packer: 0.10.1 -> 0.12.1

pkgs/development/tools/packer/default.nix

@@ -1,13 +1,17 @@
 { stdenv, lib, gox, gotools, buildGoPackage, fetchFromGitHub
-, fetchgit, fetchhg, fetchbzr, fetchsvn }:
+, fetchgit, fetchhg, fetchbzr, fetchsvn
+, writeScript, coreutils, jq, curl, git, bash, gnugrep, gnused, nix-prefetch-git, findutils, gawk
+}:
 
-stdenv.mkDerivation rec {
+let
+  deps = import ./deps.nix {
+    inherit stdenv lib gox gotools buildGoPackage fetchgit fetchhg fetchbzr fetchsvn;
+  };
+in stdenv.mkDerivation rec {
   name = "packer-${version}";
-  version = "0.10.1";
+  version = deps.version;
 
-  src = (import ./deps.nix {
-    inherit stdenv lib gox gotools buildGoPackage fetchgit fetchhg fetchbzr fetchsvn;
-  }).out;
+  src = deps.out;
 
   buildInputs = [ src.go gox gotools ];
 
@@ -40,7 +44,178 @@ stdenv.mkDerivation rec {
 
   installPhase = ''
     mkdir -p $out/bin
-    mv bin/* $out/bin
+    mv bin/* $out/bin # */
+  '';
+
+  passthru.updateScript = writeScript "update-packer" ''
+    #!${bash}/bin/bash
+    set -euo pipefail
+
+    PATH=${coreutils}/bin:${jq}/bin:${git}/bin:${gnugrep}/bin:${gnused}/bin:${nix-prefetch-git}/bin:${findutils}/bin:${gawk}/bin:${curl}/bin
+    GITHUB_SLUG=mitchellh/packer
+    REPO_BASE=github.com/$GITHUB_SLUG
+    REPO=https://$REPO_BASE
+
+    # Fetch the latest version from upstream git repo
+    latest_rev_and_ver() {
+      # Example ls-remote output
+      # 1fc1a7a7f1fc7058495c52f101cd3a498958781d        refs/tags/v0.9.0
+      # d7f5f0283158b0c478c20f1323203c5aa0dc13dc        refs/tags/v0.9.0^{}
+      # Function will return:
+      # 1fc1a7a7f1fc7058495c52f101cd3a498958781d        0.9.0
+      git ls-remote $REPO 'refs/tags/*' | grep -vF '^{}' | sort -k 2 --version-sort --reverse | sed -e 's,refs/tags/v,,' | head -n 1 # */
+    }
+
+    # packer lists all it's external go dependencies in vendor/vendor.json
+    # this function returns list of those dependencies as a series of line like:
+    #
+    # some.domain/some.go.path git-revision-id
+    vendor_packages_list() {
+      cat $VENDOR | jq --raw-output '.package[] | "\(.revision)\t\(.path)"' | sort
+    }
+
+    # In 0.12.1 there is different git revisions of crypto used for different go paths.
+    # This finds out the most frequently used revison
+    choose_x_crypto_revision() {
+      vendor_packages_list | grep -F 'golang.org/x/crypto' | awk '{print $1}' | sort | uniq -c | sort -nr | head -n 1 | awk '{print $2}'
+    }
+
+    # Different hacks. Currently only one that forces all crypto dependencies to use a single git revision.
+    fixup_revisions() {
+      local force_crypto=$(choose_x_crypto_revision)
+      sed -e 's,^.*\(golang.org/x/crypto/\),'$force_crypto'\t\1,'
+    }
+
+    # find all go package paths that correspond to unique git
+    # repositories. Assumption is that we can group all dependencies
+    # that reference the same git revision id, find out their common
+    # prefix, and use only this value as an `extraSrcs`.
+    vendor_packages() {
+      local last_rev=
+      local common_path=
+      local rev
+      local path
+
+      while read rev path ; do
+        if [[ $last_rev != $rev ]]; then
+          if [[ -n $last_rev ]]; then
+            echo -e "$last_rev\t$common_path" | sed -e 's,/$,,'
+          fi
+          common_path=$path
+          last_rev=$rev
+        else
+          common_path=$(printf "%s\n%s\n" "$common_path" "$path" | sed -e 'N;s/^\(.*\).*\n\1.*$/\1/')
+        fi
+      done < <(vendor_packages_list | fixup_revisions | sort)
+    }
+
+    # A collection of hacks to convert go package path to a (git repo
+    # url, new package path) pair. new package path is needed if
+    # original one is acutally pointing into some subdirectory in the
+    # git repo.
+    # TODO: Find out how 'go get' does it
+    path_to_repo() {
+      local path="$1"
+      case "$path" in
+        github.com/*) #*/
+          # Remove all but 2 first path components, add https
+          echo "$path" | sed -e 's,github.com/\([^/]\+\)/\([^/]\+\).*,https://github.com/\1/\2\tgit.luolix.top/\1/\2,'
+          ;;
+        golang.org/x/*) #*/
+          echo "$path" | sed -e 's,golang.org/x/\([^/]\+\).*,https://go.googlesource.com/\1\tgolang.org/x/\1,'
+          ;;
+        google.golang.org/cloud)
+          echo -e "https://code.googlesource.com/gocloud\t$path"
+          ;;
+        google.golang.org/api)
+          echo -e "https://code.googlesource.com/google-api-go-client\t$path"
+          ;;
+        google.golang.org/appengine)
+          echo -e "https://github.com/golang/appengine\t$path"
+          ;;
+        gopkg.in/*)  # */
+          echo "$path" | sed -e 's,^,https://,' -e 's,$,\t'$path','
+          ;;
+        *)
+          echo "Unknown package path: $path" 1>&2
+          return 1
+        ;;
+      esac
+    }
+
+    print_header() {
+      local version=$1
+      local ref=$2
+      cat <<EOF
+    { stdenv, lib, gox, gotools, buildGoPackage, fetchgit, fetchhg, fetchbzr, fetchsvn }:
+
+    buildGoPackage rec {
+      name = "packer-$version";
+      version = "$version";
+      rev = "$ref";
+
+      buildInputs = [ gox gotools ];
+
+      goPackagePath = "$REPO_BASE";
+
+    $(fetchgit_src $REPO $ref | prefix "  ")
+
+      extraSrcs = [
+    EOF
+    }
+
+    # Produces a "src = fetchgit { .. }" string for a given git repo url and revision.
+    # nix-prefetch-git output is massaged a bit to achieve desired result.
+    fetchgit_src() {
+      echo -n "src = fetchgit "
+      nix-prefetch-git "$1" "$2" | grep -vE '"(date|fetchSubmodules)":' | sed -e 's/"\([^"]\+\)": \(".*"\),/\1 = \2;/' | sed -e 's,},};,' # "
+    }
+
+    print_footer() {
+    cat <<EOF
+      ];
+    }
+    EOF
+    }
+
+    print_extra_pkg() {
+      local path=$1
+      local ref=$2
+      local repo=$3
+      echo    "{"
+      echo    "  goPackagePath = \"$path\";"
+      echo    ""
+      fetchgit_src $repo $ref | prefix "  "
+      echo "}"
+    }
+
+    # prepend given prefix to every line of its input. Used for pretty-printing.
+    prefix() {
+      sed -r -e "s/^/$1/" -e 's/^\s+$//'
+    }
+
+    read latest_rev latest_ver < <(latest_rev_and_ver)
+
+    if [[ $latest_ver == ${version} ]]; then
+      exit 0
+    fi
+
+    echo "Upgrading from ${version} to $latest_ver"
+    VENDOR=$(mktemp)
+    trap "rm -rf $VENDOR" EXIT
+    curl https://raw.githubusercontent.com/$GITHUB_SLUG/v$latest_ver/vendor/vendor.json -o $VENDOR
+
+    OUT=pkgs/development/tools/packer/deps.nix
+
+    print_header $latest_ver $latest_rev > $OUT
+
+    while read pkg_ref pkg_path ; do
+      read repo new_path < <(path_to_repo $pkg_path)
+      echo $pkg_path '->' $new_path '=' $repo
+      print_extra_pkg $new_path $pkg_ref $repo | prefix "    " >> $OUT
+    done < <(vendor_packages | sort -k 2)
+
+    print_footer >> $OUT
   '';
 
   meta = with stdenv.lib; {