make comment bot account optional (llnl#213)

* make comment bot account optional

users may not want to set up a github account for tagging in comments. this makes `HC_GH_BOT_USER` optional, allowing a user to tag hubcast with the `/hubcast` prefix.

* rewrite env_get to support optional values

* flip order of conditional

Co-authored-by: Alec Scott <hi@alecbcs.com>

---------

Co-authored-by: Alec Scott <hi@alecbcs.com>

Author: cmelone

src/hubcast/config.py

@@ -1,5 +1,4 @@
 import os
-from typing import Optional
 
 
 class ConfigError(Exception):
@@ -23,8 +22,10 @@ def __init__(self):
             self.ldap_map_output = env_get("HC_LDAP_MAP_OUTPUT")
             self.ldap_map_scope = env_get("HC_LDAP_MAP_SCOPE")
             # optional settings: if None, the mapper will behave accordingly
-            self.ldap_map_bind_dn = os.environ.get("HC_LDAP_MAP_BIND_DN")
-            self.ldap_map_bind_password = os.environ.get("HC_LDAP_MAP_BIND_PASSWORD")
+            self.ldap_map_bind_dn = env_get("HC_LDAP_MAP_BIND_DN", optional=True)
+            self.ldap_map_bind_password = env_get(
+                "HC_LDAP_MAP_BIND_PASSWORD", optional=True
+            )
 
         self.gh = GitHubConfig()
         self.gl = GitLabConfig()
@@ -35,7 +36,7 @@ def __init__(self):
         self.app_id = env_get("HC_GH_APP_IDENTIFIER")
         self.privkey = env_get("HC_GH_PRIVATE_KEY")
         self.webhook_secret = env_get("HC_GH_SECRET")
-        self.bot_user = env_get("HC_GH_BOT_USER")
+        self.bot_user = env_get("HC_GH_BOT_USER", optional=True)
 
 
 class GitLabConfig:
@@ -47,9 +48,24 @@ def __init__(self):
         self.callback_url = env_get("HC_GL_CALLBACK_URL")
 
 
-def env_get(key: str, default: Optional[str] = None) -> str:
-    value = os.environ.get(key) or default
-    if not value:
-        raise ConfigError(f"Required environment variable not found: {key}")
+def env_get(key: str, default=None, optional: bool = False):
+    """
+    Retrieve environment variables.
+
+    Attributes:
+    ----------
+    key: str
+        The environment variable key to retrieve.
+    default: any, optional
+        The default value to return if the environment variable is not set.
+    optional: bool, optional
+        If True, the default value is returned when the variable is not found. If False
+        and the variable is not found, a ConfigError is raised.
+    """
 
-    return value
+    try:
+        return os.environ[key]
+    except KeyError:
+        if optional:
+            return default
+        raise ConfigError(f"Required environment variable not found: {key}")

src/hubcast/web/comments.py

@@ -1,11 +1,11 @@
-def help_message(bot_user: str):
+def help_message(bot_caller: str):
     return f"""
 You can interact with me in many ways!
 
-- `@{bot_user} help`: see this message
-- `@{bot_user} approve`: sync this pull request with the destination repository and trigger a new pipeline
-- `@{bot_user} run pipeline`: request a new run of the GitLab CI pipeline for any reason
-- `@{bot_user} restart failed jobs`: restart any failed jobs in the latest CI pipeline
+- `{bot_caller} help`: see this message
+- `{bot_caller} approve`: sync this pull request with the destination repository and trigger a new pipeline
+- `{bot_caller} run pipeline`: request a new run of the GitLab CI pipeline for any reason
+- `{bot_caller} restart failed jobs`: restart any failed jobs in the latest CI pipeline
 
 If you are an outside contributor to this repository, a maintainer will need to approve and run pipelines on your behalf.
 

src/hubcast/web/github/routes.py

@@ -298,10 +298,15 @@ async def respond_comment(event, gh, gl, gl_user, *arg, **kwargs):
     response = None
     plus_one = False
 
-    if re.search(f"@{gh.bot_user} help", comment, re.IGNORECASE):
-        response = comments.help_message(gh.bot_user)
+    if gh.bot_user:
+        bot_caller = f"@{gh.bot_user}"
+    else:
+        bot_caller = "/hubcast"
+
+    if re.search(f"{bot_caller} help", comment, re.IGNORECASE):
+        response = comments.help_message(bot_caller)
 
-    elif re.search(f"@{gh.bot_user} approve", comment, re.IGNORECASE):
+    elif re.search(f"{bot_caller} approve", comment, re.IGNORECASE):
         # syncs PR changes to the destination on behalf of the commenter
         # this does not handle PR deletions, those will need to be manually cleaned by project maintainers
         pull_request_id = event.data["issue"]["number"]
@@ -313,7 +318,7 @@ async def respond_comment(event, gh, gl, gl_user, *arg, **kwargs):
         plus_one = True
 
     elif re.search(
-        f"@{gh.bot_user} (re[-]?)?(run|start) pipeline", comment, re.IGNORECASE
+        f"{bot_caller} (re[-]?)?(run|start) pipeline", comment, re.IGNORECASE
     ):
         pull_request_id = event.data["issue"]["number"]
         pull_request = await gh.get_pr(pull_request_id)
@@ -344,7 +349,7 @@ async def respond_comment(event, gh, gl, gl_user, *arg, **kwargs):
             response = "I had a problem starting the pipeline."
 
     elif re.search(
-        f"@{gh.bot_user} restart failed(?:[- ]?jobs)?", comment, re.IGNORECASE
+        f"{bot_caller} restart failed(?:[- ]?jobs)?", comment, re.IGNORECASE
     ):
         pull_request_id = event.data["issue"]["number"]
         pull_request = await gh.get_pr(pull_request_id)