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https://github.com/pcasteran/terraform-graph-beautifier

Terraform graph beautifier
https://github.com/pcasteran/terraform-graph-beautifier

cytoscapejs golang graphviz graphviz-dot terraform terraform-graph

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Terraform graph beautifier

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# Terraform graph beautifier



Command line tool allowing to convert the barely usable output of the `terraform graph` command to something more

meaningful and explanatory.



| `terraform graph` raw output | Processed output |

| :-: | :-: |

| ![?](doc/config1_raw.png) | ![?](doc/config1_cyto_embedded.png) |



## Installation



You can download the binary corresponding to the required platform from

the [release](https://github.com/pcasteran/terraform-graph-beautifier/releases) page.



You can also build the binary from the sources:



```bash

go install github.com/pcasteran/terraform-graph-beautifier

```



Finally, you can also use

the [Docker images](https://github.com/pcasteran/terraform-graph-beautifier/pkgs/container/terraform-graph-beautifier)

available for the Linux and Darwin operating systems:



```bash

# Linux

docker pull ghcr.io/pcasteran/terraform-graph-beautifier:latest-linux



# Darwin

docker pull ghcr.io/pcasteran/terraform-graph-beautifier:latest-darwin

```



## Basic usage



```bash

cd samples/config1/

terraform init



# Using the binary.

terraform graph | terraform-graph-beautifier \

    --output-type=cyto-html \

    > config1.html



# Using the Docker image.

terraform graph | docker run --rm -i \

    --name terraform-graph-beautifier \

    ghcr.io/pcasteran/terraform-graph-beautifier:latest-linux \

    --output-type=cyto-html \

    > config1.html

```



## Input and outputs



The command performs the following:



1. Parsing of the Graphviz [Dot](https://www.graphviz.org/doc/info/lang.html) script generated by `terraform graph` from

   the standard input or the specified file (`--input` parameter).

1. Extraction of the graph containing the Terraform configuration elements and their dependencies.

1. Generation of the result to the standard output or file (`--output` parameter). The following output

   types (`--output-type` parameter) are supported:

    - **cyto-html** (default): an HTML page using [Cytoscape.js](https://js.cytoscape.org/) to render the graph (

      see [example](doc/config1.html));

    - **cyto-json**: a JSON document of the graph in the

      Cytoscape.js [format](https://js.cytoscape.org/#notation/elements-json) (see [example](doc/config1.json));

    - **graphviz**: a cleaned and prettier Dot script that can be piped to a

      Graphviz [rendering command](https://linux.die.net/man/1/dot) (see [example](doc/config1.gv)).



### Input graph loading and processing



The loading of the input graph involves the following steps:



1. **Cleaning the Dot script**

    1. Renaming the nodes using a more consistent

       pattern: `[root] rsc_type.rsc_name` => `module.root.rsc_type.rsc_name`.

    1. Using the `'` character instead of `"` fot the maps keys: `buckets["artefacts"]` => `buckets['artefacts']`.

    1. Removing the nodes and edges generated by Terraform but not corresponding to configuration elements (aka TF

       junk). This can be deactivated via the `--keep-tf-junk` parameter.

1. **Filtering**

    - Using user-provided pattern(s) to exclude some elements (resource, var, module, provider, ...) from the output.

    - These patterns are [Go regexp](https://golang.org/pkg/regexp/) and are matched line by line against the output of

      the **cleaning** step, so use the `"root.rsc_type.rsc_name"` naming convention.

    - These patterns are provided using the `--exclude` parameter, you can repeat it multiple times.



### Output configuration



#### Modules embedding



An important option is to choose whether to embed a submodule in its parent module or not. The `--embed-modules`

parameter allows to control this behavior:



- if **true** (default), the modules subgraphs will be embedded inside their parent;

- if **false**, all the subgraphs are drawn at the same level and an edge is drawn from a parent to its children.



As a rule of thumb, `--embed-modules=true` works well for small to medium size graphs but for larger ones it can produce

a very dense and compact result with a lot of overlapping nodes and intersecting edges.



| Output type | `--embed-modules=true` | `--embed-modules=false` |

| :-: | :-: | :-: |

| **cyto-html** | ![?](doc/config1_cyto_embedded.png) | ![?](doc/config1_cyto_no-embedded.png) |

| **graphviz** | ![?](doc/config1_graphviz_embedded.png) | ![?](doc/config1_graphviz_no-embedded.png) |



#### HTML output templating



The command uses Go [templates](https://golang.org/pkg/text/template/) to create the HTML output.

The following annotations will be replaced during the output generation:



- **{{.PageTitle}}**: will be replaced by the graph name (see `--graph-name` parameter).

- **{{.GraphElementsJSON}}**: will be replaced by the graph elements JSON object.



A basic template, with sensible default values for the graph rendering (style and layout), is provided and is embedded

in the binary.



If you want to customize the output, you can provide your own template and specify to use it with

the `--cyto-html-template` parameter.

It is good practice to check in your custom templates alongside your Terraform configuration.