[__download] add --download (local|remote), update manual

cdist/conf/type/__download/explorer/remote_cmd

@@ -0,0 +1,19 @@
+#!/bin/sh -e
+
+if [ -f "$__object/parameter/cmd-get" ]
+then
+    cmd="$( cat "$__object/parameter/cmd-get" )"
+
+elif command -v curl > /dev/null
+then
+    cmd="curl -o - '%s'"
+
+elif command -v fetch > /dev/null
+then
+    cmd="fetch -o - '%s'"
+
+else
+    cmd="wget -O - '%s'"
+fi
+
+echo "$cmd"

cdist/conf/type/__download/gencode-local

@@ -1,8 +1,10 @@
 #!/bin/sh -e
 
+download="$( cat "$__object/parameter/download" )"
+
 state_is="$( cat "$__object/explorer/state" )"
 
-if [ "$state_is" = 'present' ]
+if [ "$download" != 'local' ] || [ "$state_is" = 'present' ]
 then
     exit 0
 fi

cdist/conf/type/__download/gencode-remote

@@ -1,7 +1,25 @@
 #!/bin/sh -e
 
-if [ -f "$__object/parameter/onchange" ] \
-    && grep -Fq "$__object_id:downloaded" "$__messages_in"
+download="$( cat "$__object/parameter/download" )"
+
+state_is="$( cat "$__object/explorer/state" )"
+
+if [ "$download" = 'remote' ] && [ "$state_is" != 'present' ]
+then
+    cmd="$( cat "$__object/explorer/remote_cmd" )"
+
+    url="$( cat "$__object/parameter/url" )"
+
+    dst="/$__object_id"
+
+    printf "$cmd > %s\n" \
+        "$url" \
+        "$dst"
+
+    echo 'downloaded' > "$__messages_out"
+fi
+
+if [ -f "$__object/parameter/onchange" ] && [ "$state" != "present" ]
 then
     cat "$__object/parameter/onchange"
 fi

cdist/conf/type/__download/man.rst

@@ -3,26 +3,28 @@ cdist-type__download(7)
 
 NAME
 ----
-cdist-type__download - Download file to local storage and copy it to target host
+cdist-type__download - Download a file
 
 
 DESCRIPTION
 -----------
-You must use persistent storage in target host for destination file
-(``$__object_id``) because it will be used for checksum calculation
-in order to decide if file must be (re-)downloaded.
+Persistent storage for destination file in target host must be used
+(``$__object_id``) because it will be used for checksum calculation in
+order to decide if file must be (re-)downloaded.
 
-By default type will try to use following locally installed utilities
-for downloading (in order): ``wget``, ``curl`` or ``fetch``.
+By default type will try to use ``wget``, ``curl`` or ``fetch`` for
+downloading.  If ``--download remote`` type will fallback to (and
+install) ``wget``.
 
-Environment variables like ``{http,https,ftp}_proxy`` etc can be used on
-cdist execution (``http_proxy=foo cdist config ...``).
+If ``--download local`` (default), then environment variables like
+``{http,https,ftp}_proxy`` etc can be used on cdist execution
+(``http_proxy=foo cdist config ...``).
 
 
 REQUIRED PARAMETERS
 -------------------
 url
-   URL from which to download the file.
+   File's URL.
 
 sum
    Checksum of file going to be downloaded.
@@ -35,6 +37,10 @@ onchange
 
 OPTIONAL PARAMETERS
 -------------------
+download
+   If ``local`` (default), then download file to local storage and copy
+   it to target host. If ``remote``, then download happens in target.
+
 cmd-get
    Command used for downloading.
    Command must output to ``stdout``.

cdist/conf/type/__download/manifest

@@ -0,0 +1,6 @@
+#!/bin/sh -e
+
+if grep -Eq '^wget' "$__object/explorer/remote_cmd"
+then
+    __package wget
+fi

cdist/conf/type/__download/parameter/default/download

@@ -0,0 +1 @@
+local

cdist/conf/type/__download/parameter/optional

@@ -1,3 +1,4 @@
 cmd-get
 cmd-sum
+download
 onchange