Network.AWS.Env

Environment and AWS specific configuration for the AWS and AWST monads.

Creating the Environment

newEnv

Arguments

:: (Applicative m, MonadIO m, MonadCatch m)

=> Credentials

Credential discovery mechanism.

-> m Env

Creates a new environment with a new Manager without debug logging and uses getAuth to expand/discover the supplied Credentials. Lenses from HasEnv can be used to further configure the resulting Env.

Since: 1.5.0 - The region is now retrieved from the AWS_REGION environment variable (identical to official SDKs), or defaults to us-east-1. You can override the Env region by using envRegion, or the current operation's region by using within.

Since: 1.3.6 - The default logic for retrying HttpExceptions now uses retryConnectionFailure to retry specific connection failure conditions up to 3 times. Previously only service specific errors were automatically retried. This can be reverted to the old behaviour by resetting the Env using envRetryCheck lens to (\_ _ -> False).

Throws AuthError when environment variables or IAM profiles cannot be read.

See: newEnvWith.

newEnvWith

Arguments

:: (Applicative m, MonadIO m, MonadCatch m)

=> Credentials

Credential discovery mechanism.

-> Maybe Bool

Preload the EC2 instance check.

-> Manager

-> m Env

See: newEnv

The Maybe Bool parameter is used by the EC2 instance check. By passing a value of Nothing, the check will be performed. Just True would cause the check to be skipped and the host treated as an EC2 instance.

Throws AuthError when environment variables or IAM profiles cannot be read.

data Env

The environment containing the parameters required to make AWS requests.

Constructors

Env

Fields

• _envRegion :: !Region
• _envLogger :: !Logger
• _envRetryCheck :: !(Int -> HttpException -> Bool)
• _envOverride :: !(Dual (Endo Service))
• _envManager :: !Manager
• _envEC2 :: !(IORef (Maybe Bool))
• _envAuth :: !Auth

Instances

ToLog Env

Methods

build :: Env -> Builder

HasEnv Env

Methods

environment :: Lens' Env Env

envRegion :: Lens' Env Region

envLogger :: Lens' Env Logger

envRetryCheck :: Lens' Env (Int -> HttpException -> Bool)

envOverride :: Lens' Env (Dual (Endo Service))

envManager :: Lens' Env Manager

envAuth :: Lens' Env Auth

envEC2 :: Getter Env (IORef (Maybe Bool))

MonadAWS AWS

Methods

liftAWS :: AWS a -> AWS a

class HasEnv a where

Minimal complete definition

environment

Methods

environment :: Lens' a Env

envRegion :: Lens' a Region

The current region.

envLogger :: Lens' a Logger

The function used to output log messages.

envRetryCheck :: Lens' a (Int -> HttpException -> Bool)

The function used to determine if an HttpException should be retried.

envOverride :: Lens' a (Dual (Endo Service))

The currently applied overrides to all Service configuration.

envManager :: Lens' a Manager

The Manager used to create and manage open HTTP connections.

envAuth :: Lens' a Auth

The credentials used to sign requests for authentication with AWS.

envEC2 :: Getter a (IORef (Maybe Bool))

A memoised predicate for whether the underlying host is an EC2 instance.

Instances

HasEnv Env

Methods

environment :: Lens' Env Env

envRegion :: Lens' Env Region

envLogger :: Lens' Env Logger

envRetryCheck :: Lens' Env (Int -> HttpException -> Bool)

envOverride :: Lens' Env (Dual (Endo Service))

envManager :: Lens' Env Manager

envAuth :: Lens' Env Auth

envEC2 :: Getter Env (IORef (Maybe Bool))

Overriding Default Configuration

override :: HasEnv a => (Service -> Service) -> a -> a

Provide a function which will be added to the existing stack of overrides applied to all service configuration.

To override a specific service, it's suggested you use either configure or reconfigure with a modified version of the default service, such as Network.AWS.DynamoDB.dynamoDB.

configure :: HasEnv a => Service -> a -> a

Configure a specific service. All requests belonging to the supplied service will use this configuration instead of the default.

It's suggested you use a modified version of the default service, such as Network.AWS.DynamoDB.dynamoDB.

See: reconfigure.

Scoped Actions

reconfigure :: (MonadReader r m, HasEnv r) => Service -> m a -> m a

Scope an action such that all requests belonging to the supplied service will use this configuration instead of the default.

It's suggested you use a modified version of the default service, such as Network.AWS.DynamoDB.dynamoDB.

See: configure.

within :: (MonadReader r m, HasEnv r) => Region -> m a -> m a

Scope an action within the specific Region.

once :: (MonadReader r m, HasEnv r) => m a -> m a

Scope an action such that any retry logic for the Service is ignored and any requests will at most be sent once.

timeout :: (MonadReader r m, HasEnv r) => Seconds -> m a -> m a

Scope an action such that any HTTP response will use this timeout value.

Default timeouts are chosen by considering:

• This timeout, if set.
• The related Service timeout for the sent request if set. (Usually 70s)
• The envManager timeout if set.
• The default ClientRequest timeout. (Approximately 30s)

Retry HTTP Exceptions

retryConnectionFailure :: Int -> Int -> HttpException -> Bool

Retry the subset of transport specific errors encompassing connection failure up to the specific number of times.