dev/run: fix handling node number seed configuration

The `--node-number` parameter is not interpreted correctly so that
the node identifiers are shifted everywhere in the same way.  For
example, the lead port and node ports are assigned with no regard
to what was set as the starting node index.

This could be a problem if, for example, one wants to simulate
mixed-version cluster configurations and launch a set of nodes
starting from a given index and use another invocation of the
script to run another set of nodes with different subset of
indexes.

At the same time, the name `--node-number` does not describe well
the purpose of this flag, therefore it is renamed to
`--node-number-seed`.

dev/run

@@ -93,7 +93,7 @@ def main():
         if ctx["cmd"]:
             run_command(ctx, ctx["cmd"])
         else:
-            join(ctx, cluster_port(ctx, 1), *ctx["admin"])
+            join(ctx, cluster_port(ctx, ctx["node_number_seed"]), *ctx["admin"])
 
 
 def setup():
@@ -174,11 +174,11 @@ def get_args_parser():
         "--haproxy-port", dest="haproxy_port", default="5984", help="HAProxy port"
     )
     parser.add_option(
-        "--node-number",
-        dest="node_number",
+        "--node-number-seed",
+        dest="node_number_seed",
         type=int,
         default=1,
-        help="The node number to seed them when creating the node(s)",
+        help="The node number to seed them when creating nodes",
     )
     parser.add_option(
         "-c",
@@ -280,8 +280,8 @@ def setup_context(opts, args):
         "no_join": opts.no_join,
         "enable_erlang_views": opts.enable_erlang_views,
         "admin": opts.admin.split(":", 1) if opts.admin else None,
-        "nodes": ["node%d" % (i + opts.node_number) for i in range(opts.nodes)],
-        "node_number": opts.node_number,
+        "nodes": ["node%d" % (i + opts.node_number_seed) for i in range(opts.nodes)],
+        "node_number_seed": opts.node_number_seed,
         "degrade_cluster": opts.degrade_cluster,
         "devdir": os.path.dirname(fpath),
         "rootdir": os.path.dirname(os.path.dirname(fpath)),
@@ -342,7 +342,7 @@ def check_boot_script(ctx):
 def setup_configs(ctx):
     for idx, node in enumerate(ctx["nodes"]):
         cluster_port, backend_port, prometheus_port = get_ports(
-            ctx, idx + ctx["node_number"]
+            ctx, idx + ctx["node_number_seed"]
         )
         env = {
             "prefix": toposixpath(ctx["rootdir"]),
@@ -908,7 +908,7 @@ def boot_nodes(ctx):
     nouveau_proc = maybe_boot_nouveau(ctx)
     if nouveau_proc is not None:
         ctx["procs"].append(nouveau_proc)
-    for idx in [(i + ctx["node_number"]) for i in range(ctx["N"])]:
+    for idx in [(i + ctx["node_number_seed"]) for i in range(ctx["N"])]:
         clouseau_proc = maybe_boot_clouseau(ctx, idx)
         if clouseau_proc is not None:
             ctx["procs"].append(clouseau_proc)
@@ -920,11 +920,12 @@ def ensure_all_nodes_alive(ctx):
         for num in range(ctx["N"]):
             if status[num]:
                 continue
-            local_port = cluster_port(ctx, num + 1)
+            idnode = ctx["node_number_seed"] + num
+            local_port = cluster_port(ctx, idnode)
             url = "http://127.0.0.1:{0}/".format(local_port)
             try:
                 check_node_alive(url)
-                maybe_check_clouseau_node_alive(ctx, num + 1)
+                maybe_check_clouseau_node_alive(ctx, idnode)
             except:
                 pass
             else:
@@ -1018,10 +1019,10 @@ def boot_node(ctx, node):
 
 @log("Running cluster setup")
 def cluster_setup(ctx):
-    lead_port = cluster_port(ctx, 1)
+    lead_port = cluster_port(ctx, ctx["node_number_seed"])
     if enable_cluster(ctx["N"], lead_port, *ctx["admin"]):
         for num in range(1, ctx["N"]):
-            node_port = cluster_port(ctx, num + 1)
+            node_port = cluster_port(ctx, ctx["node_number_seed"] + num)
             node_name = ctx["nodes"][num]
             enable_cluster(ctx["N"], node_port, *ctx["admin"])
             add_node(lead_port, node_name, node_port, *ctx["admin"])