Cache the token username

This can reduce the number of github api requests

Author: dflook

CHANGELOG.md

@@ -12,14 +12,17 @@ When using an action you can specify the version as:
 - `@v1.6` to use the latest patch release for the specific minor version
 - `@v1` to use the latest patch release for the specific major version
 
-## [1.6.0] - 2021-02-24
+## [1.6.0] - 2021-02-25
 
 ### Added
 - PR comments use a one line summary of the terraform output, with the full output in a collapsable pane.
 
   If a plan is short the output is shown by default. This can be controlled with the `TF_PLAN_COLLAPSE_LENGTH` environment
   variable for the [dflook/terraform-plan](terraform-plan) action.
 
+### Fixed
+- Now makes far fewer github api requests to avoid rate limiting.
+
 ## [1.5.2] - 2021-01-16
 
 ### Fixed

image/tools/github_pr_comment.py

@@ -5,6 +5,7 @@
 import re
 import sys
 import datetime
+import hashlib
 from typing import Optional, Dict, Iterable
 
 import requests
@@ -98,16 +99,37 @@ def find_pr() -> str:
         raise Exception(f"The {event_type} event doesn\'t relate to a Pull Request.")
 
 def current_user() -> str:
+
+    token_hash = hashlib.sha256(os.environ["GITHUB_TOKEN"].encode()).hexdigest()
+
+    try:
+        with open(f'.dflook-terraform/token-cache/{token_hash}') as f:
+            username = f.read()
+            debug(f'GITHUB_TOKEN username: {username}')
+            return username
+    except Exception as e:
+        debug(str(e))
+
     response = github_api_request('get', 'https://api.github.com/user')
     if response.status_code != 403:
         user = response.json()
         debug('GITHUB_TOKEN user:')
         debug(json.dumps(user))
 
-        return user['login']
+        username = user['login']
+    else:
+        # Assume this is the github actions app token
+        username = 'github-actions[bot]'
+
+    try:
+        os.makedirs('.dflook-terraform/token-cache', exist_ok=True)
+        with open(f'.dflook-terraform/token-cache/{token_hash}', 'w') as f:
+            f.write(username)
+    except Exception as e:
+        debug(str(e))
 
-    # Assume this is the github actions app token
-    return 'github-actions[bot]'
+    debug(f'GITHUB_TOKEN username: {username}')
+    return username
 
 class TerraformComment:
     """
@@ -129,10 +151,12 @@ def __init__(self, pr_url: str=None):
         response = github_api_request('get', self._issue_url)
         response.raise_for_status()
 
+        username = current_user()
+
         debug('Looking for an existing comment:')
         for comment in response.json():
             debug(json.dumps(comment))
-            if comment['user']['login'] == current_user():
+            if comment['user']['login'] == username:
                 match = re.match(rf'{re.escape(self._comment_identifier)}.*```(?:hcl)?(.*?)```.*', comment['body'], re.DOTALL)
 
                 if not match: