is there a good way of generating a visio diagram of an architecture (with a decent layout) if i have a list of client apps, services and databases? i would have thought there would be a decent way to generate this on the fly.
There is VisioAutomation on GitHub. If you have Visio installed it can automate the generation of a diagram. If you can model the diagram you want as a directed graph then it can automatically layout the graph for you (using MSAGL).
Here is a basic example of creating the directed graph
using VACONNECT = VisioAutomation.Shapes.Connections;
var d = new VisioAutomation.Models.DirectedGraph.Drawing();
var basic_stencil = "basic_u.vss";
var n0 = d.AddShape("n0", "Node 0", basic_stencil, "Rectangle");
n0.Size = new VA.Drawing.Size(3, 2);
var n1 = d.AddShape("n1", "Node 1", basic_stencil, "Rectangle");
var n2 = d.AddShape("n2", "Node 2", basic_stencil, "Rectangle");
var n3 = d.AddShape("n3", "Node 3", basic_stencil, "Rectangle");
var n4 = d.AddShape("n4", "Node 4\nUnconnected", basic_stencil, "Rectangle");
var c0 = d.AddConnection("c0", n0, n1, "0 -> 1", VACONNECT.ConnectorType.Curved);
var c1 = d.AddConnection("c1", n1, n2, "1 -> 2", VACONNECT.ConnectorType.RightAngle);
var c2 = d.AddConnection("c2", n1, n0, "0 -> 1", VACONNECT.ConnectorType.Curved);
var c3 = d.AddConnection("c3", n0, n2, "0 -> 2", VACONNECT.ConnectorType.Straight);
var c4 = d.AddConnection("c4", n2, n3, "2 -> 3", VACONNECT.ConnectorType.Curved);
var c5 = d.AddConnection("c5", n3, n0, "3 -> 0", VACONNECT.ConnectorType.Curved);
And then to draw it:
var options = new VisioAutomation.Models.DirectedGraph.MsaglLayoutOptions();
var page = visio_app.ActivePage;
d.Render(page,options);