Use BgpSessionProperties IPs instead peers' local IPs

[corinaminer]

The head and tail IPs in BgpSessionProperties are guaranteed to be nonnull, whereas BGP peer config IDs can have null local IPs even if they have edges in the BGP topology.

Separation of getBgpEdges() methods is solely for easier testing and should not affect functionality.

[batfish-bot]

This change is 

[codecov]

Codecov Report

Merging #3917 into master will decrease coverage by 0.04%.
The diff coverage is 85.71%.

@@             Coverage Diff              @@
##             master    #3917      +/-   ##
============================================
- Coverage     74.87%   74.82%   -0.05%     
+ Complexity    24061    24043      -18     
============================================
  Files          2027     2027              
  Lines         96681    96622      -59     
  Branches      11496    11492       -4     
============================================
- Hits          72390    72301      -89     
- Misses        19034    19063      +29     
- Partials       5257     5258       +1

Impacted Files	Coverage Δ	Complexity Δ
...va/org/batfish/question/VIModelQuestionPlugin.java	97.32% <85.71%> (-2.09%)	4 <0> (-2)
...n/java/org/batfish/common/bdd/BDDFiniteDomain.java	51.16% <0%> (-44.4%)	8% <0%> (-11%)
.../src/main/java/org/batfish/datamodel/flow/Hop.java	53.33% <0%> (-6.67%)	5% <0%> (-1%)
...org/batfish/datamodel/flow/BidirectionalTrace.java	79.54% <0%> (-4.55%)	13% <0%> (-2%)
...c/main/java/org/batfish/dataplane/rib/RibTree.java	89.79% <0%> (-4.09%)	27% <0%> (-1%)
...col/src/main/java/org/batfish/role/InferRoles.java	91.24% <0%> (-0.37%)	68% <0%> (-1%)
...batfish/src/main/java/org/batfish/main/Driver.java	38.61% <0%> (-0.25%)	29% <0%> (ø)
...java/org/batfish/dataplane/ibdp/VirtualRouter.java	87.76% <0%> (-0.23%)	240% <0%> (-1%)
...tfish/representation/cisco/CiscoConfiguration.java	83.8% <0%> (-0.13%)	530% <0%> (-1%)
... and 2 more

[progwriter]

Reviewed 1 of 2 files at r1, 1 of 1 files at r2.
Reviewable status: all files reviewed, 1 unresolved discussion (waiting on @corinaminer)

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projects/question/src/main/java/org/batfish/question/VIModelQuestionPlugin.java, line 238 at r2 (raw file):

        if (bgpPeerConfig != null && remoteBgpPeerConfig != null) {
          Ip localIp = sessionProperties.getTailIp();

isn't head the local IP?

[corinaminer]

Reviewable status: all files reviewed, 1 unresolved discussion (waiting on @progwriter)

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projects/question/src/main/java/org/batfish/question/VIModelQuestionPlugin.java, line 238 at r2 (raw file):

Previously, progwriter (Victor Heorhiadi) wrote…

isn't head the local IP?

i don't think so... i believe bgpTopology.edgeValue(id1, id2) gives the session where id1 is local and id2 is remote, so the local IP should be the tail, right?

If this were wrong, the test should surface the issue.

[corinaminer]

Reviewable status: 0 of 2 files reviewed, 1 unresolved discussion (waiting on @progwriter)

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projects/question/src/main/java/org/batfish/question/VIModelQuestionPlugin.java, line 238 at r2 (raw file):

Previously, corinaminer (Corina Miner) wrote…

i don't think so... i believe bgpTopology.edgeValue(id1, id2) gives the session where id1 is local and id2 is remote, so the local IP should be the tail, right?

If this were wrong, the test should surface the issue.

actually the test wouldn't have surfaced the issue before, but now it should.

[progwriter]

Reviewed 2 of 2 files at r3.
Reviewable status: complete! all files reviewed, all discussions resolved

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projects/question/src/main/java/org/batfish/question/VIModelQuestionPlugin.java, line 238 at r2 (raw file):

Previously, corinaminer (Corina Miner) wrote…

actually the test wouldn't have surfaced the issue before, but now it should.

Ah, I'm just in bdp-queue-mode.