# haskell-language-dockerfile
Dockerfile linter, parser, pretty-printer and embedded DSL, forked from
[hadolint](https://github.com/lukasmartinelli/hadolint).
Published on Hackage as [language-dockerfile](https://hackage.haskell.org/package/language-dockerfile).
It extends hadolint with the pretty-printer and EDSL for writting Dockerfiles in
Haskell.
- [Parsing files](#parsing-files)
- [Parsing strings](#parsing-strings)
- [Pretty-printing files](#pretty-printing-files)
- [Writing Dockerfiles in Haskell](#writing-dockerfiles-in-haskell)
- [Using the QuasiQuoter](#using-the-quasiquoter)
- [Templating Dockerfiles in Haskell](#templating-dockerfiles-in-haskell)
- [Using IO in the DSL](#using-io-in-the-dsl)
## Parsing files
```haskell
import Language.Dockerfile
main = do
ef <- parseFile "./Dockerfile"
print ef
```
## Parsing strings
```haskell
import Language.Dockerfile
main = do
c <- readFile "./Dockerfile"
print (parseString c)
```
## Pretty-printing files
```haskell
import Language.Dockerfile
main = do
Right d <- parseFile "./Dockerfile"
putStr (prettyPrint d)
```
## Writting Dockerfiles in Haskell
```haskell
{-# LANGUAGE OverloadedStrings #-}
import Language.Dockerfile
main = putStr $ toDockerfileStr $ do
from "node"
run "apt-get update"
run ["apt-get", "install", "something"]
-- ...
```
## Using the QuasiQuoter
```haskell
{-# LANGUAGE OverloadedStrings #-}
{-# LANGUAGE QuasiQuotes #-}
import Language.Dockerfile
main = putStr $ toDockerfileStr $ do
from "node"
run "apt-get update"
[edockerfile|
RUN apt-get update
CMD node something.js
|]
-- ...
```
## Templating Dockerfiles in Haskell
```haskell
{-# LANGUAGE FlexibleContexts #-}
{-# LANGUAGE OverloadedStrings #-}
import Control.Monad
import Language.Dockerfile
tags = ["7.8", "7.10", "8"]
cabalSandboxBuild packageName = do
let cabalFile = packageName ++ ".cabal"
run "cabal sandbox init"
run "cabal update"
add cabalFile ("/app/" ++ cabalFile)
run "cabal install --only-dep -j"
add "." "/app/"
run "cabal build"
main =
forM_ tags $ \tag -> do
let df = toDockerfileStr $ do
from ("haskell" `tagged` tag)
cabalSandboxBuild "mypackage"
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:
```haskell
{-# LANGUAGE OverloadedStrings #-}
import Language.Dockerfile
import qualified System.Directory as Directory
import qualified System.FilePath as FilePath
import qualified System.FilePath.Glob as Glob
main = do
str <- toDockerfileStrIO $ do
fs <- liftIO $ do
cwd <- Directory.getCurrentDirectory
fs <- Glob.glob "./test/*.hs"
return (map (FilePath.makeRelative cwd) fs)
from "ubuntu"
mapM_ (\f -> add f ("/app/" ++ FilePath.takeFileName f)) fs
putStr str
```
## License
GPLv3