gitclone: We don't have to fetch, if revision is already present in local git repository

Because revision specifies worktree state exactly, and if we have it
already, we don't need to fetch anything -- it is possible to
checkout/reset to the revision right away.

The reason for this patch is that fetching is sometimes not very fast or
even slow. For example today, gitlab.com had some outage and I've
developed this patch while waiting for it to come back.

/reviewed-by @jerome, @kazuhiko
/reviewed-on !1

slapos/recipe/gitclone.py

@@ -34,7 +34,7 @@ import time
 import traceback
 
 from zc.buildout import UserError
-from subprocess import check_call, CalledProcessError
+from subprocess import call, check_call, CalledProcessError
 import subprocess
 
 try:
@@ -244,8 +244,14 @@ class Recipe(object):
       # first cleanup pyc files
       self.deletePycFiles(self.location)
 
-      # then update
-      check_call([self.git_command, 'fetch', '--all'], cwd=self.location)
+      # then update,
+      # but, to save time, only if we don't have the revision already
+      revision_already_fetched = \
+            self.revision and   \
+            call([self.git_command, 'rev-parse', '--verify', self.revision],
+                    cwd=self.location) == 0
+      if not revision_already_fetched:
+        check_call([self.git_command, 'fetch', '--all'], cwd=self.location)
 
       # If develop parameter is set, don't reset/update.
       # Otherwise, reset --hard

[Kirill Smelkov]

@kazuhiko, @jerome, can we please make a new slapos.recipe.build release to pick up this patch in our slapos stack?

Thanks beforehand, Kirill

[Kazuhiko Shiozaki]

it looks fine for me. i wait for @jerome response and then release the new version.

[Jérome Perrin]

Looks fine to me as well 👍

[Kirill Smelkov]

@jerome, @kazuhiko, thanks. Looking forward for new release.

[Kazuhiko Shiozaki]

Released. Since I forgot to push my changes for 0.22, I pushed force to the repository, sorry...

[Kirill Smelkov]

@kazuhiko, thanks for doing the release. Please be careful next time - we try to avoid rewriting history on official branches of main repositories.

Ok to apply next patch to slapos.git?

From: Kirill Smelkov <kirr@nexedi.com>
Date: Thu, 22 Oct 2015 16:18:22 +0300
Subject: [PATCH] stack/slapos: v↑ slapos.recipe.build

---
 stack/slapos.cfg | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/stack/slapos.cfg b/stack/slapos.cfg
index e24fd97..f6a05a1 100644
--- a/stack/slapos.cfg
+++ b/stack/slapos.cfg
@@ -139,7 +139,7 @@ slapos.cookbook = 1.0.9
 slapos.core = 1.3.12
 slapos.extension.strip = 0.1
 slapos.libnetworkcache = 0.14.5
-slapos.recipe.build = 0.21
+slapos.recipe.build = 0.23
 slapos.recipe.cmmi = 0.2
 stevedore = 1.9.0
 unicodecsv = 0.14.1
-- 
2.6.2.350.g3b31934

[Kazuhiko Shiozaki]

sure 😃

[Kirill Smelkov]

Thanks, done: slapos@873517f7.