server: correctly set hostname

Signed-off-by: Antonio Murdaca <runcom@redhat.com>

libkpod/container_server.go

@@ -335,6 +335,7 @@ func (c *ContainerServer) LoadSandbox(id string) error {
 	if err != nil {
 		return err
 	}
+	sb.AddHostnamePath(m.Annotations[annotations.HostnamePath])
 	sb.AddIP(ip)
 
 	// We add a netNS only if we can load a permanent one.

libkpod/sandbox/sandbox.go

@@ -151,6 +151,7 @@ type Sandbox struct {
 	privileged     bool
 	trusted        bool
 	resolvPath     string
+	hostnamePath   string
 	hostname       string
 	portMappings   []*hostport.PortMapping
 	stopped        bool
@@ -301,6 +302,16 @@ func (s *Sandbox) ResolvPath() string {
 	return s.resolvPath
 }
 
+// AddHostnamePath adds the hostname path to the sandbox
+func (s *Sandbox) AddHostnamePath(hostname string) {
+	s.hostnamePath = hostname
+}
+
+// HostnamePath retrieves the hostname path from a sandbox
+func (s *Sandbox) HostnamePath() string {
+	return s.hostnamePath
+}
+
 // Hostname returns the hsotname of the sandbox
 func (s *Sandbox) Hostname() string {
 	return s.hostname

pkg/annotations/annotations.go

@@ -52,6 +52,9 @@ const (
 	// ResolvPath is the resolver configuration path annotation
 	ResolvPath = "io.kubernetes.cri-o.ResolvPath"
 
+	// HostnamePath is the path to /etc/hostname to bind mount annotation
+	HostnamePath = "io.kubernetes.cri-o.HostnamePath"
+
 	// SandboxID is the sandbox ID annotation
 	SandboxID = "io.kubernetes.cri-o.SandboxID"
 

server/container_create.go

@@ -818,18 +818,25 @@ func (s *Server) createSandboxContainer(ctx context.Context, containerID string,
 		options = []string{"ro"}
 	}
 	if sb.ResolvPath() != "" {
+		// TODO: selinux
+		// label.Relabel(sb.ResolvPath(), container.MountLabel, shared)
+
 		// bind mount the pod resolver file
 		specgen.AddBindMount(sb.ResolvPath(), "/etc/resolv.conf", options)
 	}
 
+	if sb.HostnamePath() != "" {
+		// TODO: selinux
+
+		specgen.AddBindMount(sb.HostnamePath(), "/etc/hostname", options)
+	}
+
 	// Bind mount /etc/hosts for host networking containers
 	if hostNetwork(containerConfig) {
 		specgen.AddBindMount("/etc/hosts", "/etc/hosts", options)
 	}
 
-	if sb.Hostname() != "" {
+	specgen.SetHostname(sb.Hostname())
-		specgen.SetHostname(sb.Hostname())
-	}
 
 	specgen.AddAnnotation(annotations.Name, containerName)
 	specgen.AddAnnotation(annotations.ContainerID, containerID)

server/sandbox_run.go

@@ -3,6 +3,7 @@ package server
 import (
 	"encoding/json"
 	"fmt"
+	"io/ioutil"
 	"os"
 	"path"
 	"path/filepath"
@@ -187,12 +188,6 @@ func (s *Server) RunPodSandbox(ctx context.Context, req *pb.RunPodSandboxRequest
 		g.SetProcessArgs([]string{s.config.PauseCommand})
 	}
 
-	// set hostname
-	hostname := req.GetConfig().Hostname
-	if hostname != "" {
-		g.SetHostname(hostname)
-	}
-
 	// set DNS options
 	if req.GetConfig().GetDnsConfig() != nil {
 		dnsServers := req.GetConfig().GetDnsConfig().Servers
@@ -208,6 +203,9 @@ func (s *Server) RunPodSandbox(ctx context.Context, req *pb.RunPodSandboxRequest
 			}
 			return nil, err
 		}
+		// TODO: selinux
+		// label.Relabel(sb.ResolvPath(), container.MountLabel, shared)
+
 		g.AddBindMount(resolvPath, "/etc/resolv.conf", []string{"ro"})
 	}
 
@@ -301,6 +299,14 @@ func (s *Server) RunPodSandbox(ctx context.Context, req *pb.RunPodSandboxRequest
 		return nil, err
 	}
 
+	hostNetwork := req.GetConfig().GetLinux().GetSecurityContext().GetNamespaceOptions().HostNetwork
+
+	hostname, err := getHostname(id, req.GetConfig().Hostname, hostNetwork)
+	if err != nil {
+		return nil, err
+	}
+	g.SetHostname(hostname)
+
 	privileged := s.privilegedSandbox(req)
 	trusted := s.trustedSandbox(req)
 	g.AddAnnotation(annotations.Metadata, string(metadataJSON))
@@ -399,8 +405,6 @@ func (s *Server) RunPodSandbox(ctx context.Context, req *pb.RunPodSandboxRequest
 
 	g.SetLinuxResourcesCPUShares(PodInfraCPUshares)
 
-	hostNetwork := req.GetConfig().GetLinux().GetSecurityContext().GetNamespaceOptions().HostNetwork
-
 	// set up namespaces
 	if hostNetwork {
 		err = g.RemoveLinuxNamespace("network")
@@ -456,6 +460,15 @@ func (s *Server) RunPodSandbox(ctx context.Context, req *pb.RunPodSandboxRequest
 	g.AddAnnotation(annotations.MountPoint, mountPoint)
 	g.SetRootPath(mountPoint)
 
+	hostnamePath := fmt.Sprintf("%s/hostname", podContainer.RunDir)
+	if err := ioutil.WriteFile(hostnamePath, []byte(hostname+"\n"), 0644); err != nil {
+		return nil, err
+	}
+	// TODO: selinux relabel
+	g.AddBindMount(hostnamePath, "/etc/hostname", []string{"ro"})
+	g.AddAnnotation(annotations.HostnamePath, hostnamePath)
+	sb.AddHostnamePath(hostnamePath)
+
 	container, err := oci.NewContainer(id, containerName, podContainer.RunDir, logPath, sb.NetNs(), labels, kubeAnnotations, "", "", "", nil, id, false, false, false, sb.Privileged(), sb.Trusted(), podContainer.Dir, created, podContainer.Config.Config.StopSignal)
 	if err != nil {
 		return nil, err
@@ -515,6 +528,23 @@ func convertPortMappings(in []*pb.PortMapping) []*hostport.PortMapping {
 	return out
 }
 
+func getHostname(id, hostname string, hostNetwork bool) (string, error) {
+	if hostNetwork {
+		if hostname == "" {
+			h, err := os.Hostname()
+			if err != nil {
+				return "", err
+			}
+			hostname = h
+		}
+	} else {
+		if hostname == "" {
+			hostname = id[:12]
+		}
+	}
+	return hostname, nil
+}
+
 func (s *Server) setPodSandboxMountLabel(id, mountLabel string) error {
 	storageMetadata, err := s.StorageRuntimeServer().GetContainerMetadata(id)
 	if err != nil {

test/network.bats

@@ -2,6 +2,72 @@
 
 load helpers
 
+@test "ensure correct hostname" {
+	start_crio
+	run crioctl pod run --config "$TESTDATA"/sandbox_config.json
+	echo "$output"
+	[ "$status" -eq 0 ]
+	pod_id="$output"
+	run crioctl ctr create --config "$TESTDATA"/container_redis.json --pod "$pod_id"
+	echo "$output"
+	[ "$status" -eq 0  ]
+	ctr_id="$output"
+	run crioctl ctr start --id "$ctr_id"
+	echo "$output"
+	[ "$status" -eq 0 ]
+
+	run crioctl ctr execsync --id "$ctr_id" sh -c "hostname"
+	echo "$output"
+	[ "$status" -eq 0 ]
+	[[ "$output" =~ "crioctl_host" ]]
+	run crioctl ctr execsync --id "$ctr_id" sh -c "echo \$HOSTNAME"
+	echo "$output"
+	[ "$status" -eq 0 ]
+	[[ "$output" =~ "crioctl_host" ]]
+	run crioctl ctr execsync --id "$ctr_id" sh -c "cat /etc/hostname"
+	echo "$output"
+	[ "$status" -eq 0 ]
+	[[ "$output" =~ "crioctl_host" ]]
+
+	cleanup_ctrs
+	cleanup_pods
+	stop_crio
+}
+
+@test "ensure correct hostname for hostnetwork:true" {
+	start_crio
+	hostnetworkconfig=$(cat "$TESTDATA"/sandbox_config.json | python -c 'import json,sys;obj=json.load(sys.stdin);obj["linux"]["security_context"]["namespace_options"]["host_network"] = True; obj["annotations"] = {}; obj["hostname"] = ""; json.dump(obj, sys.stdout)')
+	echo "$hostnetworkconfig" > "$TESTDIR"/sandbox_hostnetwork_config.json
+	run crioctl pod run --config "$TESTDIR"/sandbox_hostnetwork_config.json
+	echo "$output"
+	[ "$status" -eq 0 ]
+	pod_id="$output"
+	run crioctl ctr create --config "$TESTDATA"/container_redis.json --pod "$pod_id"
+	echo "$output"
+	[ "$status" -eq 0  ]
+	ctr_id="$output"
+	run crioctl ctr start --id "$ctr_id"
+	echo "$output"
+	[ "$status" -eq 0 ]
+
+	run crioctl ctr execsync --id "$ctr_id" sh -c "hostname"
+	echo "$output"
+	[ "$status" -eq 0 ]
+	[[ "$output" =~ "$HOSTNAME" ]]
+	run crioctl ctr execsync --id "$ctr_id" sh -c "echo \$HOSTNAME"
+	echo "$output"
+	[ "$status" -eq 0 ]
+	[[ "$output" =~ "$HOSTNAME" ]]
+	run crioctl ctr execsync --id "$ctr_id" sh -c "cat /etc/hostname"
+	echo "$output"
+	[ "$status" -eq 0 ]
+	[[ "$output" =~ "$HOSTNAME" ]]
+
+	cleanup_ctrs
+	cleanup_pods
+	stop_crio
+}
+
 @test "Check for valid pod netns CIDR" {
 	start_crio
 	run crioctl pod run --config "$TESTDATA"/sandbox_config.json