
pgserver control
****************

>>> from lovely.testlayers import pgsql
>>> import tempfile, os
>>> tmp = tempfile.mkdtemp()
>>> dbDir = os.path.join(tmp, 'db')
>>> dbDirFake = os.path.join(tmp, 'dbfake')

>>> dbName = 'testing'

Let us create a postgres server. Note that we give the absolute path
to the pg_config executable in order to use the postgresql
installation from this project.

>>> pgConfig = project_path('parts', 'postgres', 'bin', 'pg_config')
>>> srv = pgsql.Server(dbDir, port=16666, pgConfig=pgConfig, verbose=True)

Optional we could also define a path to a special postgresql.conf file
to use, otherwise defaults are used.

>>> srv.postgresqlConf
'/.../lovely/testlayers/postgresql8....conf'

>>> srvFake = pgsql.Server(dbDirFake, postgresqlConf=srv.postgresqlConf)
>>> srvFake.postgresqlConf == srv.postgresqlConf
True

The path needs to exist.

>>> pgsql.Server(dbDirFake, postgresqlConf='/not/existing/path')
Traceback (most recent call last):
...
ValueError: postgresqlConf not found '/not/existing/path'

We can also specify the pg_config executable which defaults to
'pg_config' and therefore needs to be in the path.

>>> srv.pgConfig
'/.../pg_config'

>>> pgsql.Server(dbDirFake, pgConfig='notexistingcommand')
Traceback (most recent call last):
...
ValueError: pgConfig not found 'notexistingcommand'

The server is aware of its version, which is represented as a tuple of
ints.

>>> srv.pgVersion
(8, ..., ...)

And init the db.

>>> srv.initDB()
>>> srv.start()

>>> srv.createDB(dbName)

Now we can get a list of databases.

>>> sorted(srv.listDatabases())
['postgres', 'template0', 'template1', 'testing']


Run SQL scripts
===============

We can run scripts from the filesystem.

>>> script = os.path.join(tmp, 'ascript.sql')
>>> f = file(script, 'w')
>>> f.write("""create table a (title varchar);""")
>>> f.close()
>>> srv.runScripts(dbName, [script])

Or from the shared directories by prefixing it with pg_config. So let
us install tsearch2.

>>> script = 'pg_config:share:system_views.sql'
>>> srv.runScripts(dbName, [script])


Dump and Restore
================

Let us make a dump of our database

>>> dumpA = os.path.join(tmp, 'a.sql')
>>> srv.dump(dbName, dumpA)

And now some changes

>>> import psycopg2
>>> cs = "dbname='%s' host='127.0.0.1' port='16666'" % dbName
>>> conn = psycopg2.connect(cs)
>>> cur = conn.cursor()

>>> for i in range(5):
...     cur.execute('insert into a values(%i)' % i)
>>> conn.commit()

>>> cur.close()
>>> conn.close()

Another dump.

>>> dumpB = os.path.join(tmp, 'b.sql')
>>> srv.dump(dbName, dumpB)

We restore dumpA and the table is emtpy.

>>> srv.restore(dbName, dumpA)

>>> conn = psycopg2.connect(cs)
>>> cur = conn.cursor()

>>> cur.execute('select count(*) from a')
>>> cur.fetchone()
(0L,)

>>> cur.close()
>>> conn.close()

Now restore dumpB and we have our 5 rows back.

>>> srv.restore(dbName, dumpB)

>>> conn = psycopg2.connect(cs)
>>> cur = conn.cursor()

>>> cur.execute('select count(*) from a')
>>> cur.fetchone()
(5L,)

>>> cur.close()
>>> conn.close()

If we try to restore a none existing file we gat a ValueError.

>>> srv.restore(dbName, 'asdf')
Traceback (most recent call last):
...
ValueError: No such file '.../asdf'

>>> srv.stop()


PGDB Scripts
============

We can generate a control script for use as commandline script.

The simplest script is just to define a server.

>>> dbDir2 = os.path.join(tmp, 'db2')
>>> main = pgsql.PGDBScript(dbDir2, port=16666, pgConfig=pgConfig)
>>> main.start()
>>> sorted(main.srv.listDatabases())
['postgres', 'template0', 'template1']
>>> main.stop()

We can also define a database to be created upon startup.

>>> main = pgsql.PGDBScript(dbDir2,
...                         pgConfig=pgConfig,
...                         dbName='hoschi', port=16666)
>>> main.start()
>>> sorted(main.srv.listDatabases())
['hoschi', 'postgres', 'template0', 'template1']
>>> main.stop()

The database is created only one time.

>>> main.start()
>>> main.stop()

And also scripts to be executed.

>>> main = pgsql.PGDBScript(dbDir2, dbName='hoschi2',
...                         pgConfig=pgConfig,
...                         scripts=[script], port=16666)
>>> main.start()

Note that we used the same directory here so the other db is still
there.

>>> sorted(main.srv.listDatabases())
['hoschi', 'hoschi2', 'postgres', 'template0', 'template1']

We can run the scripts again. Note that scripts should always be none-
destructive. So if a schema update is due one just needs to run all
scripts again.

>>> main.runscripts()

>>> main.stop()

Finally do some cleanup:

   >>> import shutil
   >>> shutil.rmtree(tmp)


PGDatabaseLayer
===============

Let's create a layer:

   >>> layer = pgsql.PGDatabaseLayer('testing', pgConfig=pgConfig)

We can get the store uri.

>>> layer.storeURI()
'postgres://localhost:15432/testing'

>>> layer.setUp()
>>> layer.tearDown()

The second time the server ist started it takes the snapshot.

>>> layer.setUp()
>>> layer.tearDown()

If we try to run setup twice or the port is occupied, we get an error.

>>> layer.setUp()
>>> layer.setUp()
Traceback (most recent call last):
...
RuntimeError: Port already listening: 15432
>>> layer.tearDown()

We can have appsetup definitions and sql scripts.  There is also a
convinience class that let's us execute sql statements as setup.

>>> setup = pgsql.ExecuteSQL('create table testing (title varchar)')
>>> layer = pgsql.PGDatabaseLayer('testing', setup=setup, pgConfig=pgConfig)
>>> layer.setUp()
>>> layer.tearDown()
>>> layer = pgsql.PGDatabaseLayer('testing', setup=setup, pgConfig=pgConfig)
>>> layer.setUp()
>>> layer.tearDown()

Also if the database name is different, the same snapshots can be
used.

>>> layer2 = pgsql.PGDatabaseLayer('testing2', setup=setup, pgConfig=pgConfig)
>>> layer2.setUp()
>>> layer2.tearDown()

If we do not provide the snapsotIdent the ident is built by using the
dotted name of the setup callable and the hash of the arguments.

>>> layer.snapshotIdent
u'lovely.testlayers.pgsql.ExecuteSQLf9bb47b1baeff8d57f8f0dadfc91b99a3ee56991'

Let us provide an ident and scripts.

>>> layer = pgsql.PGDatabaseLayer('testing3', setup=setup,
...                               pgConfig=pgConfig,
...                               snapshotIdent='blah',
...                               scripts=['pg_config:share:system_views.sql'])
>>> layer.snapshotIdent
'blah'
>>> layer.scripts
['pg_config:share:system_views.sql']

On setup the snapshot with the setup is created, therefore setup is
called with the server as argument.

>>> layer.setUp()

Upon testSetUp this snapshot is now restored.

>>> layer.testSetUp()

So now we should have the table there.

>>> cs = "dbname='testing3' host='127.0.0.1' port='15432'"
>>> conn = psycopg2.connect(cs)
>>> cur = conn.cursor()

>>> cur.execute('select * from testing')
>>> cur.fetchall()
[]

>>> cur.close()
>>> conn.close()

Let us add some data (we are now in a test):

>>> conn = psycopg2.connect(cs)
>>> cur = conn.cursor()

>>> cur.execute("insert into testing values('hoschi')")
>>> conn.commit()

>>> cur.execute('select * from testing')
>>> cur.fetchall()
[('hoschi',)]

>>> cur.close()
>>> conn.close()

>>> layer.testTearDown()

Now the next test comes.

>>> layer.testSetUp()

Make sure we can abort a transaction. The storm synch needs to be
removed at this time.

>>> import transaction
>>> transaction.abort()

And the data is gone but the table is still there.

>>> conn = psycopg2.connect(cs)
>>> cur = conn.cursor()

>>> cur.execute('select * from testing')
>>> cur.fetchall()
[]

>>> cur.close()
>>> conn.close()

>>> layer.tearDown()
