Download an LFS backed file from GitLab.com without git and git-lfs installed
It is possible to download a Git LFS-backed file from GitLab.com without having git or git-lfs installed by using the GitLab API directly. This article provides two shell scripts that demonstrate how to do this.
Well, the API is there and you can do it already!
Just dig into what git is doing by a test-clone with any LFS repo:
export GIT_CURL_VERBOSE=1
export GIT_TRACE_CURL=1
git clone <my-repo> 2>&1 | tee git-clone.log
From there you are able to figure out what is happening on SSH.
Now: download an LFS backed file from GitLab.com without git and git-lfs installed!
#!/usr/bin/env bash
PROJECT="${1}" # your-company/or-repo/whatever
FILEPATH="${2}" # foo/bar.tar.gz
REF="${3:-master}" # branch
SSHID="${4:-$HOME/.ssh/ecdsa_id}" # like $HOME/.ssh/mycompany
OID="$(set -o pipefail; curl -fSL -H "PRIVATE-TOKEN: ${GITLAB_TOKEN}" "https://gitlab.com/api/v4/projects/${PROJECT//
ltk%2F}/repository/files/${FILEPATH//
ltk%2F}/raw?ref=${REF}" -o - | grep '^oid' | cut -d: -f2)"
AUTH="$(set -o pipefail; ssh -o IdentitiesOnly=yes -o IdentityFile="${SSHID}" git@gitlab.com git-lfs-authenticate "${PROJECT}.git" download | jq -er '.header.Authorization')"
mkdir -p "${FILEPATH%%/*}"
curl -H "Authorization: $AUTH" "https://gitlab.com/${PROJECT}.git/gitlab-lfs/objects/${OID}" -o "${FILEPATH}"
file "${FILEPATH}"
And you can even do it without using SSH!
#!/usr/bin/env bash
PROJECT="${1}" # your-company/or-repo/whatever
FILEPATH="${2}" # foo/bar.tar.gz
BRANCH="${3:-master}" # branch
# get LFS file info
IFS=$'\n' LFS_OBJECT_INFO=($(curl -fsSL -H "PRIVATE-TOKEN: ${GITLAB_TOKEN}" "https://gitlab.com/api/v4/projects/${PROJECT//
ltk%2F}/repository/files/${FILEPATH//
ltk%2F}/raw?ref=${BRANCH}" -o -))
OID="$(echo "${LFS_OBJECT_INFO[@]}" | grep -oP "oid sha256:\K[^\s]+")"
SIZE="$(echo "${LFS_OBJECT_INFO[@]}" | grep -oP "size \K[^\s]+")"
# request actions for given lfs objects
LFS_OBJECT_REQUEST_JSON="$(jq -rnc --arg oid "$OID" --arg size "$SIZE" --arg ref "refs/heads/$BRANCH" '{"operation":"download","objects":[{"oid":$oid,"size":$size}],"transfers":["lfs-standalone-file","basic"],"ref":{"name": $ref }}')"
LFS_OBJECT_ACTION_DOWNLOAD="$(set -o pipefail; curl -sSlf -H "Content-Type: application/json" -X POST -d "$LFS_OBJECT_REQUEST_JSON" "https://oauth2:${GITLAB_TOKEN}@gitlab.com/${PROJECT}.git/info/lfs/objects/batch" | jq -er '.objects[0].actions.download')"
AUTH="$(echo "$LFS_OBJECT_ACTION_DOWNLOAD" | jq -er '.header.Authorization')"
DOWNLOAD_URL="$(echo "$LFS_OBJECT_ACTION_DOWNLOAD" | jq -er '.href')"
mkdir -p "${FILEPATH%%/*}"
curl -H "Authorization: ${AUTH}" "${DOWNLOAD_URL}" -o "${FILEPATH}"