Honor custom DNS in play|generate kube

when creating kubernetes yaml from containers and pods, we should honor
any custom dns settings the user provided. in the case of generate kube,
these would be provided by --dns, --dns-search, and --dns-opt. if
multiple containers are involved in the generate, the options will be
cumulative and unique with the exception of dns-opt.

when replaying a kube file that has kubernetes dns information, we now
also add that information to the pod creation.

the options for dnspolicy is not enabled as there seemed to be no direct
correlation between kubernetes and podman.

Fixes: #9132

Signed-off-by: baude <bbaude@redhat.com>

1 files changed, 26 insertions, 0 deletions

diff --git a/pkg/specgen/generate/kube/kube.go b/pkg/specgen/generate/kube/kube.go
index e39a700eb..0d7ee3ad2 100644
--- a/pkg/specgen/generate/kube/kube.go
+++ b/pkg/specgen/generate/kube/kube.go
@@ -3,6 +3,7 @@ package kube
 import (
 	"context"
 	"fmt"
+	"net"
 	"strings"
 
 	"github.com/containers/common/pkg/parse"
@@ -44,6 +45,31 @@ func ToPodGen(ctx context.Context, podName string, podYAML *v1.PodTemplateSpec)
 	podPorts := getPodPorts(podYAML.Spec.Containers)
 	p.PortMappings = podPorts
 
+	if dnsConfig := podYAML.Spec.DNSConfig; dnsConfig != nil {
+		// name servers
+		if dnsServers := dnsConfig.Nameservers; len(dnsServers) > 0 {
+			servers := make([]net.IP, 0)
+			for _, server := range dnsServers {
+				servers = append(servers, net.ParseIP(server))
+			}
+			p.DNSServer = servers
+		}
+		// search domans
+		if domains := dnsConfig.Searches; len(domains) > 0 {
+			p.DNSSearch = domains
+		}
+		// dns options
+		if options := dnsConfig.Options; len(options) > 0 {
+			dnsOptions := make([]string, 0)
+			for _, opts := range options {
+				d := opts.Name
+				if opts.Value != nil {
+					d += ":" + *opts.Value
+				}
+				dnsOptions = append(dnsOptions, d)
+			}
+		}
+	}
 	return p, nil
 }