From dcba9e74d9488dd08c0848d51114ba72e5dfc42b Mon Sep 17 00:00:00 2001
From: Prathamesh Musale <prathamesh.musale0@gmail.com>
Date: Tue, 10 Mar 2026 10:38:24 +0000
Subject: [PATCH] feat(k8s): support init containers via compose labels

Add support for k8s init containers defined in docker-compose files
using the `laconic.init-container` label. Services with this label
set to "true" are built as init containers instead of regular
containers in the pod spec.

This enables stacks to fetch runtime-created ConfigMaps (e.g. from
deployer jobs) before the main containers start, without requiring
manual operator steps between deployments.

Example compose usage:

  services:
    fetch-config:
      image: bitnami/kubectl:latest
      labels:
        laconic.init-container: "true"
      command: ["sh", "-c", "kubectl get configmap ..."]
      volumes:
        - shared-config:/config

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
---
 stack_orchestrator/deploy/k8s/cluster_info.py | 32 +++++++++++++++----
 1 file changed, 26 insertions(+), 6 deletions(-)

diff --git a/stack_orchestrator/deploy/k8s/cluster_info.py b/stack_orchestrator/deploy/k8s/cluster_info.py
index 8c530fc9..1f6d14f2 100644
--- a/stack_orchestrator/deploy/k8s/cluster_info.py
+++ b/stack_orchestrator/deploy/k8s/cluster_info.py
@@ -446,12 +446,16 @@ class ClusterInfo:
     ) -> tuple:
         """Build k8s container specs from parsed compose YAML.
 
-        Returns a tuple of (containers, services, volumes) where:
+        Returns a tuple of (containers, init_containers, services, volumes)
+        where:
         - containers: list of V1Container objects
+        - init_containers: list of V1Container objects for init containers
+          (compose services with label ``laconic.init-container: "true"``)
         - services: the last services dict processed (used for annotations/labels)
         - volumes: list of V1Volume objects
         """
         containers = []
+        init_containers = []
         services = {}
         global_resources = self.spec.get_container_resources()
         if not global_resources:
@@ -571,15 +575,29 @@ class ClusterInfo:
                     ),
                     resources=to_k8s_resource_requirements(container_resources),
                 )
-                containers.append(container)
+                # Services with laconic.init-container label become
+                # k8s init containers instead of regular containers.
+                svc_labels = service_info.get("labels", {})
+                if isinstance(svc_labels, list):
+                    # docker-compose labels can be a list of "key=value"
+                    svc_labels = dict(
+                        l.split("=", 1) for l in svc_labels
+                    )
+                is_init = str(
+                    svc_labels.get("laconic.init-container", "")
+                ).lower() in ("true", "1", "yes")
+                if is_init:
+                    init_containers.append(container)
+                else:
+                    containers.append(container)
         volumes = volumes_for_pod_files(
             parsed_yaml_map, self.spec, self.app_name
         )
-        return containers, services, volumes
+        return containers, init_containers, services, volumes
 
     # TODO: put things like image pull policy into an object-scope struct
     def get_deployment(self, image_pull_policy: Optional[str] = None):
-        containers, services, volumes = self._build_containers(
+        containers, init_containers, services, volumes = self._build_containers(
             self.parsed_pod_yaml_map, image_pull_policy
         )
         registry_config = self.spec.get_image_registry_config()
@@ -650,6 +668,7 @@ class ClusterInfo:
             metadata=client.V1ObjectMeta(annotations=annotations, labels=labels),
             spec=client.V1PodSpec(
                 containers=containers,
+                init_containers=init_containers or None,
                 image_pull_secrets=image_pull_secrets,
                 volumes=volumes,
                 affinity=affinity,
@@ -695,8 +714,8 @@ class ClusterInfo:
         for job_file in self.parsed_job_yaml_map:
             # Build containers for this single job file
             single_job_map = {job_file: self.parsed_job_yaml_map[job_file]}
-            containers, _services, volumes = self._build_containers(
-                single_job_map, image_pull_policy
+            containers, init_containers, _services, volumes = (
+                self._build_containers(single_job_map, image_pull_policy)
             )
 
             # Derive job name from file path: docker-compose-<name>.yml -> <name>
@@ -722,6 +741,7 @@ class ClusterInfo:
                 ),
                 spec=client.V1PodSpec(
                     containers=containers,
+                    init_containers=init_containers or None,
                     image_pull_secrets=image_pull_secrets,
                     volumes=volumes,
                     restart_policy="Never",