1.
AdamCloud (Part 2):
Lessons learned from
Docker
Sébastien Bonami, IT Engineering Student
and
David Lauzon, Researcher
École de technologie supérieure (ÉTS)
Presented at Big Data Montreal #32 + DevOps Montreal
January 12th 2015
1

2.
Plan
● AdamCloud Project
● Docker Introduction
● Lessons learned from Docker
o Dockerfiles
o Data Storage
o Networking
o Monitoring
● Conclusion
2

3.
AdamCloud Project
Brief overview
3

4.
AdamCloud Goal
● Main goal: provide a portable infrastructure
for processing genomics data
● Requirements:
o A series of softwares must be chained in a pipeline
o Centralize configuration for multiple environments
o Simple installation procedure for new students
4

5.
Potential solution
● For genomics: Adam project developed at
Berkeley AmpLab
o Snap, Adam, Avocado
o (uses Spark, HDFS)
● For infrastructure:
o Docker ?
5

6.
Adam Genomic Pipeline
6
Fastq
File
(up to
250 GB)
Sam
File
Parquet
File
Parquet
File
(~10MB)
Sequencer
Machine
Snap AvocadoAdam
Hardware
AmpLab
Genomics
Projects
File
Formats

7.
AdamCloud - Environments
3 different environments
● Development (laptop)
o All services in 1 single host
● Demo
o Mac mini cluster
● Testing
o ÉTS servers (for larger genomes)
7

8.
Docker Introduction
From now on, we will talk about Docker leaving AdamCloud
aside.
For simplicity, we chose to use MySQL to demonstrate some
examples about learning Docker.
8

9.
Docker Introduction - Key Concepts
Dockerfile Image
Docker
Hub
Registry
Internet
Container
build
push
pull
run commit
Text file
Size = ~ KB
Installation &
config instructions
Composed of many read-only layers
Typical size = ~ hundred(s) MB
Can have multiple versions (akin Git tags)
Shares the image’s read-only layers
1 private writeable layer (copy-on-write)
Initial size = 0 bytes
Can be stopped, started, paused, etc.
Free public hosting
9

10.
Docker Introduction - How does it work?
Docker
Daemon Container 1
Host OS Kernel
Docker
Storage
Backend Container 2 ...
Hardware
Setups & manage the LXC containers.
Stores the image and container’s data layers
locally.
10

11.
Lesson 0:
Playing with Docker
11

12.
Lesson 0: Playing with Docker
$ sudo sh -c "echo deb https://get.docker.com/ubuntu docker main >
/etc/apt/sources.list.d/docker.list"
$ sudo apt-get update && sudo apt-get install -y --force-yes lxc-docker
12
$ docker run -ti --rm=true ubuntu bash
root@e0a1dad9f7fa:/# whoami; hostname
root
e0a1dad9f7fa
Creates a new interactive (-i)
container with a tty (-t) from the image
ubuntu, starts a bash shell, and
automatically remove the container
when it exits (--rm=true)
Install Docker
You are now “inside” the container
with the id e0a1dad9f7fa

13.
Dockerfiles
13

14.
Dockerfiles - MySQL Example (1/3)
$ mkdir mysql-docker/
$ vi mysql-docker/Dockerfile
# Contents of file mysql-docker/Dockerfile [1]
# Pull base image (from Docker Hub)
FROM ubuntu:14.04
# Install MySQL
RUN apt-get update
RUN apt-get install -y mysql-server
[1] Source: https://registry.hub.docker.com/u/dockerfile/mysql/dockerfile/ 14

15.
Dockerfiles - MySQL Example (2/3)
# Contents of file mysql-docker/Dockerfile (continued)
# Configure MySQL: listening interface, log error, etc.
RUN sed -i 's/^(bind-addresss.*)/# 1/' /etc/mysql/my.cnf
RUN sed -i 's/^(log_errors.*)/# 1/' /etc/mysql/my.cnf
RUN echo "mysqld_safe &" > /tmp/config
RUN echo "mysqladmin --silent --wait=30 ping || exit 1" >> /tmp/config
RUN echo "mysql -e 'GRANT ALL PRIVILEGES ON *.* TO "root"@"%" WITH GRANT
OPTION;'" >> /tmp/config
RUN bash /tmp/config && rm -f /tmp/config
15

16.
Dockerfiles - MySQL Example (3/3)
# Contents of file mysql-docker/Dockerfile (continued)
# Define default command
CMD ["mysqld_safe"]
# Expose guest port. Not required, but facilitates management
# NEVER expose the public port in the Dockerfile
EXPOSE 3306
16

17.
Dockerfiles - Building MySQL image
$ docker build -t mysql-image mysql-docker/
Sending build context to Docker daemon 2.56 kB
[...]
debconf: unable to initialize frontend: Dialog
debconf: (TERM is not set, so the dialog frontend is not usable.)
debconf: falling back to frontend: Readline
debconf: unable to initialize frontend: Readline
debconf: (This frontend requires a controlling tty.)
debconf: falling back to frontend: Teletype
[...]
17

18.
Lesson 1:
Dialog-less installs
18

19.
Lesson 1: Dialog-less installs
# Contents of file mysql/Dockerfile (showing differences)
[...]
RUN DEBIAN_FRONTEND=noninteractive apt-get install -y mysql-server
[...]
$ docker run -d mysql-image
5f3695d8f5e4dfc836156f645dbf6b647e264e58a25b4e2a9724b7522591b9bc
$ docker build -t mysql-image mysql-docker/
[...]
Successfully built d5cb85b206a4
That’s our image ID
That’s our container ID
(we can use a prefix as long as it is unique)
19

20.
Lesson 1: Testing the connectivity
$ mysql -uroot -h 172.17.0.102 -e "SHOW DATABASES;"
+--------------------+
| Database |
+--------------------+
| information_schema |
| mysql |
| performance_schema |
+--------------------+
$ docker inspect 5f3695d8f5e4 |grep IPAddress |cut -d'"' -f4
172.17.0.102
Finding the IP address
of our container
From the host, we can now connect to
our MySQL box inside the container
using the Docker network bridge.
20

21.
Lesson 2:
Layers
21

22.
Lesson 2: Layers - Docker History
$ docker history mysql-image
IMAGE CREATED CREATED BY SIZE
d5cb85b206a4 41 minutes ago /bin/sh -c #(nop) EXPOSE map[3306/tcp:{}] 0 B
a3fcf7ad0e46 41 minutes ago /bin/sh -c #(nop) CMD [mysqld_safe] 0 B
e495928f5148 41 minutes ago /bin/sh -c bash /tmp/config && rm -f /tmp/con 5.245 MB
e81232406a48 41 minutes ago /bin/sh -c echo "mysql -e 'GRANT ALL PRIVILEG 131 B
3ed871742259 41 minutes ago /bin/sh -c echo "mysqladmin --silent --wait=3 59 B
7383675c6559 41 minutes ago /bin/sh -c echo "mysqld_safe &" > /tmp/config 14 B
dfa40ac0f314 45 minutes ago /bin/sh -c sed -i 's/^(log_errors.*)/# 1/ 3.509 kB
01a7a7904f29 45 minutes ago /bin/sh -c sed -i 's/^(bind-addresss.*)/# 3.507 kB
2709eaa06d42 About an hour ago /bin/sh -c DEBIAN_FRONTEND=noninteractive apt 130.2 MB
6ca9716f2565 About an hour ago /bin/sh -c apt-get update 20.8 MB
86ce37374f40 6 weeks ago /bin/sh -c #(nop) CMD [/bin/bash] 0 B
dc07507cef42 6 weeks ago /bin/sh -c apt-get update && apt-get dist-upg 0 B
78e82ee876a2 6 weeks ago /bin/sh -c sed -i 's/^#s*(deb.*universe)$/ 1.895 kB
3f45ca85fedc 6 weeks ago /bin/sh -c rm -rf /var/lib/apt/lists/* 0 B
61cb619d86bc 6 weeks ago /bin/sh -c echo '#!/bin/sh' > /usr/sbin/polic 194.8 kB
5bc37dc2dfba 6 weeks ago /bin/sh -c #(nop) ADD file:d11cc4a4310c270539 192.5 MB
511136ea3c5a 19 months ago 0 B
17 layers !
Every Docker instruction
creates a layer.
200 MB for Ubuntu
20 MB for apt-get update
130 MB for installing
MySQL
22

23.
Time to
cleanup ?
23

24.
Lesson 2: Layers - What are they?
● Think of a layer as directory of files (or blocks)
● All these “physical” layers are combined into a
“logical” file system for each individual container
o Union file system
o Copy-on-write
o Like a stack: higher layers may override lower layers
24

25.
Lesson 2: Layers - Purpose (1/4)
● Blazing fast container instantiation
o To create a new instance from an image, Docker simply creates a
new empty read-write layer
Great, but we could achieve this goal
with 1 single layer per image + 1 layer
per container
Why 17 layers ?
25

26.
Lesson 2: Layers - Purpose (2/4)
● Faster image modification
o Changing/adding a Dockerfile instruction causes only the modified
layer(s) and those following it to be rebuilt
How often do you plan on changing
your Dockerfiles ?
26

27.
Lesson 2: Layers - Purpose (3/4)
● Faster distribution
o when distributing the image (via docker push) and downloading it
(via docker pull, or docker build), only the affected layer(s)
are sent.
27

28.
Lesson 2: Layers - Purpose (4/4)
● Minimize disk space
o All the containers located on the same Docker host and parent of
the same image hierarchy will share layers.
o Ubuntu Docker image is 200 MB
o 1000 containers based on Ubuntu only takes 200 MB total
(+ the additional packages they require)
Will you have multiple variants (config and/or versions) of MySQL on
the same machine ?
How many MySQL servers will you have on the same machine ?
28

29.
Lesson 2: Layers - Layer Genocide
$ cp -r mysql-docker/ mysql-docker-grouped
$ vi mysql-docker-grouped/Dockerfile
In this example, all our MySQL containers will be the same.
Therefore, we’ll only be needing 1 single layer.
29

30.
Lesson 2: Layers - Combine multiple RUN instructions
# Contents of file mysql-docker-grouped/Dockerfile
[...]
RUN apt-get update &&
apt-get install -y mysql-server &&
sed -i 's/^(bind-addresss.*)/# 1/' /etc/mysql/my.cnf &&
sed -i 's/^(log_errors.*)/# 1/' /etc/mysql/my.cnf &&
echo "mysqld_safe &" > /tmp/config &&
echo "mysqladmin --silent --wait=30 ping || exit 1" >> /tmp/config &&
echo "mysql -e 'GRANT ALL PRIVILEGES ON *.* TO "root"@"%" WITH GRANT
OPTION;'" >> /tmp/config &&
bash /tmp/config && rm -f /tmp/config
[...]
30

31.
Lesson 2: Layers - Docker History
$ docker build -t mysql-image-grouped mysql-docker-grouped/
[...]
Successfully built d5cb85b206a4
$ docker history mysql-image-grouped
IMAGE CREATED CREATED BY SIZE
11ccd4cc6c82 About an hour ago /bin/sh -c #(nop) EXPOSE map[3306/tcp:{}] 0 B
59c9467d3360 About an hour ago /bin/sh -c #(nop) CMD [mysqld_safe] 0 B
0993d316210d About an hour ago /bin/sh -c apt-get update && DEBIAN_FRONT 151 MB
86ce37374f40 6 weeks ago /bin/sh -c #(nop) CMD [/bin/bash] 0 B
dc07507cef42 6 weeks ago /bin/sh -c apt-get update && apt-get dist-upg 0 B
78e82ee876a2 6 weeks ago /bin/sh -c sed -i 's/^#s*(deb.*universe)$/ 1.895 kB
3f45ca85fedc 6 weeks ago /bin/sh -c rm -rf /var/lib/apt/lists/* 0 B
61cb619d86bc 6 weeks ago /bin/sh -c echo '#!/bin/sh' > /usr/sbin/polic 194.8 kB
5bc37dc2dfba 6 weeks ago /bin/sh -c #(nop) ADD file:d11cc4a4310c270539 192.5 MB
511136ea3c5a 19 months ago 0 B
Freed 7 layers !
Our Docker now only
adds 3 layers on top of
the base image:
RUN, CMD, EXPOSE
31

32.
Lesson 3:
Staying fit
32

33.
Lesson 3: Staying fit - Compacting layers
$ cp -r mysql-docker-grouped/ mysql-docker-cleaned
$ vi mysql-docker-cleaned/Dockerfile
Some commands, like apt-get update, creates some
temporary files, which can be safely discarded after use.
We can save space and create smaller images by deleting
those files.
33

34.
Lesson 3: Staying fit - Removing temporary files
# Contents of file mysql-docker-cleaned/Dockerfile (partial)
[...]
RUN apt-get update &&
apt-get install -y mysql-server &&
rm -fr /var/lib/apt/lists/* &&
[...]
$ docker build -t mysql-image-cleaned mysql-docker-cleaned/
[...]
Successfully built d5cb85b206a4
Remember: you’ll need to run
apt-get update again next time
you want to install something
34

35.
Lesson 3: Staying fit - Local Docker images
$ docker images
REPOSITORY TAG IMAGE ID CREATED VIRTUAL SIZE
mysql-image-cleaned latest 032798b8e064 2 hours ago 322.8 MB
mysql-image-grouped latest 11ccd4cc6c82 2 hours ago 343.6 MB
mysql-image latest d5cb85b206a4 3 hours ago 348.9 MB
ubuntu 14.04 86ce37374f40 6 weeks ago 192.7 MB
The cleaned image occupies 17% less space than the original
mysql-image (it’s a virtual size) [1].
MySQL is small; the impact can be much bigger for other
applications.
[1] ((348-192) - (322-192)) / (348-192) = 17%
35

36.
Lesson 3: Staying fit - Smallest Docker base images
Image:Tag Size
scratch 0.0 B
busybox:ubuntu-14.04 5.6 MB
debian:7 85.0 MB
ubuntu:14.04 192.7 MB
centos:7 210.0 MB
fedora:21 241.3 MB
36

37.
Lesson 3: Staying fit - docker diff
● Show differences between container and the image
o Useful to see which files have been modified/created when writing
your Dockerfile
37

38.
Lesson 4:
Fixed as “worksforme”
38

39.
Lesson 4: Reproducibility - Package
version
● Your Dockerfile may build a different image in a few
months than today’s image
RUN apt-get install -y mysql-server
RUN apt-get install -y mysql-server=5.5.40-0ubuntu0.14.04.1
Specify the package version explicitly is better
39

40.
Lesson 4: Reproducibility - Dependency
version
RUN apt-get install -y libaio1=0.3.109-4 mysql-common=5.5.40-0ubuntu0.14.04.1
libmysqlclient18=5.5.40-0ubuntu0.14.04.1 libwrap0=7.6.q-25 libdbi-perl=1.630-
1 libdbd-mysql-perl=4.025-1 libterm-readkey-perl=2.31-1 mysql-client-core-
5.5=5.5.40-0ubuntu0.14.04.1 mysql-client-5.5=5.5.40-0ubuntu0.14.04.1 mysql-
server-core-5.5=5.5.40-0ubuntu0.14.04.1 psmisc=22.20-1ubuntu2 mysql-server-
5.5=5.5.40-0ubuntu0.14.04.1 libhtml-template-perl=2.95-1 mysql-server=5.5.40-
0ubuntu0.14.04.1 tcpd=7.6.q-25
Previous solution should be enough…
But if you need higher guarantee of reproducibility:
A. Specify the package version for the dependencies as well
B. And / or use a cache proxy, maven proxy, etc.
40

41.
Lesson 5:
Prototry
A quick and dirty attempt to develop a working
model of software. The original intent is to
rewrite the ProtoTry, using lessons learned, but
schedules never permit. Also known as legacy
code. [1]
41[1] Michael Duell, Ailments of Unsuitable Project-Disoriented Software, http://www.fsfla.org/~lxoliva/fun/prog/resign-patterns

42.
Lesson 5: Prototry - Docker Hub Registry
● Before writing your own Dockerfile, try a build from
someone else
o https://registry.hub.docker.com/
o Official builds
o Trusted (automated) builds
o Other builds
For advanced setup,
see these images:
● jenkins
● dockerfile/java
42

43.
Lesson 5: Prototry - Using other people images
PROs CONs
● Faster to get started
● Better tested
● You may end up with a mixed stack to
support
○ e.g. different versions of Java
○ Ubuntu vs Debian vs CentOS
● Not all sources use all the best practices
described in this presentation
For medium - large organisations / heavy Docker users:
Best to fork and write your own Dockerfiles
43

44.
Lesson 5: Prototry - Potential image hierarchy
FROM ubuntu:14.04
# Organization-wide tools (e.g. vim, etc.)
myorg-base
myorg-java
FROM myorg-base:1.0
# OpenJDK | OracleJDK
myorg-python
FROM myorg-base:1.0
# Install Python 2.7
python-app1
FROM myorg-python:2.7
# ...
java-app3
FROM myorg-java:oracle-jdk7
# ...
python-app2
FROM myorg-python:2.7
# ...
44

45.
Lesson 6:
Volume Design Patterns
45

46.
● Nothing to do - that’s the default Docker behavior
o Application data is stored along with the
infrastructure (container) data
● If the container is restarted, data is still there
● If the container is deleted, data is gone
Lesson 6: Inside Container Pattern
46

47.
Lesson 6: Host Directory Pattern
● A directory on the host
● To share data across containers on the
same host
● For example, put the source code on the
host and mount it inside the container with
the “-v” flag
47

48.
Lesson 6: Data-Only Container Pattern
● Run on a barebone image
● VOLUME command in the Dockerfile or “-v”
flag at run
● Just use the “--volumes-from” flag to
mount all the volumes in another container
48

49.
Lesson 7:
Storage backend
49

50.
Lesson 7: Storage backend - Overview
● Options:
o VFS
o AUFS (default, docker < 0.7)
o DeviceMapper
 Direct LVM
 Loop LVM (default in Red Hat)
o Btrfs (experimental)
o OverlayFS (experimental)
Red Hat[1] says the
fastest backends are:
1. OverlayFS
2. Direct LVM
3. BtrFS
4. Loop LVM
Lookup your current Docker backend
$ docker info |grep Driver
[1] http://developerblog.redhat.com/2014/09/30/overview-storage-scalability-docker/
50

51.
Lesson 7: Storage backend - VFS & AUFS
● Both are very basic (NOT for PROD)
● Both store each layer as a separate directory with
regular files
● VFS
o No Copy-on-Write (CoW)
● AUFS
o Original Docker backend
o File-level Copy-on-Write (CoW)
VFS & AUFS can be
useful to understand how
Docker works
Do not use in PROD
51

52.
Lesson 7: Storage backend - DeviceMapper (1/2)
● Already used by linux kernel for LVM2 (logical volume management)
o Block-level Copy-on-Write (CoW)
o Unused blocks do not use space
● Uses thin pool provisioning to implement CoW snapshots
o Each pool requires 2 block devices: data & metadata
o By default, uses loop back mounts on sparse regular files
# ls -alhs /var/lib/docker/devicemapper/devicemapper
506M -rw-------. 1 root root 100G Sep 10 20:15 data
1.1M -rw-------. 1 root root 2.0G Sep 10 20:15 metadata
Loop LVM
52

53.
Lesson 7: Storage backend - DeviceMapper (2/2)
● In production:
o Use real block devices! (Direct LVM)
o Ideally, data & metadata each on its own spindle
o Additional configuration is required
Docker does not
do that for you
53

54.
Lesson 7: Storage backend - Btrfs & OverlayFS
Btrfs:
● Requires /var/lib/docker to be on a btrfs file system
● Block-level Copy-on-Write (CoW) using Btrfs’s snapshotting
● Each layer stored as a Btrfs subvolume
● No SELinux
OverlayFS:
● Support page cache sharing
● Lower FS contains the base image (XFS or EXT4)
● Upper FS contains the deltas
● No SELinux
Claims a huge
RAM saving
54

55.
Lesson 8:
Networking
55

56.
Docker
● Ethernet bridge “docker0” created when Docker boots
● Virtual subnet on the host (default: 172.17.42.1/16)
● Each container has a pair of virtual Ethernet interfaces
● You can remove “docker0” and use your own bridge if
you want
56

57.
Weave
Why Weave?
● Docker built-in functionalities don’t provide
a solution for connecting containers on
multiple hosts
● Weave create a virtual network to permit a
distributed environment (common in the
real word)
57

58.
Weave
How does it work?
● Virtual routers establish TCP connections to
each other with a handshake
● These connections are duplex
● Use “pcap” to capture packets
● Exclude traffic between local containers
58

59.
Weave
Weave
Container
Container 1 Container 2 Container 3
Host A
Weave
Container
Container 1 Container 2 Container 3
Host B
59

60.
Weave - images
Image:Tag Size
zettio/weave:0.8.0 11 MB
zettio/weavedns:0.8.0 9.4 MB
zettio/weavetools:0.8.0 3.7 MB
60

61.
Weave - getting started
$ sudo weave launch
$ sudo weave run 10.0.0.1/24 -ti --name ubuntu-01 ubuntu:14.04
$ sudo weave launch weave-01
$ sudo weave run 10.0.0.2/24 -ti --name ubuntu-02 ubuntu:14.04
● First host: weave-01
● Second host: weave-02
Note: “weave run” invokes “docker run -d” (running as a daemon)
Starts the weave router in a container
Starts the weave router in a container and peers it
CIDR notation
61

62.
Weave - testing the connectivity (1/2)
$ sudo weave status
weave router 0.8.0
Our name is 7a:ab:c1:21:f9:3b
Sniffing traffic on &{15 65535 ethwe 56:40:66:0b:a4:c6 up|broadcast|multicast}
MACs:
56:40:66:0b:a4:c6 -> 7a:ab:c1:21:f9:3b (2015-01-11 22:27:39.23846091 +0000 UTC)
7a:ab:c1:21:f9:3b -> 7a:ab:c1:21:f9:3b (2015-01-11 22:27:40.142183122 +0000 UTC)
a2:60:ab:8b:1f:b6 -> 7a:ab:c1:21:f9:3b (2015-01-11 22:27:40.716414595 +0000 UTC)
7a:5a:98:6e:92:2e -> 7a:5a:98:6e:92:2e (2015-01-11 22:28:53.204010927 +0000 UTC)
1e:b4:78:1e:dd:23 -> 7a:5a:98:6e:92:2e (2015-01-11 22:28:53.42594994 +0000 UTC)
Peers:
Peer 7a:ab:c1:21:f9:3b (v1) (UID 17511927952474106279)
-> 7a:5a:98:6e:92:2e [192.168.1.30:47638]
Peer 7a:5a:98:6e:92:2e (v1) (UID 8527109358448991597)
-> 7a:ab:c1:21:f9:3b [192.168.1.195:6783]
Routes:
unicast:
7a:5a:98:6e:92:2e -> 7a:5a:98:6e:92:2e
7a:ab:c1:21:f9:3b -> 00:00:00:00:00:00
broadcast:
7a:ab:c1:21:f9:3b -> [7a:5a:98:6e:92:2e]
7a:5a:98:6e:92:2e -> []
Reconnects:
● First host: weave-01
Connected peers
Virtual interface used by Weave
Containers and
host points
62

63.
Weave - testing the connectivity (2/2)
$ sudo docker attach ubuntu-02
$ ping -c 4 10.0.0.1
PING 10.0.0.1 (10.0.0.1) 56(84) bytes of data.
64 bytes from 10.0.0.1: icmp_seq=1 ttl=64 time=4.22 ms
64 bytes from 10.0.0.1: icmp_seq=2 ttl=64 time=1.20 ms
64 bytes from 10.0.0.1: icmp_seq=3 ttl=64 time=1.73 ms
64 bytes from 10.0.0.1: icmp_seq=4 ttl=64 time=2.02 ms
--- 10.0.0.1 ping statistics ---
4 packets transmitted, 4 received, 0% packet loss, time 3008ms
rtt min/avg/max/mdev = 1.206/2.299/4.226/1.150 ms
● Second host: weave-02
It pings!
63

64.
Lesson 9:
Monitoring
64

65.
cAdvisor
● New tool from Google
● Specialized for Docker containers
PROs CONs
● Great web interface
● Docker image available (18 MB)
to try it in seconds
● Stats can be export to InfluxDB
(data mining to do)
● Needs more maturity
● Missing metrics
○ No data for Disk I/O
● Only keep last 60 metrics locally (not
configurable)
65

66.
Monitoring with cAdvisor
Web interface →
66

67.
Conclusion
67

68.
AdamCloud - The next steps
● Docker + Weave = success
● Open-source the project and merge it
upstream into the AmpLab genomic
pipeline.
● Support for Amazon EC2 environments
● Improve administration of Docker
containers
o Monitoring, orchestration, provisioning
68

69.
Docker Conclusion
● 1 Docker container = 1 background daemon
● Container isolation is not like a VM
● Use correct versions of images and keep a trace
● Docker is less interesting for multi-tenants use cases (no SSH in the
containers)
● Docker is FAST and VERSATILE
● cAdvisor is an interesting monitoring tool, but limited
● Docker is perfect for short lived apps (no long term data persistence)
● Data intensive apps should review the Docker docs carefully. Start
looking at Direct LVM.
69

70.
References
● Jonathan Bergknoff - Building good docker images, http://jonathan.bergknoff.com/journal/building-good-
docker-images
● Michael Crosby - Dockerfile Best Practices, http://crosbymichael.com/dockerfile-best-practices.html
● Michael Crosby - Dockerfile Best Practices - take 2, http://crosbymichael.com/dockerfile-best-practices-take-
2.html
● Nathan Leclaire - The Dockerfile is not the source of truth for your image,
http://nathanleclaire.com/blog/2014/09/29/the-dockerfile-is-not-the-source-of-truth-for-your-image/
● Docker Documentation - Understanding Docker, https://docs.docker.com/introduction/understanding-docker/
● Docker Documentation - Docker User Guide, https://docs.docker.com/userguide/
● Docker Documentation - Dockerfile Reference, https://docs.docker.com/reference/builder/
● Docker Documentation - Command Line (CLI) User Guide,
https://docs.docker.com/reference/commandline/cli/
● Docker Documentation - Advanced networking, http://docs.docker.com/articles/networking/
● Project Atomic - Supported Filesystems, http://www.projectatomic.io/docs/filesystems/
● Red Hat Developer Blog - Comprehensive Overview of Storage Scalability in Docker,
http://developerblog.redhat.com/2014/09/30/overview-storage-scalability-docker/
● Linux Kernel Documentation - DeviceMapper Thin Provisioning,
https://www.kernel.org/doc/Documentation/device-mapper/thin-provisioning.txt
● weave - the Docker network, http://zettio.github.io/weave/
● GitHub - google/cadvisor, https://github.com/google/cadvisor
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