Method Viz

pkg/compose/viz.go:32–62

(_ context.Context, project *types.Project, opts api.VizOptions)

type vizGraph map[*types.ServiceConfig][]*types.ServiceConfig

func (s *composeService) Viz(_ context.Context, project *types.Project, opts api.VizOptions) (string, error) {
	graph := make(vizGraph)
	for _, service := range project.Services {
		graph[&service] = make([]*types.ServiceConfig, 0, len(service.DependsOn))
		for dependencyName := range service.DependsOn {
			// no error should be returned since dependencyName should exist
			dependency, _ := project.GetService(dependencyName)
			graph[&service] = append(graph[&service], &dependency)
		}
	}

	// build graphviz graph
	var graphBuilder strings.Builder

	// graph name
	graphBuilder.WriteString("digraph ")
	writeQuoted(&graphBuilder, project.Name)
	graphBuilder.WriteString(" {\n")

	// graph layout
	// dot is the perfect layout for this use case since graph is directed and hierarchical
	graphBuilder.WriteString(opts.Indentation + "layout=dot;\n")

	addNodes(&graphBuilder, graph, project.Name, &opts)
	graphBuilder.WriteByte('\n')

	addEdges(&graphBuilder, graph, &opts)
	graphBuilder.WriteString("}\n")

	return graphBuilder.String(), nil
}

// addNodes adds the corresponding graphviz representation of all the nodes in the given graph to the graphBuilder
// returns the same graphBuilder