Browse Source

Support CentOS kernels

Resolves #8
tags/v1.0.0
dump_stack() 10 months ago
parent
commit
72bb8df46b
Signed by: Mikhail Klementev <blame@dumpstack.io> GPG Key ID: BE44DA8C062D87DC
3 changed files with 105 additions and 15 deletions
  1. 5
    0
      examples/kernel-module/.out-of-tree.toml
  2. 93
    8
      kernel.go
  3. 7
    7
      tools/qemu-centos-img/7/Dockerfile

+ 5
- 0
examples/kernel-module/.out-of-tree.toml View File

@@ -23,3 +23,8 @@ distro_type = "Ubuntu"
distro_release = "18.04"
# Also you can use only one kernel
release_mask = "4[.]15[.]0-23-generic"

[[supported_kernels]]
distro_type = "CentOS"
distro_release = "7"
release_mask = "3[.]10[.]0-862.el7.x86_64"

+ 93
- 8
kernel.go View File

@@ -66,6 +66,28 @@ func matchDebianHeadersPkg(container, mask string, generic bool) (
return
}

func matchCentOSDevelPkg(container, mask string, generic bool) (
pkgs []string, err error) {

cmd := "yum search kernel-devel --show-duplicates | " +
"grep '^kernel-devel' | cut -d ' ' -f 1"
output, err := dockerRun(time.Minute, container, "/tmp", cmd)
if err != nil {
return
}

r, err := regexp.Compile("kernel-devel-" + mask)
if err != nil {
return
}

for _, k := range r.FindAll([]byte(output), -1) {
pkgs = append(pkgs, string(k))
}

return
}

func dockerImagePath(sk config.KernelMask) (path string, err error) {
usr, err := user.Current()
if err != nil {
@@ -77,6 +99,16 @@ func dockerImagePath(sk config.KernelMask) (path string, err error) {
return
}

func vsyscallAvailable() (available bool, err error) {
buf, err := ioutil.ReadFile("/proc/self/maps")
if err != nil {
return
}

available = strings.Contains(string(buf), "[vsyscall]")
return
}

func generateBaseDockerImage(sk config.KernelMask) (err error) {
imagePath, err := dockerImagePath(sk)
if err != nil {
@@ -101,6 +133,11 @@ func generateBaseDockerImage(sk config.KernelMask) (err error) {
sk.DistroRelease,
)

vsyscall, err := vsyscallAvailable()
if err != nil {
return
}

switch sk.DistroType {
case config.Ubuntu:
d += "ENV DEBIAN_FRONTEND=noninteractive\n"
@@ -111,6 +148,24 @@ func generateBaseDockerImage(sk config.KernelMask) (err error) {
d += "RUN apt-get install -y libseccomp-dev\n"
}
d += "RUN mkdir /lib/modules\n"
case config.CentOS:
if sk.DistroRelease < "7" && !vsyscall {
log.Println("Old CentOS requires `vsyscall=emulate` " +
"on the latest kernels")
log.Println("Check out `A note about vsyscall` " +
"at https://hub.docker.com/_/centos")
log.Println("See also https://lwn.net/Articles/446528/")
err = fmt.Errorf("vsyscall is not available")
return
}

// enable rpms from old minor releases
d += "RUN sed -i 's/enabled=0/enabled=1/' /etc/yum.repos.d/CentOS-Vault.repo\n"
// do not remove old kernels
d += "RUN sed -i 's;installonly_limit=;installonly_limit=100500;' /etc/yum.conf\n"
d += "RUN yum -y update\n"
d += "RUN yum -y groupinstall 'Development Tools'\n"
d += "RUN yum -y install deltarpm\n"
default:
err = fmt.Errorf("%s not yet supported", sk.DistroType.String())
return
@@ -156,12 +211,32 @@ func dockerImageAppend(sk config.KernelMask, pkgname string) (err error) {
return
}

imagepkg := strings.Replace(pkgname, "headers", "image", -1)
var s string

switch sk.DistroType {
case config.Ubuntu:
imagepkg := strings.Replace(pkgname, "headers", "image", -1)

log.Printf("Start adding kernel %s for %s:%s",
imagepkg, sk.DistroType.String(), sk.DistroRelease)
log.Printf("Start adding kernel %s for %s:%s",
imagepkg, sk.DistroType.String(), sk.DistroRelease)

s := fmt.Sprintf("RUN apt-get install -y %s %s\n", imagepkg, pkgname)
s = fmt.Sprintf("RUN apt-get install -y %s %s\n", imagepkg,
pkgname)
case config.CentOS:
imagepkg := strings.Replace(pkgname, "-devel", "", -1)

log.Printf("Start adding kernel %s for %s:%s",
imagepkg, sk.DistroType.String(), sk.DistroRelease)

version := strings.Replace(pkgname, "kernel-devel-", "", -1)

s = fmt.Sprintf("RUN yum -y install %s %s\n", imagepkg,
pkgname)
s += fmt.Sprintf("RUN dracut --add-drivers 'e1000 ext4' -f "+
"/boot/initramfs-%s.img %s\n", version, version)
default:
err = fmt.Errorf("%s not yet supported", sk.DistroType.String())
}

err = ioutil.WriteFile(imagePath+"/Dockerfile",
append(raw, []byte(s)...), 0644)
@@ -239,7 +314,7 @@ func copyKernels(name string) (err error) {

func genKernelPath(files []os.FileInfo, kname string) string {
for _, file := range files {
if strings.Contains(file.Name(), "vmlinuz") {
if strings.HasPrefix(file.Name(), "vmlinuz") {
if strings.Contains(file.Name(), kname) {
return file.Name()
}
@@ -250,7 +325,9 @@ func genKernelPath(files []os.FileInfo, kname string) string {

func genInitrdPath(files []os.FileInfo, kname string) string {
for _, file := range files {
if strings.Contains(file.Name(), "initrd") {
if strings.HasPrefix(file.Name(), "initrd") ||
strings.HasPrefix(file.Name(), "initramfs") {

if strings.Contains(file.Name(), kname) {
return file.Name()
}
@@ -511,8 +588,16 @@ func generateKernels(km config.KernelMask, max int64, download bool) (err error)
}

var pkgs []string
pkgs, err = matchDebianHeadersPkg(km.DockerName(),
km.ReleaseMask, true)
switch km.DistroType {
case config.Ubuntu:
pkgs, err = matchDebianHeadersPkg(km.DockerName(),
km.ReleaseMask, true)
case config.CentOS:
pkgs, err = matchCentOSDevelPkg(km.DockerName(),
km.ReleaseMask, true)
default:
err = fmt.Errorf("%s not yet supported", km.DistroType.String())
}
if err != nil {
return
}

tools/qemu-centos-img/Dockerfile → tools/qemu-centos-img/7/Dockerfile View File

@@ -1,4 +1,4 @@
# Copyright 2018 Mikhail Klementev. All rights reserved.
# Copyright 2019 Mikhail Klementev. All rights reserved.
# Use of this source code is governed by a AGPLv3 license
# (or later) that can be found in the LICENSE file.
#
@@ -7,11 +7,13 @@
# $ docker build -t gen-centos7-image .
# $ docker run --privileged -v $(pwd):/shared -t gen-centos7-image
#
# centos7.img will be created in current directory. You can change $(pwd) to
# different directory to use different destination for image.
# out_of_tree_centos_7.img will be created in current directory.
# You can change $(pwd) to different directory to use different destination
# for image.
#
FROM centos:7

RUN yum -y update
RUN yum -y groupinstall "Development Tools"
RUN yum -y install qemu-img e2fsprogs

@@ -26,7 +28,7 @@ RUN yum --installroot=$TMPDIR \
--releasever=7 \
--disablerepo='*' \
--enablerepo=base \
-y install openssh-server
-y install openssh-server openssh-clients

RUN chroot $TMPDIR /bin/sh -c 'useradd -m user'
RUN sed -i 's/root:\*:/root::/' $TMPDIR/etc/shadow
@@ -37,13 +39,11 @@ RUN sed -i '/PermitRootLogin/d' $TMPDIR/etc/ssh/sshd_config
RUN echo PermitRootLogin yes >> $TMPDIR/etc/ssh/sshd_config

# network workaround
# FIXME kernel module compatibility issues
RUN chmod +x $TMPDIR/etc/rc.local
RUN echo 'find /lib/modules | grep e1000.ko | xargs insmod -f' >> $TMPDIR/etc/rc.local
RUN echo 'dhclient' >> $TMPDIR/etc/rc.local

ENV IMAGEDIR=/tmp/image
ENV IMAGE=/shared/centos7.img
ENV IMAGE=/shared/out_of_tree_centos_7.img

RUN mkdir $IMAGEDIR


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