[Do Not Merge] Release 1.12 (#10292)
* Update docs for fields allowed at root of CRD schema (#9973) * add plugin docs and examples (#10053) * docs update to promote TaintNodesByCondition to beta (#9626) * HPA Specificity Improvements (#8757) Updated the HPA docs to reference the `autoscaling/v2beta2` API version, and added documentation about the new fields. * adjust docs for pod ready++ (#10049) * Remove --cadvisor-port - has been deprecated since v1.10 (#10023) Change-Id: Id2a685473a243aef492a98ff450759f39e362557 * Add Documentation for Snapshot Feature (#9948) * Add documentation for snapshot feature * Update volume-snapshots.md * Add dry-run to api-concepts (#10033) * kubeadm-init: Update the offline support section (#10062) The update includes the following things (in mind with Kubernetes 1.12): - Remove the 1.8 image versions - Add the 1.10 image versions that were missing until now - Include a comment for the missing arch suffixes in 1.12 Signed-off-by: Rostislav M. Georgiev <rostislavg@vmware.com> * Say bye to `DynamicProvisioningScheduling` (#10157) The mentioned feature gate is now collapsed into `VolumeScheduling`. xref: kubernetes/kubernetes#67432 * Update ResourceQuota per PriorityClass state for 1.12 (#10229) * TokenRequest and TokenRequestProjection now beta (#10161) xref: kubernetes/kubernetes#67349 * Change feature state for kms provider to beta. (#10230) KMS Provider will be graduating to beta in v1.12, reflecting this change on the website. * coredns default (#10200) * Promote ShareProcessNamespace to beta in docs (#9996) * Add CoreDNS details to DNS Debug docs (#10201) * add coredns details * address nits, add query logging section * Update docs with topology aware dynamic provisioning (#9939) * Document topology aware volume binding feature * update for readability * Update storage-classes.md * comma splice * don't abbreviate * HPA Algorithm Information Improvements (#9780) * Update HPA docs with more algorithm details The HPA docs pointed to an out-of-date document for information on the algorithm details, which users were finding confusing. This sticks a section on the algorithm in the HPA docs instead, documenting both general behavior and corner cases. * Add glossary info, HPA docs on quantities People often ask about the quantity notation when working with the metrics APIs, so this adds a glossary entry on quantities (since they're used elsewhere in the system), and a short explantation in the HPA walkthough. * Information about HPA readiness and stabilization This adds information about the new changes to HPA readiness and stabilization from kubernetes/features#591, and other minor changes that landed in Kubernetes 1.12. * Update horizontal-pod-autoscale.md * Audit 1.12 doc (#9953) * audit 1.12 document * remove legacy audit feature https://github.com/kubernetes/kubernetes/pull/65862 * update feature gate doc * MountPropagation is now GA (#10090) * RuntimeClass documentation (#10102) * RuntimeClass documentation * Update runtime-class.md * Add documentation for Scheduler performance tuning (#10048) * Add documentation for Scheduler performance tuning * Update scheduler-perf-tuning.md * TTL controller for cleaning up finished resources (#10064) * TTL controller for cleaning up finished resources * Address comments * Update ttlafterfinished.md * Bump quota configuration api version (#10217) * Incremental update from master (#10278) * fix invalid href of cloud controller manager (#10240) * fix invalid yaml format (#10238) * update storage-limits doc with Azure disk part (#10224) update storage-limits doc with Azure disk part fix comments * Update kubelet-config-file.md (#10222) Update link to KubeletConfiguration struct. * fix a trivial misspelling (#10244) * Fix cassandra-statefulset.yaml indent level (#10243) * Mention minimum etcd versions (#10208) Source: https://groups.google.com/d/msg/kubernetes-dev/jMPA4JzKiY4/HIx2ugvLBAAJ * fix 404 error (#10250) * Small verb tweak (#10190) Present participle, ftw. * Add AnchorJS logic for header links (#10155) * Add AnchorJS JavaScript * Remove existing inpage_heading logic * Remove underline from anchor tags * Use single icon and add touch visibility * Use paragraph link icon for AnchorJS * Update Sass to use code formatting in docsContent headers * Update header size coverage to H3-H6 * fix broken link in kubefed.md (#10254) * Update the version numbers for the X-Remote-Extra- and Impersonate-Extra- key fixes (#9827) The fix was cherry picked into 1.11.3, 1.10.7, and 1.9.11: https://github.com/kubernetes/kubernetes/pull/67162 https://github.com/kubernetes/kubernetes/pull/67163 https://github.com/kubernetes/kubernetes/pull/67164 * fix typo (#10168) * fix typo * addressing comments. * Update setup-ha-etcd-with-kubeadm.md * fix typos (#10252) * fix description of contribute guide (#10253) * describe truncate feature about advanced audit (#10236) * describe truncate feature about advanced audit * Update audit.md * docs update to promote ScheduleDaemonSetPods to beta (#9923) * Dynamic volume limit updates for 1.12 (#10211) * add a placeholder commit * Update docs for csi volume limits * Update storage-limits.md * Add "MayRunAs" value among other GroupStrategies (#9888) * Add CoreDNS details to the customize DNS doc (#10228) * Add CoreDNS details to the customize DNS doc Rewrite the document to include more details about CoreDNS, since it's now the default from v1.12 * Address comments * Improve doc wording * Fix link * Update dns-custom-nameservers.md * Update dns-custom-nameservers.md * Fix secrets docs in 1.12 branch (#10056) * Fix secrets docs * Update secret.md * Revert CoreDNS Docs (#10319) * Revert "Add CoreDNS details to DNS Debug docs (#10201)" This reverts commit462817a674. * Revert "Add CoreDNS details to the customize DNS doc (#10228)" This reverts commite7319eeb8c. * Revert "coredns default (#10200)" This reverts commit698e93b441. * Add CRI installation instructions page Added cri-installation page with CRI installation instructions Referenced it from kubeadm-init and install-kubeadm pages. * kubeadm: update API types documentation for 1.12 (#10283) v1alpha2 -> v1alpha3 MasterConfiguration -> [new-api-types] * TokenRequest feature documentation (#10295) * AdvancedAuditing is now GA (#10156) xref: kubernetes/kubernetes#65862 `AdvancedAuditing` feature is GA in 1.12. This PR adjusts the related docs. * update runtime-class.md (#10332) * update runtime-class.md * Update runtime-class.md * Document cross-authorizer permissions for creating RBAC roles (#10015) * Document cross-authorizer permissions for creating RBAC roles * Update rbac.md * kubeadm: update authored content for 1.12 (reference docs and cluster creation) (#10348) * kubeadm: update authored content in reference docs for 1.12 * kubeadm: add time frame in create-cluster-kubeadm for 1.12 * add AllowedProcMountTypes and ProcMountType to docs (#9911) Signed-off-by: Jess Frazelle <acidburn@microsoft.com> * kubeadm: add new command line reference (#10306) Add: - placeholder files - include place holder files - include "renew" sub command - add missing tabs for "alpha phase kubelet" * Documenting SCTP support in Kubernetes (#10279) * Documenting SCTP support in Kubernetes Service, Endpoint, NetworkPolicy and Pod * Updates based on comments on the PR * kubectl expose update with SCTP support * Updated according to comments in the PR * Revert "kubectl expose update with SCTP support" This reverts commit 0d5a1e6720a012390cf100c83e16b4a8c0782356. * TLS Bootstrap and Server Cert Rotation feature documentation (#10232) * TokenRequest feature documentation * line wrapping to make review not insane * update content for GA without major refactor * Update kubelet-tls-bootstrapping.md * Add clarifications for volume snapshots (#10296) * Update kubadm ha installation for 1.12 (#10264) * Update kubadm ha installation for 1.12 Signed-off-by: Chuck Ha <ha.chuck@gmail.com> * update stable version Signed-off-by: Chuck Ha <ha.chuck@gmail.com> * Update stacked control plane for v1.12 (#2) * use v1alpha3 Signed-off-by: Chuck Ha <ha.chuck@gmail.com> * more v1alpha3 (#4) * updates Signed-off-by: Chuck Ha <ha.chuck@gmail.com> * Document how to run in-tree cloud providers with kubeadm (#10357) Change-Id: Iab6b996a830503d74a6eb0c507c5f8ca7a39235b * kubeadm reference doc for release 1.12 (#10359) * Revert "Revert "Add CoreDNS details to DNS Debug docs (#10201)"" This reverts commit bb30f4d1fcd6fba2fe6190778ead99f8010033b7. * Revert "Revert "Add CoreDNS details to the customize DNS doc (#10228)"" This reverts commit bc23d45c09d7b83cac130fe22a0bd91e72435862. * Revert "Revert "coredns default (#10200)"" This reverts commit 7f4350d6ab7fc554ee53126d3875e845d2e43d1f. * add missing instruction for ha guide (#10374) Signed-off-by: Chuck Ha <ha.chuck@gmail.com> * kubeadm - Ha upgrade updates (#10340) * Update HA upgrade docs * Adds external etcd HA upgrade guide Signed-off-by: Chuck Ha <ha.chuck@gmail.com> * copyedit * more edits * add runasgroup in psp (#10076) * update KubeletPluginsWatcher feature gate (#10205) * generated 1.12 docs * Building Multi-arch images with Manifests (#10379) In 1.12, a variety of images used in a typical kubernetes installation have started to using manifests to better support environments with arm or ppc64le architectures. For example all images used with kubeadm by default have manifests, another would be all the tests in the conformance test suite. Here we capture the best practices for everyone to start using manifests in their own workflows. Change-Id: I5ba4c5fe55ffc9486a8251760f3352be4f2e1494 * Upgrade docs for v1.12 (#10344) * generated assets and docs * remove 1.7 * update 1.12 * update plugin documentation under docs>tasks>extend-kubectl (#10259) * update plugin documentation under docs>tasks>extend-kubectl * Update kubectl-plugins.md
This commit is contained in:
Jim Angel
@@ -13,7 +13,7 @@ This page provides hints on diagnosing DNS problems.
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{{% capture prerequisites %}}
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* {{< include "task-tutorial-prereqs.md" >}} {{< version-check >}}
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* Kubernetes version 1.6 and above.
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* The cluster must be configured to use the `kube-dns` addon.
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* The cluster must be configured to use the `coredns` (or `kube-dns`) addons.
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{{% /capture %}}
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{{% capture steps %}}
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@@ -68,7 +68,7 @@ nameserver 10.0.0.10
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options ndots:5
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```
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Errors such as the following indicate a problem with the kube-dns add-on or
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Errors such as the following indicate a problem with the coredns/kube-dns add-on or
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associated Services:
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```
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@@ -93,6 +93,17 @@ nslookup: can't resolve 'kubernetes.default'
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Use the `kubectl get pods` command to verify that the DNS pod is running.
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For CoreDNS:
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```shell
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kubectl get pods --namespace=kube-system -l k8s-app=kube-dns
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NAME READY STATUS RESTARTS AGE
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...
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coredns-7b96bf9f76-5hsxb 1/1 Running 0 1h
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coredns-7b96bf9f76-mvmmt 1/1 Running 0 1h
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...
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```
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Or for kube-dns:
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```shell
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kubectl get pods --namespace=kube-system -l k8s-app=kube-dns
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NAME READY STATUS RESTARTS AGE
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@@ -107,8 +118,26 @@ have to deploy it manually.
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### Check for Errors in the DNS pod
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Use `kubectl logs` command to see logs for the DNS daemons.
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Use `kubectl logs` command to see logs for the DNS containers.
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For CoreDNS:
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```shell
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for p in $(kubectl get pods --namespace=kube-system -l k8s-app=kube-dns -o name); do kubectl logs --namespace=kube-system $p; done
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```
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Here is an example of a healthy CoreDNS log:
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```
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.:53
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2018/08/15 14:37:17 [INFO] CoreDNS-1.2.2
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2018/08/15 14:37:17 [INFO] linux/amd64, go1.10.3, 2e322f6
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CoreDNS-1.2.2
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linux/amd64, go1.10.3, 2e322f6
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2018/08/15 14:37:17 [INFO] plugin/reload: Running configuration MD5 = 24e6c59e83ce706f07bcc82c31b1ea1c
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```
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For kube-dns, there are 3 sets of logs:
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```shell
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kubectl logs --namespace=kube-system $(kubectl get pods --namespace=kube-system -l k8s-app=kube-dns -o name | head -1) -c kubedns
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@@ -117,8 +146,8 @@ kubectl logs --namespace=kube-system $(kubectl get pods --namespace=kube-system
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kubectl logs --namespace=kube-system $(kubectl get pods --namespace=kube-system -l k8s-app=kube-dns -o name | head -1) -c sidecar
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```
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See if there is any suspicious log. Letter '`W`', '`E`', '`F`' at the beginning
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represent Warning, Error and Failure. Please search for entries that have these
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See if there are any suspicious error messages in the logs. In kube-dns, a '`W`', '`E`' or '`F`' at the beginning
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of a line represents a Warning, Error or Failure. Please search for entries that have these
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as the logging level and use
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[kubernetes issues](https://github.com/kubernetes/kubernetes/issues)
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to report unexpected errors.
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@@ -135,6 +164,8 @@ kube-dns ClusterIP 10.0.0.10 <none> 53/UDP,53/TCP 1h
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...
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```
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Note that the service name will be "kube-dns" for both CoreDNS and kube-dns deployments.
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If you have created the service or in the case it should be created by default
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but it does not appear, see
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[debugging services](/docs/tasks/debug-application-cluster/debug-service/) for
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@@ -158,20 +189,83 @@ For additional Kubernetes DNS examples, see the
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[cluster-dns examples](https://github.com/kubernetes/examples/tree/master/staging/cluster-dns)
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in the Kubernetes GitHub repository.
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### Are DNS queries being received/processed?
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You can verify if queries are being received by CoreDNS by adding the `log` plugin to the CoreDNS configuration (aka Corefile).
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The CoreDNS Corefile is held in a ConfigMap named `coredns`. To edit it, use the command ...
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```
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kubectl -n kube-system edit configmap coredns
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```
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Then add `log` in the Corefile section per the example below.
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```
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apiVersion: v1
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kind: ConfigMap
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metadata:
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name: coredns
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namespace: kube-system
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data:
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Corefile: |
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.:53 {
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log
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errors
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health
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kubernetes cluster.local in-addr.arpa ip6.arpa {
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pods insecure
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upstream
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fallthrough in-addr.arpa ip6.arpa
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}
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prometheus :9153
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proxy . /etc/resolv.conf
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cache 30
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loop
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reload
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loadbalance
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}
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```
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After saving the changes, it may take up to minute or two for Kubernetes to propagate these changes to the CoreDNS pods.
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Next, make some queries and view the logs per the sections above in this document. If CoreDNS pods are receiving the queries, you should see them in the logs.
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Here is an example of a query in the log.
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```
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.:53
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2018/08/15 14:37:15 [INFO] CoreDNS-1.2.0
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2018/08/15 14:37:15 [INFO] linux/amd64, go1.10.3, 2e322f6
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CoreDNS-1.2.0
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linux/amd64, go1.10.3, 2e322f6
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2018/09/07 15:29:04 [INFO] plugin/reload: Running configuration MD5 = 162475cdf272d8aa601e6fe67a6ad42f
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2018/09/07 15:29:04 [INFO] Reloading complete
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172.17.0.18:41675 - [07/Sep/2018:15:29:11 +0000] 59925 "A IN kubernetes.default.svc.cluster.local. udp 54 false 512" NOERROR qr,aa,rd,ra 106 0.000066649s
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```
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## Known issues
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Kubernetes installs do not configure the nodes' resolv.conf files to use the
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cluster DNS by default, because that process is inherently distro-specific.
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Some Linux distributions (e.g. Ubuntu), use a local DNS resolver by default (systemd-resolved).
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Systemd-resolved moves and replaces `/etc/resolv.conf` with a stub file that can cause a fatal forwarding
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loop when resolving names in upstream servers. This can be fixed manually by using kubelet's `--resolv-conf` flag
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to point to the correct `resolv.conf` (With `systemd-resolved`, this is `/run/systemd/resolve/resolv.conf`).
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kubeadm 1.11 automatically detects `systemd-resolved`, and adjusts the kubelet flags accordingly.
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Kubernetes installs do not configure the nodes' `resolv.conf` files to use the
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cluster DNS by default, because that process is inherently distribution-specific.
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This should probably be implemented eventually.
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Linux's libc is impossibly stuck ([see this bug from
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2005](https://bugzilla.redhat.com/show_bug.cgi?id=168253)) with limits of just
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3 DNS `nameserver` records and 6 DNS `search` records. Kubernetes needs to
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consume 1 `nameserver` record and 3 `search` records. This means that if a
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3 DNS `nameserver` records and 6 DNS `search` records. Kubernetes needs to
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consume 1 `nameserver` record and 3 `search` records. This means that if a
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local installation already uses 3 `nameserver`s or uses more than 3 `search`es,
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some of those settings will be lost. As a partial workaround, the node can run
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some of those settings will be lost. As a partial workaround, the node can run
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`dnsmasq` which will provide more `nameserver` entries, but not more `search`
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entries. You can also use kubelet's `--resolv-conf` flag.
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entries. You can also use kubelet's `--resolv-conf` flag.
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If you are using Alpine version 3.3 or earlier as your base image, DNS may not
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work properly owing to a known issue with Alpine.
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