Network interface

Implement a new network interface to abstract CNI from libpod. The
interface is implemented for the CNI backend but in the future we can
add more backends.

The code is structured in three new packages:
- `libpod/network/types`: contains the interface definition
  and the necessary types for it.
- `libpod/network/cni` contains the interface implementation for the CNI
  backend.
- `libpod/network/util` a set of utility functions related to
  networking.

The CNI package uses ginkgo style unit tests. To test Setup/Teardown the
test must be run as root. Each test will run in their own namespace to
make the test independent from the host environment.

New features with the CNI backend:
- The default network will be created in memory if it does not exists on
  disk.
- It can set more than one static IP per container network.
- Networks are loaded once from disk and only if this interface is
  used, e.g. for commands such as `podman info` networks are not loaded.
  This reduces unnecessary disk IO.

This commit only adds the interface it is not wired into libpod. This
requires a lot of breaking changes which will be done in a followup
commit.

Once this is integrated into libpod the current network code under
`libpod/network` should be removed. Also the dependency on OCICNI
should be dropped.

Signed-off-by: Paul Holzinger <pholzing@redhat.com>

4 files changed, 10 insertions, 36 deletions

diff --git a/pkg/specgen/generate/kube/kube.go b/pkg/specgen/generate/kube/kube.go
index d6d479c67..04b4e5ab3 100644
--- a/pkg/specgen/generate/kube/kube.go
+++ b/pkg/specgen/generate/kube/kube.go
@@ -12,6 +12,7 @@ import (
 	"github.com/containers/common/pkg/parse"
 	"github.com/containers/common/pkg/secrets"
 	"github.com/containers/image/v5/manifest"
+	"github.com/containers/podman/v3/libpod/network/types"
 	ann "github.com/containers/podman/v3/pkg/annotations"
 	"github.com/containers/podman/v3/pkg/specgen"
 	"github.com/containers/podman/v3/pkg/specgen/generate"
@@ -588,8 +589,8 @@ func envVarValue(env v1.EnvVar, opts *CtrSpecGenOptions) (string, error) {
 
 // getPodPorts converts a slice of kube container descriptions to an
 // array of portmapping
-func getPodPorts(containers []v1.Container) []specgen.PortMapping {
-	var infraPorts []specgen.PortMapping
+func getPodPorts(containers []v1.Container) []types.PortMapping {
+	var infraPorts []types.PortMapping
 	for _, container := range containers {
 		for _, p := range container.Ports {
 			if p.HostPort != 0 && p.ContainerPort == 0 {
@@ -598,7 +599,7 @@ func getPodPorts(containers []v1.Container) []specgen.PortMapping {
 			if p.Protocol == "" {
 				p.Protocol = "tcp"
 			}
-			portBinding := specgen.PortMapping{
+			portBinding := types.PortMapping{
 				HostPort:      uint16(p.HostPort),
 				ContainerPort: uint16(p.ContainerPort),
 				Protocol:      strings.ToLower(string(p.Protocol)),
diff --git a/pkg/specgen/generate/ports.go b/pkg/specgen/generate/ports.go
index c00ad19fb..bd64080b1 100644
--- a/pkg/specgen/generate/ports.go
+++ b/pkg/specgen/generate/ports.go
@@ -7,6 +7,7 @@ import (
 	"strings"
 
 	"github.com/containers/common/libimage"
+	"github.com/containers/podman/v3/libpod/network/types"
 	"github.com/containers/podman/v3/utils"
 
 	"github.com/containers/podman/v3/pkg/specgen"
@@ -24,7 +25,7 @@ const (
 // Parse port maps to OCICNI port mappings.
 // Returns a set of OCICNI port mappings, and maps of utilized container and
 // host ports.
-func ParsePortMapping(portMappings []specgen.PortMapping) ([]ocicni.PortMapping, map[string]map[string]map[uint16]uint16, map[string]map[string]map[uint16]uint16, error) {
+func ParsePortMapping(portMappings []types.PortMapping) ([]ocicni.PortMapping, map[string]map[string]map[uint16]uint16, map[string]map[string]map[uint16]uint16, error) {
 	// First, we need to validate the ports passed in the specgen, and then
 	// convert them into CNI port mappings.
 	type tempMapping struct {
diff --git a/pkg/specgen/podspecgen.go b/pkg/specgen/podspecgen.go
index 893ebf675..386571d11 100644
--- a/pkg/specgen/podspecgen.go
+++ b/pkg/specgen/podspecgen.go
@@ -3,6 +3,7 @@ package specgen
 import (
 	"net"
 
+	"github.com/containers/podman/v3/libpod/network/types"
 	spec "github.com/opencontainers/runtime-spec/specs-go"
 )
 
@@ -102,7 +103,7 @@ type PodNetworkConfig struct {
 	// container, this will forward the ports to the entire pod.
 	// Only available if NetNS is set to Bridge or Slirp.
 	// Optional.
-	PortMappings []PortMapping `json:"portmappings,omitempty"`
+	PortMappings []types.PortMapping `json:"portmappings,omitempty"`
 	// CNINetworks is a list of CNI networks that the infra container will
 	// join. As, by default, containers share their network with the infra
 	// container, these networks will effectively be joined by the
diff --git a/pkg/specgen/specgen.go b/pkg/specgen/specgen.go
index 2252ef405..0c30c498a 100644
--- a/pkg/specgen/specgen.go
+++ b/pkg/specgen/specgen.go
@@ -5,6 +5,7 @@ import (
 	"syscall"
 
 	"github.com/containers/image/v5/manifest"
+	nettypes "github.com/containers/podman/v3/libpod/network/types"
 	"github.com/containers/storage/types"
 	spec "github.com/opencontainers/runtime-spec/specs-go"
 	"github.com/pkg/errors"
@@ -393,7 +394,7 @@ type ContainerNetworkConfig struct {
 	// PortBindings is a set of ports to map into the container.
 	// Only available if NetNS is set to bridge or slirp.
 	// Optional.
-	PortMappings []PortMapping `json:"portmappings,omitempty"`
+	PortMappings []nettypes.PortMapping `json:"portmappings,omitempty"`
 	// PublishExposedPorts will publish ports specified in the image to
 	// random unused ports (guaranteed to be above 1024) on the host.
 	// This is based on ports set in Expose below, and any ports specified
@@ -506,36 +507,6 @@ type SpecGenerator struct {
 	ContainerHealthCheckConfig
 }
 
-// PortMapping is one or more ports that will be mapped into the container.
-type PortMapping struct {
-	// HostIP is the IP that we will bind to on the host.
-	// If unset, assumed to be 0.0.0.0 (all interfaces).
-	HostIP string `json:"host_ip,omitempty"`
-	// ContainerPort is the port number that will be exposed from the
-	// container.
-	// Mandatory.
-	ContainerPort uint16 `json:"container_port"`
-	// HostPort is the port number that will be forwarded from the host into
-	// the container.
-	// If omitted, a random port on the host (guaranteed to be over 1024)
-	// will be assigned.
-	HostPort uint16 `json:"host_port,omitempty"`
-	// Range is the number of ports that will be forwarded, starting at
-	// HostPort and ContainerPort and counting up.
-	// This is 1-indexed, so 1 is assumed to be a single port (only the
-	// Hostport:Containerport mapping will be added), 2 is two ports (both
-	// Hostport:Containerport and Hostport+1:Containerport+1), etc.
-	// If unset, assumed to be 1 (a single port).
-	// Both hostport + range and containerport + range must be less than
-	// 65536.
-	Range uint16 `json:"range,omitempty"`
-	// Protocol is the protocol forward.
-	// Must be either "tcp", "udp", and "sctp", or some combination of these
-	// separated by commas.
-	// If unset, assumed to be TCP.
-	Protocol string `json:"protocol,omitempty"`
-}
-
 type Secret struct {
 	Source string
 	UID    uint32