Add bare git repository support with configurable source, destination, and bare flag

README.md

@@ -111,18 +111,38 @@ Each repo has at bare minimum the following configurations:
 - dusum - Path to a file to store disk usage summary results of the repository directory.
 
 ### git
-Synchronizes a git repository via git pull. To use this method, you need to have the git package installed.
+Synchronizes a git repository. To use this method, you need to have the git package installed.
+
+If the destination (`repo`) does not yet contain a git repository, it is cloned from the configured `source`. Otherwise it is updated in place. Bare repositories have no working tree, so they cannot be updated with `git pull`; instead the script clones them with `git clone --mirror` and updates them with `git remote update --prune`, which honors the repository's configured fetch refspec.
+
+Whether a repository is bare can be set explicitly with the `bare` configuration, otherwise existing repositories are auto-detected.
+
+#### source
+The git URL to clone the repository from. Required when the destination does not already contain a git repository.
+
+#### bare
+Set to `true` to treat the repository as bare. When cloning, this clones with `git clone --mirror`. When updating, this forces use of `git remote update --prune`. If unset, existing repositories are auto-detected.
 
 #### options
-Extra options appended to `git pull`.
+Extra options appended to the git command (`git clone` when cloning, `git pull` when updating a working-tree repository, or `git remote update --prune` when updating a bare repository).
 
 #### Example
 ```bash
 example_sync_method="git"
+example_source="https://github.com/example/example.git"
 example_repo="/home/mirror/http/example"
 example_timestamp="/home/mirror/timestamp/example"
 ```
 
+#### Bare repository example
+```bash
+example_sync_method="git"
+example_source="https://github.com/example/example.git"
+example_repo="/home/mirror/git/example.git"
+example_bare="true"
+example_timestamp="/home/mirror/timestamp/example"
+```
+
 ### aws
 Synchronize with an s3 bucket using aws cli. To use this, you need the aws cli package installed.
 

mirror-sync.sh

@@ -5,7 +5,7 @@ PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:$HOME/.local/
 
 # Variables for trace generation.
 PROGRAM="mirror-sync"
-VERSION="20260602"
+VERSION="20260616"
 TRACEHOST=$(hostname -f)
 mirror_hostname=$(hostname -f)
 DATE_STARTED=$(LC_ALL=POSIX LANG=POSIX date -u -R)
@@ -617,12 +617,58 @@ git_sync() {
     # Start the module.
     module_config "$1"
 
-    # Do a git pull within the repo folder to sync.
+    # Read git specific configuration.
+    eval source="\$${MODULE}_source"
+    eval bare="\$${MODULE}_bare"
+
+    # Normalize the bare flag to either "true" or empty.
+    case "${bare,,}" in
+        1|true|yes|bare) bare="true" ;;
+        *) bare="" ;;
+    esac
+
+    # If the destination does not yet contain a git repository, clone it from
+    # the configured source. Bare repositories are cloned with --mirror so the
+    # configured fetch refspec mirrors all refs from upstream.
+    if [[ ! -e "${repo:?}/.git" ]] && [[ ! -e "${repo:?}/HEAD" ]]; then
+        if [[ ! $source ]]; then
+            echo "No git repository at '${repo:?}' and no source defined to clone from."
+            exit 1
+        fi
+        echo "Cloning '${source}' into '${repo:?}'."
+        if [[ $bare ]]; then
+            eval git clone --mirror ${options:+$options} "'${source}'" "'${repo:?}'"
+        else
+            eval git clone ${options:+$options} "'${source}'" "'${repo:?}'"
+        fi
+        RT=$?
+        if (( RT == 0 )); then
+            post_successful_sync
+        else
+            post_failed_sync
+        fi
+        log_end_header
+        return
+    fi
+
+    # Move into the repo folder to sync.
     if ! cd "${repo:?}"; then
         echo "Failed to access '${repo:?}' git repository."
         exit 1
     fi
+
+    # Determine whether the repository is bare. Honor an explicit configuration
+    # if set, otherwise auto-detect. Bare repositories have no working tree, so a
+    # `git pull` is not possible; instead use `git remote update` which honors the
+    # configured fetch refspec (e.g. a mirror clone created with --mirror).
+    if [[ ! $bare ]] && [[ $(git rev-parse --is-bare-repository 2>/dev/null) == "true" ]]; then
+        bare="true"
+    fi
+    if [[ $bare ]]; then
+        eval git remote update --prune ${options:+$options}
+    else
         eval git pull ${options:+$options}
+    fi
     RT=$?
     if (( RT == 0 )); then
         post_successful_sync