new "image" mount type

Add a new "image" mount type to `--mount`.  The source of the mount is
the name or ID of an image.  The destination is the path inside the
container.  Image mounts further support an optional `rw,readwrite`
parameter which if set to "true" will yield the mount writable inside
the container.  Note that no changes are propagated to the image mount
on the host (which in any case is read only).

Mounts are overlay mounts.  To support read-only overlay mounts, vendor
a non-release version of Buildah.

Signed-off-by: Valentin Rothberg <rothberg@redhat.com>
This commit is contained in:
Valentin Rothberg
2020-10-26 11:35:02 +01:00
parent cce6c6cd40
commit 65a618886e
168 changed files with 6143 additions and 10606 deletions

View File

@@ -1,91 +0,0 @@
// Copyright 2019 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package procfs
import (
"fmt"
"io/ioutil"
"strconv"
"strings"
)
// For the proc file format details,
// see https://elixir.bootlin.com/linux/v4.17/source/net/core/net-procfs.c#L162
// and https://elixir.bootlin.com/linux/v4.17/source/include/linux/netdevice.h#L2810.
// SoftnetEntry contains a single row of data from /proc/net/softnet_stat
type SoftnetEntry struct {
// Number of processed packets
Processed uint
// Number of dropped packets
Dropped uint
// Number of times processing packets ran out of quota
TimeSqueezed uint
}
// GatherSoftnetStats reads /proc/net/softnet_stat, parse the relevant columns,
// and then return a slice of SoftnetEntry's.
func (fs FS) GatherSoftnetStats() ([]SoftnetEntry, error) {
data, err := ioutil.ReadFile(fs.proc.Path("net/softnet_stat"))
if err != nil {
return nil, fmt.Errorf("error reading softnet %s: %s", fs.proc.Path("net/softnet_stat"), err)
}
return parseSoftnetEntries(data)
}
func parseSoftnetEntries(data []byte) ([]SoftnetEntry, error) {
lines := strings.Split(string(data), "\n")
entries := make([]SoftnetEntry, 0)
var err error
const (
expectedColumns = 11
)
for _, line := range lines {
columns := strings.Fields(line)
width := len(columns)
if width == 0 {
continue
}
if width != expectedColumns {
return []SoftnetEntry{}, fmt.Errorf("%d columns were detected, but %d were expected", width, expectedColumns)
}
var entry SoftnetEntry
if entry, err = parseSoftnetEntry(columns); err != nil {
return []SoftnetEntry{}, err
}
entries = append(entries, entry)
}
return entries, nil
}
func parseSoftnetEntry(columns []string) (SoftnetEntry, error) {
var err error
var processed, dropped, timeSqueezed uint64
if processed, err = strconv.ParseUint(columns[0], 16, 32); err != nil {
return SoftnetEntry{}, fmt.Errorf("Unable to parse column 0: %s", err)
}
if dropped, err = strconv.ParseUint(columns[1], 16, 32); err != nil {
return SoftnetEntry{}, fmt.Errorf("Unable to parse column 1: %s", err)
}
if timeSqueezed, err = strconv.ParseUint(columns[2], 16, 32); err != nil {
return SoftnetEntry{}, fmt.Errorf("Unable to parse column 2: %s", err)
}
return SoftnetEntry{
Processed: uint(processed),
Dropped: uint(dropped),
TimeSqueezed: uint(timeSqueezed),
}, nil
}