Federated via graft
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248 lines
1# Tutorial
2
3This walks through mirroring one repository between a Forgejo instance and a Radicle node, from nothing. Replace the names below with your own:
4
5| Placeholder | Stands for |
6|---|---|
7| `git.example.org` | your Forgejo instance |
8| `seed.example.org` | your Radicle node's `radicle-httpd` address |
9| `alice` | the Forgejo account that owns the repo |
10| `my-project` | the repository |
11
12## Prerequisites
13
14- A Forgejo instance you can create repos and tokens on.
15- A machine with `git`, the `rad` CLI, and a running `radicle-node` — see [Radicle's own seeder guide](https://radicle.dev/guides/seeder) if you don't have one yet.
16- Go 1.23+, to build `graft`.
17
18## 1. Build graft
19
20```sh
21git clone https://git.example.org/alice/graft.git
22cd graft
23go build -o graft ./cmd/sync
24sudo mv graft /usr/local/bin/graft
25```
26
27## 2. Create a Forgejo token
28
29`graft` needs a token scoped to `write:repository` and `write:issue` on the repo it syncs.
30
31```sh
32curl -X POST -H "Authorization: token $ADMIN_TOKEN" \
33 -H "Content-Type: application/json" \
34 -d '{"name":"graft","scopes":["write:repository","write:issue"]}' \
35 https://git.example.org/api/v1/users/alice/tokens
36```
37
38Save the returned token somewhere `graft` can read and nowhere else can:
39
40```sh
41mkdir -p /etc/graft
42echo "$TOKEN" > /etc/graft/my-project.token
43chmod 600 /etc/graft/my-project.token
44chown graft:graft /etc/graft/my-project.token # the user graft actually runs as, not root
45```
46
47### Sharing a token safely
48
49`config.yaml` never holds the token itself, only `token_file`. `graft` requires `token_file` and rejects an inline value. Getting the token into that file is on you:
50
51- Scope it to `write:repository` + `write:issue`. Never admin or org-wide.
52- Never paste it into chat, email, or a ticket.
53- Prefer the token owner writing it directly into `/etc/graft/<name>.token` over their own SSH session — no third party involved.
54- If a third party must relay it, use a one-time-secret tool (Bitwarden Send, 1Password Psst, self-hosted `onetimesecret.com`), not a plain link.
55- Rotate it if its exposure is ever in doubt.
56
57See [Built-in token exchange](#built-in-token-exchange) — `graft` has a one-time secret-share page for this.
58
59## 3. Create the repo on Forgejo
60
61```sh
62curl -X POST -H "Authorization: token $TOKEN" \
63 -H "Content-Type: application/json" \
64 -d '{"name":"my-project","auto_init":true,"default_branch":"main"}' \
65 https://git.example.org/api/v1/user/repos
66```
67
68`auto_init` gives it one commit, so there's something to mirror.
69
70## 4. Create the repo on Radicle
71
72Radicle repos are created from an existing git checkout. Clone the one you just made and initialize it:
73
74```sh
75git clone https://git.example.org/alice/my-project.git
76cd my-project
77rad init --name my-project --default-branch main --public
78```
79
80This prints a Repository ID (RID), something like `rad:z3gqcJUoA1n9HaHKufZs5FCSGazv5`. Write it down — the config needs it.
81
82If you have other Radicle nodes that should also carry this repo, tell them to seed it:
83
84```sh
85rad seed rad:z3gqcJUoA1n9HaHKufZs5FCSGazv5
86```
87
88## 5. Write the config
89
90```yaml
91# /etc/graft/config.yaml
92sync_interval: 5m
93state_db: /var/lib/graft/state.db
94
95repos:
96 - name: my-project
97 forgejo:
98 base_url: https://git.example.org
99 owner: alice
100 repo: my-project
101 token_file: /etc/graft/my-project.token
102 radicle:
103 rid: rad:z3gqcJUoA1n9HaHKufZs5FCSGazv5
104 http_base_url: https://seed.example.org
105 rad_home: /home/graft/.radicle
106 sync:
107 git: true
108 issues: true
109 patches: true
110```
111
112`rad_home` is the `RAD_HOME` of the identity `graft` pushes as — usually a dedicated one, created with `rad auth` under whatever user runs `graft`.
113
114## 6. Run it once
115
116```sh
117mkdir -p /var/lib/graft
118graft -config /etc/graft/config.yaml -once
119```
120
121No output means no errors. Check both sides:
122
123```sh
124curl -s https://seed.example.org/api/v1/repos/rad:z3gqcJUoA1n9HaHKufZs5FCSGazv5
125```
126
127If you open an issue on the Forgejo repo and run `graft -once` again, it shows up on Radicle within that one pass.
128
129## 7. Run it as a service
130
131```sh
132sudo cp systemd/graft.service /etc/systemd/system/
133sudo systemctl daemon-reload
134sudo systemctl enable --now graft
135```
136
137It now mirrors both repos every `sync_interval`, in both directions, on its own.
138
139## Adding a peer to an existing federation
140
141Adding a second Forgejo instance to a repo already mirrored between one Forgejo and one Radicle node needs no new Radicle node and no change to the pairs already running.
142
143| Placeholder | Stands for |
144|---|---|
145| `git2.example.org` | the second Forgejo instance |
146| `bob` | the account on it that owns the mirrored repo |
147
148A Radicle RID replicates to every node that seeds it, independent of `graft`. Pointing a second pair's `radicle.http_base_url` at the same seed already in use doesn't create a new relationship — that seed already has the content. No Radicle-side step for this case.
149
1501. On `git2.example.org`, create the repo **without** `auto_init` (`auto_init: false` or omitted) and a token scoped `write:repository` + `write:issue`. `auto_init: true` gives the repo an unrelated first commit; `graft` sees that as a real divergence against the federation's existing history and refuses to push, logging "forgejo and rad diverged since last sync" (see Troubleshooting). An empty repo has no history to diverge from.
151
152 ```sh
153 echo "$TOKEN2" > /etc/graft/my-project-git2.token
154 chmod 600 /etc/graft/my-project-git2.token
155 chown graft:graft /etc/graft/my-project-git2.token
156 ```
157
1582. Add a second entry to `config.yaml`, under the same `series` as the first pair (defaults to the pair's own `name` if you never set one — give the *first* pair an explicit `series` too if you didn't already, so both land on the same row):
159
160 ```yaml
161 repos:
162 - name: my-project-git1
163 series: my-project # both pairs share this
164 forgejo:
165 base_url: https://git.example.org
166 owner: alice
167 repo: my-project
168 token_file: /etc/graft/my-project.token
169 radicle:
170 rid: rad:z3gqcJUoA1n9HaHKufZs5FCSGazv5
171 http_base_url: https://seed.example.org
172 rad_home: /home/graft/.radicle
173 sync: { git: true, issues: true, patches: true }
174
175 - name: my-project-git2
176 series: my-project # joins the same federation
177 forgejo:
178 base_url: https://git2.example.org
179 owner: bob
180 repo: my-project
181 token_file: /etc/graft/my-project-git2.token
182 radicle:
183 rid: rad:z3gqcJUoA1n9HaHKufZs5FCSGazv5 # same RID — not a new one
184 http_base_url: https://seed.example.org # same seed — not a new node
185 rad_home: /home/graft/.radicle # always graft's own, never the peer's
186 explorer_url: https://explorer.example.org
187 sync: { git: true, issues: true, patches: true }
188 ```
189
190 `rad_home` never changes between pairs — it's `graft`'s own local Radicle identity, the same one it pushes as for every pair it runs. Only the `forgejo` block is specific to the new peer.
191
1923. Restart: `sudo systemctl restart graft`. `config.Load` validates every field on startup — a typo surfaces immediately in the logs, not as a silent no-op.
193
1944. Confirm: the dashboard shows `git2.example.org` as a second row under `my-project`. A side with content but no direct push logged by `graft` shows colored cells instead of a normal commit/issue/patch cell — "source" (content originated here) or "replicated" (arrived via Radicle gossip or a Forgejo Authorized Integration, not a `graft`-logged push). Hover for date, origin, link.
195
196## Adding a brand-new Radicle node to the mesh
197
198Reusing an existing seed needs nothing extra. A node nobody in the mesh has talked to needs two manual steps — `graft`'s own Radicle node doesn't discover new peers on its own:
199
200```sh
201rad node connect <new-node-id>@<new-node-address>:8776
202rad seed rad:z3gqcJUoA1n9HaHKufZs5FCSGazv5
203```
204
205`rad node connect` is the first handshake — Radicle's peer discovery (`"peers": {"type": "dynamic"}` in `~/.radicle/config.json`) spreads pairs it already knows, but a never-connected node needs one explicit introduction. `rad seed` is separate: default seeding policy replicates nothing not explicitly told to. Skip either step and the node stays unreachable or empty.
206
207## Comments
208
209`graft` mirrors comments on issues and patches, both directions, from four origins:
210
211- **Forgejo → Radicle** and **Radicle → Forgejo**: native comments, polled and cross-mirrored each pass. Dedup is by content hash (`comment_seen` table) plus a `**via Forgejo:**` / `**via Radicle:**` prefix on the mirrored copy, so a mirrored comment is never mirrored back.
212- **ActivityPub**: a Mastodon reply to one of graft's posts becomes a comment, prefixed `**via Fediverse, @user:**`.
213- **AT Proto**: a Bluesky reply, same mechanism, prefixed `**via Bluesky, @handle:**`. Not verified against a live account — built from AT Proto's published lexicon (`app.bsky.notification.listNotifications`), but no Bluesky account existed to test against when this was written.
214
215Dashboard cells are colored by kind only (commit, issue, patch, comment) — never by origin. Origin shows up as a tooltip note only, on hover.
216
217## Troubleshooting
218
219**"token does not have at least one of required scope(s)"** — the Forgejo token is missing `write:issue` or `write:repository`. Regenerate it with both.
220
221**"forgejo and rad diverged since last sync"** — both sides got commits since the last pass that aren't ancestors of each other. `graft` won't guess which one wins; merge them by hand on either side and it'll pick up cleanly next pass.
222
223**"'remote-rad' is not a git command"** — `git-remote-rad` (installed alongside `rad`) isn't on `PATH` for the user running `graft`. Add its directory to the systemd unit's `Environment=PATH=...`.
224
225**A patch/PR never shows up on the other side** — check that the corresponding repo isn't still empty on the destination. The first git sync has to land before patches/issues referencing that content can be mirrored.
226
227## Self-service dashboard actions
228
229Two buttons next to the federation heatmap, plus a footer link, do the above through a browser:
230
231- **`+ Add peer`** (`/add-peer`) — join an existing series. Radicle side (RID, seed, explorer) is filled in from the chosen series, not asked for. Repo must exist on the peer, empty (no auto-init — see above). Submit Forgejo details, token, admin password. Live within one `sync_interval`.
232- **`+ New repo`** (`/new-repo`) — prerequisites listed inline (create the Forgejo repo, generate a scoped token, `rad init`, note the RID), then a form.
233- **`Share a secret, once`** (`/share/new`, footer) — the one-time-secret page below. Creating a share needs no password; claiming needs the passcode.
234
235Both onboarding forms check `admin_password` from `config.yaml` (default `graft`; `graft` logs a startup warning if unchanged). Constant-time comparison, rate-limited: 5 wrong attempts per IP or 20 total, per 15 minutes.
236
237## Built-in token exchange
238
239**Built**, reachable from the dashboard:
240
241- **One-time secret share.** `POST /share/new` encrypts the input with AES-256-GCM, keyed from a passcode and the share's own random id together. Only the id's hash is stored — a database dump alone can't derive the key. `GET/POST /share/<id>` claims it: right passcode reveals it once and deletes the record; 5 wrong passcodes deletes it too; 15 minutes unclaimed and it's gone.
242- **QR code.** `/share/<id>/qr.png` encodes the claim link only, not the passcode.
243
244**Not built:**
245
246- **Wormhole-style PAKE exchange** (the protocol behind [`magic-wormhole`](https://github.com/magic-wormhole/magic-wormhole)): both sides type the same short code into a CLI; the key exchange derives a shared secret without the code or the token crossing the wire in the clear. `graft`'s server never sees the plaintext token. Most to build — a relay endpoint for the handshake, shell access on both sides. Skipped: the share page above covers the same case at a fraction of the cost.
247
248- **Skip the handoff entirely.** If Forgejo exposes a delegated token-creation flow (peer admin clicks a link, logs into their own Forgejo, a token scoped to exactly `write:repository` + `write:issue` on exactly that repo is minted and handed to `graft` server-to-server), no plaintext secret touches a clipboard, a chat window, or a QR code. Depends on Forgejo's OAuth2/application-token APIs supporting delegated, scope-limited minting driven by a third party — unverified against a current Forgejo instance.