func TestExpandTransform(t *testing.T) {
var g Graph
g.Add(1)
g.Add(2)
g.Connect(dag.BasicEdge(1, 2))
tf := &ExpandTransform{}
out, err := tf.Transform(&testExpandable{
Result: &g,
})
if err != nil {
t.Fatalf("err: %s", err)
}
sn, ok := out.(GraphNodeSubgraph)
if !ok {
t.Fatalf("not subgraph: %#v", out)
}
actual := strings.TrimSpace(sn.Subgraph().String())
expected := strings.TrimSpace(testExpandTransformStr)
if actual != expected {
t.Fatalf("bad: %s", actual)
}
}
func (t *ProxyTransformer) Transform(g *Graph) error {
for _, v := range g.Vertices() {
pn, ok := v.(GraphNodeProxy)
if !ok {
continue
}
// If we don't want to be proxies, don't do it
if !pn.Proxy() {
continue
}
// Connect all the things that depend on this to things that
// we depend on as the proxy. See docs for GraphNodeProxy for
// a visual explanation.
for _, s := range g.UpEdges(v).List() {
for _, t := range g.DownEdges(v).List() {
g.Connect(GraphProxyEdge{
Edge: dag.BasicEdge(s, t),
})
}
}
}
return nil
}
func TestModuleInputTransformer(t *testing.T) {
var g Graph
g.Add(1)
g.Add(2)
g.Add(3)
g.Connect(dag.BasicEdge(1, 2))
g.Connect(dag.BasicEdge(1, 3))
{
tf := &ModuleInputTransformer{}
if err := tf.Transform(&g); err != nil {
t.Fatalf("err: %s", err)
}
}
actual := strings.TrimSpace(g.String())
expected := strings.TrimSpace(testModuleInputTransformStr)
if actual != expected {
t.Fatalf("bad:\n\n%s", actual)
}
}
func (t *ProviderTransformer) Transform(g *Graph) error {
// Go through the other nodes and match them to providers they need
var err error
m := providerVertexMap(g)
for _, v := range g.Vertices() {
if pv, ok := v.(GraphNodeProviderConsumer); ok {
for _, p := range pv.ProvidedBy() {
target := m[p]
if target == nil {
err = multierror.Append(err, fmt.Errorf(
"%s: provider %s couldn't be found",
dag.VertexName(v), p))
continue
}
g.Connect(dag.BasicEdge(v, target))
}
}
}
return err
}
func (t *RootTransformer) Transform(g *Graph) error {
// If we already have a good root, we're done
if _, err := g.Root(); err == nil {
return nil
}
// Add a root
var root graphNodeRoot
g.Add(root)
// Connect the root to all the edges that need it
for _, v := range g.Vertices() {
if v == root {
continue
}
if g.UpEdges(v).Len() == 0 {
g.Connect(dag.BasicEdge(root, v))
}
}
return nil
}
func (t *DestroyTransformer) transform(
g *Graph, mode GraphNodeDestroyMode) ([]dag.Edge, []dag.Edge, error) {
var connect, remove []dag.Edge
nodeToCn := make(map[dag.Vertex]dag.Vertex, len(g.Vertices()))
nodeToDn := make(map[dag.Vertex]dag.Vertex, len(g.Vertices()))
for _, v := range g.Vertices() {
// If it is not a destroyable, we don't care
cn, ok := v.(GraphNodeDestroyable)
if !ok {
continue
}
// Grab the destroy side of the node and connect it through
n := cn.DestroyNode(mode)
if n == nil {
continue
}
// Store it
nodeToCn[n] = cn
nodeToDn[cn] = n
// Add it to the graph
g.Add(n)
// Inherit all the edges from the old node
downEdges := g.DownEdges(v).List()
for _, edgeRaw := range downEdges {
// If this thing specifically requests to not be depended on
// by destroy nodes, then don't.
if i, ok := edgeRaw.(GraphNodeDestroyEdgeInclude); ok &&
!i.DestroyEdgeInclude(v) {
continue
}
g.Connect(dag.BasicEdge(n, edgeRaw.(dag.Vertex)))
}
// Add a new edge to connect the node to be created to
// the destroy node.
connect = append(connect, dag.BasicEdge(v, n))
}
// Go through the nodes we added and determine if they depend
// on any nodes with a destroy node. If so, depend on that instead.
for n, _ := range nodeToCn {
for _, downRaw := range g.DownEdges(n).List() {
target := downRaw.(dag.Vertex)
cn2, ok := target.(GraphNodeDestroyable)
if !ok {
continue
}
newTarget := nodeToDn[cn2]
if newTarget == nil {
continue
}
// Make the new edge and transpose
connect = append(connect, dag.BasicEdge(newTarget, n))
// Remove the old edge
remove = append(remove, dag.BasicEdge(n, target))
}
}
return connect, remove, nil
}
func (t *CreateBeforeDestroyTransformer) Transform(g *Graph) error {
// We "stage" the edge connections/destroys in these slices so that
// while we're doing the edge transformations (transpositions) in
// the graph, we're not affecting future edge transpositions. These
// slices let us stage ALL the changes that WILL happen so that all
// of the transformations happen atomically.
var connect, destroy []dag.Edge
for _, v := range g.Vertices() {
// We only care to use the destroy nodes
dn, ok := v.(GraphNodeDestroy)
if !ok {
continue
}
// If the node doesn't need to create before destroy, then continue
if !dn.CreateBeforeDestroy() {
continue
}
// Get the creation side of this node
cn := dn.CreateNode()
// Take all the things which depend on the creation node and
// make them dependencies on the destruction. Clarifying this
// with an example: if you have a web server and a load balancer
// and the load balancer depends on the web server, then when we
// do a create before destroy, we want to make sure the steps are:
//
// 1.) Create new web server
// 2.) Update load balancer
// 3.) Delete old web server
//
// This ensures that.
for _, sourceRaw := range g.UpEdges(cn).List() {
source := sourceRaw.(dag.Vertex)
// If the graph has a "root" node (one added by a RootTransformer and not
// just a resource that happens to have no ancestors), we don't want to
// add any edges to it, because then it ceases to be a root.
if _, ok := source.(graphNodeRoot); ok {
continue
}
connect = append(connect, dag.BasicEdge(dn, source))
}
// Swap the edge so that the destroy depends on the creation
// happening...
connect = append(connect, dag.BasicEdge(dn, cn))
destroy = append(destroy, dag.BasicEdge(cn, dn))
}
for _, edge := range connect {
g.Connect(edge)
}
for _, edge := range destroy {
g.RemoveEdge(edge)
}
return nil
}