Improve retry behavior for push operation (#1578)

* Update go-containerregistry to 0.4

* Implement --push-retry argument

vendor/github.com/prometheus/procfs/proc.go

@@ -22,6 +22,7 @@ import (
 	"strings"
 
 	"github.com/prometheus/procfs/internal/fs"
+	"github.com/prometheus/procfs/internal/util"
 )
 
 // Proc provides information about a running process.
@@ -121,13 +122,7 @@ func (fs FS) AllProcs() (Procs, error) {
 
 // CmdLine returns the command line of a process.
 func (p Proc) CmdLine() ([]string, error) {
-	f, err := os.Open(p.path("cmdline"))
-	if err != nil {
-		return nil, err
-	}
-	defer f.Close()
-
-	data, err := ioutil.ReadAll(f)
+	data, err := util.ReadFileNoStat(p.path("cmdline"))
 	if err != nil {
 		return nil, err
 	}
@@ -139,9 +134,9 @@ func (p Proc) CmdLine() ([]string, error) {
 	return strings.Split(string(bytes.TrimRight(data, string("\x00"))), string(byte(0))), nil
 }
 
-// Comm returns the command name of a process.
-func (p Proc) Comm() (string, error) {
-	f, err := os.Open(p.path("comm"))
+// Wchan returns the wchan (wait channel) of a process.
+func (p Proc) Wchan() (string, error) {
+	f, err := os.Open(p.path("wchan"))
 	if err != nil {
 		return "", err
 	}
@@ -152,6 +147,21 @@ func (p Proc) Comm() (string, error) {
 		return "", err
 	}
 
+	wchan := string(data)
+	if wchan == "" || wchan == "0" {
+		return "", nil
+	}
+
+	return wchan, nil
+}
+
+// Comm returns the command name of a process.
+func (p Proc) Comm() (string, error) {
+	data, err := util.ReadFileNoStat(p.path("comm"))
+	if err != nil {
+		return "", err
+	}
+
 	return strings.TrimSpace(string(data)), nil
 }
 
@@ -252,13 +262,11 @@ func (p Proc) MountStats() ([]*Mount, error) {
 // It supplies information missing in `/proc/self/mounts` and
 // fixes various other problems with that file too.
 func (p Proc) MountInfo() ([]*MountInfo, error) {
-	f, err := os.Open(p.path("mountinfo"))
+	data, err := util.ReadFileNoStat(p.path("mountinfo"))
 	if err != nil {
 		return nil, err
 	}
-	defer f.Close()
-
-	return parseMountInfo(f)
+	return parseMountInfo(data)
 }
 
 func (p Proc) fileDescriptors() ([]string, error) {
@@ -279,3 +287,33 @@ func (p Proc) fileDescriptors() ([]string, error) {
 func (p Proc) path(pa ...string) string {
 	return p.fs.Path(append([]string{strconv.Itoa(p.PID)}, pa...)...)
 }
+
+// FileDescriptorsInfo retrieves information about all file descriptors of
+// the process.
+func (p Proc) FileDescriptorsInfo() (ProcFDInfos, error) {
+	names, err := p.fileDescriptors()
+	if err != nil {
+		return nil, err
+	}
+
+	var fdinfos ProcFDInfos
+
+	for _, n := range names {
+		fdinfo, err := p.FDInfo(n)
+		if err != nil {
+			continue
+		}
+		fdinfos = append(fdinfos, *fdinfo)
+	}
+
+	return fdinfos, nil
+}
+
+// Schedstat returns task scheduling information for the process.
+func (p Proc) Schedstat() (ProcSchedstat, error) {
+	contents, err := ioutil.ReadFile(p.path("schedstat"))
+	if err != nil {
+		return ProcSchedstat{}, err
+	}
+	return parseProcSchedstat(string(contents))
+}