Database.Postgres.Temp.Internal.Core

This module provides the low level functionality for running initdb, postgres and createdb to make a database.

See startPlan for more details.

Documentation

data Event

Internal events for debugging

Since: 1.12.0.0

Constructors

StartPlan String

The first event. This useful for debugging what is actual passed to the initdb, createdb and postgres.

StartPostgres

The second event. Postgres is about to get called

WaitForDB

The third event. Postgres started. We are now about to setup a reconnect loop (racing with a process checker)

TryToConnect

The fourth event and (possibly all subsequent events). We are looping trying to successfully connect to the postgres process.

Instances

Eq Event

Defined in Database.Postgres.Temp.Internal.Core

Methods

(==) :: Event -> Event -> Bool

(/=) :: Event -> Event -> Bool

Ord Event

Defined in Database.Postgres.Temp.Internal.Core

Methods

compare :: Event -> Event -> Ordering

(<) :: Event -> Event -> Bool

(<=) :: Event -> Event -> Bool

(>) :: Event -> Event -> Bool

(>=) :: Event -> Event -> Bool

max :: Event -> Event -> Event

min :: Event -> Event -> Event

Show Event

Defined in Database.Postgres.Temp.Internal.Core

Methods

showsPrec :: Int -> Event -> ShowS

show :: Event -> String

showList :: [Event] -> ShowS

data StartError

A list of failures that can occur when starting. This is not and exhaustive list but covers the errors that the system catches for the user.

Since: 1.29.0.0

Constructors

StartPostgresFailed ExitCode

postgres failed before a connection succeeded. Most likely this is due to invalid configuration

InitDbFailed

initdb failed. This can be from invalid configuration or using a non-empty data directory

Fields

• startErrorStdOut :: String
• startErrorStdErr :: String
• startErrorExitCode :: ExitCode

CreateDbFailed

createdb failed. This can be from invalid configuration or the database might already exist.

Fields

• startErrorStdOut :: String
• startErrorStdErr :: String
• startErrorExitCode :: ExitCode

PlanFailed String [String]

The Plan was missing info and a complete Plan could not be created.

CompleteProcessConfigFailed String [String]

The ProcessConfig was missing info and a CompleteProcessConfig could not be created.

ConnectionTimedOut

Timed out waiting for postgres to accept a connection

DeleteDbError SqlError

EmptyDataDirectory

This will happen if a Plan is missing a initDbConfig.

CopyCachedInitDbFailed String ExitCode

This is called if copying a folder cache fails.

FailedToFindDataDirectory String

Failed to find a data directory when trying to get a cached initdb folder.

SnapshotCopyFailed String ExitCode

We tried to copy a data directory to a snapshot folder and it failed

Instances

Eq StartError

Defined in Database.Postgres.Temp.Internal.Core

Methods

(==) :: StartError -> StartError -> Bool

(/=) :: StartError -> StartError -> Bool

Show StartError

Defined in Database.Postgres.Temp.Internal.Core

Methods

showsPrec :: Int -> StartError -> ShowS

show :: StartError -> String

showList :: [StartError] -> ShowS

Exception StartError

Defined in Database.Postgres.Temp.Internal.Core

Methods

toException :: StartError -> SomeException

fromException :: SomeException -> Maybe StartError

displayException :: StartError -> String

type Logger = Event -> IO ()

A way to log internal Events

Since: 1.12.0.0

waitForDB :: Logger -> Options -> IO ()

postgres is not ready until we are able to successfully connect. waitForDB attempts to connect over and over again and returns after the first successful connection.

data CompleteProcessConfig

CompleteProcessConfig contains the configuration necessary for starting a process. It is essentially a stripped down CreateProcess.

Constructors

CompleteProcessConfig

Fields

• completeProcessConfigEnvVars :: [(String, String)]

  Environment variables

• completeProcessConfigCmdLine :: [String]

  Command line arguements

• completeProcessConfigStdIn :: Handle

  The Handle for standard input

• completeProcessConfigStdOut :: Handle

  The Handle for standard output

• completeProcessConfigStdErr :: Handle

  The Handle for standard error

Instances

Pretty CompleteProcessConfig

Defined in Database.Postgres.Temp.Internal.Core

Methods

pretty :: CompleteProcessConfig -> Doc

prettyList :: [CompleteProcessConfig] -> Doc

startProcess

Arguments

:: String

Process name

-> CompleteProcessConfig

Process config

-> IO ProcessHandle

Start a process interactively and return the ProcessHandle

stopProcess :: ProcessHandle -> IO ExitCode

Stop a ProcessHandle. An alias for waitForProcess

executeProcess

Arguments

:: String

Process name

-> CompleteProcessConfig

Process config

-> IO ExitCode

Start a process and block until it finishes return the ExitCode.

executeProcessAndTee

Arguments

:: String

Process name

-> CompleteProcessConfig

Process config

-> IO (ExitCode, String, String)

Start a process and block until it finishes return the ExitCode and the stderr output.

data CompletePostgresPlan

CompletePostgresPlan is used be startPostgresProcess to start the postgres and then attempt to connect to it.

Constructors

CompletePostgresPlan

Fields

• completePostgresPlanProcessConfig :: CompleteProcessConfig

  The process config for postgres

• completePostgresPlanClientOptions :: Options

  Connection options. Used to verify that postgres is ready.

Instances

Pretty CompletePostgresPlan

Defined in Database.Postgres.Temp.Internal.Core

Methods

pretty :: CompletePostgresPlan -> Doc

prettyList :: [CompletePostgresPlan] -> Doc

data PostgresProcess

The output of calling startPostgresProcess.

Constructors

PostgresProcess

Fields

• postgresProcessClientOptions :: Options

  Connection options

• postgresProcessHandle :: ProcessHandle

  postgres process handle

Instances

Pretty PostgresProcess

Defined in Database.Postgres.Temp.Internal.Core

Methods

pretty :: PostgresProcess -> Doc

prettyList :: [PostgresProcess] -> Doc

stopPostgresProcess :: Bool -> PostgresProcess -> IO ExitCode

Stop the postgres process after attempting to terminate all the connections.

startPostgresProcess :: Int -> Logger -> CompletePostgresPlan -> IO PostgresProcess

Start the postgres process and block until a successful connection occurs. A separate thread we continously check to see if the postgres process has crashed.

executeCreateDb :: CompleteProcessConfig -> IO ()

Call createdb and tee the output to return if there is an an exception. Throws CreateDbFailed.

data Plan

Plan is the low level configuration necessary for initializing a database cluster starting postgres and creating a database. There is no validation done on the Plan. It is recommend that one use the higher level functions such as start which will generate plans that are valid. Plans are used internally but are exposed if the higher level plan generation is not sufficent.

Constructors

Plan

Fields

• completePlanLogger :: Logger
• completePlanInitDb :: Maybe (Either CompleteProcessConfig InitDbCachePlan)
• completePlanCopy :: Maybe CompleteCopyDirectoryCommand
• completePlanCreateDb :: Maybe CompleteProcessConfig
• completePlanPostgres :: CompletePostgresPlan
• completePlanConfig :: String
• completePlanDataDirectory :: FilePath
• completePlanConnectionTimeout :: Int

Instances

Pretty Plan

Defined in Database.Postgres.Temp.Internal.Core

Methods

pretty :: Plan -> Doc

prettyList :: [Plan] -> Doc

startPlan :: Plan -> IO PostgresProcess

startPlan optionally calls initdb, optionally calls createdb and unconditionally calls postgres. Additionally it writes a "postgresql.conf" and does not return until the postgres process is ready. See startPostgresProcess for more details.

stopPlan :: PostgresProcess -> IO ExitCode

Stop the postgres process. See stopPostgresProcess for more details.