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Pandy Song

using repo to manage official sdk from vendor and local development repo

Introduction

You just get a new SDK from your vendor via repo command from vendor’s server. You have started a new project based on this SDK. However since it is not possible to push your code changes to your supplier, you have to have a local mirror (That could be done by changing the manifests.xml). But you also want to track the new updates from your vendor, how to get update from your vendor as well as maintain a local copies?

This post explains how.

TLDR: it is possible to accomplish this by using multiple git remote and “repo”’s command “repo init -b ”.

Get the SDK from your supplier

For demo purpose, I have created a manifests on github.

repo init -u git@github.com:pandysong/repo_test_manifests.git -b master -m door_phone.xml

For whom has difficulties to access the google server add following before repo command:

REPO_URL='https://mirrors.tuna.tsinghua.edu.cn/git/git-repo' repo init -u git@github.com:pandysong/repo_test_manifests.git -b master -m door_phone.xml

sync the projects:

repo sync

Start your development

Now you have the SDK ready for your own product development.

You want to change the code in “repo_test_sdk_project_a”. You check the remote of this repo and find that the remote is “SDK”.

repo_test_sdk_project_a$ git remote -v
sdk     ssh://git@github.com/pandysong/repo_test_sdk_project_a.git (fetch)
sdk     ssh://git@github.com/pandysong/repo_test_sdk_project_a.git (push)

Of case you could not push to remote “sdk” because it is on your supplier’s server.

So you need to create a repository. For demo purpose: I create a repo on my local disk (instead of creating on a server):

~/temp/repo_test/repo_test_sdk_project_a$ git init --bare

Now add an additional remote to this project:

repo_test_sdk_project_a$ git remote add idh /home/pandy/temp/repo_test/repo_test_sdk_project_a/
repo_test_sdk_project_a$ git remote -v
idh     /home/pandy/temp/repo_test_sdk_project_a.git (fetch)
idh     /home/pandy/temp/repo_test_sdk_project_a.git (push)
sdk     ssh://git@github.com/pandysong/repo_test_sdk_project_a.git (fetch)
sdk     ssh://git@github.com/pandysong/repo_test_sdk_project_a.git (push)

Now push the all the code to your own repo

repo_test_sdk_project_a$ git checkout master
repo_test_sdk_project_a$ git push idh master

Now you start the actual development and add some file to this repository.

touch file_added_by_idh.txt
git checkout -b door_phone_dev
git add file_added_by_idh.txt
git commit -m "file added for idh door phone project"
git remote -v
git push idh door_phone_dev

You could now get a new manifests.xml from the current working directies:

create a local xml

repo manifest -r -o door_phone.xml

Using this new door_phone.xml to overwrite the original one.

cp door_phone.xml .repo/manifests/door_phone.xml

We need to manually edit the door_phone.xml to have multiple remote

diff --git a/door_phone.xml b/door_phone.xml
index 0c40d9e..fc1aed7 100644
--- a/door_phone.xml
+++ b/door_phone.xml
@@ -1,9 +1,10 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <manifest>
   <remote fetch="ssh://git@github.com" name="sdk"/>
+  <remote fetch="/home/pandy/temp/" name="idh"/>

   <default remote="sdk" sync-j="4"/>

-  <project name="pandysong/repo_test_sdk_project_a.git" path="repo_test_sdk_project_a" revision="cee3730e491d3f81f865660deb39205e6622723f" upstream="master"/>
+  <project name="repo_test_sdk_project_a.git" path="repo_test_sdk_project_a" revision="19ed9158622d83a4952f3d7298526f7f44e3e6a4" upstream="door_phone_dev" remote="idh"/>
   <project name="pandysong/repo_test_sdk_project_b.git" path="repo_test_sdk_project_b" revision="132a25ac3e64a25dbfb66ee7bb472fb97fff2a02" upstream="master"/>
 </manifest>

Since this manifests is for our local usage, we need to create a local repository for the local development.

For demo purpose we create a bare git repo in the local disk

mkdir manifests_idh.git
cd manifests_idh.git/
git init --bare

Add this remote to manifests:

git remote add idh /home/pandy/temp/manifests_idh.git
git remote -v

idh     /home/pandy/temp/manifests_idh.git (fetch)
idh     /home/pandy/temp/manifests_idh.git  (push)
origin  git@github.com:pandysong/repo_test_manifests.git (fetch)
origin  git@github.com:pandysong/repo_test_manifests.git (push)

Edit the door_phone.xml file to crate

Create a development branch:

git checkout -b door_phone_dev
git add -u
git commit -m "door phone dev: add some code on repo_test_sdk_project_a"
git push idh door_phone_dev
git push idh master

use the local manifests_idh to manage the development

repo init -b door_phone_dev -u /home/pandy/temp/manifests_idh.git/ -m door_phone.xml

Now you could switch to SDK release by

repo init -b master -m door_phone.xml

Or you could use the switch to development branch

repo init -b door_phone_dev -m door_phone.xml

After switching, remember to sync:

repo sync

In the modified project, you could find two remotes:

repo_test_sdk_project_a$ git remote -v
idh     /home/pandy/temp/repo_test_sdk_project_a.git (fetch)
idh     /home/pandy/temp/repo_test_sdk_project_a.git (push)
sdk     ssh://git@github.com/pandysong/repo_test_sdk_project_a.git (fetch)
sdk     ssh://git@github.com/pandysong/repo_test_sdk_project_a.git (push)

make a release

Once a phase of development is done, you may want to make a release. Use the following command to make a snapshot of all git repository.

repo manifest -r -o door_phone.xml

If you have several tags on the door_phone_dev branch, and want to go back to some specific hash. Just checkout the specific manifests

cd .repo/manifests
git checkout 42004ea1b4392ebcde9f485f0bc3aa08f2cb6185

And then do

repo sync

It will go back to the specific version (like a time machine)

You may want to make a tag for this release.

How to upgrade the upstream

What if the upstream SDK has upgraded.

The SDK manifests is always upgraded on master, while your own project is branched out from the SDK release.

The steps to upgrade to upstream new SDK would be:

  • in the .repo/manifests, you should see two remotes one is “idh”, another should be the vendor’s. If not, use the git command to add the remote and fetch the latest changes and then checkout the manifests xml latest version.

  • then repo sync to get the latest version.

Now go to each project, you would see the master is upgraded to latest SDK version.

For the new development on new sdk, you would need to create branch and rebase the changes on the old sdk to this new branch and then using “git manifests -r -o xxx.xml” to create a new xml file and manually fix the “remote” and “upstream” elements and put this new xml on a branch from new SDK tag.