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feat(depends): Use kubernetes API for depends_on management

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We were using netcat to port to check if a service is up, but actually
we can do like Docker / Podman compose and check the status. For now,
I'm using the endpoint status, but maybe we can just check if the object
is "up".
This commit is contained in:
Patrice Ferlet
2026-03-08 23:47:13 +01:00
parent 269717eb1c
commit 78b5af747e
5 changed files with 133 additions and 13 deletions
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49
internal/generator/deployment.go
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@@ -262,9 +262,21 @@ func (d *Deployment) BindFrom(service types.ServiceConfig, binded *Deployment) {
// DependsOn adds a initContainer to the deployment that will wait for the service to be up.
func (d *Deployment) DependsOn(to *Deployment, servicename string) error {
// Add a initContainer with busybox:latest using netcat to check if the service is up
// it will wait until the service responds to all ports
logger.Info("Adding dependency from ", d.service.Name, " to ", to.service.Name)
useLegacy := false
if label, ok := d.service.Labels[labels.LabelDependsOn]; ok {
useLegacy = strings.ToLower(label) == "legacy"
}
if useLegacy {
return d.dependsOnLegacy(to, servicename)
}
return d.dependsOnK8sAPI(to)
}
func (d *Deployment) dependsOnLegacy(to *Deployment, servicename string) error {
for _, container := range to.Spec.Template.Spec.Containers {
commands := []string{}
if len(container.Ports) == 0 {
@@ -291,6 +303,39 @@ func (d *Deployment) DependsOn(to *Deployment, servicename string) error {
return nil
}
func (d *Deployment) dependsOnK8sAPI(to *Deployment) error {
script := `NAMESPACE=${NAMESPACE:-default}
SERVICE=%s
KUBERNETES_SERVICE_HOST=${KUBERNETES_SERVICE_HOST:-kubernetes.default.svc}
KUBERNETES_SERVICE_PORT=${KUBERNETES_SERVICE_PORT:-443}
until wget -q -O- --header="Authorization: Bearer $(cat /var/run/secrets/kubernetes.io/serviceaccount/token)" \
--cacert=/var/run/secrets/kubernetes.io/serviceaccount/ca.crt \
"https://${KUBERNETES_SERVICE_HOST}:${KUBERNETES_SERVICE_PORT}/api/v1/namespaces/${NAMESPACE}/endpoints/${SERVICE}" \
| grep -q '"ready":.*true'; do
sleep 2
done`
command := []string{"/bin/sh", "-c", fmt.Sprintf(script, to.Name)}
d.Spec.Template.Spec.InitContainers = append(d.Spec.Template.Spec.InitContainers, corev1.Container{
Name: "wait-for-" + to.service.Name,
Image: "busybox:latest",
Command: command,
Env: []corev1.EnvVar{
{
Name: "NAMESPACE",
ValueFrom: &corev1.EnvVarSource{
FieldRef: &corev1.ObjectFieldSelector{
FieldPath: "metadata.namespace",
},
},
},
},
})
return nil
}
// Filename returns the filename of the deployment.
func (d *Deployment) Filename() string {
return d.service.Name + ".deployment.yaml"