docs: Uniform docs for user_data and remove some implementation details

website/source/docs/builders/alicloud-ecs.html.md

@@ -177,10 +177,12 @@ builder.
 -   `TLSHandshakeTimeout` (int) - When happen "net/http: TLS handshake timeout" problem, set this environment variable
      to a bigger such as `export TLSHandshakeTimeout=30`, it will set the TLS handshake timeout value to 30s.
 
--   `user_data` (string) - The UserData of an instance must be encoded in `Base64`
-    format, and the maximum size of the raw data is `16 KB`.
+-   `user_data` (string) - User data to apply when launching the instance. Note
+    that you need to be careful about escaping characters due to the templates
+    being JSON. It is often more convenient to use `user_data_file`, instead.
 
--   `user_data_file` (string) - The file name of the userdata.
+-   `user_data_file` (string) - Path to a file that will be used for the user
+    data when launching the instance.
 
 -   `vpc_cidr_block` (string) - Value options: `192.168.0.0/16` and `172.16.0.0/16`.
     When not specified, the default value is `172.16.0.0/16`.

website/source/docs/builders/azure.html.md

@@ -113,7 +113,7 @@ Providing `temp_resource_group_name` or `location` in combination with `build_re
     `USGovernmentCloud` and `AzureUSGovernmentCloud` are also supported.
 
 -   `custom_data_file` (string) Specify a file containing custom data to inject into the cloud-init process. The contents
-    of the file are read, base64 encoded, and injected into the ARM template. The custom data will be passed to
+    of the file are read and injected into the ARM template. The custom data will be passed to
     cloud-init for processing at the time of provisioning. See [documentation](http://cloudinit.readthedocs.io/en/latest/topics/examples.html)
     to learn more about custom data, and how it can be used to influence the provisioning process.
 

website/source/docs/builders/ncloud.html.md

@@ -48,14 +48,12 @@ Platform](https://www.ncloud.com/).
     access source (`0.0.0.0/0`) and allowed port (5985) must be created in
     advance.
 
--   `user_data` (string) - Init script to run when an instance is created.
-    -   For Linux servers, Python, Perl, and Shell scripts can be used. The
-        path of the script to run should be included at the beginning of the
-        script, like \#!/usr/bin/env python, \#!/bin/perl, or \#!/bin/bash.
-    -   For Windows servers, only Visual Basic scripts can be used.
-    -   All scripts must be written in English.
--   `user_data_file` (string) - A path to a file containing a `user_data`
-    script. See above for more information.
+-   `user_data` (string) - User data to apply when launching the instance. Note
+    that you need to be careful about escaping characters due to the templates
+    being JSON. It is often more convenient to use `user_data_file`, instead.
+
+-   `user_data_file` (string) - Path to a file that will be used for the user
+    data when launching the instance.
 
 -   `region` (string) - Name of the region where you want to create an image.
     (default: Korea)

website/source/docs/builders/oracle-oci.html.md

@@ -129,13 +129,11 @@ builder.
 configuration. While this can be used to set metadata["user_data"] the explicit "user_data" and "user_data_file" values will have precedence. An instance's metadata can be obtained from at http://169.254.169.254 on the
 launched instance.
 
- - `user_data` (string) - user_data to be used by cloud
-   init. See [the Oracle docs](https://docs.us-phoenix-1.oraclecloud.com/api/#/en/iaas/20160918/LaunchInstanceDetails) for more details. Generally speaking, it is easier to use the `user_data_file`,
+ - `user_data` (string) - User data to be used by cloud-init. See [the Oracle docs](https://docs.us-phoenix-1.oraclecloud.com/api/#/en/iaas/20160918/LaunchInstanceDetails) for more details. Generally speaking, it is easier to use the `user_data_file`,
    but you can use this option to put either the plaintext data or the base64
    encoded data directly into your Packer config.
 
- - `user_data_file` (string) - Path to a file to be used as user_data by cloud
-   init. See [the Oracle docs](https://docs.us-phoenix-1.oraclecloud.com/api/#/en/iaas/20160918/LaunchInstanceDetails) for more details. Example:
+ - `user_data_file` (string) - Path to a file to be used as user data by cloud-init. See [the Oracle docs](https://docs.us-phoenix-1.oraclecloud.com/api/#/en/iaas/20160918/LaunchInstanceDetails) for more details. Example:
    `"user_data_file": "./boot_config/myscript.sh"`
 
  - `tags` (map of strings) - Add one or more freeform tags to the resulting custom image. See [the Oracle docs](https://docs.cloud.oracle.com/iaas/Content/Identity/Concepts/taggingoverview.htm) for more details. Example: