MakerFLOSS/slides/tappaas/how-to/new-module/index.md

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title: How to implement a TAPPaaS module
description: Live build of a Podman module — OrangeMaker, 24 August
---

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# Getting a module onto TAPPaaS

Live build of a **Podman** container host

OrangeMaker · 24 August

<!--
Slides are the map; the terminal is the territory. Everything here has a live
counterpart — keep the deck moving and spend the time in the shell.
-->

---

## The plan

1. **What TAPPaaS is** — a few diagrams, ten minutes, no deeper
2. **What a module actually is** — a json contract and three scripts
3. **Build one live** — the `lab1` environment, then `podman` into it
4. **Prove it works** — tests, then the web console
5. **You get a login** — your own identity on this system

You leave with: a mental model, a module you watched get built, and an account.

---

<!-- _class: invert diagram -->

## The shape of a TAPPaaS site

```mermaid
flowchart LR
  sat["satellite VPS<br/>public IP · ingress<br/>off-site backup"]
  subgraph z0["mgmt · zone mgmt"]
    cicd["tappaas-cicd"]
    net["network"]
    clu["cluster"]
    bak["backup"]
    idp["identity"]
  end
  subgraph z1["default · zone srv"]
    nc["nextcloud"]
    ha["home-assistant"]
  end
  subgraph z2["lab1 · zone lab1"]
    pod["podman — today"]
  end
  sat --> net
  cicd --> nc
  cicd --> pod
```

---

## The words we will use

| Word | Meaning |
| --- | --- |
| **Module** | The smallest deployable unit — its own VM, its own json contract. Foundation *and* apps are modules. |
| **Environment** | A tenant. `mgmt` and one named after the site always exist; add more freely. Today we add `lab1`. |
| **Zone** | A VLAN with a firewall policy. Modules land in their environment's zone. |
| **Mothership** | `tappaas-cicd` — where the managers run and where you type. |
| **Satellite** | Optional VPS, for sites with no usable public IP. |

Everything is a module. There is one model to learn, not eight.

---

<!-- _class: invert diagram -->

## Developing modules: dev instance, private branch

```mermaid
flowchart RL
  subgraph Development["Development repository"]
    dev_main["main"]
  end
  subgraph Upstream["Upstream repository"]
    up_main["main"]
    up_stable["stable"]
    up_main -->|merge| up_stable
  end
  subgraph InstanceDev["TAPPaaS instance · dev"]
    localDev["clone of Upstream"]
    localDev_dev["clone of Development"]
  end
  subgraph InstanceProd["TAPPaaS instance · prod"]
    localProd["clone of Upstream"]
  end
  localProd -->|pull| up_stable
  localDev -->|pull| up_main
  localDev_dev -->|push| dev_main
  dev_main -->|PR| up_main
```

---

<!-- _class: invert diagram -->

## Our setup tonight

```mermaid
flowchart RL
  subgraph t["TAPPaaS · codeberg"]
    stable["stable"]
    main["main"]
  end
  subgraph c["Community · codeberg"]
    cm["main"]
  end
  subgraph f["forgejo.makerfloss.eu"]
    fm["main"]
  end
  subgraph inst["Our TAPPaaS · tappaas-cicd"]
    lt["clone of TAPPaaS"]
    lc["clone of Community"]
    lf["clone of MakerFLOSS"]
  end
  lt -->|pull| main
  lc -->|pull| cm
  lf -->|pull| fm
  classDef tracked stroke:#ff8a80,stroke-width:3px
  class main tracked
```

We track **`main`**, not `stable` — this is a lab, we want the new things.

---

## A module is a contract and three scripts

```text
podman/
├── podman.json     # the contract — what it is, needs, provides
├── install.sh      # put the software in the VM        (once)
├── update.sh       # keep it patched                   (on schedule)
├── test.sh         # prove it still works              (gates updates)
├── README.md       # what it is
└── INSTALL.md      # what automation cannot do for you
```

That is the whole surface. Everything else is the platform's job.

---

## The contract, for real

```json
{
  "description": "Podman container host — Debian 13 VM with rootless Podman + Cockpit",
  "vmname": "podman", "vmid": 812,
  "dependsOn": ["cluster:vm", "templates:debian", "backup:vm",
                "network:proxy", "identity:accessControl"],
  "config": {
    "cluster:vm": { "cores": 2, "memory": "2048", "diskSize": "20G",
                    "image": "debian-13-generic-amd64.qcow2" },
    "network:proxy": { "proxyPort": 9090, "proxyUpstreamTls": true,
                       "proxyUpstreamHttp1": true, "proxyAllowedZones": ["mgmt"] }
  }
}
```

`dependsOn` is the whole trick: five services, declared — not scripted.

---

## `install.sh` — called once, at add

```bash
#!/usr/bin/env bash
set -euo pipefail
SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
exec "${SCRIPT_DIR}/update.sh" "$@"
```

By the time it runs, `cluster:vm` has built the VM and `templates:debian` has
apt-upgraded it and installed the guest agent.

For podman there is nothing install-only — **install *is* update**. Five lines is a
perfectly good `install.sh`.

---

## `update.sh` — where the work is

Runs on the **mothership**, not on the VM. It:

1. finds the node hosting the VM via `pvesh` — HA-safe, the VM may have moved
2. resolves the VM's IP through the **Proxmox guest agent**, then waits for SSH
3. `apt-get install podman podman-compose slirp4netns uidmap cockpit cockpit-podman`
4. enables the **rootless** `podman.socket`, `loginctl enable-linger`, `cockpit.socket`
5. records `/etc/tappaas-podman.version`
6. polls `https://localhost:9090` until the console answers, then prints the URL

Every step is re-runnable: apt is a no-op when current, the marker is overwritten,
the sockets are `enable --now`. That is what "idempotent" has to mean in practice.

---

## `test.sh` — the one that earns trust

| Check | How |
| --- | --- |
| VM reachable | IP resolves via the guest agent |
| podman installed | version marker + `podman --version` actually runs |
| plugin present | `dpkg -s cockpit-podman` |
| console alive | `:9090` answers `200`, `302`, `401` or `403` |

A login page **is** a pass — pre-auth, `401` is the healthy answer.

Prints `N passed, M failed` and exits non-zero on any failure. Note `curl -s`, not
`--fail`: `--fail` exits 22 on 4xx and would corrupt the `-w '%{http_code}'` we read.

Run on demand, and again before every update is merged. If `test.sh` is honest,
unattended updates are safe — that is the entire deal.

---

## What you did not have to write

- A VM — `cluster:vm` built it from the Debian 13 cloud image
- OS prep — `templates:debian` did apt + guest agent
- A VLAN, an interface, DHCP, firewall rules — the zone came with the environment
- `https://podman.lab1.makerfloss.eu` with a real certificate — `network:proxy`
- An access gate — `identity:accessControl`: only the bound groups reach the URL
- Nightly backup to PBS, scheduled updates, health reporting

A few lines of json bought all of it.

---

## Demo 1 — an environment of our own

```bash
network-manager zone add lab1 --from-zone srv
network-manager show lab1              # vlan tag, subnet, access-to
network-manager reconcile              # dry-run: drift on all 4 planes
network-manager reconcile --apply      # converge OPNsense, Proxmox, switch, AP

environment-manager add lab1 --display "MakerFLOSS lab" \
    --zone lab1 --domain lab1.makerfloss.eu
environment-manager list
environment-manager show lab1
```

A tenant with its own VLAN, firewall posture and DNS names —
`lab1.makerfloss.eu` outside, `lab1.internal` inside.

<!-- Show zones.json before/after, and the OPNsense interface appearing. -->

---

## Demo 2 — install the module

```bash
module-manager module add podman --environment lab1

module-manager module list             # what is deployed
module-manager module show podman      # the resolved config, cascade applied
```

Watch the order: dependencies resolve first, then the VM, then the network, then
`install.sh`. Install order is **computed** from every module's `dependsOn` — nobody
maintains a list.

<!-- Expect a few minutes. Good moment for questions. -->

---

## Demo 3 — prove it, then look at it

```bash
module-manager module test podman
```

Then open **`https://podman.lab1.makerfloss.eu`** — Cockpit, with the Podman page.

- Reachable from the `mgmt` zone only. Not from the internet, by declaration.
- Authentik gates the URL: no `devops` group, no console. Then Cockpit asks *again* —
  it is not an OIDC client, and a local Unix account is not optional for it.
- Two logins, honestly. `DESIGN.md` in the repo says what it would take to fix.

---

## Where this module lives

```text
Community/src/larsrossen/containers/podman/
```

Three homes for a module, all first-class:

| Home | For |
| --- | --- |
| **TAPPaaS** repo, by pull request | modules the whole project should carry |
| **Community** repo | yours, shared, no gatekeeping — today's podman |
| **Private** repo — e.g. `forgejo.makerfloss.eu` | yours, not shared |

Adding a repository is one `site-manager repository add`.

---

## Your turn — identity on this TAPPaaS

```bash
people-manager user add <you> --email <you>@example.org \
    --roles user --groups devops
people-manager reconcile          # preview
people-manager reconcile --apply  # push to Authentik

authentik-manager user-recovery-link <you>   # one-time URL: set your own password
```

One login per person, roles via groups. Nobody types a password into a chat window.

<!-- Do these live, one per participant, while the podman VM builds. -->

---

## Take it further

- **Develop a module** — tappaas.org/generated/develop-a-module
- **Every json field** — tappaas.org/generated/schemas
- **Zones and the access model** — tappaas.org/generated/zones
- **Repository topology** — tappaas.org/generated/design/cicd-git
- **This deck** — slides.makerfloss.eu/tappaas/how-to/new-module

Pick an app you want on a sovereign box. Open an issue first — someone may already
be packaging it.