Add .dazelrc.local support

README.md

@@ -41,11 +41,13 @@ Even bazel is not required!
 
 ## Configuration
 
-You can configure dazel in two ways (or combine):
-* A .dazelrc file in the current directory.
+You can configure dazel in three ways (listed in order of ascending precedence):
+* A `.dazelrc` file in the current directory.
+* A `~/.dazelrc` file in the user's `$HOME` directory.
+* A `.dazelrc.local` file in the current directory (this is for local user overrides - _should be .gitignored if used_).
 * Environment variables with the configuration parameters mentioned below.
 
-Note that specific environment variables supercede the values in the .dazelrc file.
+You may combine these methods, but note that parameter values will supercede each other in the order listed above (i.e: specific parameters specified by environment variables will supercede values in both the `.dazelrc` and the `.dazelrc.local`). Parameters whose values are lists such as `DAZEL_VOLUMES` will override each other as opposed to being merged.
 
 The possible parameters to set are (with their defaults):
 ```python

dazel.py

@@ -7,7 +7,13 @@
 import collections
 
 
-DAZEL_RC_FILE = ".dazelrc"
+# Dazel RC files and their respective environment variable path overrides (in order of ascending precedence)
+DAZEL_RC_FILE_ENVS = [
+ ("DAZEL_RC_FILE", ".dazelrc"),
+ ("DAZEL_RC_USER_FILE", "~/.dazelrc"),
+ ("DAZEL_RC_LOCAL_FILE", ".dazelrc.local")
+]
+
 DAZEL_RUN_FILE = ".dazel_run"
 BAZEL_WORKSPACE_FILE = "WORKSPACE"
 
@@ -99,7 +105,9 @@ def __init__(self, instance_name, image_name, run_command, docker_command, docke
 
  @classmethod
  def from_config(cls):
- config = cls._config_from_file()
+ config = {}
+ for (env_var, default_path) in DAZEL_RC_FILE_ENVS:
+ config.update(cls._config_from_file(filename=default_path, env_var=env_var))
  config.update(cls._config_from_environment())
  return DockerInstance(
  instance_name=config.get("DAZEL_INSTANCE_NAME", DEFAULT_INSTANCE_NAME),
@@ -487,19 +495,25 @@ def _with_docker_machine(self, cmd):
  return "eval $(docker-machine env %s) && (%s)" % (self.docker_machine, cmd)
 
  @classmethod
- def _config_from_file(cls):
+ def _config_from_file(cls, filename, env_var):
  """Creates a configuration from a .dazelrc file."""
- directory = cls._find_workspace_directory()
- local_dazelrc_path = os.path.join(directory, DAZEL_RC_FILE)
- dazelrc_path = os.environ.get("DAZEL_RC_FILE", local_dazelrc_path)
-
- if not os.path.exists(dazelrc_path):
- return { "DAZEL_DIRECTORY": os.environ.get("DAZEL_DIRECTORY", directory) }
-
- config = {}
- with open(dazelrc_path, "r") as dazelrc:
- exec(dazelrc.read(), config)
- config["DAZEL_DIRECTORY"] = os.environ.get("DAZEL_DIRECTORY", directory)
+ dazel_dir = cls._find_workspace_directory()
+ # Build the expanded path for the config file and join it to the dazel_dir if
+ # necessary
+ expanded_path = os.path.expanduser(filename)
+ if expanded_path.startswith('/'):
+ dazelrc_path = expanded_path
+ else:
+ dazelrc_path = os.path.join(dazel_dir, filename)
+ # If a custom config path was defined by the env_var, use that path
+ config_path = os.environ.get(env_var, dazelrc_path)
+
+ # Use the workspace directory by default. Lower precendence than DAZEL_DIRECTORY env var.
+ config = { "DAZEL_DIRECTORY": dazel_dir }
+ if os.path.exists(config_path):
+ with open(config_path, "r") as dazelrc:
+ # This will merge/overwrite any existing values
+ exec(dazelrc.read(), config)
  return config
 
  @classmethod

setup.py

@@ -23,7 +23,7 @@
  # Versions should comply with PEP440. For a discussion on single-sourcing
  # the version across setup.py and the project code, see
  # https://packaging.python.org/en/latest/single_source_version.html
- version='0.0.36',
+ version='0.0.37',
 
  description='Run bazel in Docker, in a reproducible and portable container.',
  long_description=long_description,