I once did this configuration and it worked, but now on other machine is not working. I followed the instruction from sendgrid:
https://sendgrid.com/docs/for-developers/sending-email/sendmail/
But when i want to send an email it says:
sm-msp-queue[4439]: 07QAbRM1009651: to=smmsp, delay=01:20:57, xdelay=00:04:22, mailer=relay, pri=301852, relay=[127.0.0.1] [127.0.0.1], dsn=4.0.0, stat=Deferred: Connection timed out with [127.0.0.1]
I think that it should not be 127.0.0.1 but the smtp.sendgrid.net.
netstat -ntlp shows:
tcp 0 0 127.0.0.1:587 0.0.0.0:* LISTEN -
I also can telnet to smtp.sendgrid.net on port 587
I found the problem. There was an iptable rule that drops all loopback connection.
-A OUTPUT -o lo -j DROP
removed with
-D OUTPUT -o lo -j DROP
Make sure to save the new rules:
iptables-save > /etc/iptables/rules.v4
I've installed, Docker, Kubectl and kubeAdm.
I want to create my device model and device CRDs (I'm following this guide.
So, when I run the command :
kubectl create -f devices_v1alpha1_devicemodel.yaml
as a user I get the following out:
The connection to the server 10.0.0.68:6443 was refused - did you
specify the right host or port?
(I have added the permission for the user to access the .kube folder)
With netstat, I get :
> ubuntu#kubernetesmaster:~/src/github.com/kubeedge/kubeedge/build/crds/devices$
> sudo netstat -atunp Active Internet connections (servers and
> established) Proto
> Recv-Q Send-Q Local Address Foreign Address State
> PID/Program name tcp 0 0 0.0.0.0:22
> 0.0.0.0:* LISTEN 1298/sshd tcp 0 224 10.0.0.68:22 160.98.31.160:52503 ESTABLISHED
> 2061/sshd: ubuntu [ tcp6 0 0 :::22 :::*
> LISTEN 1298/sshd udp 0 0 0.0.0.0:68
> 0.0.0.0:* 910/dhclient udp 0 0 10.0.0.68:123 0.0.0.0:*
> 1241/ntpd udp 0 0 127.0.0.1:123
> 0.0.0.0:* 1241/ntpd udp 0 0 0.0.0.0:123 0.0.0.0:*
> 1241/ntpd udp6 0 0 fe80::f816:3eff:fe0:123 :::*
> 1241/ntpd udp6 0 0 2001:620:5ca1:2f0:f:123 :::*
> 1241/ntpd udp6 0 0 ::1:123 :::*
> 1241/ntpd udp6 0 0 :::123 :::*
> 1241/ntpd
With lsof -i :
ubuntu#kubernetesmaster:~/src/github.com/kubeedge/kubeedge/build/crds/devices$ sudo lsof -i
COMMAND PID USER FD TYPE DEVICE SIZE/OFF NODE NAME
dhclient 910 root 6u IPv4 12765 0t0 UDP *:bootpc
ntpd 1241 ntp 16u IPv6 15340 0t0 UDP *:ntp
ntpd 1241 ntp 17u IPv4 15343 0t0 UDP *:ntp
ntpd 1241 ntp 18u IPv4 15347 0t0 UDP localhost:ntp
ntpd 1241 ntp 19u IPv4 15349 0t0 UDP 10.0.0.68:ntp
ntpd 1241 ntp 20u IPv6 15351 0t0 UDP ip6-localhost:ntp
ntpd 1241 ntp 21u IPv6 15353 0t0 UDP [2001:620:5ca1:2f0:f816:3eff:fe0a:874a]:ntp
ntpd 1241 ntp 22u IPv6 15355 0t0 UDP [fe80::f816:3eff:fe0a:874a]:ntp
sshd 1298 root 3u IPv4 18821 0t0 TCP *:ssh (LISTEN)
sshd 1298 root 4u IPv6 18830 0t0 TCP *:ssh (LISTEN)
sshd 2061 root 3u IPv4 18936 0t0 TCP 10.0.0.68:ssh->160.98.31.160:52503 (ESTABLISHED)
sshd 2124 ubuntu 3u IPv4 18936 0t0 TCP 10.0.0.68:ssh->160.98.31.160:52503 (ESTABLISHED)
I've already tried this
and:sudo swapoff -a
Please perform below steps on the master node. It works like charm.
1. sudo -i
2. swapoff -a
3. exit
4. strace -eopenat kubectl version
I am facing similar problem with following error while deploying the pod network into a cluster using flannel:
$ kubectl apply -f https://raw.githubusercontent.com/coreos/flannel/master/Documentation/kube-flannel.yml
The connection to the server 192.168.1.101:6443 was refused - did you specify the right host or port?
I performed below steps to solved the issue:
$ sudo systemctl stop kubelet
$ sudo systemctl start kubelet
$ strace -eopenat kubectl version
then apply the yml file
$ kubectl apply -f https://raw.githubusercontent.com/coreos/flannel/master/Documentation/kube-flannel.yml
podsecuritypolicy.policy/psp.flannel.unprivileged created
clusterrole.rbac.authorization.k8s.io/flannel created
clusterrolebinding.rbac.authorization.k8s.io/flannel created
serviceaccount/flannel created
configmap/kube-flannel-cfg created
daemonset.apps/kube-flannel-ds created
kubelet must be down. you need to check kubelet logs on the master and ensure api server is running and online. then only you should be able to deploy
I'll add another reason for this error that was the issue in my case.
I exported the wrong Kubeconfig file to shell and the error message was very accurate in that case - The endpoint for the API server was wrong (and of course other fields like the cluster name and the certificates - but the server endpoint is the first step in the chain).
I've encountered this problem and swapoff -a works for me though.
sudo -i
swapoff -a
exit
strace -eopenat kubectl version
This is because docker is down. Start docker on your machine.
I have tried many ways but couldn't get it work, then accidentally found the solution to my own situation:
In ~/.kube/ I have
drwxr-x--- 4 staff 128 25 Jul 22:31 cache
-rw------- 1 staff 8781 25 Jul 22:46 config
drwxr-xr-x 8 staff 256 25 Jul 22:46 configs
-rw-r--r-- 1 staff 14 25 Jul 22:31 kubectx
drwxr-xr-x 4 staff 128 29 Jun 16:59 kubens
My assumption is that there is something messed up in the .kube configuration, however I couldn't figure out which files, so I removed most of the directories/files, including cache, config. (If you don't want to keep all the configs, maybe you should remove all of them)
Then from docker dashboard to re-enable kubernetes, to get all the files installed back.
Re-config the docker-desktop by kubectl config use-context docker-desktop.
Finally, my 6443 responded.
Another suggestion is to restart your container sudo systemctl restart containerd In my situation I'm working with containerd and not a typical docker container
After doing this I think it should fix the issue for you but if doesn't work then try sudo swapoff -a
Assuming that's all the output from your netstat command and that you ran it on the master node (the one you installed Kubernetes via kubadm on), it looks to me like the installation did not complete correctly as none of the usual ports you would expect to see on a Kubernetes master node are present.
Usually on a kubernetes master node you'd expect to see kube-apiserver, kube-scheduler, kube-controller, kubelet and possibly etcd all listening on the network.
What was the output of your kubeadm init command?
I ran into this issue as well, I tried the solutions noted above and it did not work for me. Here is what worked for me:
FIX:
kubeadm init --apiserver-advertise-address=10.139.0.42 --ignore-preflight-errors all --pod-network-cidr=172.17.0.1/16 --token-ttl 0
source:
https://www.c-sharpcorner.com/article/kubernetes-installation-in-redhat-and-centos/
I faced this issue recently due to expired certificates for my K8S cluster.
I followed this blog link to renew the certificates and also replace the kube config file that I was using.
Note, it is important to replace the kube config post renewal of the certificates or else you would end up getting following error message for kubectl CLIs:
error: You must be logged in to the server (Unauthorized)
I faced same issue with the same error, You need to check that your container run time (docker/containerd) is active and running:
systemctl status containerd
systemctl restart containerd
systemctl restart kubelet
then if you check its status, it supposed to be up and running and you are able to create k8s objects right now.
In my case KUBECONFIG was the problem causing the same error.
This solved it:
export KUBECONFIG=/home/$(whoami)/.kube/config
I solved this exact problem by making sure that in the /etc/hosts file the IP address and host name was set correctly:
192.168.10.11 kube-01.testing
instead of:
127.0.1.1 kube-01.testing
(or 127.0.0.1).
This happens on Ubuntu and Debian as far as I know-
I solved this exact problem by making sure that in the /etc/hosts file the IP address and host name was set correctly:
192.168.10.11 kube-01.testing kube-01
instead of:
127.0.1.1 kube-01.testing kube-01
(or 127.0.0.1).
This happens on Ubuntu and Debian as far as I know-
If you did all the above steps (sudo swapoff -a, kubeconfig file permissions, kubelet and containerd status, etc) and nothing works for you, It is a good idea to take a look at the kubelet logs:
journalctl -xeu kubelet
In my case, I realize that the kubelet wants to download the images, but it fails.
So I turned on the VPN on the node, and after a couple of seconds, everything worked!
I have faced the same issue "The connection to the server {IP}:6443 was refused - did you specify the right host or port?"
The reason was that since Kubernetes 1.24+, kubenet has been removed.
So, when installing the Kubernetes cluster with kubeadm and using Docker as a Container Runtime, the cri-dockerd must be installed as well (otherwise I got the above error).
As it is mention in the kubernetes documentation:
On each of your nodes, install Docker for your Linux distribution as
per Install Docker Engine.
Install cri-dockerd, following the
instructions in that source code repository.
As per the error message, it is clearly says port number 6443 connection is refused.
Means
port number is blocked by firewall
if there is no firewall, then
Blockquote
the port number is not running on the specified host 6443. you can
cross verify using the below command
#netstat -tulpn | grep -i 6443.
Solution:
6443 it is kube-apiserver port number in k8s. if it is not running make sure kube-apiserver is running properly. I have faced the same problem. After that I have fix properly set the correct argument in that specific port.
/usr/local/bin/kube-apiserver \\
--advertise-address=${INTERNAL_IP} \\
--allow-privileged=true \\
--apiserver-count=3 \\
--audit-log-maxage=30 \\
--audit-log-maxbackup=3 \\
--audit-log-maxsize=100 \\
--audit-log-path=/var/log/audit.log \\
--authorization-mode=Node,RBAC \\
--bind-address=0.0.0.0 \\
--client-ca-file=/var/lib/kubernetes/ca.crt \\
--enable-admission-plugins=NodeRestriction,ServiceAccount \\
--enable-swagger-ui=true \\
--enable-bootstrap-token-auth=true \\
--etcd-cafile=/var/lib/kubernetes/ca.crt \\
--etcd-certfile=/var/lib/kubernetes/etcd-server.crt \\
--etcd-keyfile=/var/lib/kubernetes/etcd-server.key \\
--etcd-servers=https://192.168.5.11:2379,https://192.168.5.12:2379 \\
--event-ttl=1h \\
--encryption-provider-config=/var/lib/kubernetes/encryption-config.yaml \\
--kubelet-certificate-authority=/var/lib/kubernetes/ca.crt \\
--kubelet-client-certificate=/var/lib/kubernetes/kube-apiserver.crt \\
--kubelet-client-key=/var/lib/kubernetes/kube-apiserver.key \\
--kubelet-https=true \\
--runtime-config=api/all \\
--service-account-key-file=/var/lib/kubernetes/service-account.crt \\
--service-cluster-ip-range=10.96.0.0/24 \\
--service-node-port-range=30000-32767 \\
--tls-cert-file=/var/lib/kubernetes/kube-apiserver.crt \\
--tls-private-key-file=/var/lib/kubernetes/kube-apiserver.key \\
--v=2
sudo -i
swapoff -a
exit
strace -eopenat kubectl version
I'm trying to configure Sendmail to listen on on 110 POP3 on a ec2 server. I need it for a newsletter app so that it can check for bounces. When I try to telnet in on port 110 I get a connection error.
root:/# telnet sub.domain.com 110
Trying 5?.??.?.?0...
telnet: Unable to connect to remote host: Connection refused
root:/# telnet sub.domain.com 25
Trying 5?.??.?.?0...
Connected to sub.domain.com.
Escape character is '^]'.
220 ip-172-31-54-114.ec2.internal ESMTP Sendmail 8.14.4/8.14.4/Debian-4.1ubuntu1; Wed, 30 Nov 2016 10:24:50 GMT; (No UCE/UBE) logging access from: [5?.??.?.?0](FORGED)-ec2-5?-??-?-?0.compute-1.amazonaws.com [5?.??.?.?0] (may be forged)
^]
telnet> quit
Connection closed.
When I lsof on port 25 I can see that it's working but not on 110.
root:/# lsof -n -i :25
COMMAND PID USER FD TYPE DEVICE SIZE/OFF NODE NAME
sendmail- 4279 root 4u IPv4 2349285 0t0 TCP *:smtp (LISTEN)
root:/# lsof -n -i :110
root:/#
Do I need to edit the sendmail.mc file, previously I commented out the below lines so that smtp would listen to all IPs.
dnl DAEMON_OPTIONS(`Family=inet, Name=MTA-v4, Port=smtp, Addr=127.0.0.1')dnl
dnl DAEMON_OPTIONS(`Family=inet, Name=MSP-v4, Port=submission, M=Ea, Addr=127.0.0.1')dnl
I've searched the sendmail.cf & sendmail.mc for any references to pop3/port110 configuration but can't see anything.
Sendmail MTA acts like SMTP server. You need separate program/server to service POP3 protocol e.g. dovecot IMAP/POP server.
Sendmail-FAQ-4.19 : How do I configure sendmail for POP/IMAP/...?
I can ssh into the server say abc.xyz on port 22 but i can't remote debug it in Eclipse. Here is the additional info :
Server startup arguments -
-Xdebug -Xrunjdwp:transport=dt_socket,address=1234,server=y,suspend=n
Confirmation from logs -
Listening for transport dt_socket at address: 1234
When I telnet on my local system -
local-machine% telnet abc-xyz 1234
Trying xx.xx.xx.xx...
telnet: connect to address xx.xx.xx.xx: Connection timed out
telnet: Unable to connect to remote host: Connection timed out
When I telnet on the server(abc.xyz) -
abc-xyz% telnet localhost 1234
Trying 127.0.0.1...
Connected to localhost.localdomain (127.0.0.1).
Escape character is '^]'.
Connection closed by foreign host.
I've tried setting up tunnel via -
ssh -L 1234:localhost:1234 user#abc-xyz
ssh -L 1234:127.0.0.1:1234 user#abc-xyz
I'm attaching debugger in Eclipse with this config -
Connection type - Standard (Socket attach)
Host - localhost
Port - 1234
Can't get Eclipse to attach to 1234.
After setting up SSH Tunnel, if i manually try to connect to the port, i get this response -
local-machine% telnet localhost 1234
Trying 127.0.0.1...
Connected to localhost.localdomain (127.0.0.1).
Escape character is '^]'.
Connection closed by foreign host.
and I see an entry in catalina.out as:
channel 4: open failed: connect failed: Connection refused
Any help would be appreciated.
EDIT - 1:
I ran
abc-xyz% ~#
and got the following output:
The following connections are open:
#2 client-session (t4 r0 i0/0 o0/0 fd 7/8 cc -1)
#3 direct-tcpip: listening port 1234 for localhost port 1234, connect from 127.0.0.1 port 23456 (t4 r1 i0/0 o0/0 fd 10/10 cc -1)
I think ssh tunneling is working, it's just the way i'm connecting with Eclipse which is going wrong here.
I just had to increase timeout. (Can be done via Window->Preferences->Java->Debugging. Set it to some appropriate value.)
I am bit confuse , my hosts file look like :
> 127.0.0.1 localhost localhost.localdomain localhost4 localhost4.localdomain4 ::1 localhost localhost.localdomain
> localhost6 localhost6.localdomain6
> 127.0.0.1 autoreply.panel.mywebsite.com
> 127.0.0.1 myhostname
> 127.0.0.1 panel.mywebsite.com
why doesn't show the machine Ip address ?? Even so the website is working and the website is accessible from the web.
Anyone can please explain ?? Thank you
Think of /etc/hosts as a dns system override. You can specify hostnames by IP addresses in this file.
For example you could do the following:
echo "127.0.0.1 google.com" >> /etc/hosts
And proceed to ping google.com:
[jclark#jclark530 ~]$ ping -c1 google.com
PING google.com (127.0.0.1) 56(84) bytes of data.
64 bytes from localhost (127.0.0.1): icmp_seq=1 ttl=64 time=0.028 ms
Your attached server IP address(es) will show by running /sbin/ifconfig