feat(git-clone): add clone_args variable for custom git clone arguments

Allow users to pass additional arguments to the git clone command via a
new `clone_args` variable. This enables use cases like using a local
mirror with `--reference` to speed up cloning large repositories.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: 2 people

registry/coder/modules/git-clone/README.md

@@ -199,6 +199,35 @@ module "git-clone" {
 }
 ```
 
+## Custom clone arguments
+
+Pass additional arguments to the git clone command using the `clone_args` variable.
+This is useful for scenarios like using a local mirror with `--reference` to speed up cloning.
+
+```tf
+module "git-clone" {
+  count      = data.coder_workspace.me.start_count
+  source     = "registry.coder.com/coder/git-clone/coder"
+  version    = "1.2.2"
+  agent_id   = coder_agent.example.id
+  url        = "https://github.com/coder/coder"
+  clone_args = "--reference /mnt/git-mirrors/coder.git"
+}
+```
+
+You can also combine multiple arguments:
+
+```tf
+module "git-clone" {
+  count      = data.coder_workspace.me.start_count
+  source     = "registry.coder.com/coder/git-clone/coder"
+  version    = "1.2.2"
+  agent_id   = coder_agent.example.id
+  url        = "https://github.com/coder/coder"
+  clone_args = "--reference /mnt/git-mirrors/coder.git --dissociate"
+}
+```
+
 ## Post-clone script
 
 Run a custom script after cloning the repository by setting the `post_clone_script` variable.

registry/coder/modules/git-clone/main.tf

@@ -68,6 +68,12 @@ variable "post_clone_script" {
   default     = null
 }
 
+variable "clone_args" {
+  description = "Additional arguments to pass to the git clone command (e.g., '--reference /path/to/mirror' for using a local mirror)."
+  type        = string
+  default     = ""
+}
+
 locals {
   # Remove query parameters and fragments from the URL
   url = replace(replace(var.url, "/\\?.*/", ""), "/#.*/", "")
@@ -129,6 +135,7 @@ resource "coder_script" "git_clone" {
     BRANCH_NAME : local.branch_name,
     DEPTH = var.depth,
     POST_CLONE_SCRIPT : local.encoded_post_clone_script,
+    CLONE_ARGS : var.clone_args,
   })
   display_name       = "Git Clone"
   icon               = "/icon/git.svg"

registry/coder/modules/git-clone/run.sh

@@ -7,6 +7,7 @@ BRANCH_NAME="${BRANCH_NAME}"
 CLONE_PATH="$${CLONE_PATH/#\~/$${HOME}}"
 DEPTH="${DEPTH}"
 POST_CLONE_SCRIPT="${POST_CLONE_SCRIPT}"
+CLONE_ARGS="${CLONE_ARGS}"
 
 # Check if the variable is empty...
 if [ -z "$REPO_URL" ]; then
@@ -39,16 +40,20 @@ if [ -z "$(ls -A "$CLONE_PATH")" ]; then
   if [ -z "$BRANCH_NAME" ]; then
     echo "Cloning $REPO_URL to $CLONE_PATH..."
     if [ "$DEPTH" -gt 0 ]; then
-      git clone --depth "$DEPTH" "$REPO_URL" "$CLONE_PATH"
+      # shellcheck disable=SC2086
+      git clone --depth "$DEPTH" $CLONE_ARGS "$REPO_URL" "$CLONE_PATH"
     else
-      git clone "$REPO_URL" "$CLONE_PATH"
+      # shellcheck disable=SC2086
+      git clone $CLONE_ARGS "$REPO_URL" "$CLONE_PATH"
     fi
   else
     echo "Cloning $REPO_URL to $CLONE_PATH on branch $BRANCH_NAME..."
     if [ "$DEPTH" -gt 0 ]; then
-      git clone --depth "$DEPTH" -b "$BRANCH_NAME" "$REPO_URL" "$CLONE_PATH"
+      # shellcheck disable=SC2086
+      git clone --depth "$DEPTH" -b "$BRANCH_NAME" $CLONE_ARGS "$REPO_URL" "$CLONE_PATH"
     else
-      git clone "$REPO_URL" -b "$BRANCH_NAME" "$CLONE_PATH"
+      # shellcheck disable=SC2086
+      git clone -b "$BRANCH_NAME" $CLONE_ARGS "$REPO_URL" "$CLONE_PATH"
     fi
   fi
 else