Open Tomcat to external network - azure

Question

I have a CentOS 7 VM on Azure and having serious troubles to make it reachable from Internet.
Meanwhile it looks to be perfectly reachable by internal network:
[root#localhost bin]# telnet 192.168.200.128 8080
Trying 192.168.200.128...
Connected to 192.168.200.128.
Escape character is '^]'.
But i cannot reach it from internet by public IP:
> telnet x.x.x.x 8080
Connessione a x.x.x.x...Impossibile aprire una connessione con l'host. sulla porta 8080: Connessione non riuscita
(public IP removed for security purpose)
The port 8080 is correctly open on Azure NSG:
Priority
Name
Port
Protocol
Source
Destination
Action
350
Tomcat
8080
TCP
Any
Any
Allow
The port 8080 is correctly open and listening by Tomcat on VM:
[root#localhost ~]# netstat -tulpn | grep LISTEN
tcp 0 0 127.0.0.1:8005 0.0.0.0:* LISTEN 14987/java
tcp 0 0 0.0.0.0:5001 0.0.0.0:* LISTEN 14987/java
tcp 0 0 127.0.0.1:29130 0.0.0.0:* LISTEN 6594/mdsd
tcp 0 0 0.0.0.0:111 0.0.0.0:* LISTEN 616/rpcbind
tcp 0 0 0.0.0.0:8080 0.0.0.0:* LISTEN 14987/java
Firwall on VM is disabled :
[root#localhost ~]# service firewalld status
Redirecting to /bin/systemctl status firewalld.service
● firewalld.service - firewalld - dynamic firewall daemon
Loaded: loaded (/usr/lib/systemd/system/firewalld.service; disabled; vendor preset: enabled)
Active: inactive (dead)
Docs: man:firewalld(1)
I really have no idea what I'm missing here...
This is my server.xml :
<?xml version='1.0' encoding='utf-8'?>
<!--
Licensed to the Apache Software Foundation (ASF) under one or more
contributor license agreements. See the NOTICE file distributed with
this work for additional information regarding copyright ownership.
The ASF licenses this file to You under the Apache License, Version 2.0
(the "License"); you may not use this file except in compliance with
the License. You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
-->
<!-- Note: A "Server" is not itself a "Container", so you may not
define subcomponents such as "Valves" at this level.
Documentation at /docs/config/server.html
-->
<Server port="8005" shutdown="SHUTDOWN">
<!-- Security listener. Documentation at /docs/config/listeners.html
<Listener className="org.apache.catalina.security.SecurityListener" />
-->
<!--APR library loader. Documentation at /docs/apr.html -->
<Listener className="org.apache.catalina.core.AprLifecycleListener" SSLEngine="on" />
<!--Initialize Jasper prior to webapps are loaded. Documentation at /docs/jasper-howto.html -->
<Listener className="org.apache.catalina.core.JasperListener" />
<!-- Prevent memory leaks due to use of particular java/javax APIs-->
<Listener className="org.apache.catalina.core.JreMemoryLeakPreventionListener" />
<Listener className="org.apache.catalina.mbeans.GlobalResourcesLifecycleListener" />
<Listener className="org.apache.catalina.core.ThreadLocalLeakPreventionListener" />
<!-- Global JNDI resources
Documentation at /docs/jndi-resources-howto.html
-->
<GlobalNamingResources>
<!-- Editable user database that can also be used by
UserDatabaseRealm to authenticate users
-->
<Resource name="UserDatabase" auth="Container"
type="org.apache.catalina.UserDatabase"
description="User database that can be updated and saved"
factory="org.apache.catalina.users.MemoryUserDatabaseFactory"
pathname="conf/tomcat-users.xml" />
</GlobalNamingResources>
<!-- A "Service" is a collection of one or more "Connectors" that share
a single "Container" Note: A "Service" is not itself a "Container",
so you may not define subcomponents such as "Valves" at this level.
Documentation at /docs/config/service.html
-->
<Service name="Catalina">
<!--The connectors can use a shared executor, you can define one or more named thread pools-->
<!--
<Executor name="tomcatThreadPool" namePrefix="catalina-exec-"
maxThreads="150" minSpareThreads="4"/>
-->
<!-- A "Connector" represents an endpoint by which requests are received
and responses are returned. Documentation at :
Java HTTP Connector: /docs/config/http.html (blocking & non-blocking)
Java AJP Connector: /docs/config/ajp.html
APR (HTTP/AJP) Connector: /docs/apr.html
Define a non-SSL HTTP/1.1 Connector on port 8080
-->
<Connector port="8080"
protocol="HTTP/1.1"
connectionTimeout="20000"
URIEncoding="UTF-8"
useIPVHosts="true"
redirectPort="8443" />
<!-- A "Connector" using the shared thread pool-->
<!--
<Connector executor="tomcatThreadPool"
port="8080" protocol="HTTP/1.1"
connectionTimeout="20000"
redirectPort="8443" />
-->
<!-- Define a SSL HTTP/1.1 Connector on port 8443
This connector uses the JSSE configuration, when using APR, the
connector should be using the OpenSSL style configuration
described in the APR documentation -->
<!--
<Connector port="8443" protocol="HTTP/1.1" SSLEnabled="true"
maxThreads="150" scheme="https" secure="true"
clientAuth="false" sslProtocol="TLS" />
-->
<!-- Define an AJP 1.3 Connector on port 8009 -->
<Connector port="8089" protocol="AJP/1.3" redirectPort="8443" />
<!-- An Engine represents the entry point (within Catalina) that processes
every request. The Engine implementation for Tomcat stand alone
analyzes the HTTP headers included with the request, and passes them
on to the appropriate Host (virtual host).
Documentation at /docs/config/engine.html -->
<!-- You should set jvmRoute to support load-balancing via AJP ie :
<Engine name="Catalina" defaultHost="localhost" jvmRoute="jvm1">
-->
<Engine name="Catalina" defaultHost="localhost">
<!--For clustering, please take a look at documentation at:
/docs/cluster-howto.html (simple how to)
/docs/config/cluster.html (reference documentation) -->
<!--
<Cluster className="org.apache.catalina.ha.tcp.SimpleTcpCluster"/>
-->
<!-- Use the LockOutRealm to prevent attempts to guess user passwords
via a brute-force attack -->
<Realm className="org.apache.catalina.realm.LockOutRealm">
<!-- This Realm uses the UserDatabase configured in the global JNDI
resources under the key "UserDatabase". Any edits
that are performed against this UserDatabase are immediately
available for use by the Realm. -->
<Realm className="org.apache.catalina.realm.UserDatabaseRealm"
resourceName="UserDatabase"/>
</Realm>
<Host name="localhost" appBase="webapps"
unpackWARs="true" autoDeploy="true">
<!-- SingleSignOn valve, share authentication between web applications
Documentation at: /docs/config/valve.html -->
<!--
<Valve className="org.apache.catalina.authenticator.SingleSignOn" />
-->
<!-- Access log processes all example.
Documentation at: /docs/config/valve.html
Note: The pattern used is equivalent to using pattern="common" -->
<Valve className="org.apache.catalina.valves.AccessLogValve" directory="logs"
prefix="localhost_access_log." suffix=".txt"
pattern="%h %l %u %t "%r" %s %b" resolveHosts="true"/>
</Host>
</Engine>
</Service>
</Server>
Any help would be really appreciated!
Note that NGINX on port 80 is working perfectly also from internet!

Answer 1

I tried to reproduce the same in my environment I got the same error to make reachable Internet as port 8080.
To resolve this issue:
First, I have installed default Java development and runtime in CentOS 7.
sudo yum install java-1.8.0-openjdk-devel
And try to download a Tomcat bin file. I have downloaded apache-tomcat-9.0.68.tar.gz file in my directory like below.
When download is completed, try using this command to extract the tar file.
tar -xf apache-tomcat-9.0.68.tar.gz
And move the source file to the /opt/tomcat directory.
sudo mv apache-tomcat-9.0.68 /opt/tomcat/
Try following below script:
sudo mv apache-tomcat-9.0.27 /opt/tomcat/
sudo ln -s /opt/tomcat/apache-tomcat-9.0.27 /opt/tomcat/latest
sudo chown -R tomcat: /opt/tomcat
sudo sh -c 'chmod +x /opt/tomcat/latest/bin/*.sh'
I used Sudo vi for text editor create a tomcat.service unit file and pasted from document content.
sudo vi /etc/systemd/system/tomcat.service
Try to start the tomcat:
Finally, when I try to run the firewall to access the tomcat interface from the outside of the local network it's works successfully.
Result:
Check whether you have added port 8080 in your vm as below:
In your virtual machine -> networking ->add inbound port rule -> add port 8080 like below.
Reference:
Install Tomcat 9 on CentOS 7 | Linuxize