salt.sh: Drop upstream clone in favor of local git

salt.sh currently clones the full Fuel@OPNFV git repo from upstream
public mirror, preventing us from testing locally edited or new
patches.

Instead, bring back git submodule handling from old f_repos, clone
and patch each submodule locally, then copy the whole parent repo
over to cfg01.

This is also a first step towards implementing offline deploy support.

NOTE: This adds new deploy prerequisite packages:
- git (for submodule clone/update);
- make (for submodule patching);
- rsync (for parent repo replication to cfg01);

NOTE: Parent repository is expected to be a git repo, in order to
work with git submodules.

While at it, perform some minor related changes:
- add deploy artifacts (ISOs, qcow2 files) to .gitignore, also used
  to filter-out such files during rsync to cfg01;
- remove obsolete Fuel patches (old f_repos mechanism);
- rename "reclass-system-salt-model" submodule;

Change-Id: I6210d80d41010b2802e4f1b31acf249a18db7963
Signed-off-by: Alexandru Avadanii <Alexandru.Avadanii@enea.com>

1 files changed, 103 insertions, 0 deletions

diff --git a/mcp/patches/README.md b/mcp/patches/README.md
new file mode 100644
index 000000000..eab4d64e3
--- /dev/null
+++ b/mcp/patches/README.md
@@ -0,0 +1,103 @@
+Fuel@OPNFV submodule fetching and patching
+==========================================
+
+This directory holds submodule fetching/patching scripts, intended for
+working with upstream Fuel/MCP components (e.g.: reclass-system-salt-model) in
+developing/applying OPNFV patches (backports, custom fixes etc.).
+
+The scripts should be friendly to the following 2 use-cases:
+  - development work: easily cloning, binding repos to specific commits,
+    remote tracking, patch development etc.;
+  - to provide parent build scripts an easy method of tracking upstream
+    references and applying OPNFV patches on top;
+
+Also, we need to support at least the following modes of operations:
+  - submodule bind - each submodule patches will be based on the commit ID
+    saved in the .gitmodules config file;
+  - remote tracking - each submodule will sync with the upstream remote
+    and patches will be applied on top of <sub_remote>/<sub_branch>/HEAD;
+
+Workflow (development)
+----------------------
+The standard development workflow should look as follows:
+
+1. Decide whether remote tracking should be active or not:
+   NOTE: Setting the following var to any non-empty str enables remote track.
+   NOTE: Leaving unset will enable remote track for anything but stable branch.
+
+   $ export FUEL_TRACK_REMOTES=""
+
+2. All Fuel sub-projects are registered as submodules. To initialize them, call:
+   If remote tracking is active, upstream remote is queried and latest remote
+   branch HEAD is fetched. Otherwise, checkout commit IDs from .gitmodules.
+
+   $ make sub
+
+3. Apply patches from `patches/<sub-project>/*` to respective submodules via:
+
+   $ make patches-import
+
+   This will result in creation of:
+   - a tag called `${FUEL_MAIN_TAG}-opnfv-root` at the same commit as Fuel@OPNFV
+     upstream reference (bound to git submodule OR tracking remote HEAD);
+   - a new branch `opnfv-fuel` which will hold all the OPNFV patches,
+     each patch is applied on this new branch with `git-am`;
+   - a tag called `${FUEL_MAIN_TAG}-opnfv` at `opnfv-fuel/HEAD`;
+
+4. Modify sub-projects for whatever you need.
+   Commit your changes when you want them taken into account in the build.
+
+5. Re-create patches via:
+
+   $ make patches-export
+
+   Each commit on `opnfv-fuel` branch of each subproject will be
+   exported to `patches/subproject/` via `git format-patch`.
+
+   NOTE: Only commit (-f) submodules when you need to bump upstream ref.
+   NOTE: DO NOT commit patched submodules!
+
+6. Clean workbench branches and tags with:
+
+   $ make clean
+
+7. De-initialize submodules and force a clean clone with:
+
+   $ make deepclean
+
+Sub-project maintenance
+-----------------------
+1. Adding a new submodule
+   If you need to add another subproject, you can do it with `git submodule`.
+   Make sure that you specify branch (with `-b`), short name (with `--name`):
+
+   $ git submodule -b master add --name reclass-system-salt-model \
+     https://github.com/Mirantis/reclass-system-salt-model \
+     relative/path/to/submodule
+
+2. Working with remote tracking for upgrading Fuel components
+   Enable remote tracking as described above, which at `make sub` will update
+   ALL submodules (e.g. reclass-system-salt-model) to remote branch (set in
+   .gitmodules) HEAD.
+
+   * If upstream has NOT already tagged a new version, we can still work on
+     our patches, make sure they apply etc., then check for new upstream
+     changes (and that our patches still apply on top of them) by:
+
+   $ make deepclean patches-import
+
+   * If upstream has already tagged a new version we want to pick up, checkout
+     the new tag in each submodule:
+
+   $ git submodule foreach 'git checkout <newtag>'
+
+   * Once satisfied with the patch and submodule changes, commit them:
+     - enforce FUEL_TRACK_REMOTES to "yes" if you want to constatly use the
+       latest remote branch HEAD (as soon as upstream pushes a change on that
+       branch, our next build will automatically include it - risk of our
+       patches colliding with new upstream changes);
+     - stage patch changes if any;
+     - if submodule tags have been updated (relevant when remote tracking is
+       disabled, i.e. we have a stable upstream baseline), add submodules:
+
+   $ make deepclean sub && git add -f relative/path/to/submodule