builder: Use progress bar for large template downloads that are not in the cache.

TODO

@@ -554,14 +554,9 @@ virt-builder
 
  - set default timezone and language
 
- - the initial download of the template can take quite a long time
-   and needs a progress bar
-
  - how can we debug it?  at least document how to call virt-rescue
    guestfish etc to look at files
 
  - how can we give users a shell?
 
- - use a single log file and dump it out on command failure
-
  - Ubuntu templates

builder/builder.ml

@@ -415,7 +415,8 @@ let template =
     let { Index_parser.revision = revision; file_uri = file_uri } = entry in
     let template = arg, revision in
     msg (f_"Downloading: %s") file_uri;
-    Downloader.download downloader ~template file_uri in
+    let progress_bar = not quiet in
+    Downloader.download downloader ~template ~progress_bar file_uri in
   if delete_on_exit then unlink_on_exit template;
   template
 

builder/downloader.ml

@@ -39,19 +39,19 @@ let create ~debug ~curl ~cache = {
   cache = cache;
 }
 
-let rec download t ?template uri =
+let rec download t ?template ?progress_bar uri =
   match template with
   | None ->                       (* no cache, simple download *)
     (* Create a temporary name. *)
     let tmpfile = Filename.temp_file "vbcache" ".txt" in
-    download_to t uri tmpfile;
+    download_to t ?progress_bar uri tmpfile;
     (tmpfile, true)
 
   | Some (name, revision) ->
     match t.cache with
     | None ->
       (* Not using the cache at all? *)
-      download t uri
+      download t ?progress_bar uri
 
     | Some cachedir ->
       let filename = cachedir // sprintf "%s.%d" name revision in
@@ -60,14 +60,16 @@ let rec download t ?template uri =
        * If not, download it.
        *)
       if not (Sys.file_exists filename) then
-        download_to t uri filename;
+        download_to t ?progress_bar uri filename;
 
       (filename, false)
 
-and download_to t uri filename =
+and download_to t ?(progress_bar = false) uri filename =
   (* Get the status code first to ensure the file exists. *)
   let cmd = sprintf "%s%s -g -o /dev/null -I -w '%%{http_code}' %s"
-    t.curl (if t.debug then "" else " -s -S") (quote uri) in
+    t.curl
+    (if t.debug then "" else " -s -S")
+    (quote uri) in
   let chan = open_process_in cmd in
   let status_code = input_line chan in
   let stat = close_process_in chan in
@@ -100,7 +102,8 @@ and download_to t uri filename =
   (* Now download the file. *)
   let filename_new = filename ^ ".new" in
   let cmd = sprintf "%s%s -g -o %s %s"
-    t.curl (if t.debug then "" else " -s -S")
+    t.curl
+    (if t.debug then "" else if progress_bar then " -#" else " -s -S")
     (quote filename_new) (quote uri) in
   if t.debug then eprintf "%s\n%!" cmd;
   let r = Sys.command cmd in

builder/downloader.mli

@@ -27,7 +27,7 @@ type t
 val create : debug:bool -> curl:string -> cache:string option -> t
 (** Create the abstract type. *)
 
-val download : t -> ?template:(string*int) -> uri -> (filename * bool)
+val download : t -> ?template:(string*int) -> ?progress_bar:bool -> uri -> (filename * bool)
 (** Download the URI, returning the downloaded filename and a
     temporary file flag.  The temporary file flag is [true] iff
     the downloaded file is temporary and should be deleted by the
@@ -35,4 +35,8 @@ val download : t -> ?template:(string*int) -> uri -> (filename * bool)
 
     For templates, you must supply [~template:(name, revision)].  This
     causes the cache to be used (if possible).  Name and revision are
-    used for cache control (see the man page for details). *)
+    used for cache control (see the man page for details).
+
+    If [~progress_bar:true] then display a progress bar if the file
+    doesn't come from the cache.  In debug mode, progress messages
+    are always displayed. *)