Implement deleted flag for codespaces

If we are to ascertain which *currently active* codespaces are at risk of
deletion (due to 30d lifespan), we need to know the status of current and
past codespaces.

When deleted, a codespace's record is no long returned by the GitHub API
so we can assume that all codespaces that are not listed in the API response
are no longer in existence.

metrics/github/github.py

@@ -117,6 +117,7 @@ class Codespace:
     last_used_at: datetime.datetime
     has_uncommitted_changes: bool
     has_unpushed_changes: bool
+    deleted: bool
 
     @classmethod
     def from_dict(cls, data, org):
@@ -128,6 +129,7 @@ def from_dict(cls, data, org):
             last_used_at=data["last_used_at"],
             has_uncommitted_changes=data["git_status"]["has_uncommitted_changes"],
             has_unpushed_changes=data["git_status"]["has_unpushed_changes"],
+            deleted=False,
         )
 
 

metrics/github/metrics.py

@@ -87,6 +87,7 @@ def convert_codespaces_to_dicts(codespaces):
             "last_used_at": c.last_used_at,
             "has_uncommitted_changes": c.has_uncommitted_changes,
             "has_unpushed_changes": c.has_unpushed_changes,
+            "deleted": c.deleted,
         }
         for c in codespaces
     ]

metrics/tasks/codespaces.py

@@ -15,6 +15,12 @@ def main():
     codespaces = github.codespaces(org="opensafely")
     log.info(f"Got {len(codespaces)} codespaces")
 
+    log.info("Flagging old codespaces as deleted")
+    db.flag_deleted(tables.GitHubCodespaces)
+    log.info("Deletes flagged")
+
+    # Incoming data has deleted=False so previously flagged rows will be overwritten
+    # if codespace still exists.
     log.info("Writing data")
     db.upsert(tables.GitHubCodespaces, convert_codespaces_to_dicts(codespaces))
     log.info("Written data")

metrics/timescaledb/db.py

@@ -2,7 +2,7 @@
 import os
 
 import structlog
-from sqlalchemy import MetaData, create_engine, inspect, schema, text
+from sqlalchemy import Boolean, MetaData, create_engine, inspect, schema, text
 from sqlalchemy.dialects.postgresql import insert
 from sqlalchemy.engine import make_url
 
@@ -65,6 +65,17 @@ def upsert(table, rows):
             log.info("Inserted %s rows", len(values), table=table.name)
 
 
+def flag_deleted(table):
+    if "deleted" not in table.columns or not isinstance(
+        table.columns["deleted"].type, Boolean
+    ):
+        raise AttributeError("Table must have deleted column of boolean type")
+    with _get_engine().begin() as connection:
+        _ensure_table(connection, table)
+        update = table.update().values(deleted=True)
+        connection.execute(update)
+
+
 def _batch_size(table):
     max_params = 65535  # limit for postgresql
     return max_params // len(table.columns)

metrics/timescaledb/tables.py

@@ -14,6 +14,7 @@
     Column("last_used_at", TIMESTAMP(timezone=True)),
     Column("has_uncommitted_changes", Boolean),
     Column("has_unpushed_changes", Boolean),
+    Column("deleted", Boolean),
 )
 
 GitHubRepos = Table(

tests/metrics/timescaledb/test_db.py

@@ -3,6 +3,7 @@
 import pytest
 from sqlalchemy import (
     TIMESTAMP,
+    Boolean,
     Column,
     Integer,
     MetaData,
@@ -216,6 +217,27 @@ def test_write(engine, table):
     assert len(rows) == 3
 
 
+def test_flag_deleted(engine, table):
+    table.append_column(Column("deleted", Boolean))
+    # insert initial rows
+    with engine.begin() as connection:
+        db._ensure_table(connection, table)
+
+    with engine.begin() as connection:
+        rows = [
+            {
+                "value": "write" + str(i),
+                "deleted": False,
+            }
+            for i in range(1, 4)
+        ]
+        db.write(table, rows)
+        db.flag_deleted(table)
+
+    rows = get_rows(engine, table)
+    assert all(r[1] for r in rows)
+
+
 def test_upsert(engine, table):
     # add a non-PK column to the table
     table.append_column(Column("value2", Text))