The aim of this post is to understand and get confortable with the git rebase command.

Definition:

Rebasing is the process of moving or combining a sequence of commits to a new base commit. Rebasing is most useful and easily visualized in the context of a feature branching workflow.

Create a git repo

mkdir rebase-test && cd rebase-test
git init

output:

Initialized empty Git repository in /home/bmn/rebase-test/.git/

Create one commit on master branch

echo "first content from master" >> README.md
git add README.md 
git commit -m "first commit"

output:

[master (root-commit) dc5f8d2] first commit
1 file changed, 1 insertion(+)
create mode 100644 README.md

Create a feature branch from that commit

git checkout -b feature
Switched to a new branch 'feature'

Create one commit on the feature branch

echo "introducing a new feature" >> README.md

Check file:

cat README.md

output:

first content from master
introducing a new feature


git commit -am "add feature line"

output:

[feature 2212653] add feature line
1 file changed, 1 insertion(+)

Check repo graph

nohup gitg &

Create a new commit on master branch

git checkout master 
Switched to branch 'master'

Check file:

cat README.md 
first content from master

vim README.md # add a title line for example
cat README.md

output:

# Master title
first content from master

Commit that:

git commit -am "add master title"

output:

[master ec82793] add master title
 1 file changed, 1 insertion(+)

Let's say that master branch has a new commit because work on master has been delivered. Let's rebase the feature branch to this new commit, to get the new content from master and play the commit from feature branch.

Let's rebase the feature branch on the master branch

Let's move on our feature branch:

git checkout feature 

output:

Switched to branch 'feature'

And now the rebase operation itself:

git rebase -i master 

output:

Successfully rebased and updated refs/heads/feature.

Our feature branch starts now from master head commit and now git is replaying all the commit from our feature branch from this point.

The result is the following:

The file README.ms now contains the commits from master + the commit from feature.

Let's check feature branch content

cat README.md 

output:

# Master title
first content from master
introducing a new feature

Let's check master branch content

git checkout master 

output:

Switched to branch 'master'


cat README.md

output:

# Master title
first content from master

Check repo graph

nohup gitg &

Usage: getting changes from origin/branch on branch

Retrieve changes from origin:

git fetch

apply commit from that:

git checkout master
git rebase origin/master