如何让git描述来自远程存储库的输出

Question

I'm trying to sort out automatic version number generation for a buildroot based project I'm working on. At the moment there is a meta-repo that contains buildroot, the package configurations and scripts to build the project from scratch. And a second repository that contains the application specific source code that's built as one of the buildroot packages.

As buildroot runs it performs a shallow clone of the package repo at a specified branch head. I want a way to run git describe on this without having to do a full clone of the repository.

At the moment the project is able to generate a fairly accurate build number using git describe. We tag versions with major and minor versions, we then want the number of commits since the tag to be added during the build process.

I've managed to hack together a rough approximation for it using git ls-remote to generate the SHA1 hash but I can't get the commit count, does anyone know of a way to achieve this?

Answer 1

So after much toiling and searching I gave up on getting it remotely and wrote the following sections into my Makefile in order to generate the string I wanted. GIT_SITE is the address of the remote repository, GIT_BRANCH is the name of the branch that is being cloned, eg releaseCandidate/4.0

GIT_COMMIT_NUMBER = $(shell git clone $(GIT_SITE) -n -q temp && cd temp && git rev-list --count master..origin/$(GIT_BRANCH) && cd .. && rm -fr temp)

# This was easier to do, pulls the hash from the remote repo and cuts it down to be 7 characters long (same as would come out of git describe)
GIT_HASH = $(shell git ls-remote $(GIT_SITE) $(GIT_VERSION) | cut -f 1 | awk '{print substr($$0,1,7) }')

# This cuts down the branch name given to us by buildroot so that we cas use it in the build string generation
GIT_BRANCH_FLAG = $(shell echo $(GIT_BRANCH) | cut -f 1 -d '/')
GIT_BRANCH_VERSION = $(shell echo $(GIT_BRANCH) | cut -f 2 -d '/')

# Finally we put those bits together to get the outputs we want
VERSION ?= $(GIT_BRANCH_VERSION)
GIT_DESCRIBE ?= $(GIT_BRANCH_VERSION)-$(GIT_COMMIT_NUMBER)-g$(GIT_HASH)-$(GIT_BRANCH_FLAG)

Answer 2

For a shallow clone, you could try:

echo "$(git ls-remote -q --tags --refs | grep -Pio '(\d+(\.|_|-|$)){2}[\w\.-]*' | perl -pe 's|[[:punct:]]|.|g' | sort -V | tail -1)-$(git rev-list --count HEAD)-g$(git show -s --abbrev-commit --abbrev=7 --pretty=format:%h)"

This is how it works:

git ls-remote -q --tags --refs | grep -Pio '(\\d+(\\.|_|-|$)){2}[\\w\\.-]*' | perl -pe 's|[[:punct:]]|.|g' | sort -V | tail -1 git ls-remote -q --tags --refs | grep -Pio '(\\d+(\\.|_|-|$)){2}[\\w\\.-]*' | perl -pe 's|[[:punct:]]|.|g' | sort -V | tail -1 will tease out, at minimum , a regex pattern of two numbers with a separator of . _ - . _ - converting that punctuation to dots. sort -V | tail -1 sort -V | tail -1 sorts the resultant version strings in ascending order and grabs the, most recent, tag.

git rev-list --count HEAD Will count out all commits since the shallow clone. It's analogous to git describe but useless once the shallow actually picks up a commit with a tag in it.

-g means git

git show -s --abbrev-commit --abbrev=7 --pretty=format:%h Simulates the abbreviation to 7 characters.

Here's an example of vbam:

$ git ls-remote -q --tags --refs
f7f67ff6f93e836309f43f13f4ccc286156d64c7    refs/tags/Beta-3
6ecab805e00e99c37bd23c425835ca35507cb593    refs/tags/Keyboardfixes
47d56f4fade1b95d5ea40ed0a820949fb23311fa    refs/tags/VBA-M_Beta_2
9f5b04786381fcc2f9cac7f426d01bc3f74da80c    refs/tags/c7c6ad6
2e8bee117d33d63745c5dd095254986e1985fde4    refs/tags/throttle
1eb768578bc0c4fa17396f573a4b37a652f12acd    refs/tags/v2.0.0
55fa9c69c0ebef70131ae385a094cb37fcaea057    refs/tags/v2.0.1
92ba676632f65c687c32bd655584dc54598d325e    refs/tags/v2.0.2
7aa5d9398e761e121c724a420a1aba04c80154cf    refs/tags/v2.1.0
931fda459a3d003c94eabdac5b0a60ef8f570ae1    refs/tags/waylandplus

$ git describe --abbrev=7 --tags
v2.1.0-99-g3cb3842

$ echo "$(git ls-remote -q --tags --refs | grep -Pio '(\d+(\.|_|-|$)){2}[\w\.-]*' | perl -pe 's|[[:punct:]]|.|g' | sort -V | tail -1)-$(git rev-list --count HEAD)-g$(git show -s --abbrev-commit --abbrev=7 --pretty=format:%h)"
2.1.0-155-g3cb3842