Switch collect_logs from docker cp to docker logs to reliably capture
container output. The previous approach used docker cp to copy lnd log
files from inside named volumes, which silently fails in CI — the
directory gets created and the success echo prints, but no files are
ever copied, causing upload-artifact to report "No files were found".
docker logs reads directly from Docker's captured stdout/stderr buffer,
bypassing the volume entirely, and works as long as the container exists.
The backwards compatibility test was failing intermittently due to two
related timing issues in the test setup.
The issue was that Dave's `wait_graph_sync dave 3` was hanging
for up to 60 minutes. Dave's initial gossip sync with Charlie could
complete before Charlie had forwarded the alice-bob channel
announcement, leaving Dave stuck at 2 channels until lnd's historical
syncer fired at its default interval of 1 hour. After this 1-hour idle,
some routing state had become stale, causing the subsequent payment from
alice to dave to fail with FAILURE_REASON_NO_ROUTE.
This issues is now addressed by setting `--historicalsyncinterval=10s` on
all nodes. This causes nodes to periodically re-sync the full gossip
state from their peers every 10 seconds instead of every hour. Dave
therefore picks up any missed channel announcements and routing policies
within seconds, and alice's routing graph stays up-to-date throughout
the test.
Additionally, lnd debug logs from all containers are now collected
before teardown on failure and uploaded as a CI artifact, making future
failures easier to diagnose.
This commit adjusts the backwards compatability test in 2 ways:
1) we first set up the bitcoin backend before waiting for our network
nodes to start. This is so that the nodes can sync to chain and
become fully active during the `wait_for_nodes` call.
2) Then, in the `wait_for_node` helper, we use the status server
response to determine if a node is ready instead of just waiting for
`GetInfo` to return a response. This is because waiting for
SERVER_ACTIVE is a more accurate signal that the node is ready to
receive RPC calls.
