Run bridges zombienet tests on CI (#2439)

Brridges zombienet tests are non-standard - zombienet currently missing
multiple relay chains support (see e.g.
https://github.com/paritytech/zombienet/pull/796), so we need to go live
with two relay networks, their parachains + custom test runner (which
e.g. doesn't shutdown net when its tests are finished and instead waits
for both networks tests to complete). So we are stuck with native
zombienet provider => this PR is an attempt to gather everything in a
single docker container and run tests there ~Draft, because it is far
from finishing - what I want now is to see how it works on CI~

cumulus/scripts/bridges_common.sh

@@ -1,27 +1,21 @@
 #!/bin/bash
 
-function ensure_binaries() {
-    if [[ ! -f ~/local_bridge_testing/bin/polkadot ]]; then
-        echo "  Required polkadot binary '~/local_bridge_testing/bin/polkadot' does not exist!"
-        echo "  You need to build it and copy to this location!"
-        echo "  Please, check ./parachains/runtimes/bridge-hubs/README.md (Prepare/Build/Deploy)"
-        exit 1
-    fi
-    if [[ ! -f ~/local_bridge_testing/bin/polkadot-parachain ]]; then
-        echo "  Required polkadot-parachain binary '~/local_bridge_testing/bin/polkadot-parachain' does not exist!"
-        echo "  You need to build it and copy to this location!"
-        echo "  Please, check ./parachains/runtimes/bridge-hubs/README.md (Prepare/Build/Deploy)"
-        exit 1
-    fi
+function relayer_path() {
+    local default_path=~/local_bridge_testing/bin/substrate-relay
+    local path="${SUBSTRATE_RELAY_PATH:-$default_path}"
+    echo "$path"
 }
 
 function ensure_relayer() {
-    if [[ ! -f ~/local_bridge_testing/bin/substrate-relay ]]; then
-        echo "  Required substrate-relay binary '~/local_bridge_testing/bin/substrate-relay' does not exist!"
+    local path=$(relayer_path)
+    if [[ ! -f "$path" ]]; then
+        echo "  Required substrate-relay binary '$path' does not exist!"
         echo "  You need to build it and copy to this location!"
         echo "  Please, check ./parachains/runtimes/bridge-hubs/README.md (Prepare/Build/Deploy)"
         exit 1
     fi
+
+    echo $path
 }
 
 function ensure_polkadot_js_api() {

cumulus/scripts/bridges_rococo_westend.sh

@@ -132,10 +132,10 @@ LANE_ID="00000002"
 XCM_VERSION=3
 
 function init_ro_wnd() {
-    ensure_relayer
+    local relayer_path=$(ensure_relayer)
 
     RUST_LOG=runtime=trace,rpc=trace,bridge=trace \
-        ~/local_bridge_testing/bin/substrate-relay init-bridge rococo-to-bridge-hub-westend \
+        $relayer_path init-bridge rococo-to-bridge-hub-westend \
 	--source-host localhost \
 	--source-port 9942 \
 	--source-version-mode Auto \
@@ -146,10 +146,10 @@ function init_ro_wnd() {
 }
 
 function init_wnd_ro() {
-    ensure_relayer
+    local relayer_path=$(ensure_relayer)
 
     RUST_LOG=runtime=trace,rpc=trace,bridge=trace \
-        ~/local_bridge_testing/bin/substrate-relay init-bridge westend-to-bridge-hub-rococo \
+        $relayer_path init-bridge westend-to-bridge-hub-rococo \
         --source-host localhost \
         --source-port 9945 \
         --source-version-mode Auto \
@@ -160,10 +160,10 @@ function init_wnd_ro() {
 }
 
 function run_relay() {
-    ensure_relayer
+    local relayer_path=$(ensure_relayer)
 
     RUST_LOG=runtime=trace,rpc=trace,bridge=trace \
-        ~/local_bridge_testing/bin/substrate-relay relay-headers-and-messages bridge-hub-rococo-bridge-hub-westend \
+        $relayer_path relay-headers-and-messages bridge-hub-rococo-bridge-hub-westend \
         --rococo-host localhost \
         --rococo-port 9942 \
         --rococo-version-mode Auto \