main: add basic support for repo + worker (bug 1865907) (#5)

- add Repo and Worker models
- add basic support commands
- add method to initialize repo in filesystem

src/lando/lando/settings.py

@@ -132,6 +132,8 @@
 MEDIA_URL = "media/"
 MEDIA_ROOT = "/mediafiles"
 
+REPO_ROOT = f"{MEDIA_ROOT}/repos"
+
 
 # Default primary key field type
 # https://docs.djangoproject.com/en/dev/ref/settings/#default-auto-field

src/lando/main/migrations/0002_repo_worker.py

@@ -0,0 +1,66 @@
+# Generated by Django 5.0b1 on 2023-11-23 19:56
+
+import django.db.models.deletion
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+    dependencies = [
+        ("main", "0001_initial"),
+    ]
+
+    operations = [
+        migrations.CreateModel(
+            name="Repo",
+            fields=[
+                (
+                    "basemodel_ptr",
+                    models.OneToOneField(
+                        auto_created=True,
+                        on_delete=django.db.models.deletion.CASCADE,
+                        parent_link=True,
+                        primary_key=True,
+                        serialize=False,
+                        to="main.basemodel",
+                    ),
+                ),
+                ("name", models.CharField(max_length=255, unique=True)),
+                ("default_branch", models.CharField(default="main", max_length=255)),
+                ("url", models.CharField(max_length=255)),
+                ("push_path", models.CharField(max_length=255)),
+                ("pull_path", models.CharField(max_length=255)),
+                ("is_initialized", models.BooleanField(default=False)),
+                (
+                    "system_path",
+                    models.FilePathField(
+                        allow_folders=True, max_length=255, path="/mediafiles/repos"
+                    ),
+                ),
+            ],
+            bases=("main.basemodel",),
+        ),
+        migrations.CreateModel(
+            name="Worker",
+            fields=[
+                (
+                    "basemodel_ptr",
+                    models.OneToOneField(
+                        auto_created=True,
+                        on_delete=django.db.models.deletion.CASCADE,
+                        parent_link=True,
+                        primary_key=True,
+                        serialize=False,
+                        to="main.basemodel",
+                    ),
+                ),
+                ("name", models.CharField(max_length=255, unique=True)),
+                ("is_paused", models.BooleanField(default=False)),
+                ("is_stopped", models.BooleanField(default=False)),
+                ("ssh_private_key", models.TextField(blank=True, null=True)),
+                ("throttle_seconds", models.IntegerField(default=10)),
+                ("sleep_seconds", models.IntegerField(default=10)),
+                ("applicable_repos", models.ManyToManyField(to="main.repo")),
+            ],
+            bases=("main.basemodel",),
+        ),
+    ]

src/lando/main/models.py

@@ -3,6 +3,8 @@
 import datetime
 import logging
 import os
+import subprocess
+from pathlib import Path
 from typing import (
     Any,
     Iterable,
@@ -13,6 +15,7 @@
 from django.db.models import QuerySet
 from django.utils.translation import gettext_lazy
 
+from lando import settings
 from lando.utils import build_patch_for_revision
 
 logger = logging.getLogger(__name__)
@@ -179,3 +182,53 @@ def add_job_with_revisions(revisions: list[Revision], **params: Any) -> LandingJ
     for revision in revisions:
         job.revisions.add(revision)
     return job
+
+
+class Repo(BaseModel):
+    name = models.CharField(max_length=255, unique=True)
+    default_branch = models.CharField(max_length=255, default="main")
+    url = models.CharField(max_length=255)
+    push_path = models.CharField(max_length=255)
+    pull_path = models.CharField(max_length=255)
+    is_initialized = models.BooleanField(default=False)
+
+    system_path = models.FilePathField(
+        path=settings.REPO_ROOT, max_length=255, allow_folders=True
+    )
+
+    def _run(self, *args, cwd=None):
+        cwd = cwd or self.system_path
+        command = ["git"] + list(args)
+        result = subprocess.run(command, cwd=cwd)
+        return result
+
+    def initialize(self):
+        if self.is_initialized:
+            raise
+
+        self.system_path = str(Path(settings.REPO_ROOT) / self.name)
+        self.save()
+        result = self._run("clone", self.pull_path, self.name, cwd=settings.REPO_ROOT)
+        if result.returncode == 0:
+            self.is_initialized = True
+        else:
+            raise Exception(result.returncode)
+        self.save()
+
+    def update(self):
+        self._run("pull", "--all", "--prune")
+
+    def reset(self, branch=None):
+        self._run("reset", "--hard", branch or self.default_branch)
+        self._run("clean", "--force")
+
+
+class Worker(BaseModel):
+    name = models.CharField(max_length=255, unique=True)
+    is_paused = models.BooleanField(default=False)
+    is_stopped = models.BooleanField(default=False)
+    ssh_private_key = models.TextField(null=True, blank=True)
+    applicable_repos = models.ManyToManyField(Repo)
+
+    throttle_seconds = models.IntegerField(default=10)
+    sleep_seconds = models.IntegerField(default=10)