From 89817b41fd380b17972f04a45ef5ac9cf8d70bba Mon Sep 17 00:00:00 2001
From: Gabriel Gonzalez <Gabriel439@gmail.com>
Date: Mon, 13 May 2019 10:37:03 -0700
Subject: [PATCH] Build docker images for each package in CI (#950)

Fixes #513
---
 README.md      | 30 ++++++++++++++++++++++++++++++
 nix/shared.nix | 45 +++++++++++++++++++++++++++++++++------------
 release.nix    |  9 +++++++++
 3 files changed, 72 insertions(+), 12 deletions(-)

diff --git a/README.md b/README.md
index 357490c..d3c319a 100644
--- a/README.md
+++ b/README.md
@@ -57,6 +57,36 @@ $ nix-env -i "$(curl -L https://hydra.dhall-lang.org/job/dhall-haskell/master/li
 These instructions also work for any pull request, too, by replacing `master`
 with the pull request number for any of the above URLs.
 
+## Pre-built containers
+
+You can download pre-built `docker` image archives for each package using the
+following URLs:
+
+* [https://hydra.dhall-lang.org/job/dhall-haskell/master/image-dhall/latest/download/1/docker-image-dhall.tar.gz](https://hydra.dhall-lang.org/job/dhall-haskell/master/image-dhall/latest/download/1/docker-image-dhall.tar.gz)
+* [https://hydra.dhall-lang.org/job/dhall-haskell/master/image-dhall-bash/latest/download/1/docker-image-dhall-bash.tar.gz](https://hydra.dhall-lang.org/job/dhall-haskell/master/image-dhall-bash/latest/download/1/docker-image-dhall-bash.tar.gz)
+* [https://hydra.dhall-lang.org/job/dhall-haskell/master/image-dhall-json/latest/download/1/docker-image-dhall-json.tar.gz](https://hydra.dhall-lang.org/job/dhall-haskell/master/image-dhall-json/latest/download/1/docker-image-dhall-json.tar.gz)
+* [https://hydra.dhall-lang.org/job/dhall-haskell/master/image-dhall-lsp-server/latest/download/1/docker-image-dhall-lsp-server.tar.gz](https://hydra.dhall-lang.org/job/dhall-haskell/master/image-dhall-lsp-server/latest/download/1/docker-image-dhall-lsp-server.tar.gz)
+* [https://hydra.dhall-lang.org/job/dhall-haskell/master/image-dhall-nix/latest/download/1/docker-image-dhall-nix.tar.gz](https://hydra.dhall-lang.org/job/dhall-haskell/master/image-dhall-nix/latest/download/1/docker-image-dhall-nix.tar.gz)
+* [https://hydra.dhall-lang.org/job/dhall-haskell/master/image-dhall-text/latest/download/1/docker-image-dhall-text.tar.gz](https://hydra.dhall-lang.org/job/dhall-haskell/master/image-dhall-text/latest/download/1/docker-image-dhall-text.tar.gz)
+
+You can then load and run one of these archives like so:
+
+```
+$ NAME="dhall"
+
+$ curl --location --remote-name "https://hydra.dhall-lang.org/job/dhall-haskell/master/image-${NAME}/latest/download/1/docker-image-${NAME}.tar.gz"
+
+$ docker load < "docker-image-${NAME}.tar.gz"
+...
+Loaded image: dhall:vx95jiijmp2i07f5ynl8h6sllf34jggz
+
+$ docker run -i dhall:vx95jiijmp2i07f5ynl8h6sllf34jggz dhall <<< '2 + 2'
+4
+```
+
+These instructions also work for any pull request, too, by replacing `master`
+with the pull request number for any of the above URLs.
+
 ## Building from source
 
 For all of the following instructions, make sure to first check out the
diff --git a/nix/shared.nix b/nix/shared.nix
index 72481cf..88d5fb1 100644
--- a/nix/shared.nix
+++ b/nix/shared.nix
@@ -596,20 +596,34 @@ let
     # Benchmark dependencies aren't added by default
     (pkgs.haskell.lib.doBenchmark drv).env;
 
+  possibly-static = {
+    dhall            = makeStaticIfPossible "dhall"           ;
+    dhall-bash       = makeStaticIfPossible "dhall-bash"      ;
+    dhall-json       = makeStaticIfPossible "dhall-json"      ;
+    dhall-lsp-server = makeStaticIfPossible "dhall-lsp-server";
+    dhall-nix        = makeStaticIfPossible "dhall-nix"       ;
+    dhall-text       = makeStaticIfPossible "dhall-text"      ;
+  };
+
+  toDockerImage = name:
+    let
+      image =
+        pkgs.dockerTools.buildImage {
+          inherit name;
+
+          contents = [ possibly-static."${name}" ];
+        };
+
+    in
+      pkgs.runCommand "image-${name}" {} ''
+        ${pkgs.coreutils}/bin/mkdir --parents "$out/nix-support"
+        ${pkgs.coreutils}/bin/ln --symbolic '${image}' "$out/docker-image-${name}.tar.gz"
+        echo "file binary-dist $out/docker-image-${name}.tar.gz" >> $out/nix-support/hydra-build-products
+      '';
+
 in
   rec {
-    inherit trivial;
-
-    inherit pkgs;
-
-    possibly-static = {
-      dhall            = makeStaticIfPossible "dhall"           ;
-      dhall-bash       = makeStaticIfPossible "dhall-bash"      ;
-      dhall-json       = makeStaticIfPossible "dhall-json"      ;
-      dhall-lsp-server = makeStaticIfPossible "dhall-lsp-server";
-      dhall-nix        = makeStaticIfPossible "dhall-nix"       ;
-      dhall-text       = makeStaticIfPossible "dhall-text"      ;
-    };
+    inherit trivial pkgs possibly-static;
 
     tarball-dhall            = makeTarball "dhall"           ;
     tarball-dhall-bash       = makeTarball "dhall-bash"      ;
@@ -632,6 +646,13 @@ in
     shell-dhall-text       = toShell pkgs.haskell.packages."${compiler}".dhall-text      ;
     shell-dhall-try        = toShell pkgs.haskell.packages."${compiler}".dhall-try       ;
 
+    image-dhall            = toDockerImage "dhall"           ;
+    image-dhall-bash       = toDockerImage "dhall-bash"      ;
+    image-dhall-json       = toDockerImage "dhall-json"      ;
+    image-dhall-lsp-server = toDockerImage "dhall-lsp-server";
+    image-dhall-nix        = toDockerImage "dhall-nix"       ;
+    image-dhall-text       = toDockerImage "dhall-text"      ;
+
     test-dhall =
       pkgs.mkShell
         { buildInputs =
diff --git a/release.nix b/release.nix
index 77374c5..35e9703 100644
--- a/release.nix
+++ b/release.nix
@@ -85,4 +85,13 @@ in
     linux-dhall-lsp-server = shared_linux.possibly-static.dhall-lsp-server;
     linux-dhall-nix        = shared_linux.possibly-static.dhall-nix;
     linux-dhall-text       = shared_linux.possibly-static.dhall-text;
+
+    inherit (shared_linux)
+      image-dhall
+      image-dhall-bash
+      image-dhall-json
+      image-dhall-lsp-server
+      image-dhall-nix
+      image-dhall-text
+    ;
   }