gpm bootstrap command

bin/gpm

@@ -3,6 +3,9 @@
 set -eu
 
 ## Functions/
+
+## Prints out usage information
+#
 usage() {
 cat << EOF
 SYNOPSIS
@@ -27,47 +30,145 @@ SYNOPSIS
 
 USAGE
       $ gpm             # Same as 'install'.
+
       $ gpm install     # Parses the Godeps file, installs dependencies and sets
                         # them to the appropriate version.
+
+      $ gpm bootstrap   # Downloads all external top-level packages required by
+                        # your application and generates a Godeps file with their
+                        # latest tags or revisions.
+
       $ gpm version     # Outputs version information
+
       $ gpm help        # Prints this message
 EOF
 }
 
-# Iterates over Godep file dependencies and sets
-# the specified version on each of them.
+## Iterates over Godep file dependencies and sets
+## the specified version on each of them.
+#
 set_dependencies() {
   deps=$(sed 's/#.*//;/^\s*$/d' < "Godeps") || echo ""
 
   while read package version; do
     (
-      install_path="${GOPATH%%:*}/src/${package%%/...}"
-      [[ -e "$install_path/.git/index.lock" ||
-      -e "$install_path/.hg/store/lock" ||
-      -e "$install_path/.bzr/checkout/lock" ]] && wait
       echo ">> Getting package "$package""
       go get -u -d "$package"
       echo ">> Setting $package to version $version"
-      cd $install_path
-      [ -d .hg ]  && hg update    -q      "$version"
-      [ -d .git ] && git checkout -q      "$version"
-      [ -d .bzr ] && bzr revert   -q -r   "$version"
+      set_package_to_version $package $version
     ) &
   done < <(echo "$deps")
   wait
   echo ">> All Done"
 }
 
+## Sets a given package to a given revision using
+## the appropriate VCS.
+#
+set_package_to_version() {
+  cd "${GOPATH%%:*}/src/${1%%/...}"
+
+  ## Avoid multiple processes messing with the same
+  ## package at the same time.
+  [[ -e "$PWD/.git/index.lock" ||
+  -e "$PWD/.hg/store/lock" ||
+  -e "$PWD/.bzr/checkout/lock" ]] && wait
+
+  [ -d .hg ]  && hg update    -q      "$2"
+  [ -d .git ] && git checkout -q      "$2"
+  [ -d .bzr ] && bzr revert   -q -r   "$2"
+}
+
+## Gets external dependencies from the Go project, determines
+## their latest tags (or failing that, revisions), creates a
+## Godeps file and installs al pertinent packages in their desired
+## revisions.
+#
+bootstrap() {
+  echo ">> Installing dependencies."
+  go get -d
+  dependencies=`go list -f '{{join .Deps "\n"}}' |
+                xargs go list -f '{{if not .Standard}}{{.ImportPath}}{{end}}'`
+
+  while read package; do
+    #(
+      version=`find_last_tag_or_HEAD "$package"`
+      [ -n "$version" ] && (
+        echo ">> Adding package "$package" version "$version" to Godeps."
+        echo ""$package" "$version"" >> Godeps
+        set_package_to_version $package $version
+      )
+    #) &
+  done < <(echo "$dependencies")
+  #wait
+  echo ">> All Done."
+}
+
+## Returns the latest tag (or, failing that latest revision)
+## for an installed package.
+#
+find_last_tag_or_HEAD() {
+  cd "${GOPATH%%:*}/src/${1%%/...}"
+
+  ## If no repo file is found it means we are inside a repo's
+  ## subdirectory tree, we can just ignore this package.
+  [ ! -d .git ] && [ ! -d .bzr ] && [ ! -d .hg ] &&
+    echo ">> Ignored $1, not top-level package." 1>&2 && return
+
+  [ -d .git ] && (
+    # FIXME: there should be a better way,  but git tags returns in alphabetical order.
+    version=`git tag |
+            xargs -I@ git log --format=format:"%ai @%n" -1 @ |
+            sort |
+            awk '{print $4}' |
+            tail -1`
+
+
+    [ -n "$version" ] && echo "$version" && return
+
+    version=`git log -n 1 --pretty=oneline | cut -d " " -f 1`
+    echo ">> No tags on package "$1", setting version to latest revision." 1>&2
+    echo "$version" && return
+  )
+
+  [ -d .bzr ] && (
+    version=`bzr tags | tail -1 | cut -d " " -f 1`
+    [ -n "$version" ] && echo "$version" && return
+
+    version=`bzr log -r-1 --log-format=line | cut -d ":" -f 1`
+    echo ">> No tags on package "$1", setting version to latest revision." 1>&2
+    echo "$version" && return
+  )
+
+  [ -d .hg ] && (
+    version=`hg parents --template "{latesttag}"`
+
+    [ "$version" != "null" ] && echo "$version" && return
+
+    version=`hg log --template "{node}" -l 1`
+    echo ">> No tags on package "$1", setting version to latest_revision." 1>&2
+    echo "$version" && return
+  )
+
+  echo " "
+}
 ## /Functions
+
 case "${1:-"install"}" in
   "version")
     echo ">> gpm v1.0.1"
     ;;
   "install")
     [[ -f "Godeps" ]] || (echo ">> Godeps file does not exist." && exit 1)
-    (which go > /dev/null) || ( echo ">> Go is currently not installed or in your PATH" && exit 1)
+    (which go > /dev/null) ||
+      ( echo ">> Go is currently not installed or in your PATH" && exit 1)
     set_dependencies
     ;;
+  "bootstrap")
+    [[ -f "Godeps" ]] &&
+      echo ">> A Godeps file exists within this directory." && exit 1
+    bootstrap
+    ;;
   "help")
     usage
     ;;