Let us template the Dockerfiles

Author: phadej

8.8/Dockerfile

@@ -1,5 +1,5 @@
 ## Dockerfile for a haskell environment
-FROM       debian:stretch
+FROM       buildpack-deps:stretch
 
 ## ensure locale is set during build
 ENV LANG            C.UTF-8

Dockerfile.template

@@ -0,0 +1,28 @@
+## Dockerfile for a haskell environment
+FROM       buildpack-deps:{{{distribution}}}
+
+## ensure locale is set during build
+ENV LANG            C.UTF-8
+
+RUN apt-get update && \
+    apt-get install -y --no-install-recommends gnupg ca-certificates dirmngr curl git && \
+    echo 'deb http://downloads.haskell.org/debian stretch main' > /etc/apt/sources.list.d/ghc.list && \
+    apt-key adv --keyserver keyserver.ubuntu.com --recv-keys BA3CBA3FFE22B574 && \
+    apt-get update && \
+    apt-get install -y --no-install-recommends ghc-{{ghcVersion}} cabal-install-3.0 \
+        zlib1g-dev libtinfo-dev libsqlite3-dev g++ netbase xz-utils make openssh-client && \
+    curl -fSL https://github.com/commercialhaskell/stack/releases/download/v2.1.3/stack-2.1.3-linux-x86_64.tar.gz -o stack.tar.gz && \
+    curl -fSL https://github.com/commercialhaskell/stack/releases/download/v2.1.3/stack-2.1.3-linux-x86_64.tar.gz.asc -o stack.tar.gz.asc && \
+    export GNUPGHOME="$(mktemp -d)" && \
+    gpg --batch --keyserver ha.pool.sks-keyservers.net --recv-keys C5705533DA4F78D8664B5DC0575159689BEFB442 && \
+    gpg --batch --keyserver ha.pool.sks-keyservers.net --recv-keys 2C6A674E85EE3FB896AFC9B965101FF31C5C154D && \
+    gpg --batch --trusted-key 0x575159689BEFB442 --verify stack.tar.gz.asc stack.tar.gz && \
+    tar -xf stack.tar.gz -C /usr/local/bin --strip-components=1 && \
+    /usr/local/bin/stack config set system-ghc --global true && \
+    /usr/local/bin/stack config set install-ghc --global false && \
+    rm -rf "$GNUPGHOME" /var/lib/apt/lists/* /stack.tar.gz.asc /stack.tar.gz
+
+ENV PATH /root/.cabal/bin:/root/.local/bin:/opt/cabal/3.0/bin:/opt/ghc/8.8.1/bin:$PATH
+
+## run ghci by default unless a command is specified
+CMD ["ghci"]

generate.hs

@@ -0,0 +1,51 @@
+{-# LANGUAGE OverloadedStrings, RecordWildCards #-}
+-- | Script to generate dockerfiles. Obviously using Haskell.
+--
+-- If you have @cabal-env@ installed, do:
+--
+--     cabal-env microstache
+--
+module Main (main) where
+
+import Control.Monad (forM_)
+import Data.Aeson
+import Text.Microstache (compileMustacheFile, renderMustache)
+
+import qualified Data.Text.Lazy.IO as LT
+
+
+params :: [(FilePath, Params)]
+params =
+    [ mk "8.8/Dockerfile" Stretch "8.8.1"
+    ]
+  where
+    mk fp dist gv = (fp, Params dist gv)
+
+main :: IO ()
+main = do
+    template <- compileMustacheFile "Dockerfile.template"
+    forM_ params $ \(fp, p) -> do
+        let contents = renderMustache template (toJSON p)
+        LT.writeFile fp contents
+
+-------------------------------------------------------------------------------
+-- Data types
+-------------------------------------------------------------------------------
+
+data Distribution = Stretch
+  deriving (Show)
+
+instance ToJSON Distribution where
+    toJSON Stretch = "stretch"
+
+data Params = Params
+    { pDistribution :: Distribution
+    , pGhcVersion   :: String
+    }
+  deriving (Show)
+
+instance ToJSON Params where
+    toJSON Params {..} = object
+        [ "distribution" .= pDistribution
+        , "ghcVersion"   .= pGhcVersion
+        ]