Very basic git-annex-shell support, not checked repo copies yet

1 files changed, 90 insertions, 0 deletions

diff --git a/plugins/git-annex.lua b/plugins/git-annex.lua
new file mode 100644
index 0000000..a64a030
--- /dev/null
+++ b/plugins/git-annex.lua
@@ -0,0 +1,90 @@
+-- Git Annex Plugin
+--
+-- This plugin enables support for git-annex on the server-side which allows
+-- for the storage of large binary files efficiently in git.
+--
+-- Copyright 2016 Daniel Silverstone <daniel.silverstone@codethink.co.uk>
+
+local gitano = require "gitano"
+
+local sp = require "luxio.subprocess"
+
+local git_annex_short_help = "Simple git-annex command"
+local git_annex_helptext = [[
+Git Annex (http://git-annex.branchable.com/) is a mechanism for supporting
+large files in git repositories.  This plugin relies on git-annex-shell
+being available on the server, and forwards that capability on so that
+if you can write to a gitano repository you can do git-annex type things
+with it.  In theory if you can read from the repository then you can
+still sync content from it; you just can't write to it.
+
+This plugin is considered experimental, may not work entirely as expected,
+and may change without notice.
+]]
+
+local function git_annex_detect_repo(config, parsed_cmdline)
+   local repo, msg
+   if #parsed_cmdline > 2 then
+      -- Acquire the repository object for the target repo from arg 3
+      repo, msg = gitano.repository.find(config, parsed_cmdline[3])
+      if not repo then
+         gitano.log.critical("Unable to locate repository.")
+         gitano.log.critical("  * " .. (tostring(msg)))
+         return nil, nil
+      end
+
+      if repo.is_nascent then
+         gitano.log.info("Repository " .. repo.name .. " is nascent")
+      end
+   else
+      gitano.log.critical("No repository provided.")
+      return nil, nil
+   end
+   parsed_cmdline.__annex__repo_at = 3
+   return repo, parsed_cmdline
+end
+
+local function git_annex_validate(config, repo, cmdline)
+   -- All git-annex commands put the repo in cmdline[3] and all take
+   -- a directory so cmdline had best be at least 3 big...
+   if #cmdline < 3 then
+      gitano.log.error("usage: git-annex-shell <cmd> <reponame> ...")
+      return false
+   end
+   if repo.is_nascent then
+      gitano.log.error("Cannot run git-annex-shell against a nascent repo")
+      return false
+   end
+   return true
+end
+
+local function git_annex_prep(config, repo, cmdline, context)
+   local ctxcopy = {}
+   for k, v in pairs(context) do
+      ctxcopy[k] = v
+   end
+   ctxcopy.operation = "write"
+   local action, reason = repo:run_lace(ctxcopy)
+   cmdline.__annex__writeable = action == "allow"
+   context.operation = "read"
+   return repo:run_lace(context)
+end
+
+local function git_annex_run(config, repo, cmdline, env)
+   -- We need to check if we're allowed to run in write mode...
+   env.GIT_ANNEX_SHELL_LIMITED = "1"
+   env.GIT_ANNEX_SHELL_DIRECTORY = repo:fs_path()
+   if not cmdline.__annex__writeable then
+      env.GIT_ANNEX_SHELL_READONLY = "1"
+   end
+   local cmdcopy = {"git-annex-shell", env=env}
+   for i = 2, #cmdline do cmdcopy[i] = cmdline[i] end
+   cmdcopy[cmdline.__annex__repo_at] = repo:fs_path()
+   local proc = sp.spawn(cmdcopy)
+   return proc:wait()
+end
+
+assert(gitano.command.register("git-annex-shell",
+                               git_annex_short_help, git_annex_helptext,
+                               git_annex_validate, git_annex_prep, git_annex_run,
+                               true, true, false, git_annex_detect_repo, true))