aws-0.7.4: Amazon Web Services (AWS) for Haskell

Safe HaskellNone

Aws

Contents

Synopsis

Logging

data LogLevel Source

The severity of a log message, in rising order.

Constructors

Debug 
Info 
Warning 
Error 

type Logger = LogLevel -> Text -> IO ()Source

The interface for any logging function. Takes log level and a log message, and can perform an arbitrary IO action.

defaultLog :: LogLevel -> LoggerSource

The default logger defaultLog minLevel, which prints log messages above level minLevel to stderr.

Configuration

data Configuration Source

The configuration for an AWS request. You can use multiple configurations in parallel, even over the same HTTP connection manager.

Constructors

Configuration 

Fields

timeInfo :: TimeInfo

Whether to restrict the signature validity with a plain timestamp, or with explicit expiration (absolute or relative).

credentials :: Credentials

AWS access credentials.

logger :: Logger

The error / message logger.

baseConfiguration :: MonadIO io => io ConfigurationSource

The default configuration, with credentials loaded from environment variable or configuration file (see loadCredentialsDefault).

dbgConfiguration :: MonadIO io => io ConfigurationSource

Debug configuration, which logs much more verbosely.

Transaction runners

Safe runners

aws :: Transaction r a => Configuration -> ServiceConfiguration r NormalQuery -> Manager -> r -> ResourceT IO (Response (ResponseMetadata a) a)Source

Run an AWS transaction, with HTTP manager and metadata wrapped in a Response.

All errors are caught and wrapped in the Response value.

Metadata is logged at level Info.

Usage (with existing Manager): resp <- aws cfg serviceCfg manager request

awsRef :: Transaction r a => Configuration -> ServiceConfiguration r NormalQuery -> Manager -> IORef (ResponseMetadata a) -> r -> ResourceT IO aSource

Run an AWS transaction, with HTTP manager and metadata returned in an IORef.

Errors are not caught, and need to be handled with exception handlers.

Metadata is not logged.

Usage (with existing Manager): ref <- newIORef mempty; resp <- awsRef cfg serviceCfg manager request

pureAws :: Transaction r a => Configuration -> ServiceConfiguration r NormalQuery -> Manager -> r -> ResourceT IO aSource

Run an AWS transaction, with HTTP manager and without metadata.

Metadata is logged at level Info.

Usage (with existing Manager): resp <- aws cfg serviceCfg manager request

simpleAws :: (Transaction r a, AsMemoryResponse a, MonadIO io) => Configuration -> ServiceConfiguration r NormalQuery -> r -> io (MemoryResponse a)Source

Run an AWS transaction, without HTTP manager and without metadata.

Metadata is logged at level Info.

Note that this is potentially less efficient than using aws, because HTTP connections cannot be re-used.

Usage: resp <- simpleAws cfg serviceCfg request

Unsafe runners

unsafeAws :: (ResponseConsumer r a, Monoid (ResponseMetadata a), Loggable (ResponseMetadata a), SignQuery r) => Configuration -> ServiceConfiguration r NormalQuery -> Manager -> r -> ResourceT IO (Response (ResponseMetadata a) a)Source

Run an AWS transaction, without enforcing that response and request type form a valid transaction pair.

This is especially useful for debugging and development, you should not have to use it in production.

All errors are caught and wrapped in the Response value.

Metadata is wrapped in the Response, and also logged at level Info.

unsafeAwsRef :: (ResponseConsumer r a, Monoid (ResponseMetadata a), SignQuery r) => Configuration -> ServiceConfiguration r NormalQuery -> Manager -> IORef (ResponseMetadata a) -> r -> ResourceT IO aSource

Run an AWS transaction, without enforcing that response and request type form a valid transaction pair.

This is especially useful for debugging and development, you should not have to use it in production.

Errors are not caught, and need to be handled with exception handlers.

Metadata is put in the IORef, but not logged.

URI runners

awsUri :: (SignQuery request, MonadIO io) => Configuration -> ServiceConfiguration request UriOnlyQuery -> request -> io ByteStringSource

Run a URI-only AWS transaction. Returns a URI that can be sent anywhere. Does not work with all requests.

Usage: uri <- awsUri cfg request

Iterated runners

Response

Full HTTP response

type HTTPResponseConsumer a = Response (ResumableSource (ResourceT IO) ByteString) -> ResourceT IO aSource

A full HTTP response parser. Takes HTTP status, response headers, and response body.

Metadata in responses

data Response m a Source

A response with metadata. Can also contain an error response, or an internal error, via Attempt.

Response forms a Writer-like monad.

Constructors

Response 

Instances

(Monad (Response m), Monoid m, Exception e) => Failure e (Response m) 
Monoid m => Monad (Response m) 
Functor (Response m) 
(Show m, Show a) => Show (Response m a) 

readResponse :: FromAttempt f => Response m a -> f aSource

Read a response result (if it's a success response, fail otherwise).

readResponseIO :: MonadIO io => Response m a -> io aSource

Read a response result (if it's a success response, fail otherwise). In MonadIO.

Memory responses

Exception types

newtype XmlException Source

An error that occurred during XML parsing / validation.

Constructors

XmlException 

newtype HeaderException Source

An error that occurred during header parsing / validation.

Constructors

HeaderException 

newtype FormException Source

An error that occurred during form parsing / validation.

Constructors

FormException 

Query

Service configuration

Expiration

data TimeInfo Source

Whether to restrict the signature validity with a plain timestamp, or with explicit expiration (absolute or relative).

Constructors

Timestamp

Use a simple timestamp to let AWS check the request validity.

ExpiresAt

Let requests expire at a specific fixed time.

ExpiresIn

Let requests expire a specific number of seconds after they were generated.

Instances

Transactions

class (SignQuery r, ResponseConsumer r a, Loggable (ResponseMetadata a)) => Transaction r a | r -> a, a -> rSource

Associates a request type and a response type in a bi-directional way.

This allows the type-checker to infer the response type when given the request type and vice versa.

Note that the actual request generation and response parsing resides in SignQuery and ResponseConsumer respectively.

class Transaction r a => IteratedTransaction r a | r -> a, a -> rSource

A transaction that may need to be split over multiple requests, for example because of upstream response size limits.

Credentials

data Credentials Source

AWS access credentials.

Constructors

Credentials 

Fields

accessKeyID :: ByteString

AWS Access Key ID.

secretAccessKey :: ByteString

AWS Secret Access Key.

Instances

credentialsDefaultFile :: MonadIO io => io FilePathSource

The file where access credentials are loaded, when using loadCredentialsDefault.

Value: <user directory>/.aws-keys

credentialsDefaultKey :: TextSource

The key to be used in the access credential file that is loaded, when using loadCredentialsDefault.

Value: default

loadCredentialsFromFile :: MonadIO io => FilePath -> Text -> io (Maybe Credentials)Source

Load credentials from a (text) file given a key name.

The file consists of a sequence of lines, each in the following format:

keyName awsKeyID awsKeySecret

loadCredentialsFromEnv :: MonadIO io => io (Maybe Credentials)Source

Load credentials from the environment variables AWS_ACCESS_KEY_ID and AWS_ACCESS_KEY_SECRET (or AWS_SECRET_ACCESS_KEY), if possible.

loadCredentialsFromEnvOrFile :: MonadIO io => FilePath -> Text -> io (Maybe Credentials)Source

Load credentials from environment variables if possible, or alternatively from a file with a given key name.

See loadCredentialsFromEnv and loadCredentialsFromFile for details.

loadCredentialsDefault :: MonadIO io => io (Maybe Credentials)Source

Load credentials from environment variables if possible, or alternative from the default file with the default key name.

Default file: <user directory>/.aws-keys Default key name: default

See loadCredentialsFromEnv and loadCredentialsFromFile for details.