Add a pause image for the net container.

The pause image is a 240KB image that simply pauses waiting on a signal.
Use this for the net container which only needs to act as a placeholder.
Current net image is ~2.5MB. From my tests, this reduces startup time
for the net container from ~14s to ~6s.
This commit is contained in:
Victor Marmol 2014-07-19 00:09:43 -07:00
parent 3398646170
commit 88317efb42
7 changed files with 114 additions and 6 deletions

3
build/pause/Dockerfile Normal file
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@ -0,0 +1,3 @@
FROM scratch
ADD pause /
ENTRYPOINT ["/pause"]

8
build/pause/pause.go Normal file
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package main
import "syscall"
func main() {
// Halts execution, waiting on signal.
syscall.Pause()
}

6
build/pause/prepare.sh Executable file
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#!/bin/bash
set -e
set -x
go build --ldflags '-extldflags "-static" -s' pause.go

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@ -541,7 +541,10 @@ func (kl *Kubelet) WatchEtcd(watchChannel <-chan *etcd.Response, updateChannel c
}
}
const networkContainerName = "net"
const (
networkContainerName = "net"
networkContainerImage = "kubernetes/pause:latest"
)
// Create a network container for a manifest. Returns the docker container ID of the newly created container.
func (kl *Kubelet) createNetworkContainer(manifest *api.ContainerManifest) (DockerID, error) {
@ -552,12 +555,11 @@ func (kl *Kubelet) createNetworkContainer(manifest *api.ContainerManifest) (Dock
ports = append(ports, container.Ports...)
}
container := &api.Container{
Name: networkContainerName,
Image: "busybox",
Command: []string{"sh", "-c", "rm -f nap && mkfifo nap && exec cat nap"},
Ports: ports,
Name: networkContainerName,
Image: networkContainerImage,
Ports: ports,
}
kl.DockerPuller.Pull("busybox")
kl.DockerPuller.Pull(networkContainerImage)
return kl.runContainer(manifest, container, nil, "")
}

19
third_party/pause/LICENSE vendored Normal file
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The Expat/MIT License
Permission is hereby granted, free of charge, to any person obtaining a
copy of this software and associated documentation files (the "Software"),
to deal in the Software without restriction, including without limitation
the rights to use, copy, modify, merge, publish, distribute, sublicense,
and/or sell copies of the Software, and to permit persons to whom the
Software is furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
DEALINGS IN THE SOFTWARE.

13
third_party/pause/Makefile vendored Normal file
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pause: pause.asm
ifneq ($(shell uname), Linux)
echo "Must build on Linux"
exit 1
else
nasm -o $@ $<
chmod +x pause
endif
all: pause
clean:
rm -f pause

57
third_party/pause/pause.asm vendored Normal file
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; This is heavily based on https://github.com/tianon/dockerfiles/tree/master/true
; which is in turn especially thanks to:
; http://blog.markloiseau.com/2012/05/tiny-64-bit-elf-executables/
BITS 64
org 0x00400000 ; Program load offset
; 64-bit ELF header
ehdr:
; 1), 0 (ABI ver.)
db 0x7F, "ELF", 2, 1, 1, 0 ; e_ident
times 8 db 0 ; reserved (zeroes)
dw 2 ; e_type: Executable file
dw 0x3e ; e_machine: AMD64
dd 1 ; e_version: current version
dq _start ; e_entry: program entry address (0x78)
dq phdr - $$ ; e_phoff program header offset (0x40)
dq 0 ; e_shoff no section headers
dd 0 ; e_flags no flags
dw ehdrsize ; e_ehsize: ELF header size (0x40)
dw phdrsize ; e_phentsize: program header size (0x38)
dw 1 ; e_phnum: one program header
dw 0 ; e_shentsize
dw 0 ; e_shnum
dw 0 ; e_shstrndx
ehdrsize equ $ - ehdr
; 64-bit ELF program header
phdr:
dd 1 ; p_type: loadable segment
dd 5 ; p_flags read and execute
dq 0 ; p_offset
dq $$ ; p_vaddr: start of the current section
dq $$ ; p_paddr: " "
dq filesize ; p_filesz
dq filesize ; p_memsz
dq 0x200000 ; p_align: 2^11=200000 = section alignment
; program header size
phdrsize equ $ - phdr
_start:
; pause()
mov al, 34 ; pause syscall number
syscall
; sys_exit(return_code)
mov al, 60 ; sys_exit syscall number
cdq ; Sign-extend eax into edi to return 0 (success)
syscall
; File size calculation
filesize equ $ - $$