new: ``host-resources`` implementation.

bin/compose

@@ -299,6 +299,10 @@ export -f image_exposed_ports_0
 ## Generic
 ##
 
+fn.exists() {
+    declare -F "$1" >/dev/null
+}
+
 str_matches() {
     local str="$1"
     shift
@@ -1104,6 +1108,95 @@ EOF
 }
 
 
+host_resource_get() {
+    local location="$1" cfg="$2"
+    type=$(echo "$cfg" | shyaml get-value type 2>/dev/null) || {
+        err "Missing ${WHITE}type$NORMAL option in ${WHITE}get$NORMAL config for location '$location'"
+        return 1
+    }
+    if fn.exists host_resource_get_$type; then
+        host_resource_get_$type "$location" "$cfg"
+    else
+        err "Source ${WHITE}source$NORMAL type '$type' unknown for" \
+            "${WHITE}host-resource$NORMAL '$location' defined in" \
+            "$DARKYELLOW$subservice$NORMAL config."
+        return 1
+    fi
+}
+export -f host_resource_get
+
+
+host_resource_get_git() {
+    local location="$1" cfg="$2" branch parent url
+    branch=$(echo "$cfg" | shyaml get-value branch 2>/dev/null)
+    branch=${branch:-master}
+
+    url=$(echo "$cfg" | shyaml get-value url 2>/dev/null)
+    parent="$(dirname "$location")"
+    (
+        mkdir -p "$parent" && cd "$parent" &&
+            git clone -b "$branch" "$url" "$(basename "$location")"
+    ) || return 1
+}
+export -f host_resource_get_git
+
+
+host_resource_get_git-sub() {
+    local location="$1" cfg="$2" branch parent url
+    branch=$(echo "$cfg" | shyaml get-value branch 2>/dev/null)
+    branch=${branch:-master}
+
+    url=$(echo "$cfg" | shyaml get-value url 2>/dev/null)
+    parent="$(dirname "$location")"
+    (
+        mkdir -p "$parent" && cd "$parent" &&
+            git sub clone -b "$branch" "$url" "$(basename "$location")"
+    ) || return 1
+}
+export -f host_resource_get_git-sub
+
+
+setup_host_resources () {
+    local services="$1" action="$2" loaded location cfg
+
+    declare -A loaded
+    for service in $services; do
+        for subservice in $(get_ordered_service_dependencies "$service"); do
+            if [ "${loaded[$subservice]}" ]; then
+                ## Prevent double inclusion of same service if this
+                ## service is deps of two or more of your
+                ## requirements.
+                continue
+            fi
+
+            service_def=$(get_compose_service_def "$subservice") || return 1
+            while read-0 location cfg; do
+                ## XXXvlab: will it be a git resources always ?
+                if [ -d "$location" -a ! -d "$location/.git" ]; then
+                    err "Hum, location '$location' does not seem to be a git directory."
+                    return 1
+                fi
+                if [ -d "$location" ]; then
+                    info "host resource '$location' already set up."
+                    continue
+                fi
+                get=$(echo "$cfg" | shyaml get-value get 2>/dev/null)
+
+                if [ -z "$get" ]; then
+                    err "No host directory '$location' found, and no ${WHITE}source$NORMAL" \
+                        "specified for $DARKYELLOW$subservice$NORMAL."
+                    return 1
+                fi
+                host_resource_get "$location" "$get" || return 1
+            done < <(echo "$service_def" | shyaml key-values-0 host-resources 2>/dev/null)
+
+            loaded[$subservice]=1
+        done
+    done
+    return 0
+}
+
+
 relation-get () {
     local key="$1"
     cat "$RELATION_DATA_FILE" | shyaml get-value "$key" 2>/dev/null
@@ -2240,6 +2333,8 @@ esac
 if [ "$full_init" ]; then
     ## init in order
     if [ -z "$no_init" ]; then
+        Section setup host resources
+        setup_host_resources "$services" || exit 1
         Section initialisation
         run_service_hook "$services" init || exit 1
     fi