Build details page: normalize/trim command paths (#9815)

* Build details page: normalize/trim command paths

Small hack to trim/normalize command paths when displaying them to the user
under the build detail's page.

This is a simple hack and there are more we can do here. Probably, there are
some edge cases this is not catching. However, the worst it can happens is the
path not being trimmed.

* Make regex to work locally and in production

* pre-commit

Author: humitos

readthedocs/api/v2/serializers.py

@@ -1,6 +1,9 @@
 """Defines serializers for each of our models."""
 
+import re
+
 from allauth.socialaccount.models import SocialAccount
+from django.conf import settings
 from rest_framework import serializers
 
 from readthedocs.builds.models import Build, BuildCommandResult, Version
@@ -127,11 +130,41 @@ class VersionAdminSerializer(VersionSerializer):
 class BuildCommandSerializer(serializers.ModelSerializer):
 
     run_time = serializers.ReadOnlyField()
+    command = serializers.SerializerMethodField()
 
     class Meta:
         model = BuildCommandResult
         exclude = []
 
+    def get_command(self, obj):
+        # HACK: remove unreadable paths from the command outputs when returning it from the API.
+        # We could make this change at build level, but we want to avoid undoable issues from now
+        # and hack a small solution to fix the immediate problem.
+        #
+        # This converts:
+        #   $ /usr/src/app/checkouts/readthedocs.org/user_builds/
+        #        <container_hash>/<project_slug>/envs/<version_slug>/bin/python
+        #   $ /home/docs/checkouts/readthedocs.org/user_builds/
+        #        <project_slug>/envs/<version_slug>/bin/python
+        # into
+        #   $ python
+        project_slug = obj.build.version.project.slug
+        version_slug = obj.build.version.slug
+        docroot = settings.DOCROOT.rstrip("/")  # remove trailing '/'
+
+        # Remove Docker hash from DOCROOT when running it locally
+        # DOCROOT contains the Docker container hash (e.g. b7703d1b5854).
+        # We have to remove it from the DOCROOT it self since it changes each time
+        # we spin up a new Docker instance locally.
+        container_hash = "/"
+        if settings.RTD_DOCKER_COMPOSE:
+            docroot = re.sub("/[0-9a-z]+/?$", "", settings.DOCROOT, count=1)
+            container_hash = "/[0-9a-z]+/"
+
+        regex = f"{docroot}{container_hash}{project_slug}/envs/{version_slug}(/bin/)?"
+        command = re.sub(regex, "", obj.command, count=1)
+        return command
+
 
 class BuildSerializer(serializers.ModelSerializer):