taskFile := filepath.Join("/sys/fs/cgroup/pids", cgroupPath, "tasks")
-
-	logrus.Debug("reading pids from ", taskFile)
-
-	content, err := ioutil.ReadFile(taskFile)
-	if err != nil {
-		return []string{}, errors.Wrapf(err, "unable to read pids from %s", taskFile)
-	}
-	return strings.Fields(string(content)), nil
-}
-
-// GetContainerPidInformation calls ps with the appropriate options and returns
-// the results as a string and the container's PIDs as a []string.  Note that
-// the ps output columns of each string are separated by a '\t\'.  Currently,
-// the args argument is overwriten with []string{"-ef"} until there is a
-// portable library for ps-1 or to parse the procFS to extract all data.
-func (c *Container) GetContainerPidInformation(args []string) ([]string, error) {
-	// XXX(ps-issue): args is overwriten with []{"-ef"} as the ps-1 tool
-	// doesn't support a generic way of splitting columns, rendering its
-	// output hard to parse.  Docker first deterimes the number of columns
-	// and merges all exceeding ones into the last one.  We believe that
-	// writing a go library which parses procFS in a ps-compatible way may
-	// be more beneficial in the long run.  Until then, args will be
-	// ignored.
-	args = []string{"-ef"}
-
-	if !c.batched {
-		c.lock.Lock()
-		defer c.lock.Unlock()
-		if err := c.syncContainer(); err != nil {
-			return []string{}, errors.Wrapf(err, "error updating container %s state", c.ID())
-		}
-	}
-	pids, err := c.getContainerPids()
-	if err != nil {
-		return []string{}, errors.Wrapf(err, "unable to obtain pids for ", c.ID())
-	}
-	args = append(args, "-p", strings.Join(pids, ","))
-	logrus.Debug("Executing: ", strings.Join(args, " "))
-	results, err := utils.ExecCmd("ps", args...)
-	if err != nil {
-		return []string{}, errors.Wrapf(err, "unable to obtain information about pids")
-	}
-
-	filteredOutput, err := filterPids(results, pids)
-	if err != nil {
-		return []string{}, err
-	}
-	return filteredOutput, nil
-}
-
-func filterPids(psOutput string, pids []string) ([]string, error) {
-	var output []string
-	results := strings.Split(psOutput, "\n")
-	// The headers are in the first line of the results
-	headers := fieldsASCII(results[0])
-	// We need to make sure PID in headers, so that we can filter
-	// Pids that don't belong.
-
-	// append the headers back in
-	output = append(output, strings.Join(headers, "\t"))
-
-	pidIndex := -1
-	for i, header := range headers {
-		if header == "PID" {
-			pidIndex = i
-		}
-	}
-	if pidIndex == -1 {
-		return []string{}, errors.Errorf("unable to find PID field in ps output. try a different set of ps arguments")
-	}
-	for _, l := range results[1:] {
-		if l == "" {
-			continue
-		}
-		cols := fieldsASCII(l)
-		pid := cols[pidIndex]
-		if util.StringInSlice(pid, pids) {
-			// XXX(ps-issue): Strip cols down to the header's size
-			// and merge exceeding fields. This is required to
-			// "merge" the overhanging CMD entries which can
-			// contain white spaces.
-			out := cols[:len(headers)-1]
-			out = append(out, strings.Join(cols[len(headers)-1:], " "))
-			output = append(output, strings.Join(out, "\t"))
-		}
-	}
-	return output, nil
-}
-
-// Detects ascii whitespaces
-func fieldsASCII(s string) []string {
-	fn := func(r rune) bool {
-		switch r {
-		case '\t', '\n', '\f', '\r', ' ':
-			return true
-		}
-		return false
-	}
-	return strings.FieldsFunc(s, fn)
-}
diff --git a/libpod/container_top_linux.go b/libpod/container_top_linux.go
new file mode 100644
index 000000000..450130add
--- /dev/null
+++ b/libpod/container_top_linux.go
@@ -0,0 +1,30 @@
+// +build linux
+
+package libpod
+
+import (
+	"strconv"
+	"strings"
+
+	"github.com/containers/psgo/ps"
+)
+
+// GetContainerPidInformation returns process-related data of all processes in
+// the container.  The output data can be controlled via the `descriptors`
+// argument which expects format descriptors and supports all AIXformat
+// descriptors of ps (1) plus some additional ones to for instance inspect the
+// set of effective capabilities.  Eeach element in the returned string slice
+// is a tab-separated string.
+//
+// For more details, please refer to github.com/containers/psgo.
+func (c *Container) GetContainerPidInformation(descriptors []string) ([]string, error) {
+	pid := strconv.Itoa(c.state.PID)
+	format := strings.Join(descriptors, ",")
+	return ps.JoinNamespaceAndProcessInfo(pid, format)
+}
+
+// GetContainerPidInformationDescriptors returns a string slice of all supported
+// format descriptors of GetContainerPidInformation.
+func GetContainerPidInformationDescriptors() ([]string, error) {
+	return ps.ListDescriptors(), nil
+}
diff --git a/libpod/container_top_unsupported.go b/libpod/container_top_unsupported.go
new file mode 100644
index 000000000..1e6fb836d
--- /dev/null
+++ b/libpod/container_top_unsupported.go
@@ -0,0 +1,21 @@
+// +build !linux
+
+package libpod
+
+// GetContainerPidInformation returns process-related data of all processes in
+// the container.  The output data can be controlled via the `descriptors`
+// argument which expects format descriptors and supports all AIXformat
+// descriptors of ps (1) plus some additional ones to for instance inspect the
+// set of effective capabilities.  Eeach element in the returned string slice
+// is a tab-separated string.
+//
+// For more details, please refer to github.com/containers/psgo.
+func (c *Container) GetContainerPidInformation(descriptors []string) ([]string, error) {
+	return nil, ErrNotImplemented
+}
+
+// GetContainerPidInformationDescriptors returns a string slice of all supported
+// format descriptors of GetContainerPidInformation.
+func GetContainerPidInformationDescriptors() ([]string, error) {
+	return nil, ErrNotImplemented
+}