feat: add post_clone_script to dotfiles in order to support startup dependencies/coordination (#679)

## Description

Adds post_clone_script variable to the dotfiles module, enabling startup
coordination with other scripts that depend on dotfiles.

An example of how to use this, which assumes the PR has been merged:

```
module "dotfiles" {
  count                = data.coder_workspace.me.start_count
  source               = "registry.coder.com/coder/dotfiles/coder"
  version              = "1.3.0"
  agent_id             = coder_agent.main.id
  default_dotfiles_uri = "https://github.com/someuser/somedotfiles"
  post_clone_script    = <<-EOF
    coder exp sync start dotfiles && coder exp sync complete dotfiles
  EOF
}

resource "coder_script" "personalize" {
  count        = data.coder_workspace.me.start_count
  agent_id     = coder_agent.main.id
  display_name = "Personalize"
  icon         = "/icon/personalize.svg"
  run_on_start = true
  script       = <<-EOF
    trap 'coder exp sync complete personalize' EXIT
    coder exp sync want personalize dotfiles
    coder exp sync start personalize
    SCRIPT="$HOME/.config/coderv2/dotfiles/personalize"
    if [ -f "$SCRIPT" ] && [ -x "$SCRIPT" ]; then
      $SCRIPT
    fi
  EOF
}
```

## Type of Change

- [ ] New module
- [ ] New template
- [ ] Bug fix
- [x] Feature/enhancement
- [ ] Documentation
- [ ] Other

## Module Information

**Path:** `registry/coder/modules/dotfiles`  
**New version:** `v1.3.0`  
**Breaking change:** [ ] Yes [x] No

## Testing & Validation

- [ ] Tests pass (`bun test`)
- [ ] Code formatted (`bun fmt`)
- [x] Changes tested locally

## Related Issues

#678

registry/coder/modules/dotfiles/README.md

@@ -18,7 +18,7 @@ Under the hood, this module uses the [coder dotfiles](https://coder.com/docs/v2/
 module "dotfiles" {
   count    = data.coder_workspace.me.start_count
   source   = "registry.coder.com/coder/dotfiles/coder"
-  version  = "1.2.4"
+  version  = "1.3.0"
   agent_id = coder_agent.example.id
 }
 ```
@@ -31,7 +31,7 @@ module "dotfiles" {
 module "dotfiles" {
   count    = data.coder_workspace.me.start_count
   source   = "registry.coder.com/coder/dotfiles/coder"
-  version  = "1.2.4"
+  version  = "1.3.0"
   agent_id = coder_agent.example.id
 }
 ```
@@ -42,7 +42,7 @@ module "dotfiles" {
 module "dotfiles" {
   count    = data.coder_workspace.me.start_count
   source   = "registry.coder.com/coder/dotfiles/coder"
-  version  = "1.2.4"
+  version  = "1.3.0"
   agent_id = coder_agent.example.id
   user     = "root"
 }
@@ -54,14 +54,14 @@ module "dotfiles" {
 module "dotfiles" {
   count    = data.coder_workspace.me.start_count
   source   = "registry.coder.com/coder/dotfiles/coder"
-  version  = "1.2.4"
+  version  = "1.3.0"
   agent_id = coder_agent.example.id
 }
 
 module "dotfiles-root" {
   count        = data.coder_workspace.me.start_count
   source       = "registry.coder.com/coder/dotfiles/coder"
-  version      = "1.2.4"
+  version      = "1.3.0"
   agent_id     = coder_agent.example.id
   user         = "root"
   dotfiles_uri = module.dotfiles.dotfiles_uri
@@ -76,7 +76,7 @@ You can set a default dotfiles repository for all users by setting the `default_
 module "dotfiles" {
   count                = data.coder_workspace.me.start_count
   source               = "registry.coder.com/coder/dotfiles/coder"
-  version              = "1.2.4"
+  version              = "1.3.0"
   agent_id             = coder_agent.example.id
   default_dotfiles_uri = "https://github.com/coder/dotfiles"
 }

registry/coder/modules/dotfiles/main.tf

@@ -84,6 +84,12 @@ variable "manual_update" {
   default     = false
 }
 
+variable "post_clone_script" {
+  description = "Custom script to run after applying dotfiles. Runs every time, even if dotfiles were already applied."
+  type        = string
+  default     = null
+}
+
 data "coder_parameter" "dotfiles_uri" {
   count        = var.dotfiles_uri == null ? 1 : 0
   type         = "string"
@@ -104,13 +110,15 @@ data "coder_parameter" "dotfiles_uri" {
 locals {
   dotfiles_uri              = var.dotfiles_uri != null ? var.dotfiles_uri : data.coder_parameter.dotfiles_uri[0].value
   user                      = var.user != null ? var.user : ""
+  encoded_post_clone_script = var.post_clone_script != null ? base64encode(var.post_clone_script) : ""
 }
 
 resource "coder_script" "dotfiles" {
   agent_id = var.agent_id
   script = templatefile("${path.module}/run.sh", {
     DOTFILES_URI : local.dotfiles_uri,
-    DOTFILES_USER : local.user
+    DOTFILES_USER : local.user,
+    POST_CLONE_SCRIPT : local.encoded_post_clone_script
   })
   display_name = "Dotfiles"
   icon         = "/icon/dotfiles.svg"
@@ -127,7 +135,8 @@ resource "coder_app" "dotfiles" {
   group        = var.group
   command = templatefile("${path.module}/run.sh", {
     DOTFILES_URI : local.dotfiles_uri,
-    DOTFILES_USER : local.user
+    DOTFILES_USER : local.user,
+    POST_CLONE_SCRIPT : local.encoded_post_clone_script
   })
 }
 

registry/coder/modules/dotfiles/run.sh

@@ -43,3 +43,14 @@ if [ -n "$${DOTFILES_URI// }" ]; then
     sudo -u "$DOTFILES_USER" "$CODER_BIN" dotfiles "$DOTFILES_URI" -y 2>&1 | tee "$DOTFILES_USER_HOME/.dotfiles.log"
   fi
 fi
+
+POST_CLONE_SCRIPT="${POST_CLONE_SCRIPT}"
+
+if [ -n "$POST_CLONE_SCRIPT" ]; then
+  echo "Running post-clone script..."
+  POST_CLONE_TMP=$(mktemp)
+  echo "$POST_CLONE_SCRIPT" | base64 -d > "$POST_CLONE_TMP"
+  chmod +x "$POST_CLONE_TMP"
+  $POST_CLONE_TMP
+  rm "$POST_CLONE_TMP"
+fi