Develop Reference

How to set intellij remote debug?

I am trying to debug my app in testing environment, my app is running in pod, I said 'pod' because I am not familiar with Kubernetes, its manage client looks like this:app running schematic diagram. I have learn I should set idea like this idea RUN/Debug Configurations schematic diagram. And should restart and redeploy my app, I changed Dockfile firstly. the origin instruction is FROM xxx/java:alpine VOLUME /tmp ADD recruitment.jar app.jar ENTRYPOINT ["java","-Xmx2048m","-jar","/app.jar"] and I changed this to FROM xxx/java:alpine VOLUME /tmp ADD recruitment.jar app.jar ENTRYPOINT ["java","-agentlib:jdwp=transport=dt_socket,server=y,suspend=n,address=5005","-jar","/app.jar"] but it always show error like this Error running 'face_remote': Unable to open debugger port (888.88.888.888[not real]:5005): java.io.IOException "handshake timeout". I am not sure with this ip,sicne I use 'ping 888.88.888.888' instruction can not success. I use this ip because Swagger request url's domain name's ip is this.this main enter image description here. and I guess if the app is running in docker or k8s and it will have a different Interactive mode. not same like just running in linux

most of the attached image are not visible.
IP address should be accessible from your local system
[888.88.888.888] note sure this is correct.
debug port also need to be mapped from your local system
-use port forwarding
ex:kubectl port-forward 5005:5005
If you have configure port forwarding then you can use localhost:5005 for debugging

I see three things that you can check:
Check the IP address:
The jar file runs inside a Docker container, which runs inside a pod. To access the pod you usually go through a service and an ingress. The ip you are using is most likely hitting the ingress/service or any other higher layer.
To attach a remote debugger, you will need to connect directly to the PodIP. One way of doing this is to first connect to your kubernetes cluster using the tool kubectl (some configuration required) and make a port forward from your pod: kubectl port-forward my-pod-c93b8b6df-8c4aa 5005:5005 pod (as an example, the pod instance name is my-pod-c93b8b6df-8c4aa).
This will open a connection from your local computer into the pod. Then you will need to identify the PodIP by kubectl describe pods my-pod-c93b8b6df-8c4aa and use that in IntelliJ
Check if the port is exposed:
Make sure you expose the port 5005 from the pod in your test environment (similar to exposing a port when you run the container locally).
How to do this depends a bit on how you are running your Kubernetes cluster. If you use Helm chart, you can just add a configuration like this in the port section of your deployment yaml:
- containerPort: 5005
name: debug
protocol: TCP
Check debug-command address:
Last thing is to make sure you are adding the correct address in the command line option. As IntelliJ suggest in the debug editor: for JDK9+ use …suspend=n,address=*:5005 and for JDK8 and below use …suspend=n,address=5005

How to limit AEM access to localhost?

To load some code, I need a clean local AEM Author instance running on my laptop. I start it using CLI like :
bash$ java -jar aem-author-p4502.jar -nointeractive
Default user/password is then admin/admin to access AEM on http://localhost:4502. I'm ok with that but I've tested from another computer and port 4502 is open from full local network.
I'd like to limit access only from localhost, maybe by configuring listener address to 127.0.0.1 only. How ?

Recent AEM versions uses Apache Felix Lightweight HTTP Service as HTTP Server. I found how to bind it to 127.0.0.1 when it is embedded in AEM.
Configuration file is crx-quickstart/launchpad/config/org/apache/felix/http.config. I added last line :
:org.apache.felix.configadmin.revision:=L"1"
org.apache.felix.http.session.timeout=I"10"
org.apache.felix.https.jetty.protocols.excluded=[ \
"SSLv3", \
]
org.apache.felix.proxy.load.balancer.connection.enable=B"true"
service.pid="org.apache.felix.http"
org.apache.felix.http.host="127.0.0.1"
Now AEM Author is available only from localhost.

Maybe you can try to add an exception on your firewall to the port 4502 and only enable connections from your local and deny the others.
Regards,

cannot use both TOMCAT server and my internet connection

I cannot have my tomcat server started and at the same time use internet.
either I can start Tomcat (in Eclipse) and internet is not available.
or I can access the internet but tomcat cannot be started.
Here the original probleme I had when I first wanted to use Tomcat and display my html page on localhost.
GRAVE: StandardServer.await: create[localhost:8005]: I find a way to start the Tomcat Server: in the terminal:
sudo lsof -i : 8005 # checks port 80
sudo route -n flush
sudo route add default 192.168.1.1
then I can use tomcat and localhost:8080 but my internet connexion is dead
if I want my internet connexion then I stop the tomcat server by clicking on the red square in eclipse and then in the terminal I do:
sudo route -n flush
sudo route add default 192.168.0.1
THen I can use internet but tomcat cannot be restarted. I have to undergo the first process.
this of course is a very boring process and I would like to know what 's wrong and how I could fix it.
I use tomcat 9 / Mac OS sierra / Eclipse Neon3

When you say "my internet connexion is dead", do you mean that your network connection drops or that your DNS lookups fail? (What do you think this command is doing and why are you performing it: sudo route add default 192.168.1.1?)
If your program is modifying your system's connectivity settings, I would strongly recommend against preventing it from doing that. There's no reason for it to do so at that level, a more appropriate place to set settings would be at some deploy stage.
Alternatively, you could run your app in a Docker container which I strongly suspect will solve your problem. Visit www.docker.com to learn more.

Connect JVisualVM to a Remote Wildfly Instance?

I'm trying to connect JVisualVM, running on my local machine, to a remote machine which is running a WildFly server (version 8.1.0, to be specific.)
I didn't configure the WildFly server myself, and I don't know who did, but I do know that I can log in as an administrative user from my local machine by pointing my browser at:
https://[ip address of the remote machine]:9443/console
Note that it's https, not ordinary http, and that the port for that has been set to 9443 (I think the default is 8080 or 9990 or something... IDK, I saw a lot of port numbers online. I have been explicitly told that http was disabled for this WildFly server).
I can SSH into the remote machine. I can navigate to the bin directory for WildFly and run jboss-client.sh. I have to connect on port 9999 (I think the default is 9990 for that?)
I copied the jboss-client.jar (under bin/client) to my local machine and ran JVisualVM from the command line like this:
.\jvisualvm.exe -cp:a C:\[path to]\jboss-client.jar
It launches fine. File > Add Remote Host: Then I entered the IP. OK. I right clicked on it under Remote in the tree and picked Add JMX Connection. I entered
service:jmx:http-remoting-jmx://[ip]:9999
I checked off that I wanted to use the security credentials and entered the username and password. Checked off to save the security credentials. Left "Do not require SSL Connection" unchecked. Hit OK. It immediately spat out the message
Cannot connect to admin#service:jmx:http-remoting-jmx://[ip]:9999 using service:jmx:http-remoting-jmx://[ip]:9999
I also tried the port 9443, 9990, and 8080 instead. None of those worked. I tried https instead of http in the protocol name. That also didn't work.
What am I missing? How is it that I can access the console, and connect with jboss-client.sh, but I can't use JVisualVM? Is there some log I can use somewhere to see what's wrong? Maybe someone can point out a configuration I've missed somewhere?
Not sure if it's important or not, but my local machine is running Windows 10 with JDK8 installed. The WildFly server is using Java 6 on CentOS 6.3.

You need to add the jboss-client.jar (or jboss-cli-client.jar) to the class path for JVisualVM. The library can be found in the bin/client directory of the WildFly install.
I used the following command to add the library to the class path.
jvisualvm --cp:a ~/servers/wildfly-10.0.0.Final/bin/client/jboss-client.jar
Then I used service:jmx:remote+http://[ip]:[port] and was able to connect.

I don't know if someone else is also (still) having the same issue (Wildfly10 on a remote machine where management console is available at 9443 with HTTPS). The following worked for me.
For ssh connections:
Starting jvisualvm with jboss-client.jar
jvisualvm --cp:a #JBOSS_HOME/bin/client/jboss-client.jar
Using the following connection string:
service:jmx:remote+https://remote-server:9443
NOTE: I used here remote+https
Provide username and password
Hope this helps.

you missed run jstatd command in remote host ,
this little program is RMI server that possible connection from client to remote host though you using jmx connection it used jmxrmi protocol for that connection .
so first in remote host create file name as security.policy with this contain :
grant codebase "file:${java.home}/../lib/tools.jar" {
permission java.security.AllPermission;
};
off course you must in file section for linux put explicit path and then of creation this file put it in bin directory of jdk.home
then you should run this command on remote host
$JAVA_HOME/bin/jstatd -J-Djava.security.policy=path of /security.policy -J-Djava.rmi.server.hostname=remote ip address -J-Djava.net.preferIPv4Stack=true
then you could connect to server off course with correct settings.

Include jboss-cli-client.jar and jboss-client.jar under \lib\visualvm\platform\lib and restart jvisualvm to pickup new jars.

Rabbitmq exception com.rabbitmq.client.PossibleAuthenticationFailureException: Possibly caused by authentication failure [duplicate]

I've installed the latest RabbitMQ server (rabbitmq-server-3.3.0-1.noarch.rpm) on a fresh Centos 5.10 VM according to the instructions on the official site.
I've done this many times before during development and never had any issues. However, this time I cannot log into the management web interface using the default guest/guest user.
In the logs, I see the following:
=ERROR REPORT==== 4-Apr-2014::00:55:15 ===
webmachine error: path="api/whoami"
"Unauthorized"
What could be causing this?

It's new features since the version 3.3.0
http://www.rabbitmq.com/release-notes/README-3.3.0.txt
server
------
...
25603 prevent access using the default guest/guest credentials except via
localhost.
If you want enable the guest user read this or this RabbitMQ 3.3.1 can not login with guest/guest
# remove guest from loopback_users in rabbitmq.config like this
[{rabbit, [{loopback_users, []}]}].
# It is danger for default user and default password for remote access
# better to change password
rabbitmqctl change_password guest NEWPASSWORD
If you want create a new user with admin grants:
rabbitmqctl add_user test test
rabbitmqctl set_user_tags test administrator
rabbitmqctl set_permissions -p / test ".*" ".*" ".*"
Now you can access using test test.

If you still can't access the management console after a fresh install, check if the management console was enabled. To enable it:
Go to the RabbitMQ command prompt.
Type:
rabbitmq-plugins enable rabbitmq_management

Something that just happened to me and caused me some headaches:
I have set up a new Linux RabbitMQ server and used a shell script to set up my own custom users (not guest!).
The script had several of those "code" blocks:
rabbitmqctl add_user test test
rabbitmqctl set_user_tags test administrator
rabbitmqctl set_permissions -p / test ".*" ".*" ".*"
Very similar to the one in Gabriele's answer, so I take his code and don't need to redact passwords.
Still I was not able to log in in the management console. Then I noticed that I had created the setup script in Windows (CR+LF line ending) and converted the file to Linux (LF only), then reran the setup script on my Linux server.
... and was still not able to log in, because it took another 15 minutes until I realized that calling add_user over and over again would not fix the broken passwords (which probably ended with a CR character). I had to call change_password for every user to fix my earlier mistake:
rabbitmqctl change_password test test
(Another solution would have been to delete all users and then call the script again)

If on Windows and installed using chocolatey make sure firewall is allowing the default ports for it:
netsh advfirewall firewall add rule name="RabbitMQ Management" dir=in action=allow protocol=TCP localport=15672
netsh advfirewall firewall add rule name="RabbitMQ" dir=in action=allow protocol=TCP localport=5672
for the remote access.

I also couldn't log in to Rabbit's web interface. in my case, cookies were disabled in the browser for this web interface. I allowed cookies to be saved and rebooted chrome. and I was able to log in again.

If you are in Mac OS, you need to open the /usr/local/etc/rabbitmq/rabbitmq-env.conf and
set NODE_IP_ADDRESS=, it used to be 127.0.0.1. Then add another user as the accepted answer suggested.
After that, restart rabbitMQ, brew services restart rabbitmq