当前正在处理与CoreDNS相关的问题，该问题是在Raspberry PI上的全新Kubernetes设置上发生的。
问题：CoreDNS将所有DNS查询转发到本地网关/路由器，而无论具体情况如何，都不知道如何解析任何集群内服务名称。
我如何诊断该问题：
执行任何nslookup查询都会导致NXDOMAIN响应，这意味着不存在域。此响应始终来自本地路由器。
注意：在以下输出中，10.32.0.2是其中一个CoreDNS Pod的IP，soc.local是群集的域名，wpad.fritz.box是本地路由器的主机名。
$ kubectl run -ti --rm alpine --image=alpine --restart=Never -- ash
/ # nslookup kubernetes 10.32.0.2
Server: 10.32.0.2
Address: 10.32.0.2:53
** server can't find kubernetes: NXDOMAIN
** server can't find kubernetes: NXDOMAIN
/ # nslookup kubernetes.default 10.32.0.2
Server: 10.32.0.2
Address: 10.32.0.2:53
** server can't find kubernetes.default: NXDOMAIN
** server can't find kubernetes.default: NXDOMAIN
/ # nslookup kubernetes.default.soc 10.32.0.2
Server: 10.32.0.2
Address: 10.32.0.2:53
** server can't find kubernetes.default.soc: NXDOMAIN
** server can't find kubernetes.default.soc: NXDOMAIN
/ # nslookup kubernetes.default.soc.local 10.32.0.2
Server: 10.32.0.2
Address: 10.32.0.2:53
** server can't find kubernetes.default.soc.local: NXDOMAIN
** server can't find kubernetes.default.soc.local: NXDOMAIN
以下是tcpdump的输出以及与nslookup的{{1}}查询关联的网络流量：
kubernetes以下是与/ # tcpdump -i weave host 10.32.0.2 and port 53
tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on weave, link-type EN10MB (Ethernet), capture size 262144 bytes
16:57:48.047794 IP 10.32.0.5.54782 > 10.32.0.2.53: 42507+ A? kubernetes. (28)
16:57:48.048136 IP 10.32.0.5.54782 > 10.32.0.2.53: 43025+ AAAA? kubernetes. (28)
16:57:48.048576 IP 10.32.0.2.35867 > wpad.fritz.box.53: 42507+ A? kubernetes. (28)
16:57:48.048576 IP 10.32.0.2.37755 > wpad.fritz.box.53: 43025+ AAAA? kubernetes. (28)
16:57:48.050611 IP wpad.fritz.box.53 > 10.32.0.2.35867: 42507 NXDomain 0/1/0 (103)
16:57:48.050916 IP wpad.fritz.box.53 > 10.32.0.2.37755: 43025 NXDomain 0/1/0 (103)
16:57:48.051109 IP 10.32.0.2.53 > 10.32.0.5.54782: 42507 NXDomain 0/1/0 (103)
16:57:48.051503 IP 10.32.0.2.53 > 10.32.0.5.54782: 43025 NXDomain 0/1/0 (103)
查询相对应的CoreDNS日志：
nslookup以下是CoreDNS Corefile的配置图：
[INFO] 10.32.0.5:53591 - 23327 "AAAA IN kubernetes. udp 28 false 512" NXDOMAIN qr,aa,rd,ra 103 0.000318349s
[INFO] 10.32.0.5:53591 - 22735 "A IN kubernetes. udp 28 false 512" NXDOMAIN qr,aa,rd,ra 103 0.000447718s
[INFO] 10.32.0.5:58545 - 49038 "AAAA IN kubernetes.default. udp 36 false 512" NXDOMAIN qr,rd,ra 111 0.0314311s
[INFO] 10.32.0.5:58545 - 48445 "A IN kubernetes.default. udp 36 false 512" NXDOMAIN qr,rd,ra 111 0.033794968s
[INFO] 10.32.0.5:53665 - 62210 "A IN kubernetes.default.soc. udp 40 false 512" NXDOMAIN qr,rd,ra 115 0.047918913s
[INFO] 10.32.0.5:53665 - 62802 "AAAA IN kubernetes.default.soc. udp 40 false 512" NXDOMAIN qr,rd,ra 115 0.067865341s
[INFO] 10.32.0.5:56021 - 47416 "A IN kubernetes.default.soc.local. udp 46 false 512" NXDOMAIN qr,aa,rd 127 0.000430478s
[INFO] 10.32.0.5:56021 - 48046 "AAAA IN kubernetes.default.soc.local. udp 46 false 512" NXDOMAIN qr,aa,rd 127 0.000551032s
我的问题是：为什么CoreDNS不处理这些针对群集内服务名称的DNS查询？
不知道还要调试什么。令人遗憾的是，CoreDNS图像没有外壳，因此我可以看看$ k get cm coredns -n kube-system -o yaml
apiVersion: v1
data:
Corefile: |
.:53 {
log
errors
health {
lameduck 5s
}
ready
kubernetes soc.local in-addr.arpa ip6.arpa {
pods insecure
fallthrough in-addr.arpa ip6.arpa
ttl 30
}
prometheus :9153
forward . /etc/resolv.conf
cache 30
loop
reload
loadbalance
}
kind: ConfigMap
metadata:
creationTimestamp: "2020-07-07T20:58:06Z"
managedFields:
- apiVersion: v1
fieldsType: FieldsV1
fieldsV1:
f:data: {}
manager: kubeadm
operation: Update
time: "2020-07-07T20:58:06Z"
- apiVersion: v1
fieldsType: FieldsV1
fieldsV1:
f:data:
f:Corefile: {}
manager: kubectl
operation: Update
time: "2020-07-28T17:21:46Z"
name: coredns
namespace: kube-system
resourceVersion: "2464367"
selfLink: /api/v1/namespaces/kube-system/configmaps/coredns
uid: c6a603c3-30b6-4156-b62e-a98d53761541
文件。
有什么建议吗？
答案 0 :(得分：1)
发布问题后不久，我重新阅读了有关debugging DNS name resolution的Kubernetes文档，并且在“已知问题”部分的最后一段中提到了一些存在DNS问题的Alpine版本。尽管链接的github票证没有以相同的方式明确描述我的问题，但似乎Alpine版本就是问题所在：
aws s3 ls --summarize --human-readable --recursive s3://mybucket.com