我在服务器里新新建了个tomcat的docker，开的端口是8080，使用ip:8080访问时可以看到tomcat的欢迎页面
然后我在本地使用maven命令行打包到tomcat里上传也已经成功，在manager页面里也能看到我的程序
但是我按照ip:8080/demo的方式来访问的时候提示我404
请问这是为什么，我是遗漏了哪里吗
补充:这是docker的日志
Nov 01, 2017 8:54:41 AM org.apache.catalina.startup.HostConfig deployWAR
INFO: Deploying web application archive /usr/local/tomcat/webapps/deploy.war
Nov 01, 2017 8:54:41 AM org.apache.catalina.loader.WebappClassLoaderBase validateJarFile
INFO: validateJarFile(/usr/local/tomcat/webapps/deploy/WEB-INF/lib/tomcat-embed-core-8.5.20.jar) - jar not loaded. See Servlet Spec 3.0, section 10.7.2. Offending class: javax/servlet/Servlet.class
Nov 01, 2017 8:54:41 AM org.apache.catalina.loader.WebappClassLoaderBase validateJarFile
INFO: validateJarFile(/usr/local/tomcat/webapps/deploy/WEB-INF/lib/tomcat-embed-el-8.5.20.jar) - jar not loaded. See Servlet Spec 3.0, section 10.7.2. Offending class: javax/el/Expression.class
Nov 01, 2017 8:54:41 AM org.apache.catalina.deploy.WebXml setVersion
WARNING: Unknown version string [3.1]. Default version will be used.
Nov 01, 2017 8:54:43 AM org.apache.catalina.startup.TldConfig execute
INFO: At least one JAR was scanned for TLDs yet contained no TLDs. Enable debug logging for this logger for a complete list of JARs that were scanned but no TLDs were found in them. Skipping unneeded JARs during scanning can improve startup time and JSP compilation time.
Nov 01, 2017 8:54:43 AM org.apache.catalina.startup.HostConfig deployWAR
INFO: Deployment of web application archive /usr/local/tomcat/webapps/deploy.war has finished in 1,973 ms