Add hierarchy back to builds in releases.

This adds the notion of hierarchy to builds within a release.
If a build has a symlink named "parent" in its directory, then it will
inherit barclamp metadata from the build that the parent symlink points to.

This patch also adds more paranoia when doing builds using a git
managed build cache.

build_lib.sh

@@ -820,7 +820,8 @@ test_iso() {
 get_repo_cfg() { in_repo git config --get "$1"; }
 git_config_has() { git config --get "$1" &>/dev/null; }
 current_build() { get_repo_cfg 'crowbar.build'; }
-build_exists() [[ -f $CROWBAR_DIR/releases/$1/barclamp-crowbar ]]
+build_exists() [[ -f $CROWBAR_DIR/releases/$1/barclamp-crowbar || \
+    -L $CROWBAR_DIR/releases/$1/parent ]]
 
 barclamp_exists_in_build() { 
     local build=${1%/*} bc=${1##*/}
@@ -862,23 +863,59 @@ barclamp_finder() {
     done < <(find "$CROWBAR_DIR/releases/$1" -name 'barclamp-*') |sort -u
 }
 
-barclamps_in_build() {
+barclamps_from_build() {
     flat_checkout || die "Cannot get list of barclamps, must flatten build first!"
     local build bc
     build="${1:-$(current_build)}"
     barclamp_finder "$build" '/barclamp-(.+)$'
 }
 
+parent_build() {
+    build_exists "$1" || die "Cannot find parent of nonexistent build $1"
+    [[ -L $CROWBAR_DIR/releases/$1/parent ]] || return 0
+    local p
+    p="$(readlink -f "$CROWBAR_DIR/releases/$1/parent")"
+    echo "${p##*releases/}"
+}
+
+barclamps_in_build() {
+    local build bc p
+    build="${1:-$(current_build)}"
+    p="$(parent_build "$build")"
+    [[ $p ]] && barclamps_in_build "$p"
+    barclamps_from_build "$build"
+}
+
 barclamps_in_release() {
     local release="${1:-$(current_release)}"
     release_exists "$release" || return 1
     barclamp_finder "$release" '/barclamp-(.+)$'
 }
 
 builds_in_release() {
-    local release="${1:-$(current_release)}"
+    local release="${1:-$(current_release)}" p build b
+    local -A builds
     release_exists "$release" || return 1
-    barclamp_finder "$release" "releases/.+/([^/]+)/barclamp-crowbar"
+    for build in $(barclamp_finder "$release" "releases/.+/([^/]+)/barclamp-crowbar"); do
+        p=$(parent_build "$release/$build")
+        if [[ $p && ${builds[$p]} != echoed  ]]; then
+            builds["$release/$build"]="$p"
+        else
+            echo "$build"
+            builds["$release/$build"]="echoed"
+        fi
+    done
+    while [[ true ]]; do
+        b=true
+        for build in "${!builds[@]}"; do
+            p="${builds[$build]}"
+            [[ $p = echoed || ${builds[$p]} != echoed ]] && continue
+            echo "${build##*/}"
+            builds[$build]=echoed
+            b=false
+        done
+        [[ $b = true ]] && break
+    done
 }
 
 all_barclamps() {

releases/development/cloudera-build/parent

@@ -0,0 +1 @@
+../cloudera-os-build

releases/development/cloudera-os-build/parent

@@ -0,0 +1 @@
+../master

releases/development/hadoop-build/parent

@@ -0,0 +1 @@
+../hadoop-os-build

releases/development/hadoop-os-build/parent

@@ -0,0 +1 @@
+../master

releases/development/openstack-build/parent

@@ -0,0 +1 @@
+../openstack-os-build

releases/development/openstack-os-build/parent

@@ -0,0 +1 @@
+../master

releases/elefante/cloudera-build/parent

@@ -0,0 +1 @@
+../cloudera-os-build

releases/elefante/cloudera-os-build/parent

@@ -0,0 +1 @@
+../master

releases/essex-hack/openstack-build/parent

@@ -0,0 +1 @@
+../openstack-os-build

releases/essex-hack/openstack-os-build/parent

@@ -0,0 +1 @@
+../master