As we've seen elsewhere, the SDK now wants nils instead of empty arrays
for collections
fixes#1696
thanks @jstremick for pointing me in the right direction
When you specify `-verbose` you'll get the whole graph of operations,
which gives a better idea of the operations terraform performs and in
what order.
The DOT graph is now generated with a small internal library instead of
simple string building. This allows us to ensure the graph generation is
as consistent as possible, among other benefits.
We set `newrank = true` in the graph, which I've found does just as good
a job organizing things visually as manually attempting to rank the nodes
based on depth.
This also fixes `-module-depth`, which was broken post-AST refector.
Modules are now expanded into subgraphs with labels and borders. We
have yet to regain the plan graphing functionality, so I removed that
from the docs for now.
Finally, if `-draw-cycles` is added, extra colored edges will be drawn
to indicate the path of any cycles detected in the graph.
A notable implementation change included here is that
{Reverse,}DepthFirstWalk has been made deterministic. (Before it was
dependent on `map` ordering.) This turned out to be unnecessary to gain
determinism in the final DOT-level implementation, but it seemed
a desirable enough of a property that I left it in.
The `TargetTransform` was dropping provisioner nodes, which caused graph
validation to fail with messages about uninitialized provisioners when a
`terraform destroy` was attempted.
This was because `destroy` flops the dependency calculation to try and
address any nodes in the graph that "depend on" the target node. But we
still need to keep the provisioner node in the graph.
Here we switch the strategy for filtering nodes to only drop
addressable, non-targeted nodes. This should prevent us from having to
whitelist nodes to keep in the future.
closes#1541
Most CBD-related cycles include destroy nodes, and destroy nodes were
all being pruned from the graph before staring the Validate walk.
In practice this meant that we had scenarios that would error out with
graph cycles on Apply that _seemed_ fine during Plan.
This introduces a Verbose option to the GraphBuilder that tells it to
generate a "worst-case" graph. Validate sets this to true so that cycle
errors will always trigger at this step if they're going to happen.
(This Verbose option will be exposed as a CLI flag to `terraform graph`
in a second incoming PR.)
refs #1651
Sander van Harmelen