haskell-language-docker
Dockerfile parser, pretty-printer and embedded DSL
Provides de ability to parse docker files, a pretty-printer and EDSL for
writting Dockerfiles in Haskell.
Parsing files
import Language.Docker
main = do
ef <- parseFile "./Dockerfile"
print ef
Parsing strings
import Language.Docker
main = do
c <- readFile "./Dockerfile"
print (parseString c)
Pretty-printing files
import Language.Docker
main = do
Right d <- parseFile "./Dockerfile"
putStr (prettyPrint d)
Writing Dockerfiles in Haskell
{-# LANGUAGE OverloadedStrings #-}
{-# LANGUAGE OverloadedLists #-}
import Language.Docker
main = putDockerfileStr $ do
from "node"
run "apt-get update"
run ["apt-get", "install", "something"]
-- ...
Using the QuasiQuoter
{-# LANGUAGE OverloadedStrings #-}
{-# LANGUAGE QuasiQuotes #-}
import Language.Docker
main = putDockerfileStr $ do
from "node"
run "apt-get update"
[edockerfile|
RUN apt-get update
CMD node something.js
|]
-- ...
Templating Dockerfiles in Haskell
{-# LANGUAGE FlexibleContexts #-}
{-# LANGUAGE OverloadedStrings #-}
{-# LANGUAGE OverloadedLists #-}
import Control.Monad
import Language.Docker
import Data.String (fromString)
import qualified Data.Text.Lazy.IO as L
tags = ["7.8", "7.10", "8"]
cabalSandboxBuild packageName = do
let cabalFile = packageName ++ ".cabal"
run "cabal sandbox init"
run "cabal update"
add [fromString cabalFile] (fromString $ "/app/" ++ cabalFile)
run "cabal install --only-dep -j"
add "." "/app/"
run "cabal build"
main =
forM_ tags $ \tag -> do
let df = toDockerfileText $ do
from ("haskell" `tagged` tag)
cabalSandboxBuild "mypackage"
L.writeFile ("./examples/templating-" ++ tag ++ ".dockerfile") df
Using IO in the DSL
By default the DSL runs in the Identity
monad. By running in IO we can
support more features like file globbing:
{-# LANGUAGE OverloadedStrings #-}
{-# LANGUAGE OverloadedLists #-}
import Language.Docker
import qualified System.Directory as Directory
import qualified System.FilePath as FilePath
import qualified System.FilePath.Glob as Glob
import Data.List.NonEmpty (fromList)
import qualified Data.Text.Lazy.IO as L
main = do
str <- toDockerfileTextIO $ do
fs <- liftIO $ do
cwd <- Directory.getCurrentDirectory
fs <- Glob.glob "./test/*.hs"
let relativeFiles = map (FilePath.makeRelative cwd) fs
return (fromList relativeFiles)
from "ubuntu"
copy $ (toSources fs) `to` "/app/"
L.putStr str