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author | Lars Wirzenius <lars.wirzenius@codethink.co.uk> | 2013-07-04 13:17:24 +0000 |
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committer | Lars Wirzenius <lars.wirzenius@codethink.co.uk> | 2013-07-05 14:35:46 +0000 |
commit | 0d8e4d45e87f7cfa9bc41bf155fe18aa5e091a5a (patch) | |
tree | afbeb384c86299c73851ea8873cd48474418e429 /morphlib | |
parent | b2c4e13664209cffc9c0d58bb842e2e90a6e0c32 (diff) | |
download | morph-0d8e4d45e87f7cfa9bc41bf155fe18aa5e091a5a.tar.gz |
Improve docstring for "morph petrify"
Diffstat (limited to 'morphlib')
-rw-r--r-- | morphlib/plugins/branch_and_merge_plugin.py | 38 |
1 files changed, 35 insertions, 3 deletions
diff --git a/morphlib/plugins/branch_and_merge_plugin.py b/morphlib/plugins/branch_and_merge_plugin.py index de87bbda..b6d9483b 100644 --- a/morphlib/plugins/branch_and_merge_plugin.py +++ b/morphlib/plugins/branch_and_merge_plugin.py @@ -1026,10 +1026,42 @@ class BranchAndMergePlugin(cliapp.Plugin): update_working_tree=True) def petrify(self, args): - '''Convert all chunk refs in a system branch to be fixed SHA1s + '''Convert all chunk refs in a system branch to be fixed SHA1s. + + This modifies all git commit references in system and stratum + morphologies, in the current system branch, to be fixed SHA + commit identifiers, rather than symbolic branch or tag names. + This is useful for making sure none of the components in a system + branch change accidentally. + + Consider the following scenario: + + * The `master` system branch refers to `gcc` using the + `baserock/morph` ref. This is appropriate, since the main line + of development should use the latest curated code. + + * You create a system branch to prepare for a release, called + `TROVE_ID/release/2.0`. The reference to `gcc` is still + `baserock/morph`. + + * You test everything, and make a release. You deploy the release + images onto devices, which get shipped to your customers. + + * A new version GCC is committed to the `baserock/morph` branch. + + * Your release branch suddenly uses a new compiler, which may + or may not work for your particular system at that release. + + To avoid this, you need to _petrify_ all git references + so that they do not change accidentally. If you've tested + your release with the GCC release that is stored in commit + `94c50665324a7aeb32f3096393ec54b2e63bfb28`, then you should + continue to use that version of GCC, regardless of what might + happen in the master system branch. If, and only if, you decide + that a new compiler would be good for your release should you + include it in your release branch. This way, only the things + that you change intentionally change in your release branch. - This isolates the branch from changes made by other developers in the - chunk repositories. ''' # Stratum refs are not petrified, because they must all be edited to |