[Feature] External Relay Chain Support (#39)

* Add --relay-chain-rpc-urls feature
* Add Molecule test

---------

Co-authored-by: Bulat Saifullin <bulat@parity.io>

roles/node/defaults/main.yml

@@ -170,6 +170,10 @@ node_parachain_chainspec: ""
 # It has to be a link to wasm runtime. It will be used by the "--wasm-runtime-overrides" CLI flag
 node_parachain_wasm_runtime: ""
 
+### Experimental Feature
+# Remote Relay Chain via RPC
+node_parachain_relay_chain_rpc_urls: []
+
 ### Keys
 ## p2p key
 # If it's empty, the node will generate default key file

roles/node/molecule/parachain_remote_rc/converge.yml

@@ -0,0 +1,15 @@
+---
+- name: Converge
+  hosts: all
+  gather_facts: true
+  tasks:
+    - name: "parachain"
+      ansible.builtin.include_role:
+        name: "node"
+      vars:
+        node_app_name: "parachain-shell"
+        node_parachain_chain: "shell"
+        node_parachain_role: "collator"
+        node_parachain_chain_backup_restoring_type: "none"
+        node_parachain_relay_chain_rpc_urls: ["ws://127.0.0.1:9944"]
+        node_prometheus_file_exporter_path: "/tmp/substrate-pc.prom"

roles/node/molecule/parachain_remote_rc/group_vars/all.yml

@@ -0,0 +1,11 @@
+## Molecule
+ansible_user: root
+
+# Common
+node_app_name: "dummy"
+node_binary_version: v0.9.430
+node_legacy_rpc_flags: false
+node_parachain_rpc_port: 9954
+node_binary: https://github.com/paritytech/cumulus/releases/download/{{ node_binary_version }}/polkadot-parachain
+node_binary_signature: https://github.com/paritytech/cumulus/releases/download/{{ node_binary_version }}/polkadot-parachain.asc
+#node_binary_deployment: false

roles/node/molecule/parachain_remote_rc/molecule.yml

@@ -0,0 +1,29 @@
+---
+dependency:
+  name: galaxy
+driver:
+  name: ${DRIVER:-docker}
+platforms:
+  - name: molecule-instance-node-parachain-remote-rc
+    source:
+      alias: debian/bullseye/amd64
+    # DOCKER
+    image: "paritytech/debian11:latest"
+    command: ${MOLECULE_DOCKER_COMMAND:-""}
+    privileged: true
+    pre_build_image: true
+provisioner:
+  name: ansible
+  options:
+    D: True
+  config_options:
+    defaults:
+      callbacks_enabled: timer
+verifier:
+  name: ansible
+  options:
+    D: True
+lint: |
+  set -e
+  yamllint .
+  ansible-lint

roles/node/molecule/parachain_remote_rc/prepare.yml

@@ -0,0 +1,29 @@
+- name: Prepare
+  hosts: all
+  gather_facts: false
+  pre_tasks:
+    - name: Install Python
+      ansible.builtin.raw: apt -y update && apt install -y python3
+      changed_when: false
+    - name: Install required packages
+      ansible.builtin.apt:
+        name:
+          - gpg
+        update_cache: no
+      changed_when: false
+  tasks:
+    - name: "relaychain"
+      ansible.builtin.include_role:
+        name: "node"
+      vars:
+        node_app_name: "relaychain-shell"
+        node_data_root_path: "/opt/{{ node_app_name }}"
+        node_chain: "rococo-dev"
+        node_custom_options: [ '--alice' ]
+        node_binary_version: v0.9.43
+        node_legacy_rpc_flags: false
+        node_binary: https://github.com/paritytech/polkadot/releases/download/{{ node_binary_version }}/polkadot
+        node_binary_signature: https://github.com/paritytech/polkadot/releases/download/{{ node_binary_version }}/polkadot.asc
+        node_rpc_port: 9944
+        node_chain_backup_restoring_type: "none"
+        node_prometheus_file_exporter_path: "/tmp/substrate-rc.prom"

roles/node/molecule/parachain_remote_rc/verify.yml

@@ -0,0 +1,34 @@
+---
+- name: Verify
+  hosts: all
+  gather_facts: false
+  tasks:
+  - name: Collect service facts
+    ansible.builtin.service_facts:
+
+  - name: Print service facts
+    ansible.builtin.debug:
+      var: ansible_facts.services['parachain-shell.service']
+
+  - name: check service
+    ansible.builtin.assert:
+      that: ansible_facts.services['parachain-shell.service'].state == 'running'
+
+  - name: Get parachain system_health
+    ansible.builtin.uri:
+      url: "http://127.0.0.1:{{ node_parachain_rpc_port }}"
+      method: POST
+      body:
+        {"id":1, "jsonrpc":"2.0", "method":"system_health", "params":[]}
+      body_format: json
+      headers:
+        Content-Type: 'application/json'
+      use_proxy: false
+    until: _parachain_system_health_result.status is defined and _parachain_system_health_result.status == 200
+    retries: 3
+    delay: 10
+    register: _parachain_system_health_result
+
+  - name: Print system_health
+    ansible.builtin.debug:
+      msg: "Parachain: {{ _parachain_system_health_result.json }}"

roles/node/tasks/001-health-check.yml

@@ -21,7 +21,7 @@
 
   - name: Health check | Run health check
     ansible.builtin.uri:
-      url: "http://127.0.0.1:{{ node_rpc_port }}"
+      url: "http://127.0.0.1:{{ ( node_parachain_relay_chain_rpc_urls | length != 0 ) | ternary(node_parachain_rpc_port, node_rpc_port) }}"
       method: "POST"
       body_format: "json"
       body:
@@ -46,7 +46,7 @@
 
   - name: Health check | Check the current version using API
     ansible.builtin.uri:
-      url: "http://127.0.0.1:{{ node_rpc_port }}"
+      url: "http://127.0.0.1:{{ ( node_parachain_relay_chain_rpc_urls | length != 0 ) | ternary(node_parachain_rpc_port, node_rpc_port) }}"
       method: "POST"
       body_format: "json"
       body:

roles/node/tasks/100-tests.yml

@@ -20,7 +20,10 @@
 - name: Test | Check node_chain
   ansible.builtin.fail:
     msg: "The 'node_chain' variable can't be empty!"
-  when: node_chain == '' and node_chainspec == ''
+  when:
+    - node_chain == ''
+    - node_chainspec == ''
+    - node_parachain_relay_chain_rpc_urls == []
 
 - name: Test | Check node_parachain_chain
   ansible.builtin.fail:

roles/node/templates/env.j2

@@ -6,6 +6,7 @@ COMMON="\
 --detailed-log-output
 {%- endif %}"
 
+{% if ( node_parachain_relay_chain_rpc_urls | length ) == 0 %}
 RC_NAME="{% if node_parachain_has_name_fix  %}--name {{ node_public_name }}{% endif %}"
 
 RC_KEY="
@@ -99,6 +100,7 @@ RC_CUSTOM_OPTIONS="\
 {{ option }}{% if not loop.last %} \
 {% endif %}
 {%- endfor %}"
+{%- endif %}
 
 {% if node_log_trace_enable or node_parachain_log_trace_enable %}
 RUST_BACKTRACE=1
@@ -135,6 +137,12 @@ PC_CHAIN="
 --chain {{ node_parachain_chain }}
 {%- endif %}"
 
+PC_REMOTE_RC_URLS="
+{%- if ( node_parachain_relay_chain_rpc_urls | length ) != 0 %}
+--relay-chain-rpc-urls {% for url in node_parachain_relay_chain_rpc_urls %}'{{ url }}'{% if not loop.last %} {% endif %}{% endfor %}
+{%- endif %}"
+
+
 PC_ADDR="\
 --listen-addr=/ip4/{{ node_parachain_p2p_bind_addr }}/tcp/{{ node_parachain_p2p_port }}
 {%- if node_enable_public_ip_detection %} \

roles/node/templates/node.service.j2

@@ -11,11 +11,15 @@ MemoryHigh={{ node_memory_high }}
 MemoryMax={{ node_memory_max }}
 ExecStart={{ _node_binary_file }} \
     $COMMON \
-{% if node_parachain_role != '' %}
+{% if node_parachain_role != '' and node_parachain_relay_chain_rpc_urls != [] %}
+    $PC_NAME $PC_ROLE_SPECIFIC $PC_KEY $PC_CHAIN $PC_REMOTE_RC_URLS $PC_ADDR $PC_CONNECTIONS $PC_DB $PC_TELEMETRY $PC_PRUNING $PC_LOGS $PC_METRICS $PC_WS $PC_RPC $PC_WASM_RUNTIME $PC_CUSTOM_OPTIONS
+{% elif node_parachain_role != '' %}
     $PC_NAME $PC_ROLE_SPECIFIC $PC_KEY $PC_CHAIN $PC_ADDR $PC_CONNECTIONS $PC_DB $PC_TELEMETRY $PC_PRUNING $PC_LOGS $PC_METRICS $PC_WS $PC_RPC $PC_WASM_RUNTIME $PC_CUSTOM_OPTIONS \
     -- \
 {% endif %}
+{% if node_parachain_relay_chain_rpc_urls == [] %}
     $RC_NAME $RC_ROLE_SPECIFIC $RC_KEY $RC_CHAIN $RC_ADDR $RC_CONNECTIONS $RC_DB $RC_TELEMETRY $RC_PRUNING $RC_LOGS $RC_METRICS $RC_WS $RC_RPC $RC_WASM_RUNTIME $RC_CUSTOM_OPTIONS
+{% endif %}
 
 {% if node_syslog_labels != '' %}
 SyslogIdentifier={{ node_syslog_labels }}

roles/node/vars/main.yml

@@ -120,4 +120,3 @@ _node_parachain_chain_backup_data:
   node_parachain_chain +
   ('-paritydb' if node_parachain_paritydb_enable else '-rocksdb') + ('-prune' if node_parachain_pruning > 0 else '-archive') }}"
   custom_http_url: "{{ node_parachain_chain_backup_http_url }}"
-