aws natgateways parsing

[ratulm]

this is mostly parsing. deeper integration of nat gateways is not done. opened issue #681 for that.

---

This change is 

[arifogel]

One comment about warning verbosity, and one about static routes. Otherwise looks good.

---

Reviewed 9 of 9 files at r1.
Review status: all files reviewed at latest revision, 2 unresolved discussions.

---

projects/batfish/src/main/java/org/batfish/representation/aws_vpcs/AwsVpcConfiguration.java, line 256 at r1 (raw file):

    for (NatGateway ngw : _natGateways.values()) {
      _warnings.redFlag("NAT functionality not yet implemented for " + ngw.getId());

Is it really necessary to warn for every NAT gateway?

---

projects/batfish/src/main/java/org/batfish/representation/aws_vpcs/Route.java, line 117 at r1 (raw file):

        case NatGateway:
          // TODO: it is NOT clear that this is the right thing to do
          // for NATs with multiple interfaces, we should probably match on private IPs?

I think we need to generalize this function to produce a List<StaticRoute>. For NatGateway, there should be one for each next-hop-ip.

---

Comments from Reviewable

[ratulm]

Review status: all files reviewed at latest revision, 2 unresolved discussions.

---

projects/batfish/src/main/java/org/batfish/representation/aws_vpcs/AwsVpcConfiguration.java, line 256 at r1 (raw file):

Previously, arifogel (Ari Fogel) wrote…

Is it really necessary to warn for every NAT gateway?

no, but it was easiest that way. we'll add more support soon anyway.

---

projects/batfish/src/main/java/org/batfish/representation/aws_vpcs/Route.java, line 117 at r1 (raw file):

Previously, arifogel (Ari Fogel) wrote…

I think we need to generalize this function to produce a List<StaticRoute>. For NatGateway, there should be one for each next-hop-ip.

ack. will do as part of proper nat processing

---

Comments from Reviewable

[arifogel]

---

Review status: all files reviewed at latest revision, all discussions resolved, all commit checks successful.

---

Comments from Reviewable