Bug 1826996

Summary:	e2e for dns forwarding
Product:	OpenShift Container Platform	Reporter:	Daneyon Hansen <dhansen>
Component:	Networking	Assignee:	Daneyon Hansen <dhansen>
Networking sub component:	router	QA Contact:	Arvind iyengar <aiyengar>
Status:	CLOSED ERRATA	Docs Contact:
Severity:	unspecified
Priority:	unspecified	CC:	aiyengar, aos-bugs
Version:	4.5
Target Milestone:	---
Target Release:	4.5.0
Hardware:	Unspecified
OS:	Unspecified
Whiteboard:
Fixed In Version:		Doc Type:	If docs needed, set a value
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2020-07-13 17:30:26 UTC	Type:	Bug
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:

Description Daneyon Hansen 2020-04-23 01:07:41 UTC

Description of problem:
DNS forwarding was added in 4.4. Although [1] included unit tests, no test exists to verify e2e functionality. See [2] for additional details.

Version-Release number of selected component (if applicable):
4.5

How reproducible:
always

Steps to Reproduce:
N/A

Actual results:
N/A

Expected results:
N/A

Additional info:
[1] https://github.com/openshift/cluster-dns-operator/pull/139
[2] https://issues.redhat.com/browse/NE-257

Comment 3 Arvind iyengar 2020-05-12 07:07:15 UTC

This patch was merged and originally released in "4.5.0-0.nightly-2020-05-01-183457" version. At the time of writing, the functionality has been tested and verified in "4.5.0-0.nightly-2020-05-11-011730" release.

The outcome of manual testing is as follows:

Executing the test from local spawns a DNS resolver pod which resolve "www.foo.com" to "1.2.3.4"
-----
$ go get -v github.com/openshift/cluster-dns-operator
github.com/openshift/cluster-dns-operator (download)
package github.com/openshift/cluster-dns-operator: no Go files in /home/aiyengar/go/src/github.com/openshift/cluster-dns-operator

$ WATCH_NAMESPACE=openshift-ingress-operator  go test -v -tags e2e -count 1 -run TestDNSForwarding ./test/e2e/operator_test.go  ./test/e2e/utils.go
=== RUN   TestDNSForwarding
I0512 10:29:18.849267   14074 request.go:621] Throttling request took 1.000174166s, request: GET:https://api.aiyengar-oc45-1105-1826996.qe.devcluster.openshift.com:6443/apis/coordination.k8s.io/v1beta1?timeout=32s
--- PASS: TestDNSForwarding (119.03s)
PASS
ok  	command-line-arguments	119.038s


$ oc -n openshift-dns get all
NAME                    READY   STATUS    RESTARTS   AGE
pod/dns-default-98k8j   3/3     Running   0          24h
pod/dns-default-9qv5d   3/3     Running   0          24h
pod/dns-default-fkbgr   3/3     Running   0          24h
pod/dns-default-lrtsd   3/3     Running   0          24h
pod/dns-default-mt5g6   3/3     Running   0          24h
pod/dns-default-nlb2d   3/3     Running   0          24h
pod/test-upstream       1/1     Running   0          75s   <-----
NAME                    TYPE        CLUSTER-IP      EXTERNAL-IP   PORT(S)                  AGE
service/dns-default     ClusterIP   172.30.0.10     <none>        53/UDP,53/TCP,9154/TCP   24h
service/test-upstream   ClusterIP   172.30.94.112   <none>        53/UDP,53/TCP            60s  <----

NAME                         DESIRED   CURRENT   READY   UP-TO-DATE   AVAILABLE   NODE SELECTOR            AGE
daemonset.apps/dns-default   6         6         6       6            6           kubernetes.io/os=linux   24h

$ oc -n openshift-dns logs pod/test-upstream
.:5353
CoreDNS-1.6.6
linux/amd64, go1.13.4, 
-----

With tools like "nslookup" or "dig" command to resolve "www.foo.com", results in the queries being forwarded to the resolver and it points to "1.2.3.4" correctly:
-----
/srv $ nslookup www.foo.com
Server:    (null)
Address 1: ::1 localhost
Address 2: 127.0.0.1 localhost

Name:      www.foo.com
Address 1: 1.2.3.4

/srv $ nslookup www.foo.com
Server:    (null)
Address 1: ::1 localhost
Address 2: 127.0.0.1 localhost

Name:      www.foo.com
Address 1: 1.2.3.4

/srv $ nslookup www.foo.com
Server:    (null)
Address 1: ::1 localhost
Address 2: 127.0.0.1 localhost

Name:      www.foo.com
Address 1: 1.2.3.4


The query logs seen in the upstream resolved pod:

$ oc -n openshift-dns logs pod/test-upstream -f     
.:5353
CoreDNS-1.6.6
linux/amd64, go1.13.4, 
[INFO] 10.131.0.2:44843 - 10401 "A IN www.foo.com. udp 29 false 512" NOERROR qr,aa,rd 56 0.000155751s
[INFO] 10.131.0.2:50239 - 11332 "AAAA IN www.foo.com. udp 29 false 512" NOERROR qr,aa,rd 29 0.000218299s
[INFO] 10.128.2.2:45400 - 64391 "A IN www.foo.com. udp 29 false 512" NOERROR qr,aa,rd 56 0.00013468s
[INFO] 10.128.2.2:47011 - 38 "AAAA IN www.foo.com. udp 29 false 512" NOERROR qr,aa,rd 29 0.00018034s
[INFO] 10.131.0.2:51722 - 65510 "AAAA IN www.foo.com. udp 29 false 512" NOERROR qr,aa,rd 29 0.000134256s
[INFO] 10.131.0.2:43119 - 64386 "A IN www.foo.com. udp 29 false 512" NOERROR qr,aa,rd 56 0.000259561s
[INFO] 10.130.0.19:47883 - 39385 "AAAA IN www.foo.com. udp 29 false 512" NOERROR qr,aa,rd 29 0.000115228s
-----

Comment 4 errata-xmlrpc 2020-07-13 17:30:26 UTC

Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory, and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

https://access.redhat.com/errata/RHBA-2020:2409