[WIP] Add and remove servers from upstreams

README.md

@@ -12,6 +12,8 @@ Table of Contents
 * [Functions](#functions)
     * [get_upstreams](#get_upstreams)
     * [get_servers](#get_servers)
+    * [add_upstream_peer](#add_upstream_peer)
+    * [remove_server_from_upstream](#remove_server_from_upstream)
     * [get_primary_peers](#get_primary_peers)
     * [get_backup_peers](#get_backup_peers)
     * [set_peer_down](#set_peer_down)
@@ -126,6 +128,24 @@ The return value is an array-like Lua table. Each table entry is a hash-like Lua
 
 [Back to TOC](#table-of-contents)
 
+add_upstream_peer
+-----------
+`syntax: ok, err = upstream.add_upstream_peer(upstream_name, ip:port, optional weight = 1, optional max_fails = 1, optional fail_timeout = 10, optional backup = false)`
+
+The return values are a boolean denoting the success of the operation and an associated error if one occurs.
+
+[Back to TOC](#table-of-contents)
+
+remove_server_from_upstream
+-----------
+`syntax: err = upstream.remove_server_from_upstream(upstream_name, server_name)`
+
+Removes a server from an upstream given the upstream and server names. The server name is expected to match the `name` field on the server in the upstream.
+
+The return value is an error string or nil.
+
+[Back to TOC](#table-of-contents)
+
 get_primary_peers
 ---------
 `syntax: peers = upstream.get_primary_peers(upstream_name)`
@@ -329,4 +349,3 @@ See Also
 * the [lua-resty-upstream-healthcheck](https://github.com/openresty/lua-resty-upstream-healthcheck) library which makes use of the Lua API provided by this module.
 
 [Back to TOC](#table-of-contents)
-

src/ngx_http_lua_upstream_module.c

@@ -23,6 +23,7 @@ static ngx_int_t ngx_http_lua_upstream_init(ngx_conf_t *cf);
 static int ngx_http_lua_upstream_create_module(lua_State * L);
 static int ngx_http_lua_upstream_get_upstreams(lua_State * L);
 static int ngx_http_lua_upstream_get_servers(lua_State * L);
+static int ngx_http_lua_upstream_add_upstream_peer(lua_State * L);
 static ngx_http_upstream_main_conf_t *
     ngx_http_lua_upstream_get_upstream_main_conf(lua_State *L);
 static int ngx_http_lua_upstream_get_primary_peers(lua_State * L);
@@ -37,6 +38,7 @@ static int ngx_http_lua_upstream_set_peer_down(lua_State * L);
 static int ngx_http_lua_upstream_current_upstream_name(lua_State *L);
 
 
+
 static ngx_http_module_t ngx_http_lua_upstream_ctx = {
     NULL,                           /* preconfiguration */
     ngx_http_lua_upstream_init,     /* postconfiguration */
@@ -90,6 +92,9 @@ ngx_http_lua_upstream_create_module(lua_State * L)
     lua_pushcfunction(L, ngx_http_lua_upstream_get_servers);
     lua_setfield(L, -2, "get_servers");
 
+    lua_pushcfunction(L, ngx_http_lua_upstream_add_upstream_peer);
+    lua_setfield(L, -2, "add_upstream_peer");
+
     lua_pushcfunction(L, ngx_http_lua_upstream_get_primary_peers);
     lua_setfield(L, -2, "get_primary_peers");
 
@@ -141,6 +146,127 @@ ngx_http_lua_upstream_get_upstreams(lua_State * L)
     return 1;
 }
 
+static int
+ngx_http_lua_upstream_add_upstream_peer(lua_State * L)
+{
+    ngx_http_request_t            *r;
+
+    ngx_http_upstream_srv_conf_t  *us;
+
+    ngx_http_upstream_rr_peers_t  *peers;
+    ngx_http_upstream_rr_peer_t   *peer, *last;
+
+    u_char                        *url;
+
+    ngx_url_t                     upstream;
+    ngx_str_t                     host;
+    ngx_int_t                     weight = 1;
+    ngx_int_t                     max_fails = 1;
+    time_t                        fail_timeout = 10;
+    ngx_uint_t                    backup = 0;
+
+    if ((lua_gettop(L) < 2) || (lua_gettop(L) > 6)) {
+        /*
+        * "upstream name", "host:port", "weight", "max_fails", "fail_timeout", "backup"
+        */
+        return luaL_error(L, "at least 2 arguments are required and as many as 6 are allowed");
+    }
+
+    r = ngx_http_lua_get_request(L);
+    if (r == NULL) {
+        lua_pushnil(L);
+        lua_pushliteral(L, "could not retrieve request\n");
+        return 2;
+    }
+
+    host.data = (u_char *) luaL_checklstring(L, 1, &host.len);
+
+    ngx_memzero(&upstream, sizeof(ngx_url_t));
+
+    url = (u_char *) luaL_checklstring(L, 2, &upstream.url.len);
+    upstream.default_port = 80;
+
+    if (lua_gettop(L) >= 3) {
+      weight = (ngx_int_t) luaL_checkint(L, 3);
+    }
+
+    if (lua_gettop(L) >= 4) {
+      max_fails = (ngx_int_t) luaL_checkint(L, 4);
+    }
+
+    if (lua_gettop(L) >= 5) {
+      fail_timeout = (time_t) luaL_checklong(L, 5);
+    }
+
+    if (lua_gettop(L) >= 6) {
+      backup = lua_toboolean(L, 6);
+    }
+
+#if (NGX_DEBUG)
+    ngx_log_error(NGX_LOG_ALERT, r->connection->log, 0, "%s %s params: %s,%s,%d,%d,%d,%d\n", __FILE__, __FUNCTION__, host.data, url, weight, max_fails, fail_timeout, backup);
+#endif
+
+    us = ngx_http_lua_upstream_find_upstream(L, &host);
+    if (us == NULL) {
+        lua_pushnil(L);
+        lua_pushliteral(L, "upstream not found\n");
+        return 2;
+    }
+
+    peers = us->peer.data;
+
+    for (peer = peers->peer, last = peer; peer; peer = peer->next){
+        if (len(url) == peer->name.len && ngx_strncmp(url, peer->name.data, peer->name.len) == 0) {
+            lua_pushnil(L);
+            lua_pushliteral(L, "server already exists\n");
+            return 2;
+        }
+      last = peer;
+    }
+
+    upstream.url.data = ngx_pcalloc(r->pool, upstream.url.len + 1);
+    ngx_memcpy(upstream.url.data, url, upstream.url.len);
+
+    // validate URL
+    if (ngx_parse_url(r->pool, &upstream) != NGX_OK) {
+        if (upstream.err) {
+            lua_pushnil(L);
+            lua_pushliteral(L, "url parser error\n");
+            return 2;
+        }
+    }
+
+    last->next = ngx_pcalloc(r->pool, sizeof(ngx_http_upstream_rr_peer_t));
+
+    if (last->next == NULL) {
+        lua_pushnil(L);
+        lua_pushliteral(L, "failed to allocate memory\n");
+        return 2;
+    }
+
+    last->next->name = upstream.url;
+    last->next->server = upstream.url;
+    last->next->sockaddr = upstream.addrs[0].sockaddr;
+    last->next->socklen = upstream.addrs[0].socklen;
+
+    last->next->weight = weight;
+    last->next->effective_weight = weight;
+    last->next->current_weight = weight;
+
+    last->next->max_fails = max_fails;
+
+    last->next->fail_timeout = fail_timeout;
+
+    last->next->backup = backup;
+
+    peers->number++;
+    peers->total_weight += last->next->weight;
+    peers->single = (peers->number == 1);
+    peers->weighted = (peers->total_weight != peers->number);
+
+    lua_pushboolean(L, 1);
+    return 1;
+}
 
 static int
 ngx_http_lua_upstream_get_servers(lua_State * L)
@@ -551,7 +677,6 @@ ngx_http_lua_upstream_find_upstream(lua_State *L, ngx_str_t *host)
     return NULL;
 }
 
-
 static int
 ngx_http_lua_upstream_current_upstream_name(lua_State *L)
 {

t/sanity.t

@@ -648,3 +648,35 @@ nil
 --- no_error_log
 [error]
 
+
+
+=== TEST 19: add server to pre-defined upstream
+--- http_config
+    upstream foo {
+      server 127.0.0.2;
+    }
+
+--- config
+    location /t {
+        content_by_lua '
+            local ljson = require "ljson"
+            local upstream = require "ngx.upstream"
+            local ok, err = upstream.add_upstream_peer("foo", "127.0.0.10")
+            if err then
+              ngx.say(err)
+            else
+              local peers, err = upstream.get_primary_peers("foo")
+              if not peers then
+                  ngx.say("failed to get primary peers from upstream foo: " .. err)
+              else
+                ngx.say(json.encode(peers))
+              end
+            end
+        ';
+    }
+--- request
+    GET /t
+--- response_body
+[{"addr": "127.0.0.2:80", "weight": 1, "fail_timeout": 10, "name": "127.0.0.2", "max_fails": 1}, {"addr": "127.0.0.10:80", "weight": 1, "fail_timeout": 1, "name": "127.0.0.10", "max_fails": 1}]
+--- no_error_log
+[error]