tfmanual creation

collections/tfmanual/documentation/developers/internals/zos/internals/container/readme.md

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+<h1>Container Module</h1>
+
+<h2> Table of Contents </h2>
+
+- [ZBus](#zbus)
+- [Home Directory](#home-directory)
+- [Introduction](#introduction)
+  - [zinit unit](#zinit-unit)
+- [Interface](#interface)
+
+***
+
+## ZBus
+
+Storage module is available on zbus over the following channel
+
+| module | object | version |
+|--------|--------|---------|
+| container|[container](#interface)| 0.0.1|
+
+## Home Directory
+
+contd keeps some data in the following locations
+| directory | path|
+|----|---|
+| root| `/var/cache/modules/containerd`|
+
+## Introduction
+
+The container module, is a proxy to [containerd](https://github.com/containerd/containerd). The proxy provides integration with zbus.
+
+The implementation is the moment is straight forward, which includes preparing the OCI spec for the container, the tenant containerd namespace,
+setting up proper capabilities, and finally creating the container instance on `containerd`.
+
+The module is fully stateless, all container information is queried during runtime from `containerd`.
+
+### zinit unit
+
+`contd` must run after containerd is running, and the node boot process is complete. Since it doesn't keep state, no dependency on `stroaged` is needed
+
+```yaml
+exec: contd -broker unix:///var/run/redis.sock -root /var/cache/modules/containerd
+after:
+  - containerd
+  - boot
+```
+
+## Interface
+
+```go
+package pkg
+
+// ContainerID type
+type ContainerID string
+
+// NetworkInfo defines a network configuration for a container
+type NetworkInfo struct {
+    // Currently a container can only join one (and only one)
+    // network namespace that has to be pre defined on the node
+    // for the container tenant
+
+    // Containers don't need to know about anything about bridges,
+    // IPs, wireguards since this is all is only known by the network
+    // resource which is out of the scope of this module
+    Namespace string
+}
+
+// MountInfo defines a mount point
+type MountInfo struct {
+    Source  string   // source of the mount point on the host
+    Target  string   // target of mount inside the container
+    Type    string   // mount type
+    Options []string // mount options
+}
+
+//Container creation info
+type Container struct {
+    // Name of container
+    Name string
+    // path to the rootfs of the container
+    RootFS string
+    // Env env variables to container in format {'KEY=VALUE', 'KEY2=VALUE2'}
+    Env []string
+    // Network network info for container
+    Network NetworkInfo
+    // Mounts extra mounts for container
+    Mounts []MountInfo
+    // Entrypoint the process to start inside the container
+    Entrypoint string
+    // Interactivity enable Core X as PID 1 on the container
+    Interactive bool
+}
+
+// ContainerModule defines rpc interface to containerd
+type ContainerModule interface {
+    // Run creates and starts a container on the node. It also auto
+    // starts command defined by `entrypoint` inside the container
+    // ns: tenant namespace
+    // data: Container info
+    Run(ns string, data Container) (ContainerID, error)
+
+    // Inspect, return information about the container, given its container id
+    Inspect(ns string, id ContainerID) (Container, error)
+    Delete(ns string, id ContainerID) error
+}
+```