Fix & Document static deployment CLI support

docs/howto-deploy-learn-ocaml-statically.md

@@ -0,0 +1,65 @@
+How to deploy learn-ocaml statically
+====================================
+
+This section explains how to deploy a static version of learn-ocaml on
+an HTTP server.
+
+## Using pre-built docker images
+
+You will just need to:
+
+- install Docker Engine (<https://docs.docker.com/get-docker/>)
+- build the `www` folder by using the commands below
+- use an HTTP server to serve learn-ocaml statically.
+
+Assuming your exercise repository is in directory `$REPOSITORY` and
+you want to generate the website contents in directory `$TARGET/www`
+to serve it at `$URL` (the base URL **without trailing slash**), then
+you can run:
+
+```bash
+# Remove old version
+cd "$TARGET"
+rm -fr www
+# Get the last (dev) version of learn-ocaml
+sudo docker pull ocamlsf/learn-ocaml:master
+# Build the site within a Docker container
+sudo docker run --rm -i --entrypoint="" \
+  -v "$REPOSITORY:/repository" -v "$TARGET:/home/learn-ocaml/target" \
+  ocamlsf/learn-ocaml:master \
+  sh -c "learn-ocaml build --repo=/repository --base-url $URL && mv www target/"
+```
+
+Regarding the `--base-url` option, if you plan to deploy the `www`
+directory with **GitHub Pages**, assuming the underlying GitHub repo
+(either public or private) is `https://github.com/user-name/repo-name`
+then you should first run:
+
+```bash
+export URL=https://user-name.github.io/repo-name
+```
+
+For a comprehensive example of one such deployment, you may take a
+look at the following repository:
+- <https://github.com/pfitaxel/pfitaxel-demo>
+- deployed to <https://pfitaxel.github.io/pfitaxel-demo>
+- thanks to this [`deploy` script](https://github.com/pfitaxel/pfitaxel-demo/blob/master/deploy).
+
+## Manual compilation
+
+Note: you need a working `opam` environment (version 2.0+) as well as
+an `opam switch` and a compiled version of `learn-ocaml` (see
+[How to deploy a learn-ocaml instance](howto-deploy-a-learn-ocaml-instance.md#manual-compilation)
+for details).
+
+Assuming your exercise repository is in directory `$REPOSITORY` and
+you want to generate the website contents in directory `$TARGET/www`
+to serve it at `$URL` (the base URL **without trailing slash**), then
+you can run:
+
+```bash
+rm -fr "$TARGET/www"
+cd .../learn-ocaml  # go to the learn-ocaml git repo
+learn-ocaml build --repo=$REPOSITORY --base-url $URL
+mv www "$TARGET/www"
+```

src/app/learnocaml_config.ml

@@ -13,8 +13,8 @@ class type learnocaml_config = object
   method enablePlayground: bool Js.optdef_prop
   method txtLoginWelcome: Js.js_string Js.t Js.optdef_prop
   method txtNickname: Js.js_string Js.t Js.optdef_prop
-  method root: Js.js_string Js.t Js.optdef_prop
+  method baseUrl: Js.js_string Js.t Js.optdef_prop
 end
 
 let config : learnocaml_config Js.t = Js.Unsafe.js_expr "learnocaml_config"
-let api_server = Js.(to_string (Optdef.get config##.root (fun () -> string "")))
+let api_server = Js.(to_string (Optdef.get config##.baseUrl (fun () -> string "")))

src/app/learnocaml_config.mli

@@ -17,7 +17,7 @@ class type learnocaml_config = object
   method enablePlayground: bool Js.optdef_prop
   method txtLoginWelcome: Js.js_string Js.t Js.optdef_prop
   method txtNickname: Js.js_string Js.t Js.optdef_prop
-  method root: Js.js_string Js.t Js.optdef_prop
+  method baseUrl: Js.js_string Js.t Js.optdef_prop
 end
 
 val config : learnocaml_config Js.t

src/main/learnocaml_main.ml

@@ -47,6 +47,15 @@ module Args = struct
       "Directory where the app should be generated for the $(i,build) command, \
        and from where it is served by the $(i,serve) command."
 
+  let base_url =
+    value & opt string "" &
+      info ["base-url"] ~docv:"BASE_URL" ~env:(Arg.env_var "LEARNOCAML_BASE_URL") ~doc:
+        "Set the base URL of the website. \
+         Should not end with a trailing slash. \
+         Currently, this has no effect on the backend - '$(b,learn-ocaml serve)'. \
+         Mandatory for '$(b,learn-ocaml build)' if the site is not hosted in path '/', \
+         which typically occurs for static deployment."
+
   module Grader = struct
     let info = info ~docs:"GRADER OPTIONS"
 
@@ -180,27 +189,22 @@ module Args = struct
       value & opt int 1 & info ["jobs";"j"] ~docv:"INT" ~doc:
         "Number of building jobs to run in parallel"
 
-    let root =
-      value & opt string "" & info ["root"] ~docv:"ROOT" ~doc:
-        "Set the root of all documents.  Use only for static deployment.\
-         Should not end with a trailing slash."
-
     type t = {
       contents_dir: string;
       try_ocaml: bool option;
       lessons: bool option;
       exercises: bool option;
       playground: bool option;
       toplevel: bool option;
-      root: string
+      base_url: string
     }
 
     let builder_conf =
       let apply
-        contents_dir try_ocaml lessons exercises playground toplevel root
-        = { contents_dir; try_ocaml; lessons; exercises; playground; toplevel; root }
+        contents_dir try_ocaml lessons exercises playground toplevel base_url
+        = { contents_dir; try_ocaml; lessons; exercises; playground; toplevel; base_url }
       in
-      Term.(const apply $contents_dir $try_ocaml $lessons $exercises $playground $toplevel $root)
+      Term.(const apply $contents_dir $try_ocaml $lessons $exercises $playground $toplevel $base_url)
 
     let repo_conf =
       let apply repo_dir exercises_filtered jobs =
@@ -241,16 +245,16 @@ module Args = struct
       { commands; app_dir; repo_dir; grader; builder; server }
     in
     Term.(const apply $commands $app_dir $repo_dir
-          $Grader.term $Builder.term $Server.term app_dir)
+          $Grader.term $Builder.term $Server.term app_dir base_url)
 end
 
 open Args
 
-let process_html_file orig_file dest_file root =
+let process_html_file orig_file dest_file base_url =
   let transform_tag e tag attrs attr =
     let attr_pair = ("", attr) in
     match List.assoc_opt attr_pair attrs with
-    | Some url -> `Start_element ((e, tag), (attr_pair, root ^ url) :: (List.remove_assoc attr_pair attrs))
+    | Some url -> `Start_element ((e, tag), (attr_pair, base_url ^ url) :: (List.remove_assoc attr_pair attrs))
     | None -> `Start_element ((e, tag), attrs) in
   Lwt_io.open_file ~mode:Lwt_io.Input orig_file >>= fun ofile ->
   Lwt_io.open_file ~mode:Lwt_io.Output dest_file >>= fun wfile ->
@@ -322,11 +326,13 @@ let main o =
          let json_config = ServerData.build_config preconfig in
          Learnocaml_store.write_to_file ServerData.config_enc json_config www_server_config
        >>= fun () ->
+         if o.builder.Builder.base_url <> "" then
+           Printf.printf "Base URL: %s\n%!" o.builder.Builder.base_url;
        Lwt_unix.files_of_directory o.builder.Builder.contents_dir
        |> Lwt_stream.iter_s (fun file ->
               if Filename.extension file = ".html" then
                 process_html_file (o.builder.Builder.contents_dir/file)
-                  (o.app_dir/file) o.builder.Builder.root
+                  (o.app_dir/file) o.builder.Builder.base_url
               else
                 Lwt.return_unit) >>= fun () ->
        let if_enabled opt dir f = (match opt with
@@ -363,14 +369,14 @@ let main o =
               \  enableLessons: %b,\n\
               \  enableExercises: %b,\n\
               \  enableToplevel: %b,\n\
-              \  root: \"%s\"\n\
+              \  baseUrl: \"%s\"\n\
                }\n"
               (tutorials_ret <> None)
               (playground_ret <> None)
               (lessons_ret <> None)
               (exercises_ret <> None)
               (o.builder.Builder.toplevel <> Some false)
-              o.builder.Builder.root >>= fun () ->
+              o.builder.Builder.base_url >>= fun () ->
        Lwt.return (tutorials_ret <> Some false && exercises_ret <> Some false)))
     else
       Lwt.return true
@@ -383,14 +389,18 @@ let main o =
           let open Server in
           ("--app-dir="^o.app_dir) ::
           ("--sync-dir="^o.server.sync_dir) ::
+          ("--base-url="^o.builder.Builder.base_url) ::
           ("--port="^string_of_int o.server.port) ::
           (match o.server.cert with None -> [] | Some c -> ["--cert="^c])
         in
         Unix.execv native_server (Array.of_list (native_server::server_args))
-      else
-        Printf.printf "Starting server on port %d\n%!"
-          !Learnocaml_server.port;
-      Learnocaml_server.launch ()
+      else begin
+          Printf.printf "Starting server on port %d\n%!"
+            !Learnocaml_server.port;
+          if o.builder.Builder.base_url <> "" then
+            Printf.printf "Base URL: %s\n%!" o.builder.Builder.base_url;
+          Learnocaml_server.launch ()
+        end
     else
       Lwt.return true
   in

src/main/learnocaml_server_args.ml

@@ -34,12 +34,13 @@ let port =
 
 type t = {
   sync_dir: string;
-  cert: string option;
+  base_url: string;
   port: int;
+  cert: string option;
 }
 
-let term app_dir =
-  let apply app_dir sync_dir port cert =
+let term app_dir base_url =
+  let apply app_dir sync_dir base_url port cert =
     Learnocaml_store.static_dir := app_dir;
     Learnocaml_store.sync_dir := sync_dir;
     let port = match port, cert with
@@ -52,8 +53,9 @@ let term app_dir =
        | Some base -> Some (base ^ ".pem", base ^ ".key");
        | None -> None);
     Learnocaml_server.port := port;
-    { sync_dir; port; cert }
+    Learnocaml_server.base_url := base_url;
+    { sync_dir; base_url; port; cert }
   in
   (* warning: if you add any options here, remember to pass them through when
      calling the native server from learn-ocaml main *)
-  Term.(const apply $app_dir $sync_dir $port $cert)
+  Term.(const apply $ app_dir $ sync_dir $ base_url $ port $ cert)

src/main/learnocaml_server_args.mli

@@ -8,8 +8,9 @@
 
 type t = {
   sync_dir: string;
-  cert: string option;
+  base_url: string;
   port: int;
+  cert: string option;
 }
 
-val term: string Cmdliner.Term.t -> t Cmdliner.Term.t
+val term: string Cmdliner.Term.t -> string Cmdliner.Term.t -> t Cmdliner.Term.t

src/main/learnocaml_server_main.ml

@@ -24,6 +24,8 @@ let signal_waiter =
 let main o =
   Printf.printf "Learnocaml server v.%s starting on port %d\n%!"
     Learnocaml_api.version o.port;
+  if o.base_url <> "" then
+    Printf.printf "Base URL: %s\n%!" o.base_url;
   let rec run () =
     let minimum_duration = 15. in
     let t0 = Unix.time () in
@@ -68,9 +70,18 @@ let app_dir =
     "Directory where the app has been generated by the $(b,learn-ocaml build) \
      command, and from where it will be served."
 
+let base_url =
+  let open Cmdliner.Arg in
+  value & opt string "" &
+    info ["base-url"] ~docv:"BASE_URL" ~env:(env_var "LEARNOCAML_BASE_URL") ~doc:
+      "Set the base URL of the website. \
+       Should not end with a trailing slash. \
+       Currently, this has no effect on the backend - '$(b,learn-ocaml serve)'. \
+       Mandatory for '$(b,learn-ocaml build)' if the site is not hosted in path '/', \
+       which typically occurs for static deployment."
 
 let main_cmd =
-  Cmdliner.Term.(const main $ Learnocaml_server_args.term app_dir),
+  Cmdliner.Term.(const main $ Learnocaml_server_args.term app_dir base_url),
   Cmdliner.Term.info
     ~man
     ~doc:"Learn-ocaml web-app manager"

src/server/learnocaml_server.ml

@@ -15,11 +15,19 @@ let cert_key_files = ref None
 
 let log_channel = ref (Some stdout)
 
+let base_url = ref ""
+
 let args = Arg.align @@
   [ "-static-dir", Arg.Set_string static_dir,
     "PATH where static files should be found (./www)" ;
     "-sync-dir", Arg.Set_string sync_dir,
     "PATH where sync tokens are stored (./sync)" ;
+    "-base-url", Arg.Set_string base_url,
+    "BASE_URL of the website. \
+     Should not end with a trailing slash. \
+     Currently, this has no effect on the native backend. \
+     Mandatory for 'learn-ocaml build' if the site is not hosted in path '/', \
+     which typically occurs for static deployment." ;
     "-port", Arg.Set_int port,
     "PORT the TCP port (8080)" ]
 

src/server/learnocaml_server.mli

@@ -10,6 +10,7 @@
 
 val port: int ref
 val cert_key_files: (string * string) option ref
+val base_url: string ref
 
 val args: (Arg.key * Arg.spec * Arg.doc) list
 

static/exercise.html

@@ -33,7 +33,7 @@
     </div>
     <script language="JavaScript">
       var n = Math.floor (Math.random () * 8.99) + 1;
-      document.getElementById('chamo-img').src = learnocaml_config.root + '/icons/tryocaml_loading_' + n + '.gif';
+      document.getElementById('chamo-img').src = learnocaml_config.baseUrl + '/icons/tryocaml_loading_' + n + '.gif';
     </script>
     <!-- Anything below could be recreated dynamically, but IDs must be kept. -->
     <div id="learnocaml-exo-toolbar">

static/partition-view.html

@@ -33,7 +33,7 @@
     </div>
     <script language="JavaScript">
       var n = Math.floor (Math.random () * 8.99) + 1;
-      document.getElementById('chamo-img').src = '/icons/tryocaml_loading_' + n + '.gif';
+      document.getElementById('chamo-img').src = learnocaml_config.baseUrl + '/icons/tryocaml_loading_' + n + '.gif';
     </script>
     <!-- Anything below could be recreated dynamically, but IDs must be kept. -->
     <div id="learnocaml-exo-toolbar">

static/playground.html

@@ -32,7 +32,7 @@
     </div>
     <script language="JavaScript">
       var n = Math.floor (Math.random () * 8.99) + 1;
-      document.getElementById('chamo-img').src = learnocaml_config.root + '/icons/tryocaml_loading_' + n + '.gif';
+      document.getElementById('chamo-img').src = learnocaml_config.baseUrl + '/icons/tryocaml_loading_' + n + '.gif';
     </script>
     <!-- Anything below could be recreated dynamically, but IDs must be kept. -->
     <div id="learnocaml-exo-toolbar">

static/student-view.html

@@ -33,7 +33,7 @@
     </div>
     <script language="JavaScript">
       var n = Math.floor (Math.random () * 8.99) + 1;
-      document.getElementById('chamo-img').src = '/icons/tryocaml_loading_' + n + '.gif';
+      document.getElementById('chamo-img').src = learnocaml_config.baseUrl + '/icons/tryocaml_loading_' + n + '.gif';
     </script>
     <!-- Anything below could be recreated dynamically, but IDs must be kept. -->
     <div id="learnocaml-exo-toolbar">