refactor and decouple QEMU for better testing

apps/virtuerl/src/virtuerl_app.erl

@@ -19,7 +19,15 @@ start(_StartType, _StartArgs) ->
             ok
     end,
 
-    virtuerl_sup:start_link().
+    {ok, Pid} = virtuerl_sup_sup:start_link(),
+
+    Servers = case application:get_env(servers) of
+                  undefined -> #{};
+                  {ok, Servers0} -> Servers0
+              end,
+    [ virtuerl_server:start(Name, Conf) || {Name, Conf} <- maps:to_list(Servers) ],
+
+    {ok, Pid}.
 
 
 start() ->

apps/virtuerl/src/virtuerl_mgt.erl

@@ -2,7 +2,7 @@
 
 -behaviour(gen_server).
 
--export([start_link/0,
+-export([start_link/2,
          home_path/0,
          image_from_domain/2,
          domain_update/1,
@@ -29,71 +29,103 @@
 -define(SERVER,      ?MODULE).
 -define(APPLICATION, virtuerl).
 
--record(state, {table, idmap}).
+-record(state, {server_id, vm_proc_mod, table, idmap}).
 
 
-create_vm() ->
-    gen_server:call(?SERVER, {domain_create, {default}}).
+create_vm() -> create_vm({default, ?MODULE}).
 
 
-%%create_vm(#{cpus := NumCPUs, memory := Memory}) ->
-domain_create(Conf) ->
-    gen_server:call(?SERVER, {domain_create, Conf}, infinity).
+create_vm(Ref) ->
+    gen_server:call({via, virtuerl_reg, Ref}, {domain_create, {default}}).
 
 
-domain_delete(Conf) ->
-    gen_server:call(?SERVER, {domain_delete, Conf}, infinity).
+domain_create(Conf) -> domain_create({default, ?MODULE}, Conf).
 
 
-domain_get(Conf) ->
-    gen_server:call(?SERVER, {domain_get, Conf}).
+domain_create(Ref, Conf) ->
+    gen_server:call({via, virtuerl_reg, Ref}, {domain_create, Conf}, infinity).
 
 
--spec domains_list() -> #{}.
-domains_list() ->
-    gen_server:call(?SERVER, domains_list).
+domain_delete(Conf) -> domain_delete({default, ?MODULE}, Conf).
 
 
-domain_update(Conf) ->
-    gen_server:call(?SERVER, {domain_update, Conf}).
+domain_delete(Ref, Conf) ->
+    gen_server:call({via, virtuerl_reg, Ref}, {domain_delete, Conf}, infinity).
 
 
-domain_stop(Id) ->
-    gen_server:call(?SERVER, {domain_update, #{id => Id, state => stopped}}).
+domain_get(Conf) -> domain_get({default, ?MODULE}, Conf).
 
 
-domain_start(Id) ->
-    gen_server:call(?SERVER, {domain_update, #{id => Id, state => running}}).
+domain_get(Ref, Conf) ->
+    gen_server:call({via, virtuerl_reg, Ref}, {domain_get, Conf}).
 
 
-image_from_domain(DomainId, ImageName) ->
-    gen_server:call(?SERVER, {image_from_domain, #{id => DomainId, image_name => ImageName}}, infinity).
+domains_list() -> domains_list({default, ?MODULE}).
 
 
--spec add_port_fwd(binary(), #{protos := [tcp | udp], source_port := integer(), target_port := integer()}) -> term().
-add_port_fwd(DomainId, PortFwd) ->
-    gen_server:call(?SERVER, {add_port_fwd, DomainId, PortFwd}).
+domains_list(Ref) ->
+    gen_server:call({via, virtuerl_reg, Ref}, domains_list).
+
+
+domain_update(Conf) -> domain_update({default, ?MODULE}, Conf).
+
+
+domain_update(Ref, Conf) ->
+    gen_server:call({via, virtuerl_reg, Ref}, {domain_update, Conf}).
+
+
+domain_stop(Id) -> domain_stop({default, ?MODULE}, Id).
+
+
+domain_stop(Ref, Id) ->
+    gen_server:call({via, virtuerl_reg, Ref}, {domain_update, #{id => Id, state => stopped}}).
+
+
+domain_start(Id) -> domain_start({default, ?MODULE}, Id).
+
+
+domain_start(Ref, Id) ->
+    gen_server:call({via, virtuerl_reg, Ref}, {domain_update, #{id => Id, state => running}}).
 
 
+image_from_domain(DomainId, ImageName) -> image_from_domain({default, ?MODULE}, DomainId, ImageName).
+
+
+image_from_domain(Ref, DomainId, ImageName) ->
+    gen_server:call({via, virtuerl_reg, Ref}, {image_from_domain, #{id => DomainId, image_name => ImageName}}, infinity).
+
+
+add_port_fwd(DomainId, PortFwd) -> add_port_fwd({default, ?MODULE}, DomainId, PortFwd).
+
+
+add_port_fwd(Ref, DomainId, PortFwd) ->
+    gen_server:call({via, virtuerl_reg, Ref}, {add_port_fwd, DomainId, PortFwd}).
+
+
+-spec domains_list() -> #{}.
+
+
+-spec add_port_fwd(binary(), #{protos := [tcp | udp], source_port := integer(), target_port := integer()}) -> term().
+
 %%%===================================================================
 %%% Spawning and gen_server implementation
 %%%===================================================================
 
-
 home_path() ->
     application:get_env(?APPLICATION, home, "var").
 
 
-start_link() ->
-    gen_server:start_link({local, ?SERVER}, ?MODULE, [], []).
+start_link(ServerId, Conf) ->
+    gen_server:start_link({via, virtuerl_reg, {ServerId, ?MODULE}}, ?MODULE, [ServerId, Conf], []).
 
 
-init([]) ->
+init([ServerId, Conf]) ->
+    #{vm_proc_mod := VmProcMod} = Conf,
     net_kernel:monitor_nodes(true),
-    {ok, #state{idmap = #{}}, {continue, sync_domains}}.
+    {ok, #state{server_id = ServerId, vm_proc_mod = VmProcMod, idmap = #{}}, {continue, sync_domains}}.
 
 
-handle_continue(sync_domains, #state{idmap = IdMap} = State) ->
+handle_continue(sync_domains, #state{vm_proc_mod = VmProcMod, idmap = IdMap} = State) ->
     {ok, DomainsMap} = khepri:get_many([domain, ?KHEPRI_WILDCARD_STAR]),
     Domains = [ {Id, Dom} || #{id := Id} = Dom <- maps:values(DomainsMap) ],
     TargetDomains = maps:from_list(
@@ -122,11 +154,12 @@ handle_continue(sync_domains, #state{idmap = IdMap} = State) ->
     VmPids = [ {Id,
                 supervisor:start_child({virtuerl_sup, Node},
                                        {Id,
-                                        {virtuerl_qemu, start_link, [maps:get(Id, maps:from_list(Domains))]},
+                                        {VmProcMod, start_link, [maps:get(Id, maps:from_list(Domains))]},
                                         transient,
                                         infinity,
                                         worker,
                                         []})} || {Id, Node} <- maps:to_list(ToAdd), lists:member(Node, AllNodes) ],
+    [ virtuerl_pubsub:send({domain_started, DomId}) || {DomId, _} <- VmPids ],
     VmPidToDomId = maps:from_list([ {VmPid, DomId} || {DomId, {ok, VmPid}} <- VmPids ]),
     [ monitor(process, VmPid) || {_, {ok, VmPid}} <- VmPids ],
 

apps/virtuerl/src/virtuerl_reg.erl

@@ -0,0 +1,57 @@
+-module(virtuerl_reg).
+
+-behaviour(gen_server).
+
+-export([start_link/0, register_name/2, unregister_name/1, whereis_name/1, send/2]).
+%% Callbacks for `gen_server`
+-export([init/1, handle_call/3, handle_cast/2]).
+
+-type name() :: {atom(), atom()}.
+
+
+-spec register_name(Name :: name(), Pid :: pid()) -> yes | no.
+register_name(Name, Pid) -> gen_server:call(?MODULE, {register_name, Name, Pid}).
+
+
+-spec unregister_name(Name :: name()) -> _.
+unregister_name(Name) -> gen_server:cast(?MODULE, {unregister_name, Name}).
+
+
+-spec whereis_name(Name :: name()) -> pid() | undefined.
+whereis_name(Name) -> gen_server:call(?MODULE, {whereis_name, Name}).
+
+
+-spec send(Name :: name(), Msg :: term()) -> pid().
+send(Name, Msg) ->
+    case whereis_name(Name) of
+        undefined -> exit({badarg, Name, Msg});
+        Pid -> Pid ! Msg, Pid
+    end.
+
+
+start_link() ->
+    gen_server:start_link({local, ?MODULE}, ?MODULE, [], []).
+
+
+init([]) ->
+    {ok, #{}}.
+
+
+% -spec handle_call({register_name, name(), pid()}, _From :: _, State :: #{}) -> {reply, no | yes, #{}}.
+handle_call({register_name, Name, Pid}, _From, State) ->
+    {Res, NewState} = case State of
+                          #{Name := _} -> {no, State};
+                          _ -> {yes, State#{Name => Pid}}
+                      end,
+    {reply, Res, NewState};
+
+handle_call({whereis_name, Name}, _From, State) ->
+    Res = case State of
+              #{Name := Pid} -> Pid;
+              _ -> undefined
+          end,
+    {reply, Res, State}.
+
+
+handle_cast({unregister_name, Name}, State) ->
+    {noreply, ok, maps:remove(Name, State)}.

apps/virtuerl/src/virtuerl_server.erl

@@ -0,0 +1,27 @@
+-module(virtuerl_server).
+
+% -behaviour(gen_server).
+
+-export([start/2]).
+
+%% Callbacks for `gen_server`
+% -export([init/1, handle_call/3, handle_cast/2]).
+
+% start_link([]) ->
+%     gen_server:start_link({local, ?MODULE}, ?MODULE, []).
+
+% init([]) ->
+%     _ = ets:new(virtuerl_servers, [named_table]),
+%     Tab = ets:whereis(virtuerl_servers),
+%     erlang:error(not_implemented).
+
+% handle_call({update_config, Name, Conf},_From,State) ->
+
+% handle_cast(Request,State) ->
+%     erlang:error(not_implemented).
+
+
+start(Name, Conf) ->
+    {ok, SupPid} = supervisor:start_child(virtuerl_sup_sup,
+                                          #{id => Name, start => {virtuerl_sup, start_link, [Name, Conf]}, type => supervisor}),
+    {ok, SupPid}.

apps/virtuerl/src/virtuerl_sup.erl

@@ -2,17 +2,17 @@
 
 -behaviour(supervisor).
 
--export([start_link/0]).
+-export([start_link/2]).
 -export([init/1]).
 
 -define(SERVER, ?MODULE).
 
 
-start_link() ->
-    supervisor:start_link({local, ?SERVER}, ?MODULE, []).
+start_link(ServerId, Conf) ->
+    supervisor:start_link({local, ?SERVER}, ?MODULE, [ServerId, Conf]).
 
 
-init([]) ->
+init([ServerId, Conf]) ->
     SupFlags = #{
                  strategy => one_for_one,
                  intensity => 300,
@@ -37,7 +37,7 @@ init([]) ->
                    worker,
                    []},
                   {virtuerl_mgt,
-                   {virtuerl_mgt, start_link, []},
+                   {virtuerl_mgt, start_link, [ServerId, Conf]},
                    permanent,
                    infinity,
                    worker,

apps/virtuerl/src/virtuerl_sup_sup.erl

@@ -0,0 +1,20 @@
+-module(virtuerl_sup_sup).
+
+-behaviour(supervisor).
+
+-export([start_link/0]).
+-export([init/1]).
+
+
+start_link() ->
+    supervisor:start_link({local, ?MODULE}, ?MODULE, []).
+
+
+init([]) ->
+    SupFlags = #{
+                 strategy => one_for_one,
+                 intensity => 300,
+                 period => 5
+                },
+    ChildSpecs = [#{id => virtuerl_reg, start => {virtuerl_reg, start_link, []}}],
+    {ok, {SupFlags, ChildSpecs}}.

config/sys.config

@@ -10,5 +10,6 @@
             max_no_bytes => 10485760,
             formatter => {logger_formatter, #{single_line => false}}}}
       ]}]},
-  {erlexec, []}
+  {erlexec, []},
+  {virtuerl, [{servers, #{default => #{vm_proc_mod => virtuerl_qemu}}}]}
 ].

config/test.sys.config

@@ -0,0 +1,14 @@
+[{kernel,
+  [{logger_level, all},
+    {logger,
+      [{handler, default, logger_std_h,
+        #{ level => info,
+            formatter => {logger_formatter, #{single_line => false}}}},
+       {handler, debug, logger_disk_log_h,
+        #{ level => debug,
+            config => #{file => "var/log/virtuerl.log"},
+            max_no_bytes => 10485760,
+            formatter => {logger_formatter, #{single_line => false}}}}
+      ]}]},
+  {erlexec, []}
+].

rebar.config

@@ -11,7 +11,7 @@
 {shell, [{config, "config/sys.config"},
          {apps, [virtuerl, virtuerl_ui]}]}.
 
-{ct_opts, [{sys_config, ["config/sys.config"]}]}.
+{ct_opts, [{sys_config, ["config/test.sys.config"]}]}.
 
 {project_plugins, [erlfmt,
                    rebar3_efmt,