Mermaid support (#139)

* mermaid support wip

* feat: adding support for mermaid output

* feat: adding support for mermaid output

Co-authored-by: ljacobsson <lars@mathem.se>

README.md

@@ -130,6 +130,25 @@ Renders a simple Ascii-art diagram of your template directly in the console. Use
 Video demo of using the `--watch` option:
 [![Demo of watch command](https://img.youtube.com/vi/2V3zimGWTcU/0.jpg)](https://www.youtube.com/watch?v=2V3zimGWTcU)
 
+### Mermaid
+```
+Usage: cfn-dia mermaid|m [options]
+
+Generates a mermaid graph from a template
+
+Options:
+  -t, --template-file [templateFile]  Path to template or cdk.json file (default: "template.yaml or cdk.json")
+  -all --render-all                   If set, all nested stacks will be rendered. By default only root template is rendered (default: false)
+  -o, --output-path [outputPath]      Name of output file
+  -co, --cdk-output [cdkOutputPath]   CDK synth output path (default: "cdk.out")
+  -s, --skip-synth                    Skips CDK synth (default: false)
+  -h, --help                          display help for command
+```
+
+Renders a [mermaid](https://mermaid-js.github.io/mermaid/#/) diagram of your template directly in the console or to a file. Useful to gain a quick overview of smaller stacks and to generate as part of your CI/CD flow for up-to-date documentation.
+
+![Demo](https://raw.githubusercontent.com/mhlabs/cfn-diagram/master/images/demo-mermaid.gif)
+
 
 ### CI-mode
 This functionality lives in its own CLI, [cfn-diagram-ci](https://github.com/mhlabs/cfn-diagram-ci). This is beacuse it requires headless Chromium to be installed which makes the package size very large

commands/mermaid/index.js

@@ -0,0 +1,100 @@
+const Vis = require("../../graph/Vis");
+const program = require("commander");
+const template = require("../../shared/templateParser");
+const fs = require("fs");
+program
+  .command("mermaid")
+  .alias("m")
+  .option(
+    "-t, --template-file [templateFile]",
+    "Path to template or cdk.json file",
+    "template.yaml or cdk.json"
+  )
+  .option("-all --render-all", "If set, all nested stacks will be rendered. By default only root template is rendered", false)
+  .option(
+    "-o, --output-path [outputPath]",
+    "Name of output file"
+  )
+  .option("-co, --cdk-output [cdkOutputPath]", "CDK synth output path", `cdk.out`)
+  .option("-s, --skip-synth", "Skips CDK synth", false)
+  .description("Generates a mermaid graph from a template")
+  .action(async (cmd) => {
+    ciMode = cmd.ciMode;
+    const templateObj = template.get(cmd);
+    const graph = await Vis.makeGraph(
+      templateObj.template,
+      "root",
+      false,
+      cmd.renderAll
+    );
+
+    const groups = {};
+    for (const edge of graph.edges) {
+      const owner = edge.from.split(".")[0];
+
+      if (edge.to.startsWith(`${owner}.`) && edge.from.startsWith(`${owner}.`)) {
+        if (!groups[owner]) {
+          groups[owner] = [];
+        }
+        groups[owner].push(edge);
+      } else {
+        if (!groups["crossgroup"]) {
+          groups["crossgroup"] = [];
+        }
+        groups["crossgroup"].push(edge);
+      }
+    }
+    const uniqueRelations = [];
+    let mermaidString = `\`\`\`mermaid\n\tflowchart TB;\n`;
+    for (const groupKey in groups) {
+      const group = groups[groupKey];
+      if (groupKey !== "crossgroup") {
+        mermaidString += `\t\tsubgraph ${groupKey !== "root" ? groupKey : " "}\n`;
+      }
+
+      mermaidString += `${group.map(p => {
+        const fromResource = graph.nodes.find(n => n.id === p.from);
+        const toResource = graph.nodes.find(n => n.id === p.to);
+
+        const from = createShape(fromResource);
+        const to = createShape(toResource);
+        const relation = `\t\t${from}-->${to}`;
+        if (!uniqueRelations.includes(relation)) {
+          uniqueRelations.push(relation);
+          return relation;
+        }
+      }).filter(p => p).join("\n")}
+
+  `
+      if (groupKey !== "crossgroup") {
+        mermaidString += `\tend\n`;
+      }
+
+    }
+
+    mermaidString += `\n\`\`\``;
+    if (cmd.outputPath) {
+      fs.writeFileSync(cmd.outputPath, mermaidString);
+      console.log(`Wrote Mermaid diagram to ${cmd.outputPath}`);
+    } else {
+      console.log(mermaidString)
+    }
+  });
+
+function createShape(resource, cmd) {
+  const label = resource.label.replace(/[^a-z0-9\n]/gmi, "").replace(/\s+/g, "");
+  const id = resource.id.replace(/[^a-z0-9\n]/gmi, "").replace(/\s+/g, "");;
+  const type = resource.type.replace("AWS::", "");
+  switch (resource.type) {
+    case "AWS::Serverless::Function":
+    case "AWS::Lambda::Function":
+      return `${id}[[${label}<br/>${type}]]`;
+    case "AWS::Serverless::SimpleTable":
+    case "AWS::DynamoDB::Table":
+    case "AWS::RDS::DBInstance":
+    case "AWS::RDS::DBCluster":
+      return `${id}[(${label}<br/>${type})]`;
+  }
+  return `${id}[${label}<br/>${type}]`;
+
+}

graph/Vis.js

@@ -227,4 +227,5 @@ async function renderTemplate(
 module.exports = {
   renderTemplate,
   reset,
+  makeGraph
 };

index.js

@@ -4,6 +4,7 @@ require("./commands/draw.io");
 require("./commands/html");
 require("./commands/asciiart");
 require("./commands/browse");
-const package = require("./package.json");
-program.version(package.version, "-v, --vers", "output the current version");
+require("./commands/mermaid");
+const packag = require("./package.json");
+program.version(packag.version, "-v, --vers", "output the current version");
 program.parse(process.argv);