├── .dockerignore
├── Dockerfile
├── README.md
├── image-graph-cmd.rb
├── image-graph-web.rb
├── image-graph.sh
├── public
    ├── index.html
    └── texture-noise.png
├── sample-cmd.png
└── sample-web.png


/.dockerignore:
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1 | README.md
2 | *.png
3 | 


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/Dockerfile:
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 1 | FROM ubuntu
 2 | 
 3 | MAINTAINER ian.miell@gmail.com
 4 | 
 5 | RUN apt-get update
 6 | 
 7 | RUN DEBIAN_FRONTEND=noninteractive apt-get install -y graphviz ruby-dev gem build-essential
 8 | RUN gem install docker-api sinatra
 9 | 
10 | ADD . /usr/src/app/
11 | WORKDIR /usr/src/app
12 | RUN chmod +x image-graph.sh
13 | 
14 | CMD [""]
15 | ENTRYPOINT ["./image-graph.sh"]
16 | 


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/README.md:
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 1 | ## image-graph
 2 | Generates a nice graph showing the hierarchy of Docker images in your local
 3 | image cache.
 4 | 
 5 | Looks at all of the Docker image layers cached on the local system and
 6 | generates a PNG image showing the relationship of the various layers.
 7 | 
 8 | ### Usage
 9 | 
10 | The Ruby *image-graph* script is itself packaged as a Docker image so it can
11 | easily be executed with the Docker *run* command.
12 | 
13 | Since the script interacts with the Docker API in order to inspect your local
14 | image cache it needs access to the Docker API socket. When starting the container, the `-v` flag needs to be used to make the Docker socket available inside the container.
15 | 
16 | By default, when the container is started it will generate a PNG that is streamed to `stdout`:
17 | 
18 |     docker run --rm -v /var/run/docker.sock:/var/run/docker.sock \
19 |       centurylink/image-graph > docker_images.png
20 | 
21 | You'll need to redirect the container's output to a file in order to save/view the generated image. The name of the output file does not matter, but it is recommended that you use a `.png` extension so that your image viewer will properly recognize the format of the file.
22 | 
23 | If you supply an environment variabled named *PORT* using the `-e` flag the container will spin-up a web server on the designated port that hosts a web-based version of the image graph:
24 | 
25 |     docker run -d -v /var/run/docker.sock:/var/run/docker.sock \
26 |       -e PORT=3000 -p 3000:3000 centurylink/image-graph 
27 |       
28 | In the example above, the web server will be started on port 3000. When using this option you'll also want to use the `-p` flag to map the container port to a port on the host so that you can access the server from outside the container. The container port you specify with the `-p` flag should match the value you specified for the *PORT* environment variable.
29 | 
30 | When a value for the *PORT* envrionment variable is provided, the PNG version of the image is **not** streamed to `stdout`. 
31 | 
32 | ### Example
33 | 
34 | Here's an example graph generated by this utility:
35 | 
36 | ![Sample Image](https://github.com/CenturyLinkLabs/docker-image-graph/raw/master/sample-cmd.png)
37 | 
38 | And the web-based graph:
39 | 
40 | ![Sample Image](https://github.com/CenturyLinkLabs/docker-image-graph/raw/master/sample-web.png)
41 | 
42 | ### FAQs
43 | 
44 | **How is this different than running `docker images --viz | dot -Tpng`?**
45 | 
46 | Actually, it's not different at all. The Ruby script executed by the image
47 | essentially generates the same output that the `--viz` flag does and then pipes
48 | it to the Graphviz *dot* tool to generate the graph.
49 | 
50 | **So, why do we need to execute a container when the same thing can be
51 | achieved with a one-line Docker command?**
52 | 
53 | While this will work for some versions of Docker, the `--viz` flag has been
54 | marked as deprecated and will likely be removed in some future release.
55 | 
56 | Additionally, my primary Docker environment is CoreOS which does not have
57 | Graphviz installed and provides no way for me to install it myself -- in
58 | an environment like this, the only option is to run Graphviz inside a
59 | container.
60 | 
61 | 


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/image-graph-cmd.rb:
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 1 | #! /usr/local/bin/ruby
 2 | require 'open3'
 3 | require 'docker'
 4 | 
 5 | dot_file = []
 6 | dot_file << 'digraph docker {'
 7 | 
 8 | Docker::Image.all(all: true).each do |image|
 9 | 
10 |   id = image.id[0..11]
11 |   tags = image.info['RepoTags'].reject { |t| t == '<none>:<none>' }.join('\n')
12 |   parent_id = image.info['ParentId'][0..11]
13 | 
14 |   if parent_id.empty?
15 |     dot_file << "base -> \"#{id}\" [style=invis]"
16 |   else
17 |     dot_file << "\"#{parent_id}\" -> \"#{id}\""
18 |   end
19 | 
20 |   unless tags.empty?
21 |     dot_file << "\"#{id}\" [label=\"#{id}\\n#{tags}\",shape=box,fillcolor=\"paleturquoise\",style=\"filled,rounded\"];"
22 |   end
23 | end
24 | 
25 | dot_file << 'base [style=invisible]'
26 | dot_file << '}'
27 | 
28 | Open3.popen3('/usr/bin/dot -Tpng') do |stdin, stdout, stderr|
29 |   stdin.puts(dot_file.join("\n"))
30 |   stdin.close
31 |   STDOUT.write stdout.read
32 | end
33 | 


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/image-graph-web.rb:
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 1 | require 'sinatra'
 2 | require 'docker'
 3 | 
 4 | set :port, ENV['PORT']
 5 | set :bind, '0.0.0.0'
 6 | 
 7 | get '/' do
 8 |   File.read(File.join('public', 'index.html'))
 9 | end
10 | 
11 | get '/images.json' do
12 | 
13 |   Docker::Image.all(all: 1).map do |image|
14 |     label = "#{image.short_id} &mdash; #{image.size} MB<span class=\"tags\">#{image.tags}</span>"
15 | 
16 |     [ { v: image.id, f: label }, image.parent_id, image.cmd, ]
17 |   end.to_json
18 | end
19 | 
20 | delete '/images/:image_id.json' do
21 |   image = Docker::Image.get(params['image_id'])
22 | 
23 |   begin
24 |     image.remove()
25 |     "true"
26 |   rescue => ex
27 |     "false"
28 |   end
29 | end
30 | 
31 | class Docker::Image
32 | 
33 |   NOP_PREFIX = '#(nop) '
34 | 
35 |   def short_id
36 |     id[0..11]
37 |   end
38 | 
39 |   def parent_id
40 |     info['ParentId']
41 |   end
42 | 
43 |   def size
44 |     info['VirtualSize'] / 1024 / 1024
45 |   end
46 | 
47 |   def tags
48 |     info['RepoTags'].reject { |t| t == '<none>:<none>' }.join(', ')
49 |   end
50 | 
51 |   def cmd
52 |     cmd = json['ContainerConfig']['Cmd']
53 | 
54 |     if cmd && cmd.size == 3
55 |       cmd = cmd.last
56 | 
57 |       if cmd.start_with?(NOP_PREFIX)
58 |         cmd = cmd.split(NOP_PREFIX).last
59 |       else
60 |         cmd = "RUN #{cmd}".squeeze(' ')
61 |       end
62 |     end
63 | 
64 |     cmd
65 |   rescue => ex
66 |     ''
67 |   end
68 | end
69 | 


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/image-graph.sh:
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1 | #! /bin/bash
2 | 
3 | if [ -z "$PORT"]; then
4 |   ruby ./image-graph-cmd.rb
5 | else
6 |   ruby ./image-graph-web.rb
7 | fi
8 | 


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/public/index.html:
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  1 | <html>
  2 |   <head>
  3 |     <script type='text/javascript' src='https://www.google.com/jsapi'></script>
  4 |     <script type="text/javascript" src="https://ajax.googleapis.com/ajax/libs/jquery/1.10.2/jquery.min.js"></script>
  5 |     <script type='text/javascript'>
  6 | 
  7 |       var timer, chart, data;
  8 | 
  9 |       var init = function() {
 10 |         chart = new google.visualization.OrgChart(document.getElementById('chart'));
 11 |         google.visualization.events.addListener(chart, 'collapse', onCollapse);
 12 |         google.visualization.events.addListener(chart, 'select', onSelect);
 13 |         $('body').keypress(onKeyPress);
 14 |         onTimeout();
 15 |       }
 16 | 
 17 |       var onTimeout = function() {
 18 |         clearTimeout(timer);
 19 |         drawChart();
 20 |         restartTimer();
 21 |       };
 22 | 
 23 |       var onCollapse = function() {
 24 |         clearTimeout(timer);
 25 | 
 26 |         if (chart.getCollapsedNodes().length == 0) {
 27 |           restartTimer();
 28 |         }
 29 |       };
 30 | 
 31 |       var onSelect = function(e) {
 32 |         clearTimeout(timer);
 33 | 
 34 |         if (chart.getSelection().length == 0) {
 35 |           restartTimer();
 36 |         }
 37 |       };
 38 | 
 39 |       var onKeyPress = function(e) {
 40 |         if (e.keyCode == 120) {
 41 |           var rows = chart.getSelection();
 42 | 
 43 |           if (rows.length > 0) {
 44 |             var image_id = data.getValue(rows[0].row, 0);
 45 | 
 46 |             $.ajax({
 47 |               url: "/images/" + image_id + ".json",
 48 |               type: "DELETE",
 49 |               dataType: "json"
 50 |             }).done(function(e) {
 51 |               if (!e) {
 52 |                 alert("Layer could not be deleted");
 53 |               }
 54 |               restartTimer();
 55 |             });
 56 |           }
 57 |         }
 58 |       }
 59 | 
 60 |       var drawChart = function() {
 61 | 
 62 |         var jsonData = $.ajax({
 63 |           url: "/images.json",
 64 |           dataType:"json",
 65 |           async: false
 66 |         }).responseJSON;
 67 | 
 68 |         data = new google.visualization.DataTable();
 69 |         data.addColumn('string', 'ID');
 70 |         data.addColumn('string', 'Parent');
 71 |         data.addColumn('string', 'ToolTip');
 72 |         data.addRows(jsonData);
 73 | 
 74 |         chart.draw(data, {
 75 |           allowHtml:true,
 76 |           allowCollapse: true,
 77 |           nodeClass: 'layer',
 78 |           size: 'small'
 79 |         });
 80 | 
 81 |       };
 82 | 
 83 |       var restartTimer = function() {
 84 |         timer = setTimeout(onTimeout, 1000);
 85 |       };
 86 | 
 87 |       google.load('visualization', '1', { packages: ['orgchart'] });
 88 |       google.setOnLoadCallback(init);
 89 |     </script>
 90 | 
 91 |     <style>
 92 |       body {
 93 |         background: url(texture-noise.png);
 94 |       }
 95 | 
 96 |       header {
 97 |         font-family: "Helvetica Neue", Helvetica;
 98 |         font-size: 36px;
 99 |         font-weight: 300;
100 |         text-shadow: 0 1px 0 #fff;
101 |         margin: 10px 10px;
102 |       }
103 | 
104 |       header .hint {
105 |         font-size: 12px;
106 |         color: #999;
107 |       }
108 | 
109 |       .layer {
110 |         text-align: center;
111 |         vertical-align: middle;
112 |         font-family: Consolas, "Andale Mono WT", "Andale Mono", "Lucida Console", "Lucida Sans Typewriter", "DejaVu Sans Mono", "Bitstream Vera Sans Mono", "Liberation Mono", "Nimbus Mono L", Monaco, "Courier New", Courier, monospace;
113 |         border: 2px solid #b5d9ea;
114 |         -webkit-border-radius: 5px;
115 |         -webkit-box-shadow: rgba(0, 0, 0, 0.5) 3px 3px 3px;
116 |         background-color: #edf7ff;
117 |         -webkit-gradient(linear, left top, left bottom, from(#edf7ff), to(#cde7ee))
118 |       }
119 | 
120 |       .tags {
121 |         font-family: "Helvetica Neue", Helvetica;
122 |         display: block;
123 |         font-weight: bold;
124 |         margin-top: 3px;
125 |       }
126 |     </style>
127 |   </head>
128 | 
129 |   <body>
130 |     <header>
131 |       Docker Image Cache
132 |       <div class="hint">- Double-click on node to collapse/expand</div>
133 |       <div class="hint">- Select node and press 'x' to delete</div>
134 |     </header>
135 | 
136 |     <div id='chart'></div>
137 |   </body>
138 | </html>
139 | 


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/public/texture-noise.png:
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https://raw.githubusercontent.com/docker-in-practice/docker-image-graph/a7c4b4c753f60d437f34de9360764cc99b60fb4e/public/texture-noise.png


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/sample-cmd.png:
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https://raw.githubusercontent.com/docker-in-practice/docker-image-graph/a7c4b4c753f60d437f34de9360764cc99b60fb4e/sample-cmd.png


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/sample-web.png:
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https://raw.githubusercontent.com/docker-in-practice/docker-image-graph/a7c4b4c753f60d437f34de9360764cc99b60fb4e/sample-web.png


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