Refactoring a bit...

Author: jkachmar

.envrc

@@ -0,0 +1 @@
+use nix

.gitignore

@@ -1,3 +1 @@
-.stack-work
-# JetBrains' IDEs
-.idea
+.direnv

1_ghc/build-gmp.mk ghc/build-gmp.mk1_ghc/build-gmp.mk renamed to ghc/build-gmp.mk

@@ -17,26 +17,32 @@ cd "$( git rev-parse --show-toplevel )"
 # cf. https://sookocheff.com/post/bash/parsing-bash-script-arguments-with-shopts/
 ################################################################################
 
-container="builder-ghc"
-image="builder-ghc"
+alpine_ver="3.14"
+container="ghc"
+image="ghc"
 ghc_ver="8.10.7"
 # NOTE: The logic associated with this will have to change for GHC 9.x and up to
 # support the changes introduced with the switch to `ghc-bignum`.
 numeric="gmp"
 
 usage="USAGE: $0
-    -h           show this help text
-    -c CONTAINER override the default container name
-                 default: ${container}
-    -g GHC_VER   override the numeric library GHC is built against; either 'gmp' or 'simple'
-                 default: ${ghc_ver}
-    -i IMAGE     override the default image name
-                 default: ${image}
-    -n NUMERIC   override the numeric library GHC is built against; either 'gmp' or 'simple'
-                 default: ${numeric}"
-
-while getopts "c:g:i:n:h" opt; do
+    -h            show this help text
+    -a ALPINE_VER override the default Alpine version
+                  default: ${alpine_ver}
+    -c CONTAINER  override the default container name
+                  default: ${container}
+    -g GHC_VER    override the numeric library GHC is built against; either 'gmp' or 'simple'
+                  default: ${ghc_ver}
+    -i IMAGE      override the default image name
+                  default: ${image}
+    -n NUMERIC    override the numeric library GHC is built against; either 'gmp' or 'simple'
+                  default: ${numeric}"
+
+while getopts "a:c:g:i:n:h" opt; do
   case ${opt} in
+    a ) {
+          alpine_ver="${OPTARG}"
+    };;
     c ) {
           container="${OPTARG}"
     };;
@@ -76,7 +82,7 @@ container="${container}-${numeric}-${ghc_ver}"
 image="${image}-${numeric}:${ghc_ver}"
 
 ################################################################################
-# Container and dependencies.
+# Container.
 ################################################################################
 
 # Create the container that will be used to compile GHC from source.
@@ -89,35 +95,49 @@ image="${image}-${numeric}:${ghc_ver}"
 buildah \
     --signature-policy=./policy.json \
     --name "${container}" \
-    from --pull "base-${numeric}" \
-    || true
+    from --pull "docker.io/library/alpine:${alpine_ver}"
+
+################################################################################
+# Copy `ghcup` from another container.
+################################################################################
+
+# XXX: Maybe the `"ghcup"` image name should be fully qualified (i.e.
+# "localhost/ghcup" for an image built locally)...?
+buildah unshare ./ghc/copy_ghcup.sh "ghcup" "${container}"
+
+################################################################################
+# Dependencies.
+################################################################################
 
 buildah run "${container}" \
     apk add --no-cache \
         autoconf \
         automake \
         binutils-gold \
         build-base \
+        curl \
         coreutils \
         cpio \
         ghc \
+        git \
         linux-headers \
         libffi-dev \
         musl-dev \
         ncurses-dev \
         perl \
         python3 \
         py3-sphinx \
-        zlib-dev
+        zlib-dev \
+        xz
 
 # Copy the appropriate build file, depending on the chosen numeric library.
 if [ "${numeric}" = "gmp" ]; then
   buildah copy --chmod 444 "${container}" \
-      ./1_ghc/build-gmp.mk \
+      ./ghc/build-gmp.mk \
       /tmp/build.mk
 elif [ "${numeric}" = "simple" ]; then
   buildah copy --chmod 444 "${container}" \
-      ./1_ghc/build-simple.mk \
+      ./ghc/build-simple.mk \
       /tmp/build.mk
 else # Should be impossible...
     echo "This code path should be unreachable!" >&2
@@ -128,12 +148,12 @@ fi;
 
 # Copy all patches that will be applied to the GHC source tree.
 buildah copy --chmod 444 "${container}" \
-    ./1_ghc/patches \
+    ./ghc/patches \
     /tmp/patches
 
 # Copy wrapper script that will invoke `ghcup` to compile GHC.
 buildah copy --chmod 111 "${container}" \
-    ./1_ghc/compile_ghc.sh \
+    ./ghc/compile_ghc.sh \
     /tmp/compile_ghc.sh
 
 ################################################################################
@@ -156,16 +176,6 @@ buildah run "${container}" \
 # Generate the final image.
 ################################################################################
 
-# NOTE: Using images for all of these intermediate stages is sort of a
-# carry-over from multi-stage Docker builds.
-#
-# It might be preferable to keep this container around for future build steps
-# and just mount it to copy the files over manually.
-#
-# The tradeoff with this is that the image building process stops being
-# "declarative", since it depends on the intermediate state of a particular
-# container on the host builder's system.
-
 buildah \
     --signature-policy=./policy.json \
-    commit "${container}" "${image}"
+    commit --rm "${container}" "${image}"

1_ghc/build-simple.mk ghc/build-simple.mk1_ghc/build-simple.mk renamed to ghc/build-simple.mk

@@ -12,4 +12,5 @@ SPHINXBUILD=/usr/bin/sphinx-build-3 \
         --config /tmp/build.mk \
         --patchdir /tmp/patches \
         --bootstrap-ghc /usr/bin/ghc \
+        --set \
         --version "${ghc_ver}"

1_ghc/builder.sh ghc/builder.sh1_ghc/builder.sh renamed to ghc/builder.sh

@@ -0,0 +1,13 @@
+#!/usr/bin/env sh
+
+ghcup_img="$1"
+builder_cnt="$2"
+
+ghcup_cnt=$(buildah from --signature-policy=./policy.json "${ghcup_img}")
+ghcup_mnt=$(buildah mount "${ghcup_cnt}")
+builder_mnt=$(buildah mount "${builder_cnt}")
+
+cp "${ghcup_mnt}/usr/bin/ghcup" "${builder_mnt}/usr/bin/ghcup"
+
+# Clean up intermediate container.
+buildah rm "${ghcup_cnt}"

1_ghc/compile_ghc.sh ghc/compile_ghc.sh1_ghc/compile_ghc.sh renamed to ghc/compile_ghc.sh

@@ -17,38 +17,30 @@ cd "$( git rev-parse --show-toplevel )"
 # cf. https://sookocheff.com/post/bash/parsing-bash-script-arguments-with-shopts/
 ################################################################################
 
-container="base"
-image="base"
-# NOTE: The logic associated with this will have to change for GHC 9.x and up to
-# support the changes introduced with the switch to `ghc-bignum`.
-numeric="gmp"
+alpine_ver="3.14"
+container="ghcup"
+image="ghcup"
 
 usage="USAGE: $0
     -h           show this help text
+    -a ALPINE_VER override the default Alpine version
+                  default: ${alpine_ver}
     -c CONTAINER override the default container name
                  default: ${container}
-    -i IMAGE     override the default image name
-                 default: ${image}
-    -n NUMERIC   override the numeric library GHC is built against; either 'gmp' or 'simple'
-                 default: ${numeric}"
+    -i IMAGE      override the default image name
+                  default: ${image}"
 
-while getopts "c:i:n:h" opt; do
+while getopts "a:c:i:h" opt; do
   case ${opt} in
+    a ) {
+          alpine_ver="${OPTARG}"
+    };;
     c ) {
           container="${OPTARG}"
     };;
     i ) {
           image="${OPTARG}"
     };;
-    n ) {
-        if [ "${OPTARG}" = "gmp" ] || [ "${OPTARG}" = "simple" ]; then
-          numeric="${OPTARG}"
-        else
-            echo "Invalid NUMERIC argument (i.e. '-n')." >&2
-            echo "Expected either 'gmp' or 'simple', got '${OPTARG}'" >&2
-            exit 1
-        fi;
-    };;
     h ) {
           echo "${usage}"
           exit 0
@@ -65,26 +57,14 @@ if [ "$#" -ne 0 ]; then
   exit 1
 fi
 
-# Add the numeric library to container and image names.
-container="${container}-${numeric}"
-image="${image}-${numeric}"
-
 ################################################################################
 # Container and basic dependencies.
 ################################################################################
 
-# Create the "base" container that will be used elsewhere in the project.
-#
-# NOTE: Alternatively: `buildah commit --rm` (at the end of the script) removes
-# the working container.
-#
-# XXX: Reusing the container by name if it exists seems like not the best idea
-# but it's convenient for development.
 buildah \
     --signature-policy=./policy.json \
     --name "${container}" \
-    from --pull docker.io/library/alpine:3.14 \
-    || true
+    from --pull docker.io/library/alpine:3.14
 
 # Update index files and upgrade the currently installed packages.
 #
@@ -96,23 +76,14 @@ buildah run "${container}" \
 buildah run "${container}" \
     apk add \
       curl \
-      gcc \
-      git \
-      libc-dev \
       xz
 
-if [ "${numeric}" = "gmp" ]; then
-  echo "Installing 'libgmp'."
-  buildah run "${container}" \
-      apk add gmp-dev
-fi;
-
 ################################################################################
 # Download and install `ghcup`.
 ################################################################################
 
-ghcup_version="0.1.16.2"
-ghcup_expected_checksum="d5e43b95ce1d42263376e414f7eb7c5dd440271c7c6cd9bad446fdeff3823893"
+ghcup_version="0.1.17.2"
+ghcup_expected_checksum="e9adb022b9bcfe501caca39e76ae7241af0f30fbb466a2202837a7a578607daf"
 
 # Fetch `ghcup`.
 buildah run "${container}" \
@@ -122,7 +93,7 @@ buildah run "${container}" \
 
 # Copy the checksum validation script into the container...
 buildah copy --chmod 111 "${container}" \
-    ./0_base/validate_checksum.sh \
+    ./ghcup/validate_checksum.sh \
     /tmp/validate_checksum.sh
 
 # ...and verify that the expected and actual actual `ghcup` checksums match.
@@ -147,6 +118,7 @@ buildah run "${container}" \
 # Generate the final image.
 ################################################################################
 
+# NOTE: Tagging the image with the `ghcup_version` for convenience.
 buildah \
     --signature-policy=./policy.json \
-    commit "${container}" "${image}"
+    commit --rm "${container}" "${image}:${ghcup_version}"

ghc/copy_ghcup.sh

@@ -1,7 +1,7 @@
 #!/usr/bin/env sh
 set -eu
 
-ghcup_path=$1
+ghcup_path="$1"
 ghcup_expected_checksum="$2"
 
 if ! echo "${ghcup_expected_checksum}  ${ghcup_path}" | sha256sum -c -; then