I created the Ubuntu virtual machine on that I created the Go environment after that I successfully imported and installed the skx/dns-api-go
I followed this doc: https://github.com/skx/dns-api-go for to set up the environment also I installed the required dependencies like
Dancer,Plack::Middle ware::Throttle::Lite,Net::DNS::Resolver,twiggy,
libdancer-perl ,libnet-cidr-lite-perl ,
libplack-middleware-reverseproxy-perl.
after that, at last, I run the following command:
dns-api-go -redis-server localhost:6379
then am getting the following result :
Launching the server on http://127.0.0.1:9999 redis: 2018/09/25
11:18:56 ring.go:263: ring shard state changed: Redis is down.
when I changed the port number in web preview in cloud shell it is showing as your server is not listing to 6379 port number, but in the instance level when I run the netstat -an command it is showing as the server is listing for 6379 port
please help me in resolving these issue.
6379 is redis server port which is there for rate limiting feature. If you go through the main.go file, you'll see go server port is 9999. Just run "dns-api-go" command and hit http://localhost:9999/
Related
We have an application which uses SSH to copy artifact from one node to other. While creating the Docker image (Linux Centos 8 based), I have installed the Openssh server and client, when I run the image from Docker command and exec into it, I am successfully able to run the SSH command and I also see the port 22 enabled and listening ( $ lsof -i -P -n | grep LISTEN).
But if I start a POD/Container using the same image in the Kubernetes cluster, I do not see port 22 enabled and listening inside the container. Even if I try to start the sshd from inside the k8s container then it gives me below error:
Redirecting to /bin/systemctl start sshd.service Failed to get D-Bus connection: Operation not permitted.
Is there any way to start the K8s container with SSH enabled?
There are three things to consider:
Like David said in his comment:
I'd redesign your system to use a communication system that's easier
to set up, like with HTTP calls between pods.
If you put a service in front of your deployment, it is not going to relay any SSH connections. So you have to point to the pods directly, which might be pretty inconvenient.
In case you have missed that: you need to declare port 22 in your deployment template.
Please let me know if that helped.
I am trying out okd but it fails for me during the oc cluster up port check step. The debug output is not very verbose to be polite. Do you have an idea what to look for.
$ oc cluster up
Getting a Docker client ...
Checking if image openshift/origin-control-plane:v3.11 is available ...
Checking type of volume mount ...
Determining server IP ...
Checking if OpenShift is already running ...
Checking for supported Docker version (=>1.22) ...
Checking if insecured registry is configured properly in Docker ...
Checking if required ports are available ...
error: a port needed by OpenShift is not available
But the required ports 53 and 8443 are not taken
sudo netstat -tulpn | grep '\(:8443\|:53\)'
At least netstat returns nothing
Versions:
$ oc version
oc v3.11.0+0cbc58b
kubernetes v1.11.0+d4cacc0
features: Basic-Auth GSSAPI Kerberos SPNEGO
and
CentOS Linux release 7.6.1810 (Core)
I have not been able to find out how to turn debugging on so that it is possible to see what it really checks for.
Has the user you are running the command as enough priveledges to open privileged ports (ports <1024) on your host machine?
try running cluster up as root or with sudo
yes I starting whole okd as root user
Background
I have a machine in production running an elixir application (no access to iex, only to erl) and I am tasked with running an analysis on why we are consuming so much CPU. The idea here would be to launch observer, check the processes tab and see the processes with the most reductions.
How am I connecting?
To connect I am following a tutorial from a blog:
https://sgeos.github.io/elixir/erlang/observer/2016/09/16/elixir_erlang_running_otp_observer_remotely.html 1
Their instructions are as follows:
launch the app in the production machine with a cookie and a name
from local run: ssh user#public_ip "epmd -names" to get the name of the app and the port used
from local create a ssh tunnel to the remote machine: ssh -L 4369:user#public_ip:4369 -L 42877:user#public_ip:42877 user#public_ip (4369 is the epmd port by default, 42877 is the port of the app)
from local connect to the remote machine using the node's name: erl -name "user#app_name" -setcookie "mah_cookie" -hidden -run observer
Problem
And now in theory I should be able to use observer on the machine. Instead however I am greeted with the following error:
Protocol ‘inet_tcp’: register/listen error: epmd_close
So, after scouring the dark side of internet, I decided to use sudo journalctl -f to check all the logs of the machine and I found this:
channel 3: open failed: administratively prohibited: open failed
my_app_name sshd[8917]: error: connect_to flame#99.999.99.999: unknown host (Name or service not known)
/scripts/watchdog.sh")
my_app_name CRON[9985]: pam_unix(cron:session): session closed for user flame
Where:
erlang -name: my_app_name
machine user: flame
machine public ip: 99.999.99.999 (obviously not real)
so it tells me, unknown host ?? I am confused since 99.999.99.999 is the public IP of the machine itself!
Questions
What am I doing wrong?
I read that in older versions of erlang I can’t monitor a machine with observer if they are in different networks (which is the case, because I want to monitor this machine from my localhost) but I didn’t find any information regarding this in modern days.
If this is in fact impossible, what alternatives do I have?
Solution
After 3 days of non-stop searching, I finally found something that works.
To summarize I am putting it here everything I did.
All steps in local machine:
get the ports from the remote server:
> ssh remote-user#remote-ip "epmd -names"
epmd: up and running on port 4369 with data:
name super_duper_app at port 43175
create a ssh tunel with the ports:
ssh remote-user#remote-ip -L4369:localhost:4369 -L43175:localhost:43175
On another terminal in your local machine, run a iex terminal with the cookie the app in your remote server is using. Then connect to it and start observer:
iex --name observer#127.0.0.1 --cookie super_duper_cookie
Node.connect :"super_duper_app#127.0.0.1"
> true
:observer.start
With observer started, select the machine from the Nodes menu.
Possible setbacks
If you have tried this and it didn't work there are a few things you can check for:
Check if the EPMD port on your local machine is free, if not, kill the process using it and free it.
Check your ssh tunneling keys and configurations for permissions. As #Roberto Aloi pointed out this link can be useful: https://unix.stackexchange.com/questions/14160/ssh-tunneling-error-channel-1-open-failed-administratively-prohibited-open
So I just installed the latest version of rabbitmq and I've been trying to get it to work. The server is running and I've restarted it once just to be sure it's a consistent problem.
If I telnet localhost 5672, I get
Trying 127.0.0.1...
Connected to localhost.
Escape character is '^]'.
Connection closed by foreign host.
As you can see, the connection is accepted but rabbitmq does not accept any input. The connection is closed immediately. No further information shows up in logs.
rabbitmqctl works without any problems.
This is running on Windows Subsystem for Linux / Ubuntu. I don't have any other options for a local dev environment because I'm on a work computer which is locked down pretty tightly.
I ran into the same issue, using Ubuntu(16.04) as a subsystem on Windows and rabbitmq 3.7.8. I noticed that when running sudo rabbitmqctl status the listeners showed the following:
{listeners,[{clustering,25672,"::"},{amqp,5672,"::"}]}
I fixed this issue by creating a rabbitmq config file and specifying the localhost and port 5762
Here is what i did step by step.
Using sudo && vim, I created a 'rabbitmq.conf' file, located in
/etc/rabbitmq/
sudo vim /etc/rabbimq/rabbitmq.conf
I specified the localhost(127.0.0.1) and port(5672) for the default
tcp listener in the rabbitmq.conf file
listeners.tcp.default = 127.0.0.1:5672
Restart rabbitmq
sudo service rabbitmq-server stop
then
sudo service rabbitmq-server start
Check sudo rabbitmqctl status and look at the listeners, you should see your new tcp listener with the localhost ip sepcified
{listeners,[{clustering,25672,"::"},{amqp,5672,"127.0.0.1"}]}
Here is the config docs from rabbitmq that may help clarify some of these steps.
Telnet lets you confirm the system is listening and allows incoming connections.
But even an "out of the box" install of RabbitMQ expects credentials for connections.
rabbitmqctl list_users to see which users are configured.
If guest present, typical creds are guest / guest
Either install management plugin (or confirm it is installed),
or script your test, most languages have a package available for connecting to RabbitMQ.
I have installed aerospike on my mac my following this installation steps
All the validations are working fine. I am able to connect to the cluster using browser chrome. Below is the screen shot.
I have also installed the AQL tools following the instructions here.
But I'm unable to connect to local node from aql.
$ aql
2017-11-21 16:06:09 WARN Failed to connect to seed 127.0.0.1 3000.
AEROSPIKE_ERR_CONNECTION Bad file descriptor, 127.0.0.1:3000
Error -1: Failed to connect
$ asadm
Aerospike Interactive Shell, version 0.1.11
ERROR: Not able to connect any cluster.
Also, I have noticed the Java client is giving error.
AerospikeClient client = new AerospikeClient("localhost", 3000);
when I changed the localhost to actual Ip returned by vagrant ssh -c "ip addr"|grep 'global eth1' it is working fine.
How to connect with aql using customer parameters? I want to pass ip address and port as parameters to aql. Any suggestions.
$ aql --help
https://www.aerospike.com/docs/tools/aql/index.html - discusses all various command line options.
$ aql -h a.b.c.d -p 1234
There is another possibility, you have your owned port instead of the default 3000, so when you try to connect to aerospike, you can try to run command like : aql -p4000
Hope this may help you
Seems like the port is not getting freed even after exiting the vagrant console.
Tried closing all the terminal windows and then starting again. But no luck.
Finally, restarting the system resolved the issue.