docs(srv): add srv x vpc ref content

Author: SamyOubouaziz

pages/serverless-containers/reference-content/containers-private-networks.mdx

@@ -0,0 +1,54 @@
+---
+title: Serverless Containers and Private Networks integration
+description: This page contains details on how Serverless Containers interacts with Virtual Private Cloud and Private Networks
+dates:
+  - posted: 2025-07-29
+  - validation: 2025-07-29
+---
+
+## Description
+
+Attach a Serverless Function or Container to a Private Network.
+
+### Availability
+
+- Binding is done per Function or Container, not per namespace: multiple functions/containers in the same namespace can be attached to different PNs
+- Works for both sandboxes (v1, v2)
+- Feature is free of charge
+
+### Features
+Container to PN resources (egress)
+Currently, no ingress (PN resources to container)
+but container still available through public traffic
+
+- All internal traffic (to PN) will be routed through the private interface, but external traffic (Internet) will be through the public (already existing) interface
+
+- All DNS resolution is done through PN (using DNS server `169.254.169.254` (=VPC dns server)). This allows to resolve `*.internal` records
+
+
+
+
+## Users limitations
+
+### API
+
+- A Function/Container can **only** be attached to a single PN
+- extra quota for VPC via Containers (Container Unique Private Networks) 5/10
+- UPDATE QUOTAS DOC
+
+
+
+### Infrastructure
+
+- **VPC routing** (custom routes) doesn't work yet
+
+- Each Function/Container instance will have a unique IP in the PN, assigned by Scaleway. this implies:
+  - it won't be possible for a user to **preemptively book an IP** in IPAM, and reference it in the attachment
+  - this can result in a **large number of IPs** being used in the PN. It might be confusing for clients as a single resource (a given Function/Container) with multiple instances will have multiple IPs
+
+- **Cold-starts will be slightly longer** due to the additional steps required to attach the node to the PN and book an IP.
+
+Also, as of today, only ingress is implemented (phase 1: call a resource in the PN from a Function/Container). 
+
+Egress (phase 2: calling a Function/Container from a resource in the PN) will be done [later](../#phases).
+