Introduction to Docker and CoreOS with 2 mindmaps.

1. Docker
&
CoreOS
a
study
note
Richard Kuo

2. Agenda
• Review
of
Docker,
demo
– Pull,
build,
Docker
container
repo
• Overview
of
CoreOS,
demo
– Build,
install
container,
destroy/rejoin
host
• Use
cases
and
potenDal
architecture
• Discussions
10/20/14
CreaDve
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3. It
will
be
nice
to
have
computer
resources…
•
General
– Agile,
fault
tolerant,
HA
– New
resource
joins
pool
automaDcally
in-­‐out,
uDlizaDon
-­‐
release
resources
for
other
to
use
– User
friendly,
reasonable
learn
curve
to
use
it,
and
low
maintenance
– Scalable
• SoPware
– Configurable
auto
update,
increment,
transparent
– Run
mulDple
versions
of
app
at
the
same
Dme
– Across
physical
boundary
– Self-­‐content,
defensive,
not
effected
by
other
apps
10/20/14
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5. VirtualizaDon
ExecuDon
Environment
(VE)
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6. Docker
• Virtualize
host
OS
(mainly
Linux).
• Standard
format
to
package
the
applicaDon
with
its
dependency.
• Isolated
environment
for
program
execuDon.
• Has
its
own
IP
Address.
• Has
version
control,
like
git.
• Can
pull/push
Docker
container
images
from
public
or
private
repository.
• Can
assemble
mulDple
containers
to
form
a
more
complicate
applicaDon,
like
Lego.
10/20/14
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7. File
Layers
in
Container
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8. Why
do
we
care?
• Beaer
use
of
computer
resources,
IBM
report.
• Open
Source
and
supports
all
major
OS
(Linux,
MacOS
and
Windows).
• Can
be
on
many
devices,
from
Raspberry
Pi,
Android
device,
laptop,
server
to
Data
Center.
• Game
Changer,
Awesome!
Opportuni;es!
10/20/14
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9. 10/20/14
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10. DEMO
10/20/14
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12. It
is
Alpha!
There
are
beta
and
stable
channels
too.
Image
credit
hap://quoteko.com/stork-­‐boy.html
10/20/14
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13. CoreOS
• CoreOS
is
a
minimal
Linux
OS,
was
originally
based
on
Gentoo.
• Linux
Kernel
+
Docker
Containers.
• Built
for
running
HA
clusters.
• Updates,
patches
applies
automaDcally
(configurable).
• Uses
systemd,
has
3
main
components:
–
fleet:
cluster
service
management
–
etcd:
distributed
key-­‐value
store
–
docker:
container
10/20/14
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14. Why
CoreOS?
• Designed
for
massive
server
deployments.
• Support
Docker
container
out
of
box.
• Support
cloud
plamorm
– Digital
Ocean
– OpenStack
– Google
Compute
Engine
– Amazon
EC2
– Rackspace
Cloud
– Brightbox
Cloud
• Available
on
Linux,
Mac
and
Windows.
10/20/14
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15. 10/20/14
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15

16. Update
• If
there
is
an
update
available
it
is
downloaded
and
installed
to
root
B.
To
ensure
we
don’t
disrupt
your
applicaDon,
we
rate
limit
the
disk
and
network
I/O
this
process
is
allowed
to
use
with
Linux
cgroups.
• Using
this
dual-­‐root
scheme
is
an
improvement
on
the
exisDng
workflow
of
yum
or
apt-­‐get.
Using
these
tools
during
upgrading
has
been
known
to
cause
the
package
manager
to
force
daemons
to
use
new
libraries
or
move
configuraDon
files
around.
With
CoreOS,
a
system
update
is
an
atomic
operaDon
that
can
be
rolled
back.
10/20/14
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17. Systemd
haps://en.wikipedia.org/wiki/Systemd
• System
management
daemon
• Services,
Dmers,
and
one-­‐off
jobs
• Logging
through
journal,
support
json
10/20/14
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18. Fleet
• Cluster-­‐level
service
management
• Schedules
jobs
across
cluster
• Reschedules
units
on
failure
10/20/14
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19. etcd
• etcd
is
a
distributed
key
value
store.
• Shared
configuraDon,
applicaDons
can
read
and
write
data
into
etcd.
• Distributed
locking.
• etcd
uses
RaP
protocol,
gracefully
handles
master
elecDon
during
network
parDDons
and
the
loss
of
the
current
master.
10/20/14
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BY
19

20. Docker
• Only
packaging
method
in
CoreOS
• Container
is
self
contain
• Isolated
from
other
applicaDons
• Less
overhead
than
VMs
10/20/14
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21. DEMO
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22. Lessons
Learnt
and
ToDo
• Docker
and
CoreOS
offer
new
architecture
design
opDons
for
applicaDons,
plamorm
and
data
centers.
• They
allow
more
efficient
app
design,
test,
deployment
and
workflows
for
developers.
• New
programming
language
and
design
paradigms.
10/20/14
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23. Architecture
OpDons
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24. BACKUP
SLIDES
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25. From
LXC
to
libcontainer
• Move
from
using
LXC
to
libcontainer
as
default
at
release
0.9
– Standardize
interface
with
Linux,
can
be
controlled
as
expected.
– Joint
efforts.
– Cross-­‐plamorm,
in
Windows
too.
– Large
momentum
behind
Docker
technology.
10/20/14
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26. Cloudy
Performance:
Steady
State
Packing
hap://www.slideshare.net/dotCloud/performance-­‐characterisDcs-­‐of-­‐tradiDonal-­‐v-­‐ms-­‐vs-­‐docker-­‐containers
10/20/14
26
CPU
Usage
In
Percent
0
20
40
60
80
1
9
17
25
33
41
49
57
65
73
81
89
97
105
113
121
129
137
145
153
161
169
177
185
193
201
209
217
225
233
241
249
257
265
273
281
289
297
305
313
321
Time
Docker:
Compute
Node
CPU
(full
test
dura;on)
usr
sys
0.54
–
Averages
–
0.17
CPU
Usage
In
Percent
0
20
40
60
80
1
9
17
25
33
41
49
57
65
73
81
89
97
105
113
121
129
137
145
153
161
169
177
185
193
201
209
217
225
233
241
249
257
265
273
281
289
297
305
313
321
329
337
345
Time
KVM:
Compute
Node
CPU
(full
test
dura;on)
usr
sys
7.64
–
Averages
–
1.4
CreaDve
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27. Cloudy
Performance:
Steady
State
Packing
10/20/14
27
CPU
Usage
In
Percent
-­‐1
4
9
14
1
6
11
16
21
26
31
36
41
46
51
56
61
66
71
76
81
86
91
96
101
106
111
116
121
126
131
136
141
146
151
156
161
166
171
176
181
186
191
196
201
206
211
Time
(31s
–
243s)
Docker:
Compute
Node
Steady-­‐State
CPU
(segment:
31s
–
243s)
usr
sys
CPU
Usage
In
Percent
-­‐1
4
9
14
1
6
11
16
21
26
31
36
41
46
51
56
61
66
71
76
81
86
91
96
101
106
111
116
121
126
131
136
141
146
151
156
161
166
171
176
181
186
191
196
201
206
211
Time
(95s
-­‐
307s)
KVM:
Compute
Node
Steady-­‐State
CPU
(segment:
95s
–
307s)
usr
sys
0.2
–
Averages
–
0.03
1.91
–
Averages
–
0.36
31
seconds
243
seconds
95
seconds
307
seconds
CreaDve
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28. Cloudy
Performance:
Steady
State
Packing
7.00E+09
6.00E+09
5.00E+09
4.00E+09
3.00E+09
2.00E+09
1.00E+09
0.00E+00
Docker
/
KVM:
Compute
Node
Used
Memory
(Overlay)
1
10
19
28
37
46
55
64
73
82
91
100
109
118
127
136
145
154
163
172
181
190
199
208
217
226
235
244
253
262
271
280
289
298
307
316
325
334
Memory
Used
Axis
Title
docker
Delta
734
MB
Per
VM
49
MB
KVM
Delta
4387
MB
Per
VM
292
MB
kvm
docker
10/20/14
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28