How to host the MCP server on Azure Container Apps¶

The MCP server has a local face (stdio) and a remote face (Streamable HTTP + OAuth). This guide is the recipe for the remote face: running dna mcp serve --transport http hosted on Azure Container Apps, behind an HTTPS ingress, authenticated with Microsoft Entra — so a web/agent MCP client reaches your live DNA over the network, composed live and scoped to the caller's tenant by the token.

It is Phase A of DNA-hosted: one azd up stands up your own instance, and the same recipe is the base the multi-tenant DNA Cloud offering builds on. The full, runnable recipe (Dockerfile + bicep + runbook) lives in deploy/azure/; this page is the map.

The shape¶

Everything is keyless. The image pull uses a user-assigned Managed Identity; Entra tokens are validated against Entra's public JWKS. No secret lives in the template or the container.

Piece	What it is
`Dockerfile`	`dna mcp serve --transport http` on `python:3.12-slim`, non-root, port 8080
`resources.bicep`	Log Analytics + Container Apps env + ACR + user-assigned Managed Identity (AcrPull) + Azure Files share (the DNA source, mounted read-only at `/mnt/dna`) + the Container App (external HTTPS ingress, Entra-JWT auth env)
`azure.yaml`	the `azd` project — one service `mcp`, `remoteBuild: true` (no local Docker needed)
`scripts/push-scope.sh`	seed / update the mounted DNA source, then restart the revision

Auth — Microsoft Entra as the IdP¶

The Container App is an OAuth 2.1 Resource Server. You register the MCP server as an Entra app registration, Expose an API with a scope, and the app validates presented bearer JWTs against Entra's JWKS. The auth↔tenancy bridge then maps the token's claim to a DNA tenant and enforces it.

The bicep derives the Entra endpoints from your tenant id (nothing to hand-copy) and wires them as the --auth jwt environment:

DNA_MCP_JWKS_URI      https://login.microsoftonline.com/<tenant>/discovery/v2.0/keys
DNA_MCP_JWT_ISSUER    https://login.microsoftonline.com/<tenant>/v2.0
DNA_MCP_JWT_AUDIENCE  api://<mcp-app-client-id>
DNA_MCP_RESOURCE_URL  https://<the-app>            # advertised in PRM (RFC 9728)
DNA_MCP_AUTH_SERVERS  https://login.microsoftonline.com/<tenant>/v2.0
DNA_MCP_TENANT_CLAIM  tenant                       # or `tid` to bind each Entra directory to a DNA tenant

The login host is derived via Bicep's environment(), so the template is correct across Azure clouds (Public / Gov / China). A declarative front-end for the same wiring (dna.config.yaml with auth.providers: [entra]) is sketched in deploy/azure/dna.config.sample.yaml.

Deploy it¶

$ cd deploy/azure
$ azd env set ENTRA_TENANT_ID   <your-entra-tenant-guid>
$ azd env set ENTRA_MCP_AUDIENCE api://<your-mcp-app-client-id>
$ azd up

azd up provisions the stack, builds the image in ACR, and deploys it. Its outputs give you MCP_ENDPOINT (https://…/mcp/) and AUTH_MODE.

Then seed your real DNA source (a fresh provision serves a tiny baked demo scope so the endpoint is queryable immediately):

$ ./scripts/push-scope.sh ../../.dna

Prove it¶

# Discovery doc served (expect 200):
$ curl -s https://<the-app>/.well-known/oauth-protected-resource/mcp | jq .

# Unauthenticated call denied (expect 401):
$ curl -i -X POST https://<the-app>/mcp/ -H 'Accept: application/json, text/event-stream' \
    -H 'Content-Type: application/json' \
    -d '{"jsonrpc":"2.0","id":1,"method":"initialize","params":{"protocolVersion":"2025-06-18","capabilities":{},"clientInfo":{"name":"s","version":"0"}}}'

# With an Entra token (expect 200, server "dna"):
$ TOKEN=$(az account get-access-token --scope api://<client-id>/.default --query accessToken -o tsv)
$ curl -s -X POST https://<the-app>/mcp/ -H "Authorization: Bearer $TOKEN" \
    -H 'Content-Type: application/json' -H 'Accept: application/json, text/event-stream' \
    -d '{"jsonrpc":"2.0","id":1,"method":"initialize","params":{"protocolVersion":"2025-06-18","capabilities":{},"clientInfo":{"name":"s","version":"0"}}}'

The step-by-step runbook — the Entra app registration, the owner checklist, and azd down — is deploy/azure/README.md.

Why this matters¶

dna emit materializes DNA into a runtime's static artifact; the MCP server is the live face. Hosting it on Container Apps + Entra makes that live face reachable, authenticated, and multi-tenant — the same server the CLI serves over stdio, now a networked endpoint that scopes each client to its own tenant by the token. That is the base the DNA Cloud offering is built on.