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Add helper sidecar container to the Pod Spec generated on Podman
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As explained in [1], this helper sidecar container (aptly named "odo-helper-port-forwarding")
will hold the actual container/host ports mapping in the spec
(to overcome the limitation of using hostPort against a container app listening on the loopback interface);
this running container will be used to execute the actual port-forwarding commands (based on socat), e.g:

```
apiVersion: v1
kind: Pod
metadata:
  name: my-component-app
  labels:
    app: my-component-app
spec:
  containers:
  - name: runtime
    command: [ 'tail', '-f', '/dev/null']
    # Omitted for brevity, but imagine an application being executed by odo
    # and listening on both 0.0.0.0:3000 and 127.0.0.1:5858

  - name: odo-helper-port-forwarding
    image: quay.io/devfile/base-developer-image:ubi8-latest
    command: [ 'tail', '-f', '/dev/null']
    ports:
    - containerPort: 20001
      # A command will be executed by odo, e.g.: 'socat -d -d tcp-listen:20001,reuseaddr,fork tcp:localhost:3000'
      hostPort: 20001
    - containerPort: 20002
      # A command will be executed by odo, e.g.: 'socat -d -d tcp-listen:20002,reuseaddr,fork tcp:localhost:5858'
      hostPort: 20002

# ... Omitted for brevity
```

In this scope, port-forwarding from 20002 to 5858 for example will be equivalent of executing
a socat command in this helper container, like so:

socat -d tcp-listen:20002,reuseaddr,fork tcp:localhost:5858

In the command above, this will open up port 20001 on the helper container,
and forwarding requests to localhost:5858
(which would be in the 'runtime' container, part of the same Pod)

[1] redhat-developer#6510
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@rm3l
rm3l committed Feb 10, 2023
1 parent 7e2afb0 commit fb70875
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Showing 2 changed files with 126 additions and 97 deletions.
210 changes: 118 additions & 92 deletions pkg/dev/podmandev/pod.go
View file
Original file line number Diff line number Diff line change
Expand Up @@ -23,42 +23,112 @@ import (
"k8s.io/klog"
)

func getPortMapping(devfileObj parser.DevfileObj, debug bool, randomPorts bool, usedPorts []int) ([]api.ForwardedPort, error) {
containerComponents, err := devfileObj.Data.GetComponents(common.DevfileOptions{
ComponentOptions: common.ComponentOptions{ComponentType: v1alpha2.ContainerComponentType},
})
if err != nil {
return nil, err
}
ceMapping := libdevfile.GetContainerEndpointMapping(containerComponents, debug)

var existingContainerPorts []int
for _, endpoints := range ceMapping {
for _, ep := range endpoints {
existingContainerPorts = append(existingContainerPorts, ep.TargetPort)
}
}

isPortUsedInContainer := func(p int) bool {
for _, port := range existingContainerPorts {
if p == port {
return true
}
}
return false
}

var result []api.ForwardedPort
startPort := 20001
endPort := startPort + 10000
usedPortsCopy := make([]int, len(usedPorts))
copy(usedPortsCopy, usedPorts)
for containerName, endpoints := range ceMapping {
epLoop:
for _, ep := range endpoints {
portName := ep.Name
isDebugPort := libdevfile.IsDebugPort(portName)
if !debug && isDebugPort {
klog.V(4).Infof("not running in Debug mode, so skipping Debug endpoint %s (%d) for container %q",
portName, ep.TargetPort, containerName)
continue
}
var freePort int
if randomPorts {
if len(usedPortsCopy) != 0 {
freePort = usedPortsCopy[0]
usedPortsCopy = usedPortsCopy[1:]
} else {
rand.Seed(time.Now().UnixNano()) //#nosec
for {
freePort = rand.Intn(endPort-startPort+1) + startPort //#nosec
if !isPortUsedInContainer(freePort) && util.IsPortFree(freePort) {
break
}
time.Sleep(100 * time.Millisecond)
}
}
} else {
for {
freePort, err = util.NextFreePort(startPort, endPort, usedPorts)
if err != nil {
klog.Infof("%s", err)
continue epLoop
}
if !isPortUsedInContainer(freePort) {
break
}
startPort = freePort + 1
time.Sleep(100 * time.Millisecond)
}
startPort = freePort + 1
}
fp := api.ForwardedPort{
Platform: commonflags.PlatformPodman,
PortName: portName,
IsDebug: isDebugPort,
ContainerName: containerName,
LocalAddress: "127.0.0.1",
LocalPort: freePort,
ContainerPort: ep.TargetPort,
Exposure: string(ep.Exposure),
}
result = append(result, fp)
}
}
return result, nil
}

func createPodFromComponent(
devfileObj parser.DevfileObj,
componentName string,
appName string,
debug bool,
buildCommand string,
runCommand string,
debugCommand string,
randomPorts bool,
usedPorts []int,
) (*corev1.Pod, []api.ForwardedPort, error) {
fwPorts []api.ForwardedPort,
) (*corev1.Pod, error) {
containers, err := generator.GetContainers(devfileObj, common.DevfileOptions{})
if err != nil {
return nil, nil, err
return nil, err
}
if len(containers) == 0 {
return nil, nil, fmt.Errorf("no valid components found in the devfile")
return nil, fmt.Errorf("no valid components found in the devfile")
}

containers, err = utils.UpdateContainersEntrypointsIfNeeded(devfileObj, containers, buildCommand, runCommand, debugCommand)
if err != nil {
return nil, nil, err
}
utils.AddOdoProjectVolume(&containers)
utils.AddOdoMandatoryVolume(&containers)

// get the endpoint/port information for containers in devfile
containerComponents, err := devfileObj.Data.GetComponents(common.DevfileOptions{
ComponentOptions: common.ComponentOptions{ComponentType: v1alpha2.ContainerComponentType},
})
if err != nil {
return nil, nil, err
}
ceMapping := libdevfile.GetContainerEndpointMapping(containerComponents, debug)
fwPorts := addHostPorts(containers, ceMapping, debug, randomPorts, usedPorts)

volumes := []corev1.Volume{
{
Name: storage.OdoSourceVolume,
Expand All @@ -80,7 +150,7 @@ func createPodFromComponent(

devfileVolumes, err := storage.ListStorage(devfileObj)
if err != nil {
return nil, nil, err
return nil, err
}

for _, devfileVolume := range devfileVolumes {
Expand All @@ -94,10 +164,34 @@ func createPodFromComponent(
})
err = addVolumeMountToContainer(containers, devfileVolume)
if err != nil {
return nil, nil, err
return nil, err
}
}

containers, err = utils.UpdateContainersEntrypointsIfNeeded(devfileObj, containers, buildCommand, runCommand, debugCommand)
if err != nil {
return nil, err
}

// Remove all containerPorts, as they will be set afterwards in the helper container
for i := range containers {
containers[i].Ports = nil
}
// Add helper container for port-forwarding
pfHelperContainer := corev1.Container{
Name: "odo-helper-port-forwarding",
Image: "quay.io/devfile/base-developer-image:ubi8-latest",
Command: []string{"tail"},
Args: []string{"-f", "/dev/null"},
}
for _, fwPort := range fwPorts {
pfHelperContainer.Ports = append(pfHelperContainer.Ports, corev1.ContainerPort{
ContainerPort: int32(fwPort.LocalPort),
HostPort: int32(fwPort.LocalPort),
})
}
containers = append(containers, pfHelperContainer)

pod := corev1.Pod{
Spec: corev1.PodSpec{
Containers: containers,
Expand All @@ -108,89 +202,21 @@ func createPodFromComponent(
pod.APIVersion, pod.Kind = corev1.SchemeGroupVersion.WithKind("Pod").ToAPIVersionAndKind()
name, err := util.NamespaceKubernetesObject(componentName, appName)
if err != nil {
return nil, nil, err
return nil, err
}
pod.SetName(name)

runtime := component.GetComponentRuntimeFromDevfileMetadata(devfileObj.Data.GetMetadata())
pod.SetLabels(labels.GetLabels(componentName, appName, runtime, labels.ComponentDevMode, true))
labels.SetProjectType(pod.GetLabels(), component.GetComponentTypeFromDevfileMetadata(devfileObj.Data.GetMetadata()))

return &pod, fwPorts, nil
return &pod, nil
}

func getVolumeName(volume string, componentName string, appName string) string {
return volume + "-" + componentName + "-" + appName
}

func addHostPorts(containers []corev1.Container, ceMapping map[string][]v1alpha2.Endpoint, debug bool, randomPorts bool, usedPorts []int) []api.ForwardedPort {
var result []api.ForwardedPort
startPort := 20001
endPort := startPort + 10000
usedPortsCopy := make([]int, len(usedPorts))
copy(usedPortsCopy, usedPorts)
for i := range containers {
var ports []corev1.ContainerPort
for _, port := range containers[i].Ports {
containerName := containers[i].Name
portName := port.Name
isDebugPort := libdevfile.IsDebugPort(portName)
if !debug && isDebugPort {
klog.V(4).Infof("not running in Debug mode, so skipping container Debug port: %v:%v:%v",
containerName, portName, port.ContainerPort)
continue
}
var freePort int
if randomPorts {
if len(usedPortsCopy) != 0 {
freePort = usedPortsCopy[0]
usedPortsCopy = usedPortsCopy[1:]
} else {
rand.Seed(time.Now().UnixNano()) //#nosec
for {
freePort = rand.Intn(endPort-startPort+1) + startPort //#nosec
if util.IsPortFree(freePort) {
break
}
time.Sleep(100 * time.Millisecond)
}
}
} else {
var err error
freePort, err = util.NextFreePort(startPort, endPort, usedPorts)
if err != nil {
klog.Infof("%s", err)
continue
}
startPort = freePort + 1
}
// Find the endpoint in the container-endpoint mapping
containerPort := int(port.ContainerPort)
fp := api.ForwardedPort{
Platform: commonflags.PlatformPodman,
PortName: portName,
IsDebug: isDebugPort,
ContainerName: containerName,
LocalAddress: "127.0.0.1",
LocalPort: freePort,
ContainerPort: containerPort,
}

for _, ep := range ceMapping[containerName] {
if ep.TargetPort == containerPort {
fp.Exposure = string(ep.Exposure)
break
}
}
result = append(result, fp)
port.HostPort = int32(freePort)
ports = append(ports, port)
}
containers[i].Ports = ports
}
return result
}

func addVolumeMountToContainer(containers []corev1.Container, devfileVolume storage.LocalStorage) error {
for i := range containers {
if containers[i].Name == devfileVolume.Container {
Expand Down
13 changes: 8 additions & 5 deletions pkg/dev/podmandev/reconcile.go
View file
Original file line number Diff line number Diff line change
Expand Up @@ -154,16 +154,19 @@ func (o *DevClient) deployPod(ctx context.Context, options dev.StartOptions) (*c
spinner := log.Spinner("Deploying pod")
defer spinner.End(false)

pod, fwPorts, err := createPodFromComponent(
fwPorts, err := getPortMapping(*devfileObj, options.Debug, options.RandomPorts, o.usedPorts)
if err != nil {
return nil, nil, err
}

pod, err := createPodFromComponent(
*devfileObj,
componentName,
appName,
options.Debug,
options.BuildCommand,
options.RunCommand,
"",
options.RandomPorts,
o.usedPorts,
options.DebugCommand,
fwPorts,
)
if err != nil {
return nil, nil, err
Expand Down

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