How can I set up a local paclet server? (easy package sharing via shared DropBox)

Question

I want to set up a local paclet server (i.e. on my own machine, not the web), how can I do this?

---

Sample Reason

My very numerous group of very real friends like to work on very real projects together.

We'd like to set up local shared DropBox account to store our packages (which will of course be versioned with git), and would like to be able to load our packages via the <<PackageName` syntax.

On the other hand we do not want to put this folder on $Path or add it with PacletDirectoryAdd for control reasons.

Much better would be able to use it as if it were a local paclet server.

Answer 1

So the trick here is to use the file:// URL protocol:

First set up a paclet server in the standard way (see also my brief explanation here)

Next we need to set up our file:// URL properly. For example, I keep the local version of my paclet server here, before pushing it to the cloud:

serverDir =
  FileNameJoin@
   {
    $UserBaseDirectory,
    "ApplicationData",
    "WebSites",
    "PacletServer"
    };

To create an appropriate file URL we'll need to tweak the output of URLBuild like so:

serverURL =
  StringReplace["file:" -> "file://"]@
   URLBuild@
    <|
     "Scheme" -> "file",
     "Path" ->
      FileNameSplit[serverDir]
     |>;

Then we can install a paclet like so:

PacletInstall[
 "SiteBuilder",
 "Site" -> serverURL
 ]

PacletManager`Paclet[
"Name" -> "SiteBuilder", "Version" -> "1.0.8", 
 "Creator" -> "[email protected]", 
 "Description" -> "Implements a configuration scheme for building and \
deploying sites a la pelican.\n  Forked from BTools.", 
 "Extensions" -> {{
   "Kernel", "Root" -> ".", "Context" -> {"SiteBuilder`"}}}, 
 "Tags" -> {"web"}, "Categories" -> {"Services"}, 
 "Location" -> "~/Library/Mathematica/Paclets/Repository/\
SiteBuilder-1.0.8"]

Note for pre-11.2:

Owing to a bug in the PacletManager that seems to have been fixed in 11.2, the file:// protocol was not appropriately supported. If you're using 11.1 or below you'll need to patch the PacletInstall functions like so:

If[$VersionNumber < 11.2,
 PacletManager`Services`Private`finishPacletSiteUpdate[
   {
    PacletManager`Private`siteURL_, 
    PacletManager`Private`file_, 
    PacletManager`Private`interactive_, 
    PacletManager`Private`async_, 
    0}
   ] := 
  PacletManager`Services`Private`finishPacletSiteUpdate[
   {
    PacletManager`Private`siteURL, 
    PacletManager`Private`file, 
    PacletManager`Private`interactive, 
    PacletManager`Private`async, 
    200}
   ];
 PacletManager`Package`getTaskData[task_] := 
  Block[{PacletManager`Private`$override = True}, 
    Replace[PacletManager`Package`getTaskData[task], 
     {
       PacletManager`Private`a_, 
       PacletManager`Private`b_, 
       PacletManager`Private`c_, 
       PacletManager`Private`d_, 
       PacletManager`Private`e_, 0, 
       PacletManager`Private`rest__} :> 
      {
       PacletManager`Private`a, 
       PacletManager`Private`b, 
       PacletManager`Private`c, 
       PacletManager`Private`d, 
       PacletManager`Private`e,
        200, 
       PacletManager`Private`rest}]
    ] /; ! TrueQ[PacletManager`Private`$override]
 ]

Helper Function:

We can wrap all of this up into a convenient local-install function:

localPacletPull[pacletName_, dir : (_String | _File)?DirectoryQ] :=

  With[{
    serverURL =
     StringReplace["file:" -> "file://"]@
      URLBuild@
       <|
        "Scheme" -> "file",
        "Path" ->
         FileNameSplit[dir]
        |>
    },
   If[$VersionNumber < 11.2,
    PacletManager`Services`Private`finishPacletSiteUpdate[
      {
       PacletManager`Private`siteURL_, 
       PacletManager`Private`file_, 
       PacletManager`Private`interactive_, 
       PacletManager`Private`async_, 
       0}
      ] := 
     PacletManager`Services`Private`finishPacletSiteUpdate[
      {
       PacletManager`Private`siteURL, 
       PacletManager`Private`file, 
       PacletManager`Private`interactive, 
       PacletManager`Private`async, 
       200}
      ];
    PacletManager`Package`getTaskData[task_] := 
     Block[{PacletManager`Private`$override = True}, 
       Replace[PacletManager`Package`getTaskData[task], 
        {
          PacletManager`Private`a_, 
          PacletManager`Private`b_, 
          PacletManager`Private`c_, 
          PacletManager`Private`d_, 
          PacletManager`Private`e_, 0, 
          PacletManager`Private`rest__} :> 
         {
          PacletManager`Private`a, 
          PacletManager`Private`b, 
          PacletManager`Private`c, 
          PacletManager`Private`d, 
          PacletManager`Private`e, 200, 
          PacletManager`Private`rest}]
       ] /; ! TrueQ[PacletManager`Private`$override]
    ];
   If[Length@PacletFind[pacletName] > 0,
    PacletUpdate[pacletName,
     "Site" -> serverURL
     ],
    PacletInstall[pacletName,
     "Site" -> serverURL
     ]
    ]
   ];

So, e.g., if I know my paclet server is at ~/Dropbox/PacletServer, I can do:

localPacletPull[paclet, "~/Dropbox/PacletServer"]

And it will install / update that paclet from my DropBox server