This is probably a very basic question for you, but I'm just getting into consul and for testing purposes, I wanna run multiple servers on my PC. For example, I run the first server with
consul agent -server -bootstrap-expect=1 -dc=dev -data-dir=/tmp/consul -ui-dir="c:/consul 0.5.2/dist"
and then I try to run the second server with
consul agent -server -data-dir=/tmp/consul2 -dc=dc2
but it returns
==> Error starting agent: Failed to start Consul server: Failed to start RPC lay
er: listen tcp 0.0.0.0:8300: bind: Only one usage of each socket address (protoc
ol/network address/port) is normally permitted.
What am I missing from my command?
You are launching two consul servers using mostly default values. In this case the problem is that you use default ports.
When you read the error message you will notice that your second consul server tries to bind to port 8300. But your first server is already using this port, causing the second server to fail at startup. (note: consul binds to a variety of ports, each having another purpose and default setting. Take a look at the documentation).
As suggested by LenW, you can use Vagrant to set your environment. You could follow the consul tutorial.
If you do not want to use vagrant or set up any virtual machines on your own. You could change the defaults of the second server.
If you are trying to simulate a production topology on your dev machine I would look at using Vagrant in combination with VirtualBox to simulate a couple of machines for testing.
Related
SUMMARY
I have installed zabbix on OpenShift cluster. I am trying to monitor a host(vm) outside the cluster but the zabbix server is unable to connect to it. In the /etc/zabbix/zabbix_agentd.conf file I have mentioned the DNS name of the server zabbix-server but it looks like there server is trying to connect through a different public IP. I am not sure what this IP is.
OS / ENVIRONMENT / Used docker-compose files
I applied the kubernetes.yaml file present in this repo - https://github.com/zabbix/zabbix-docker/blob/6.2/kubernetes.yaml - on an OpenShift cluster.
CONFIGURATION
In the /etc/zabbix/zabbix_agentd.conf file Server=zabbix-server.
STEPS TO REPRODUCE
Apply the kubernetes.yaml file on Openshift cluster and try to monitor any external vm.
EXPECTED RESULTS
The zabbix server should be able to connect to the vm.
ACTUAL RESULTS
Zabbix server logs.
Defaulted container "zabbix-server" out of: zabbix-server, zabbix-snmptraps
\*\* Updating '/etc/zabbix/zabbix_server.conf' parameter "DBHost": 'mysql-server'...added
287:20230120:060843.131 Zabbix agent item "system.cpu.load\[all,avg5\]" on host "Host-C" failed: first network error, wait for 15 seconds
289:20230120:060858.592 Zabbix agent item "system.cpu.num" on host "Host-C" failed: another network error, wait for 15 seconds
289:20230120:060913.843 Zabbix agent item "system.sw.arch" on host "Host-C" failed: another network error, wait for 15 seconds
289:20230120:060929.095 temporarily disabling Zabbix agent checks on host "Host-C": interface unavailable
Logs from the agent installed on the vm.
350446:20230122:103232.230 failed to accept an incoming connection: connection from "9.x.x.219" rejected, allowed hosts: "zabbix-server"
350444:20230122:103332.525 failed to accept an incoming connection: connection from "9.x.x.219" rejected, allowed hosts: "zabbix-server"
350445:20230122:103432.819 failed to accept an incoming connection: connection from "9.x.x.210" rejected, allowed hosts: "zabbix-server"
350446:20230122:103533.114 failed to accept an incoming connection: connection from "9.x.x.217" rejected, allowed hosts: "zabbix-server"
If I add this IP in /etc/zabbix/zabbix_agentd.conf it will work. But what IP is this? Is this a service? Or any node/pod IP? It keeps on changing. Everytime I cannot change this id in the conf file. I need something more stable.
Kindly help me out with this issue.
So I don't know zabbix. So I have to make some educated guesses both in how the agent works and how the server works.
But, to summarize, unlike something like docker compose where you are running the zabbix server on a known server, in Openshift/Kubernetes you are deploying into a cluster of machines with their own networking. In other words, the whole point of OpenShift is that OpenShift will control where the application's pod gets deployed and will relocate/restart that pod as needed. With a different IP every time. (And the DNS name is meaningless since the two systems aren't sharing DNS anyway.) Most likely the IP's you are seeing are the pod's randomly assigned IPs.
So, what are you to do when you have a situation like yours where an external application requires a predicable IP? Well, option 1, is to remove that requirement. Using something like a certificate is obviously more secure and more reliable than depending on an IP anyway. But another option is to use an egress IP. This is a feature of OpenShift where you essentially use a proxy to provide an external application with a consistent IP.
in some cluster environments, there are pair servers that are HA 2 by 2. for example i have server1 with IP 22.1.1.1 and server2 with IP 22.1.1.2.
server1 is giving service and server2 is standby. there is this virtual IP 22.1.1.3 that other servers connect to it to get services from server1 and server2.
now i need to monitor this virtual IP to see if it is up and other servers outside its VLAN can connect to it. how i can do this in zabbix?
i don't have an actual physical server to create in zabbix according to this question. i tried to create one but i got errors. also this question is asked 3 years ago. is there any new features i can use to solve this problem?
You can create a host with agent ip 22.1.1.3 and monitor it in agentless mode.
You can ping it (icmpping), connect to a tcp port that you know it's open (net.tcp.service) or, in case of a web service, do a http call with the http agent and react accordingly.
Just create the correct items/templates according to the simple check and http agent documentation.
You do not need a physical server to create a host.
You can create a host with the target IP address and use various items against it - based on your question, you do not need agent items, but some other (remote) type.
Hopefully I'm doing something wrong, I've read all documentation and scoured forums but can't seem to get to the bottom of an issue I'm experiencing. I'm using OSX btw.
Things that are working:
Connect to cloud SQL from local OS using proxy via either TCP or Socket
Connect to cloud SQL from local OS using proxy in container via TCP
Connect to cloud SQL from GKE using proxy in the same pod via TCP
Things that are not working:
Connect to cloud SQL from local OS using proxy in contain via sockets
Connect to cloud SQL from GKE using proxy in the same pod via socket
I suspect both of these problems are actually the same problem. I'm using this command to run the proxy inside of the container:
docker run -v [PATH]:/cloudsql \
gcr.io/cloudsql-docker/gce-proxy /cloud_sql_proxy -dir=/cloudsql \
-instances=[INSTANCE_CONNECTION_NAME] -credential_file=/cloudsql/[FILE].json
And the associated socket is being generated with the directory. However when I attempt to connect I get the following error:
ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/cloudsql/node-sql:us-central1:nodedb' (61)
The proxy doesn't generate a new line when I try to connect which makes me think that it's not receiving the request, it simply says Ready for new connections and waits.
Any idea what's going wrong, or how I could troubleshoot this further?
For "Connect to cloud SQL from GKE using proxy in the same pod via socket" can you please follow the tutorial at https://cloud.google.com/sql/docs/mysql/connect-kubernetes-engine? We have a working WordPress example there that has the cloudsql-proxy as a sidecar container (i.e. in the same Pod, but over TCP).
I don't think you can do "in the same pod via socket" unless you’re running multiple processes in a single container (which you shouldn’t as a best practice). If you do a sidecar container, you can use TCP, so you don’t need a unix socket (moreover, I'm not sure how you’d share files between containers of a Pod).
Also, the docker run -v /local.sock:/remote.sock (I think) will be creating a file/directory locally as /local.sock and making that available inside the container as /remote.sock. This might not work because the docker-engine doesn't know that /local.sock is meant to be a Unix socket and it creates a regular file.
I have been stuck trying to figure out why my Cloud SQL VM is refusing my connection from my machine (whom ip address I have added as a subnet). I cann SSH into the VM but i cannot access the VM from a browser to make SQLs. I have scoured the internet for days trying to find a fix but i cannot seem to get pass this point. My apache listens to port 80. Also Id like to add that I have been connecting to my Mysql db for months through php and making sqls so I do not believe the problem is with apache. However if it is please point me to where i should be looking.
It sounds like you have MySQL running on a GCE VM, not an actual CloudSQL instance (that is a different service from GCE). Is that right?
If so, then if you are trying to connect from your local machine directly to the mysql instance, you are probably getting blocked by the firewall. Go to the networks tab (under Compute Engine) on the cloud console and see what firewall rules you have enabled. You might need to add one for 3306 or whatever port you are using.
I am trying to run JBoss(5.1) on remote system connecting it using RDC. Which ever port I try, it's says already in use and throwing java.net.BindException Cannot assign requested address: JVM_Bind
I have tried to change the port using jboss service binding configuration located at below path:
jboss\server\Server_Instance\conf\bindingservice.beans\META-INF\bindings-jboss-beans.xml
I have tried various options like ports-01, ports-02 ,ports-03 and then customizing the default port configurations as well with No luck.
I am just wondering how it is possible that it's not allowing any port whichever I try. One thing I would like to let you know here is that the remote system has 3 different logins and all of the users are using the system.
Appreciated if you can provide me any assistance please.
You can pass the -b ${IPofMachine} to bind to an IP. This will also make it externally accessible. You can do 0.0.0.0 which will bind to all available IP's