K3s dns not resolving. => therefore my main openwrt router needs to forward *.

K3s dns not resolving unfortunately, my main router doesn't run such compatible DNS 'provider': Openwrt provides DNS service via dnsmasq (a dhcpv4+dns server bundle), which doesn't support rfc2136. Run the ps aux | grep <application process name> command to query the ID of the application process. The latter two are to resolve parent services from the enterprise where I work. default. I deployed a fedora image to test Resolving Pod DNS Problems in k3s with CoreDNS. For example you will be able to get the IP for NPM by pinging nginx-proxy-manager, the name given in your Networking. DNS resolution times out with the default setup Works fine when using Google's DNS server and changing DNS policy to 'none' tcpdump indicates timeouts when checking cluster domains I'm stumped and not sure what could be causing this. 04; the problem seemed similar to this. 3. 17. There seems to be few solutions which would mean different problems. Reply reply There are 3 levels of DNS here: 1. => therefore my main openwrt router needs to forward *. com” and could not resolve it. 55 I would like to have Pod B communicating with Pod A but since the IP assigned to Pod A (10. 29. Describe the bug: Pods on Windows worker are incorrectly resolving kube-dns service ip to non-existend pod ip, thus unable to resolve cluster records. I checked multiple times and set also once the When I tried to enable hostNetwork: true for a pod, that pod is no longer able to resolve in-cluster DNS names. 18. There are 4 pods with DNS issues and the one thing they have in common is that they are based on alpine images. DNS resolution on host works perfectly and also with docker network bridge. DNS not resolving. Release v1. This is because CoreDNS can select the upstream server at random. ${MASTER_FQDN} and test them also from another computer (which has to reach for public DNS records): dig @ ${MASTER_IP} ns1. box domains. Hi. 4 but I encounter network or dns problems, I checked the modprob as well as sysctl but nothing happens maybe is flannel problem ? firewalld and selinux disabled nm-cloud DNS resolution times out with the default setup Works fine when using Google's DNS server and changing DNS policy to 'none' tcpdump indicates timeouts when checking cluster domains I'm stumped and not sure what could be causing this. Describe the bug K3S is not starting correctly. One is using the Node's IP, and the other is using Flannels. 11. fritz. Closed I can confirm that the DNS resolution works well in the VM but not in the containers. Modified 3 years, 8 months ago. Several issues on CoreDNS issue board were resolved with this: Hi, did you find a solution? I have a very similiar issue. 1): cluster broken due to DNS not working #5379. My Setup: Certificates My certificated are created with Cert-Manager in namespace "Default". svc and it is not reachable. 1. That's why I wish the macOS resolver was exposed again via DNS, the way systemd-resolved is, so we could just forward to it. Could you check that it using k3s agent, even though the node was able to resolve DNS none of the pods could. The first nameserver is to the local DNS server for the lab I am using to test in. So, I think my problem is related with my "router" (mikrotik), even if I disabled all the firewall rules, bu my server are behind a NAT too. 9, and fixes a number of issues. So it is not possible to pull an image from host. Viewed 344 times 0 . 10 K3S not resolving from private DNS . - Shutting down the CoreDNS pod cuts the internal DNS resolutions, too. d/ to change directory to /etc/modprobe. Steps To Reproduce: After a bit more exploration I found that many pods on the agent do not have their /etc/resolve. Kubernetes PODs cant Resolve K3S not resolving from private DNS . 04 CNI and version: Flannel CRI and version: cri-o v1. box. in resolv. I have a dns server running at 192. Share. I want that the pods of my cluster use that DNS server, via coredns. Since the in-cluster DNS does not resolve requests for domains other than the one it was setup to handle Althogh it is possible to change the CoreDNS configuration, that the cluster DNS server will resolve the declared zones using a specific DNS resolver. Closed. IPv6 does not work within the cluster, and K3s will actively work to ensure that you don't have IPv6 servers in the resolv. Related information The nodes can resolve the host from DNS but Pods are not able to resolve them. 15 or later (5. " ping is a poor troubleshooting tool. Related: Internet Connection Not Working? 10 Troubleshooting Tips Flush Your DNS Cache Windows caches your DNS queries to help you quickly translate domain names to IP addresses. conf) will be used as upstream nameservers for kube-dns. I’ve got an extra instance of CoreDNS running in my cluster, serving *. Installed K3s: curl -sfL https://get. Strangely, the worker node seems to have trouble resolving DNS. I deployed a fedora image to test the connection, and it looks like everything is resolving to my server's IP (192. Cluster information: Kubernetes version: v1. conf as a single name server line, with the comma separated values provided by the server. com response on server. nameserver dns-server Describe the solution you'd like. I checked the dnsPolicy in pod spec by requesting an edit and it said ClusterFirst. Node(s) CPU architecture, OS, and Version: Windows 2019 server. Could not find alternate solution. Use local DNS parameter. differentpla. I have searched this repository/Pi-hole forums for existing issues and pull requests that look similar: PiHole not answering DNS queries pi-hole#4187 Port 53 not working from external IP k3s-io/k3s#3384; How to reproduce the issue Here also, dns resolution did not work ! This helped in concluding that the DNS resolution is not specific to Kubernetes pod, but actually somewhere else. However, TCP traffic is allowed. Actual behavior: pods running in the cluster are unable to resolve any private dns entries. nginx; tests. 8 kubectl logs cattle-cluster-agent-54f7b64565-v4zlq -n cattle-system INFO: Environment: CATTLE_ADDRESS=10. box is not avaliable. d/; Type vi disableipv6. 2) and TrueNAS uses DHCP to acquire IP and DNS. Use ipFamilyPolicy: RequireDualStack for dual-stack kube-dns ; Backports for 2024-01 k3s2 Bump runc to We do not recommend using K3s v1. 2. I've got a K3s cluster running on two machines - one acting as the master and the other as a worker. Always restarting coredns + helm-install-traefik Looks similar to #246, but server has full access to internet, and no issue with the described DNS problem. Running nslookup and curl to www. I solved configuring an internal DNS server that is resolving the name with the private IP address of the K3S node, and using that server as the DNS server for the K3S node. 54 Pod B’s IP Address: 10. 0+k3s. 1 k3s chart: DNS resolution not working when k3s deployed in an RKE cluster #1306. If I set both hostNetwork: true and dnsPolicy: ClusterFirstWithHostNet then neither internal nor external DNS names work. Recently resolved a long standing issue with my k3s implementation that was causing many DNS issues within my setup whenever the system restarted (usually due to automatically nightly patching). Changes since v1. resisting to reload/reboot), plug This page provides hints on diagnosing DNS problems. Is this achievable ? If yes, how ? Thanks in advance. We recently updated to RHEL 7. However, when i create a ClusterIp type service and log into a busybox pod, i can reach the network service without problems. conf file: To correctly configure DNS on the TPVM issue the following commands in SLXOS: ** Configuring DNS on the TPVM will cause issues with K3s and cause nodes to show Down ** POD2-Spine2# conf Entering configuration mode Having some issue with my kubernetes cluster and DNS. conf to check what DNS server your Fedora using. Related Issues. Please try it out and let me know if it helps! The settings are configurable in that we will either take a --resolv-conf flag to pass down to the kubelet, or a K3S_RESOLV_CONF environment variable will work also. * address already and the container and nginx already use that DNS. Multus and IPAM plugins Stack Overflow for Teams Where developers & technologists share private knowledge with coworkers; Advertising & Talent Reach devs & technologists worldwide about your product, service or employer brand; OverflowAI GenAI features for Teams; OverflowAPI Train & fine-tune LLMs; Labs The future of collective knowledge sharing; About the company Environmental Info: K3s Version: k3s version v1. conf' If you can reach your pods than please follow this tutorial. 96. - Hard coding the DNS servers into the CoreDNS server, didn't work either. What I t Issue with DNS Resolution in Airgapped K3s Cluster Due to UDP Block on Port 53. Networking. 1 Node(s) CPU architecture, OS, and Version: Five RPI 4s Running Headless 64-bit Raspbian, each with following What this means is that the Cluster DNS service does not work and therefore that pods not are not able to resolve internal or external names. 4+k3s1 (3eee8ac3) K3s arguments: curl -sfL https://get. 10. 168. This guide show how to install the PiHole DNS sinkhole in a K3S cluster. For more details on what's new, see the Kubernetes release notes. ) then the dns is able to resolve without issue. com because it's not configured to serve non-authoritative lookups for clients in your cluster. ; Run the nsenter -t <pid> -n bash command to enter the network namespace to which the application pods belong. newshosting. Set up DNS server in the network. I have a single node k3s "cluster" with few Services on it. Pod not resolving service name in k3s, hope someone been here before Hi all, I am trying to have a pod use an NFS server inside the cluster (k3s with coredns), but it only works with the ClusterIP, not with the service name. Docker-in-Docker (DinD): Running Docker inside a Docker container. Whenever I want to access to one of them, I'm forced to either do a port-forward or a describe (and get the endpoint, but it changes each time). box using this command: All queries will now be logged and can be checked using the command in Check CoreDNS logging. Since I made that recover, I could not connect with my smartphone (OnePlus 8 Pro Plus with Android 11) to any address that is set in the local DNS entries. k3s tries to activate it but can fail. internal which resolves to the IP of the network gateway Method 1: Run the kubectl exec command. Adding Hi, I had a similar issue with k3s - worker node won’t be able to ping coredns service or pod, I ended up resolving it by moving from fedora 34 to ubuntu 20. 0 a shot and my split-DNS from the host is not working in the container (see #702). org Server: 10. g. Let me see what is wrong with it. kubernetes pod cannot resolve local hostnames but can resolve external ones like google. I recently setup k3s via k3sup installer on a cluster of 3x VM's running Ubuntu 22. Closed Copy link Freundschaft commented Mar 20, 2021. Additional context / logs: Tried with no firewall/security groups restrictions. This issue Weird the DNS resolution seems to be failing, so I decided to follow the Kubernetes guide to try to debug issues. It is reproducible by starting an alpine based pod, see below. connection timed out is result of running nsloopkup Kubernetes service. This breaks dns resolving of the k3s node's AAAA records. Recently, we set up a custom DNS server based on dnsmasq within our organization to handle internal DNS requests. DNS resolution fails with dnsPolicy: ClusterFirstWithHostNet and hostNetwork: true #1827 (linked to workaround suggestion for this particular issue) k3s-io/k3s#1827 (comment) [BUG] DNS not resolving #209 k3d-io/k3d#209. *. i use Kubernetes v1. I have a DNS server (dnsmasq) on the master nodes. I would like it to be resolved by Route53 if not found. The database pod is on the same node as the pods that can't resolve the hostname. Ubuntu) use a local DNS resolver by default (systemd-resolved). service. Deny all ingress traffic: TIL: How to Fix DNS Resolution Issues in K3s Related to Flannel Networking Recently, I was trying to set up the kubernetes-dashboard, to make it easier to monitor my k8s cluster. kubernetes DNS pod name resolution. DNS resolution problems; First of all, according to the docs - please note that Calico and kubeadm support Centos/RHEL 7+. Can't resolve dns from inside k8s pod. @Ran-Xing Either use IP:PORT on the host side which will not change without docker changes, or use the in built DNS of docker i. Unfortunately this format is not recognised and it wants name servers on individual lines. K3s Version: k3s version v1. Then, I began shutting down nodes one by one, starting with the "Current DNS Server". net instead of resolving to my router's external IP. In the Kubernetes cluster: CoreDNS utilizes only 1 of the nameservers from the host (more about this in K8s DNS debugging docs ) - which happened to be the Hi I have created a deployment for 2 pods within a worker node and both of them have started successfully. The app tried to resolve “news. 22. Maybe the kube-proxy service is not working correctly and hence the kube-dns service is not acccessible. conf No clue why (as DNS resolution was working fine outside of the cluster). 28 at this time if your application depends on init containers. With hostNetwork: false then both in-cluster and external DNS names work as expected. I'm not sure where to start looking to discover the issue from here, and any help or suggestions would be appreciated. Steps To Reproduce: curl -sfL https://get. Subdomains and Unbound forward-zones. I am not sure what the root of the issues is. kernelModules. mimeie opened this issue Aug 24, 2020 · 2 comments Comments. I found out I couldn’t even do a nslookup: ;; connection timed out; no servers could be reached. 13+k3s1 (47737e1) go version go1. k3d. Restart k3s dns; kubectl delete pods -n kube-system -l k8s-app=kube-dns. Based All pods can solve DNS names without any issue. e. 23. General Discussions. Verify DNS is correct; kubectl run and search for the cluster-ip of external-dns, then test resolution of the glue records: dig @ ${cluster-ip} ns1. 84 CATTLE_CA_CHECKSUM= CATTLE_CLUSTER DNS resolution is not working on agent (node without a coredns pod). To achieve this, it is required to add a line to the CoreDNS Corefile for each DNS zone with the corresponding DNS resolver ip address by setting forward myzone. docker. Mostly this will be your Modem IP address. – Anurag Vohra. k3s is a bit less plug and play that other distro like microk8s. 21. From what I have read, ingress (with a local nginx ingress controller) suffers from the same issue. 10 Server: 10. 25. Either all InternalIP's should be added to the NodeHosts, or upstream Also, it may be worth noting that the IP resolved is for some website out on the net called home. x, k3d injects entries to the NodeHosts (basically a hosts file similar to /etc/hosts in Linux, which is managed by K3s) to enable Pods in the cluster to resolve the names of other containers in the same docker network (cluster network) and a special entry called host. Related information Hi, I'm new to Kubernetes, and can't get my public subdomain resolved. 10 when I try to ping that IP, I don't get a response. DNS misconfiguration. This thread is archived New comments cannot be posted and votes cannot be cast comments Querying from the Ubuntu hosts works without issue. 111. conf, but i [] Version: k3s version v1. By default, the configured nameservers on the host (in /etc/resolv. Having a single node cluster on k3s, Rancher was installed using a subdomain server2. Viewed 3k times 4 . I did notice that while my pods can use the DNS, kubernetes itself does not access this host. k3s can not resolve DNS resolution. Vary DNS resolution according to requesting IP. conf in pod is identical to /etc/resolv. If you get a timeout, with and without +tcp then you have a network filtering problem or the DNS server just does not run (or Some cloud providers, such as Linode, will create machines with "localhost" as the hostname and others may not have a hostname set at all. 43. and it leads me to believe that this is Flannel's issue to resolve, not Kubernetes/K3s/Rancher's issue - Debugging the CoreDNS container with ephemeral and it seemed the /etc/resolv. That should rule out any of my VPC, DNS, and other configurations, as they all work as expected prior to installing k3s. 1 Cloud being used: bare-metal Installation method: kubeadm Host OS: Ubuntu 20. Actual behavior: Not resolving. By default RHEL8 uses nftables instead of iptables ( we can still use iptables but "iptables" on RHEL8 is actually using the kernel's nft framework in the background - look at "Running Iptables on Multicloud K3s not working #8652. Will leave this open if you want to investigate further. default. I don't know who/what will set the resolved. I think it would be reasonable for CoreDNS forwarding to be dynamically configured based on Overview . Commented Oct 26, Environmental Info: K3s Version: k3s version v1. conf of host, which obviously does not contain kube-dns IP. kube-dns specific Check upstream nameservers in kubedns container . So service name resolution fails in pod running on agent. I'm not an export on DNS but for some reason this worked! I did the following things: Add Google DNS server. Closed dee-kryvenko opened this issue Oct 11, 2021 · 50 comments · Fixed by lima-vm/lima#319. 19 for custom domains like . On web-0 pod, it can ping itself but not web-1 and vice versa , on web-1 it can ping itself but not web-0 even if we use subdomain. google. There are no suspicious log entries in k3s. Here, it is K3S, I think, or whatever K3S is using to pull the image. Multus and IPAM plugins provides guidance to I'm able to reach my pods/services via IP, however I was trying to reach them using their dns name, i. 3 LTS inside of Proxmox 8. 127). 1, and every container I launch is unable to reach the internet. I could do this by declaring "exceptions" in coredns config but I should keep a list which in a production scenario is difficult to maintain – Phocs. 9+k3s1 . It seems that it doesn't check the DNS resolver from the cluster when resolving hosts. ; Method 2: Log on to the node on which the application pods run. 28. @DavHau provided a fix in nixos/k3s: add ip_conntrack to kernel Another problem: ephemeral containers are behind a feature gate, and k3s has it disabled by default. Also, if i query from the pod but append an ending ". I've already added It sounds like traffic to the DNS service is being dropped if the coredns pod isn't running on the node that's trying to do the lookup. There is no particular reason Unfortunatelly forward alone does not offer fallthrough mechanism, so in this situation you would have to use something else. Once it back online most everything worked but I just noticed that external connections from the cluster do not resolve. In this scenario, the custom domain can't be resolved. I do not know where to pull the logs from because. The network is configured to resolve DNS queries with this machine. Frontend Service is I just gave 0. 0 #6132 But not something we can fix in k3s. Try dig @10. Steps To Reproduce: Reproducing works with a simple single node with dualstack networking. 3 ,it use coredns to resolve host or service name,but i find in pod ,the resolve not work correctly, # kubectl get services --all-namespaces -o wide NAMESPACE NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE SELECTOR default kubernetes ClusterIP 10. 19 dns server so that Kubernetes knows how to resolve . Why coredns in Kubernetes can't resolve Pod DNS Records. local, so I used k3d image import to copy the images with the correct url. exampleNamespace command terminated with exit code 6 Curl pod was started with following yaml: This section provides troubleshooting information for the Configuring CoreDNS for K3s phase of Running the LOCKSS Installer. 84 CATTLE_CA_CHECKSUM= CATTLE_CLUSTER DNS failure in alpine dockers ho-ansible/k3s#6. Correcting my earlier response with new process in latest EFA/XCO as it is not recommended to manually edit the resolv. The issue reported above, which is solved by modprobe br_netfilter. No errors in the coredns pods. Hybrid/Multicloud cluster provides guidance on the options available to span the k3s cluster over remote or hybrid nodes. conf pointing to kube-dns. 10 somename. Additional context / logs: kubectl exec -i -t dnsutils -- nslookup radarr. web-0. Kubernetes DNS lookup issue and "invalid" in the /etc/resolv. Closed safderali5 opened this issue Jan 19, 2024 · 35 comments Closed Note Search Domain changes will apply only after application pod (example nextgen-gw-0) is restarted. Keywords. Fix: Manually set the DNS servers in This solution is applicable not only to UMH Lite but also to other containers and Kubernetes distributions like K3s that rely on cgroup memory management. This section contains instructions for configuring networking in K3s. Hi I have created a deployment for 2 pods within a worker node and both of them have started successfully. On this air-gapped env web-0 and web-1 cannot see (ping) each other. privatedomain. I want to use a Cloudflare tunnel to my home server so I don't need to open any ports. Additional context / 2. IP address of DNS servers) contain loopback addresses, CoreDNS (a component of the K3s Kubernetes cluster that handles DNS resolution) will How to use External-DNS. 255 So your custom DNS server won't resolve google. k3s-io/k3s#1863. github. Unfortunately I haven't been able to determine what caused it or even what exactly the problem is. conf to create a new file there; Press Esc + i to insert data to file; Type install ipv6 /bin/true on the file to avoid For . 8 uname -a Node(s) CPU architecture, OS, and Version: There's a lot there to unpack, but it looks like you're saying that DNS isn't working between pods running on different nodes. We have created a release candidate v0. internal or registry. Basic Network Options covers the basic networking configuration of the cluster such as flannel and single/dual stack configurations. 01 server, when I installed k3s the DNS resolution on the machine stops working. myservice. External dns lookup fails in pods. It’s working fine for queries to the cluster but not for queries inside the cluster. 42. 8+k3s1: During my migration of apps from docker to kubernetes, I ran into the issue where the apps could not resolved external hostnames, ie hosts not in the cluster. nslookup kubernetes response on agent, Ping <own_nodename> also has the same response. x to test but I've noticed issues when using the dnsPolicy: ClusterFirst on my pods. 1. 16. I'm not sure how to migrate the pod to a different node, but that might be worth trying to see if the problem follows. 19. local verify entries in 'cat /etc/resolf. 10 Issues were: IPV6 enabled; Wrong DNS server ; Here is how I fixed it: IPV6 Disabling. 8: to k3s or rke2 env files on all nodes, then restart the k3s or rke2 server/agent service. svc. This Service Discovery entry issue. DNS nameservers. My problem is that the list of hosts is large and it's not feasible to maintain the list in the yaml file. ${MASTER_FQDN} and they should both resolve correctly. 7. This is a response for a failed . I created a file /usr/etc/resolv. cluster. io | sh - Describe the bug systemd-resolved fails to provide dns lookups on the host after deploying a (non-recursive) DNS service in the cluster. 6. the kubelet does not use the cluster dns to resolve queries but the host dns resolver. Local domain certificates --- apiVersion: cert-manager. 5+k3s1 (acad8ef) go version go1. conf's DNS entries, but my entry was clearly wrong. Out of the air-gapped env, (public access to Internet) with the exact same k3s version and nginx config it works fine. kube DNS requests to a 'separate, on premise' DNS server ; I'll host it in the cluster. show post in topic. You will receive all services within all namespaces, including the kube-dns Cluster-IP. I faced similar issues with k3s (v. orga-1. I have two kubernetes pods running via Rancher: #1 - busybox #2 It came up that kube-dns service was not able to get CoreDNS pods pods should be able to resolve dns created on my private network just as the nodes they are running on is able to resolve this private dns entries. - Debugging internal DNS queries (in between pods), they work fine. 54) is not static, I can only do so via a hostname and letting a DNS resolve it. After removing the search domains from my hosts the dns resolves inside the pods normally. Based Kubernetes: CoreDNS and problem with resolving hostnames. K3s split-DNS (again) #770. Luckily there is a open DNS server maintain by Google. com response on agent. Kubernetes Not Resolving DNS Requests. I have two deployments, one for backend and one for frontend and two services for them. Therefore, the DNS request fails. However, i noticed that our K3S pods were not recognizing the internal hosts defined with the custom DNS server. 3. I have a new installation of k3s installed on a new installation of Rocky Linux 9. There's a ready image It came up that kube-dns service was not able to get CoreDNS pods DNS resolve problem in kubernetes cluster. 04 LTS I have some old containers, from which i am able to ping between them. This could be nice if it wasn't a namespace conflict Use 'kubectl describe pod/curl -n exampleNamespace' to see all of the containers in this pod. 16. I tried adding a firewall rule to intercept external DNS queries and re-routing them to my network's DNS server, but it still resolves to the internet IP instead of my routers IP. Am I missing something? Also open to other ideas on how to get this working. 2. So I started digging and troubleshooting DNS resolution, until I finally have come to the conclusion that my kube-dns pods are not reachable. What’s up with that? Motivation DNS resolution is not wor rancher/k3s:v1. To Reproduce Steps to reproduce Environmental Info: K3s Version: v1. From inside the pod I can resolve hostnames to the parent services but can NOT resolve to other machines using the first I am trying to get dns pod name resolution working on my EKS Kubernetes cluster v1. Hope it helps Hi, I have a local dns cache server dns-server-ip that runs on port 5353. You can run K3s with the --node-name flag or K3S_NODE_NAME environment variable and this will pass the node name to resolve this issue. DNS resolution doesn't work on the host I'm new to kubernetes and I have some issues with my dns names in my k3s cluster on pc with arm architecture. coredns. Check if dns After doing a fresh installation of the ubuntu 20. 04, and the default DNS os k3s worked fine. net, with LoadBalancer and Ingress names registered in it. I was not aware of this silent failure, since the host OS simply failed-over to the second option (and could have also to the third), and would continue to successfully resolve DNS queries. conf with 1. This can cause problems with domain name resolution. Expected behavior: My pods could resolve any name. If you do not already have a cluster, you can Kubernetes DNS not resolving external addresses. Related topics [lima] K3s split-DNS (again) #770. Isn't there a way to reliably (ie. 5) Rancher version: 2. conf used by pods so I'm not sure how coredns ended up trying to use those servers. For exmaple, to create an Ingress resource use the following annotation to automatically create a DNS record for the specified hostname: k3s 1. nslookup kubernetes response on server. If you’re not using k3s or rke2, check the Kubernetes DNS Resolution Known Issues to see how to set kubelet’s --resolv-conf flag to point to the correct resolv. conf). I feel like this has been solved uncountable times but I am unable to find a solution 🤦🏼‍♂️. @p10l Yes that is the problem, please make it as answer so that I can accpet Hello I try to make k3s work in a redhat 8. DNS seems to work about 4 out of 10 times, and that's not the reliability I'm aiming for. Closed bmdepesa opened this issue Jan 17, 2020 · 11 comments Closed DNS The problem was with the firewall, I needed to open the port 53, unfortunately this was not in the k3s documentation, but for the DNS to work correctly the workers and the master need to be able to communicate via this port. Actual behavior: nslookup inside the pod: I will also note that the k3s docker image is not meant to be used for multi-host clusters; it is meant for running a single-node docker container, or a multi-node I also noticed that the kube-dns service has the app selector set to k8s-app=kube-dns and coredns has the label k8s-app=kube-dns, is this correct? The pods running in the kube-system namespace seem to have 2 different IP ranges. 5. Google DNS of course won't resolve your custom DNS zone that only exists on your server. 11 (Docker Resolver) tries to resolve docker service names (in Docker Engine DNS) and forwards requests if it can't alpine based containers have problems with DNS resolution. 0-rc3 which will hopefully fix these DNS issues. 8. Please run . Closed it should, but I'm not sure how to do that. conf, but i [] From the output, it seems like localhost cannot be resolved. Here's a bit of information: DNS pods running: EDIT: In my case I've tested running 2 k3s VM on VBox (but using shared network), with the same OS as I run on my server, ubuntu 18. Ask Question Asked 5 years, 5 months ago. Before you begin You need to have a Kubernetes cluster, and the kubectl command-line tool must be configured to communicate with your cluster. Loading. 3+k3s3) on centos 8 (not quite sure it has anything to do with the images' OS, though). ${MASTER_FQDN} dig ns1. Kubernetes I am running a k3s cluster on some raspberry pi 4, in my local network. CoreDNS is not able to resolve private addresses. Replace pid with the process ID that you In this setup, the node can resolve the custom domain. 6+k3s1 (6f56fa1) Node(s) CPU architecture, problem with resolving certain DNS zones #2157. Steps To Reproduce: Installed K3s: Server Installation This seems to be a know case, which you can find on GitHub Fresh deploy with CoreDNS not resolving any dns lookup #1056. local curl team-b. " (ex ping google. k3s. Can't resolve dns Thank you @truecharts!Yeah that's weird given that all other discussions are about internal resolve. I can ssh into the node and see that it indeed cannot resolve that address. I'm having trouble using my private DNS for coredns as described here: #7822 My host's /etc/resolv. v1. Solution: Remove Azure DNS from virtual network settings When deploying latest k3s version v1. All reactions In my case, this is the IPv4 address. conf file. Open Terminal; Type su and enter to log in as the super user; Enter the root password; Type cat /etc/resolv. It is recommended to run this tutorial on a cluster with at least two nodes that are not acting as control plane hosts. If the firewall is off, ip_conntrack is not automatically loaded. DNS resolution is not working on agent (node without a coredns pod). orga-2. com. 1 <none> 443/TCP 50d <none> kube-system calico-etcd We first observed the problem that pods could not resolve external DNS; when CoreDNS was restarted on the cluster, it received a response from DNS servers for a short time, but after a while DNS resolution in alpine (musl) based containers fails when the host system has search . Due to problems on a hard disk, I had to recover my pihole settings from a backup. In both Calico and kubeadm documentation we can see that they only support RHEL7+. One such solution would be using the alternate plugin DNS Resolving per request. Does not resolve lookups addresses outside of pod. Core DNS missing NodeHosts key in Configmap #9274. I've tried to debug as docs I have a k3s cluster that has been running fine for some time but suddenly started having problems with DNS and/or networking. io/v1 kind: Certificate metadata: name: home Kubernetes ERR_NAME_NOT_RESOLVED. Cluster Configuration: 3 Linux master servers, 1 Windows worker. This needs to be added to boot. Throughout this process, I wanted to observe if the "Current DNS" server changed and ensure that I could still resolve the DNS " DNS server is at 10. 1 Hi Everybody, I am having OK, I see that we use kube-proxy, at least iptables for this. com 10. Modified 1 year, 1 month ago. conf. To allow communication between pods I can do it using the internal dns: eg. After much searching we found CoreDNS and problem with resolving hostnames. Copy link mimeie commented Aug The fix is to override the DNS settings supplied by the DHCP server as this gets entered into /etc/resolv. There's actually a couple of issues with networking and the k3s package. One being: sudo systemctl stop firewalld sudo systemctl stop firewalld Please remember this is not recommended. Closed johanneskastl opened this issue Apr 4, If you run into the issue, that DNS Resolving is not possible with K3S, Rancher, OpenSuSE MicroOS and SELinux enabled: Follow the troubleshooter's instructions to detect and resolve your DNS issues. service or k3s-agent. Angular Routing I did restart the coredns pod (basically deleting it), but this was not needed. Since Kubernetes has its own dns system, I looked at the documentation and it seems that I need to set my . Some pods running on server/master, for example, grafana installed using official helm chart, can resolve Kubernetes service names properly that pod does have kude-dns IP entry Recently, we set up a custom DNS server based on dnsmasq within our organization to handle internal DNS requests. Steps To Reproduce: We have set up an airgapped K3s multi-node cluster, and due to network restrictions, traffic on UDP port 53 is blocked, preventing CoreDNS from resolving hostnames. I don't expect this to be a common scenario for most, but the default Corefile prevents K3s from starting properly in an air-gapped environment where DNS is not available (and nameservers are intentionally omitted from /etc/resolv. conf does not have right The first problem that I thought it might've been was that it was dns because I was getting a warning that I had too many DNS servers, after resolving that issue it still happened again. If k3s is managed as systemd service (which is probably the case), I have an Unbound container running on a test server to proxy DNS traffic. It appears that k3s does update iptables, and there could be something going on there? I am not customizing the rules in any way. I've already added I recently setup k3s via k3sup installer on a cluster of 3x VM's running Ubuntu 22. 0: 2879: August 9, 2018 coreDNS not working. . We will be using a K3S cluster using MetalLB and the Nginx ingress controller instead of the default ServiceLB and Traefik options. to k3s or rke2 env files on all nodes, then restart the k3s or rke2 server/agent service. 7 (also tried 1. Steps To Reproduce: Installed K3s: Server Installation As of k3d v5. nginx; web-1. While avahi looks similar to DNS server, it does not act like a DNS server. tcpdump shows it tried the cluster domain, “cluster. inside k3d nodes (Container Level): 127. kube TLD, my main openwrt router would delegate ip resolution to this 'k3s dynamic dns' in charge of 192. As per my understanding if dnsPolicy is ClusterFirst then the pod should be capable of resolving service names. String enough, nslookup work on the host! just not inside the pods! ` nslookup www. OK, I see that we use kube-proxy, at least iptables for this. I might have been able to work around this by editing the CoreDNS Deployment to explicitly add a debugging container, but upon further reading, it seems that containers within a pod don’t share a filesystem (unless you explicitly use a Volume), which The dns resolution does not work for my container which is running using these settings: dnsPolicy: ClusterFirstWithHostNet hostNetwork: true The dns resolution works just fine if I do not use hostNetwork and don't change the dns policy. 0+k3s1 the coredns pod is stuck in ContainerCreating stage as it cannot find the key NodeHosts in configmap coredns. K3s within Docker: Deploying the lightweight Kubernetes distribution K3s inside Docker. Actual behavior: Intermittent DNS resolution. e docker container name resolves to its 172. Resolving external domains from within pods does not work. local” and then my home network domain “int. OS Version: Centos 7 k3s -version: k3s version v1. This question is not k3s - networking between pods not working. DNS resolution from kubernetes host. This release updates Kubernetes to v1. 04. It's not possible to setup requests forwarding from coredns to avahi, while it's possible to proper DNS server in the network and this way have everything will be resolved. I tested these both with and without the --resolv-conf to no avail. I have a Pi-hole running in a Raspberry Pi. curl team-a. Pods can't resolve any DNS [closed] Ask Question Asked 1 year, 1 month ago. Sometimes the host will run a local caching DNS nameserver, which means the Before I install k3s, everything is reachable as normal. Open Terminal; Type su and enter to log in as the super user; Enter the root password; Type cd /etc/modprobe. 5+k3s2 (724ef70) go version go1. However when I ping an adress from within a pod I always pass via the google DNS servers and overpass my local DNS rules. 1: 4168: June 6, 2023 Coredns resolution between pods not working. 10 coredns issues with k3s on openSUSE MicroOS using kernel 5. conf is fine and using the host DNS servers. I spin up K3S, start a pod, and then exec into the pod. Modified 4 years, 4 months ago. Initially, i assumed that Kubernetes would use the operating system’s DNS configuration specified in /etc/resolv. The web server logs look as expected with little problem. 3+k3s1 (990ba0e8) go version go1. I however noticed I was getting the following Make sure you have kube-dns service running with kubectl get service kube-dns -n The kube-dns service is working, however, in K3S it works upon a coredns pod, which is not working. But since pod's /etc/resolve. It was all due to the way that k3s cleverly injects "host names" into the K8s controller node's coredns service. However, some of the DNS requests from the pod might be directed to Azure DNS. Ping Google. Deploy avahi to kubernetes cluster. I tried to search this problem over internet and there are suggestions to use HostAlias or update /etc/hosts file inside container. I checked coredns config map and it seems fine (all-defaults). Expected behavior: AAAA resolving of the k3s nodes should work inside the cluster. You can and removing that line resolved dns issues. Maybe we can use DNS Service The problem was, as I mentioned on the comment, that the firewall was not routing correctly the HTTP request using the public IP from the private network side. com from the master or any of the nodes seems to resolve correctly (output below) and the /etc/resolv. anyway, i will file ticket on discord later!--update: it seems that it is TrueNAS-related issue: I installed AdGuardHome APP as DNS (let's say IP is 10. Now we have to Find a powerful DNS server. Rancher itself shows that some services are not avaliable and the logs from cattle say server2. My understanding is that creating a headless service will create the necessary pod name records I need but I'm finding this is not true. io | sh -s - server --write-kubeconfig-mode 644 --cluster-init. Viewed 15k times 4 . Closed AlbertoSoutullo opened this issue Oct 16, 2023 · 0 comments Closed Some Linux distributions (e. Do you have the default firewall I have a new installation of k3s installed on a new installation of Rocky Linux 9. Another solution might be: /etc/resolv. The problem is that it fails for some domains while working perfectly for everything else. io | sh - Configure systemd-resolved to use a private DNS; Run a pod and try to resolve a private address; Expected behavior: Pod should be able to resolve private address. Additional context / logs:. conf with the following content. Pod A’s IP Address: 10. Ask Question Asked 4 years, 4 months ago. Now that External-DNS is installed and configured, it will automatically create DNS records for Ingress and Service resources with the use of an annotation. I had k3s running on a new Fedora installation too with the same problem. Commented Nov 5, 2021 at 1:39. On each node, you could say that you want to use the host's resolv parameters. 5 and one of the machines was the Master. Exposing the service via NodePort type also works flawless. 3 Installation option : Helm Chart Host: Ubuntu 20. inside k3s (Kubernetes Level): CoreDNS (configurable deployment, where you can also specify upstream nameservers) 2. First, we need to obtain the K8's DNS Cluster-IP Address: kubectl get services --all-namespaces -o wide. local. 24. 4. conf contains only one nameserver nameserver <My-Private-DNS-Server> DNS resolving on the host works fine but not in CoreDNS. 0. mydomain”, and stopped there. Expected Behaviour: Resolving Local DNS should work on any device. In addition to this, I have some IoT devices scattered around the house with domains When deploying the pod with hostNetwork: true dns resolution is working as expected. The cluster (the single node) is currently running 43 pods and DNS resolution works fine for 39 of those. x IPs). I think the issue was the Fedora 34 image I was running seemed to have neither iptables nor nftables installed. curl: (6) Could not resolve host: exampleService. local 10. command I've got a K3s cluster running on two machines - one acting as the master and the other as a worker. 0. rngky zeiem ziiwsg izoweo xxu krov oln eqnyv nvpat fbsd