Declare the forge-account provision, its provider bundle, its fact and the keys it reads (issue 955 F4)

modules/gitea/README.md

@@ -221,3 +221,15 @@ whenever the tools' account is set up, with the administrator's login (`GiteaAdm
 account is no repository's administrator, so no tool can. A rule found keeps the statuses it requires; a repository
 with none is given one that requires none. `judgeProtectionChange` refuses, for `main`, a change that enables
 push, drops the merge whitelist or widens it past that account.
+
+## The forge account for git over ssh (novox/hq ADR 0399, ADR 0400, issue 955)
+
+Gitea provides `forge-account`, and `cmd/forge-account-provider` answers its consumers (the `ssh-client` of each
+machine). The provision has no credential: a public key is no secret. For a machine whose ssh-client has reported its
+key in the state `keys` (read, `ssh-client.keys`), the provider makes the account `agent-<node>` in the agents team
+(`internal/forgeaccount`, the code `cmd/agent-token` shares), registers the key under the title `mesh:<node>.<account>`,
+and serves the entry values `user`, `ssh_host` (the forge machine's mesh name, from the fact `forge-host`), `ssh_port`,
+`known_host` (read from the forge's own sshd with `ssh-keyscan`), `ssh_base` and `https_base`. A machine that has
+reported no key gets no entry, and its client says it waits. Keys titled `mesh:` that are no longer wanted are removed,
+a key added by hand never is. Every consumer is made again every ten minutes and at once when a key changes.
+`go test ./cmd/forge-account-provider ./internal/forgeaccount` runs it against a fake forge.

modules/gitea/files/consumers.json

@@ -0,0 +1 @@
+${consumers:forge-account}

modules/gitea/module.json

@@ -177,6 +177,12 @@
       "default": "mesh-tools mesh-admin jschoubben"
     }
   },
+  "facts": {
+    "forge-host": {
+      "path": "/etc/gitea/forge-host",
+      "template": "{{range .Machines}}{{if eq .Name $.Node}}{{.FQDN}}{{end}}{{end}}\n"
+    }
+  },
   "resources": [
     {
       "id": "mesh-state",
@@ -313,6 +319,13 @@
         "agent-read-teams"
       ]
     },
+    {
+      "id": "consumers",
+      "type": "file",
+      "path": "${dir:state}/consumers.json",
+      "mode": "0600",
+      "template": "files/consumers.json"
+    },
     {
       "id": "agent-teams",
       "type": "process",
@@ -353,6 +366,10 @@
         "issued-by": "software",
         "tool": "gitea_agent_token"
       }
+    },
+    {
+      "name": "forge-account",
+      "scope": "mesh"
     }
   ],
   "build": {
@@ -451,6 +468,25 @@
         "loads": [
           "agent-teams"
         ]
+      },
+      {
+        "name": "forge-account-provider",
+        "kind": "bundle",
+        "language": "go",
+        "system": "arch",
+        "from": "cmd/forge-account-provider",
+        "binary": "forge-account-provider",
+        "loads": [
+          "forge-account-provider"
+        ],
+        "env": {
+          "MESH_GITEA_URL": "http://127.0.0.1:${port:3000}",
+          "MESH_GITEA_ADMIN_USER": "mesh-admin",
+          "MESH_GITEA_ADMIN_PASSWORD_FILE": "${dir:state}/admin.secret",
+          "MESH_GITEA_ORIGINS_FILE": "${dir:mesh-state}/origins",
+          "MESH_GITEA_SSH_PORT": "222",
+          "MESH_FORGE_HOST_FILE": "/etc/gitea/forge-host"
+        }
       }
     ]
   },
@@ -460,5 +496,11 @@
       "failregex": "^.*Failed authentication attempt for .* from <HOST>(?::\\d+)?\\s*$\n            ^.*Invalid user .* from <HOST> port \\d+\\s*$\n            ^.*User \\S+ from <HOST> not allowed because .*$",
       "jail": "backend = systemd\njournalmatch = CONTAINER_NAME=gitea\nport = http,https,222\nmaxretry = 3\nfindtime = 1d\nbantime = 1d"
     }
+  ],
+  "state": [
+    "bound"
+  ],
+  "reads": [
+    "ssh-client.keys"
   ]
 }