add image check when combine (#26)

prod/upload/combine.lua

@@ -5,12 +5,18 @@ uuid.seed()
 local file_dir = ngx.var.tmp_file_dir
 ngx.req.read_body()
 local req_body = cjson.decode(ngx.req.get_body_data())
-
-local data = req_body["data"]
+ngx.log(ngx.INFO, 'REQ_BODY -> ', ngx.req.get_body_data())
+local data = req_body["data"]["images"]
 local combined = file_dir .. "/" .. uuid.generate_v4() .. ".jpeg";
 local len = table.getn(data)
+if len == 0 then
+    ngx.status = 500
+    ngx.say("No images to combine!")
+    return;
+end
 local origin = {}
 for i = 1, len do
+    ngx.log(ngx.INFO, "COMBINE FILE ->", data[i]) 
     origin[i] = file_dir .. "/" .. data[i] .. " "
 end
 -- 从 nginx 变量取
@@ -26,7 +32,9 @@ if not magick then
     magick = ""
 end
 
-local result, _, code = os.execute(magick .. " convert -append " .. table.concat(origin, " ") .. " " .. combined)
+local cmd = magick .. " convert -append " .. table.concat(origin, " ") .. " " .. combined  
+ngx.log(ngx.INFO, 'CMD -> ', cmd)
+local result, _, code = os.execute(cmd)
 if result and code == 0 then
     local file = io.open(combined)
     local content = file:read("*all")
@@ -36,4 +44,4 @@ if result and code == 0 then
 else
     ngx.status = 500
     ngx.say("image combine failed.")
-end
+end