Automatically detect whether we should run the postgres tests (#114)

This makes the developer experience smoother and will increase our
test coverage for Postgres. Also ensure that we keep testing without
Postgres installed, to ensure we don't start depending on Postgres
being present on the client side.

Finally, fix the Postgres-specific test that was failing due to the
--xlogdir argument of `postgres` having been renamed.

Author: ldionne

.github/workflows/tox.yaml

@@ -7,10 +7,12 @@ on:
 jobs:
   build:
     runs-on: ubuntu-latest
+    name: "Python ${{ matrix.python-version }}, Postgres=${{ matrix.with-postgres }}"
 
     strategy:
       matrix:
         python-version: ["3.10", "3.11", "3.12", "3.13", "3.14"]
+        with-postgres: [true, false]
       fail-fast: false
 
     steps:
@@ -25,6 +27,11 @@ jobs:
       run: |
         python -m pip install --upgrade pip
         pip install tox tox-gh-actions
+    - name: Install PostgreSQL
+      if: ${{ matrix.with-postgres }}
+      uses: tj-actions/install-postgresql@v3
+      with:
+        postgresql-version: 17
     - name: Tox flake8
       run: tox -e flake8
     - name: Tox docs

docs/developer_guide.rst

@@ -51,12 +51,6 @@ Optional Tests
 Some tests require additional tools to be installed and are not enabled by
 default. You can enable them by passing additional flags to ``lit``:
 
-  ``-Dpostgres=1``
-    Enable postgres database support testing. This requires at least
-    postgres version 9.2 and the ``initdb`` and ``postgres`` binaries in your path.
-    Note that you do not need to setup an actual server, the tests will create
-    temporary instances on demand.
-
   ``-Dmysql=1``
     Enable mysql database support testing. This requires MySQL-python to be
     installed and expects the ``mysqld`` and ``mysqladmin`` binaries in your path.
@@ -74,7 +68,7 @@ default. You can enable them by passing additional flags to ``lit``:
 
 Example::
 
-    lit -sv -Dpostgres=1 -Dmysql=1 -Dtidylib=1 ./tests
+    lit -sv -Dmysql=1 -Dtidylib=1 ./tests
 
 Publishing a new version of LNT
 -------------------------------

pyproject.toml

@@ -66,7 +66,9 @@ dev = [
     "filecheck",
     "Flake8-pyproject",
     "flake8",
+    "gunicorn>=19.9.0",
     "lit",
+    "psycopg2>=2.9.0",
     "tox",
     "twine",
 ]
@@ -120,7 +122,7 @@ allowlist_externals = ["rm", "lit"]
 deps = [".[dev]"]
 commands = [
     ["rm", "-rf", "test_run_tmp"],
-    ["lit", "-sv", "tests"],
+    ["lit", "-sv", "--show-unsupported", "tests"],
 ]
 
 [tool.tox.env.flake8]

tests/SharedInputs/postgres_wrapper.sh

@@ -1,4 +1,4 @@
-#!/bin/sh
+#!/usr/bin/env bash
 # Setup minimalistic postgres instance in specified directory, start a server,
 # run the given command and shutdown the server. Use
 # `postgresql://pgtest@localhost:9100` to connect to the server.
@@ -10,7 +10,7 @@
 set -u
 TEST_DIR=$1
 shift
-DB_DIR="$(mktemp -d -t lnt)"
+DB_DIR="$(mktemp -d -t lnt.XXXXX)"
 if [ -d "${TEST_DIR}" ]; then
     echo 1>&2 "${TEST_DIR} already exists"
     exit 1
@@ -19,15 +19,17 @@ fi
 mkdir -p "${TEST_DIR}"
 ln -s ${TEST_DIR}/db_root ${DB_DIR}
 
+INITDB_FLAGS=""
 INITDB_FLAGS+=" --pgdata=${DB_DIR}/db"
-INITDB_FLAGS+=" --xlogdir=${DB_DIR}/db"
+INITDB_FLAGS+=" --waldir=${DB_DIR}/db"
 INITDB_FLAGS+=" --nosync"
 INITDB_FLAGS+=" --no-locale"
 INITDB_FLAGS+=" --auth=trust"
 INITDB_FLAGS+=" --username=pgtest"
 echo "$ initdb $INITDB_FLAGS >& ${DB_DIR}/initdb_log.txt"
 initdb ${INITDB_FLAGS} >& ${DB_DIR}/initdb_log.txt
 
+POSTGRES_FLAGS=""
 POSTGRES_FLAGS+=" -p 9100"
 POSTGRES_FLAGS+=" -D ${DB_DIR}/db"
 POSTGRES_FLAGS+=" -k ${DB_DIR}/db"
@@ -49,4 +51,3 @@ kill -15 ${PG_PID}
 wait ${PG_PID}
 [ ${RC} -ne 0 ] && (rm -rf ${DB_DIR})
 exit ${RC}
-

tests/lit.cfg

@@ -2,7 +2,7 @@
 
 import os
 import platform
-import glob
+import shutil
 
 import lit.formats
 import lit.util
@@ -46,9 +46,11 @@ config.substitutions.append(('%{test_exec_root}', config.test_exec_root))
 if lit_config.params.get('long', None):
     config.available_features.add('long')
 
-# Enable postgres testing. This requires postgres binaries in PATH.
-# (You do not need to start a server, the tests will create ad-hoc instances).
-if lit_config.params.get('postgres', None):
+# Enable postgres database support testing if the postgres binary can be found.
+# Note that you do not need to setup an actual server, the tests will create
+# temporary instances on demand.
+postgres = shutil.which('postgres')
+if postgres is not None:
     config.available_features.add('postgres')
 
 # Enable MySQL testing. This requires mysqld and mysqladmin binaries in PATH.

tests/lnttool/PostgresDB.shtest

@@ -1,6 +1,6 @@
 # REQUIRES: postgres
 # RUN: rm -rf "%t.install"
-# RUN: %{shared_inputs}/postgres_wrapper.sh "%t.install" /bin/sh %s "%t.install" postgresql://pgtest@localhost:9100 "%{shared_inputs}"
+# RUN: %{shared_inputs}/postgres_wrapper.sh "%t.install" bash %s "%t.install" postgresql://pgtest@localhost:9100 "%{shared_inputs}"
 set -eux
 
 TESTDIR="$1"