kubernetes-client
Example
{-# LANGUAGE OverloadedStrings #-} module Main where import Data.Function ((&)) import Kubernetes.Client (defaultTLSClientParams, disableServerCertValidation, disableServerNameValidation, disableValidateAuthMethods, loadPEMCerts, newManager, setCAStore, setClientCert, setMasterURI, setTokenAuth) import Kubernetes.OpenAPI (Accept (..), MimeJSON (..), dispatchMime, newConfig) import qualified Kubernetes.OpenAPI.API.CoreV1 as CoreV1 import Network.TLS (credentialLoadX509) main :: IO () main = do -- We need to first create a Kubernetes.Core.KubernetesConfig and a Network.HTTP.Client.Manager. -- Currently we need to construct these objects manually. Work is underway to construct these -- objects automatically from a kubeconfig file. See https://github.com/kubernetes-client/haskell/issues/2. kcfg <- newConfig & fmap (setMasterURI "https://mycluster.example.com") -- fill in master URI & fmap (setTokenAuth "mytoken") -- if using token auth & fmap disableValidateAuthMethods -- if using client cert auth myCAStore <- loadPEMCerts "/path/to/ca.crt" -- if using custom CA certs myCert <- -- if using client cert credentialLoadX509 "/path/to/client.crt" "/path/to/client.key" >>= either error return tlsParams <- defaultTLSClientParams & fmap disableServerNameValidation -- if master address is specified as an IP address & fmap disableServerCertValidation -- if you don't want to validate the server cert at all (insecure) & fmap (setCAStore myCAStore) -- if using custom CA certs & fmap (setClientCert myCert) -- if using client cert manager <- newManager tlsParams dispatchMime manager kcfg (CoreV1.listPodForAllNamespaces (Accept MimeJSON)) >>= print
Watch Example
Following is a simple example which just streams to stdout. First some setup - this assumes kubernetes is accessible at http://localhost:8001, e.g. after running kubectl proxy:
> import qualified Data.ByteString.Streaming.Char8 as Q > manager <- newManager defaultManagerSettings > defaultConfig <- newConfig > config = defaultConfig { configHost = "http://localhost:8001", configValidateAuthMethods = False } > request = listEndpointsForAllNamespaces (Accept MimeJSON)
Launching 'dispatchWatch' with the above we get a stream of endpoints data:
> dispatchWatch manager config request Q.stdout {"type":\"ADDED\","object":{"kind":\"Endpoints\","apiVersion":"v1","metadata":{"name":"heapster" ....
A more complex example involving some ggprocessing of the stream, the following prints out the event types of each event. First, define functions to allow us apply a parser to a stream:
import Data.Aeson import qualified Data.ByteString.Streaming.Char8 as Q import Data.JsonStream.Parser import qualified Streaming.Prelude as S -- | Parse the stream using the given parser. streamParse :: FromJSON a => Parser a -> Q.ByteString IO r -> Stream (Of [a]) IO r streamParse parser byteStream = do byteStream & Q.lines & parseEvent parser -- | Parse a single event from the stream. parseEvent :: (FromJSON a, Monad m) => Parser a -> Stream (Q.ByteString m) m r -> Stream (Of [a]) m r parseEvent parser byteStream = S.map (parseByteString parser) (S.mapped Q.toStrict byteStream)
Next, define the parser and apply it to the stream:
> eventParser = value :: Parser (WatchEvent V1Endpoints) > withResponseBody body = streamParse eventParser body & S.map (map eventType) > dispatchWatch manager config request (S.print . withResponseBody) [\"ADDED\"] [\"ADDED\"] [\"MODIFIED\"] ...
Packages in this example:
