There are a lot of environment variables in any Meteor version. You probably know MONGO_URL and ROOT_URL , but how many others are there ? Do the Meteor guide and the Meteor docs reveal them all ? Guess no longer: just ask the source.

To find them all, all it takes is this one-liner:

grep -roP "process\.env\.([\w]+)" ~/.meteor/ | sed 's/.*:process\.env\.//' | sort | uniq | pr -3Tw140

Just for fun, here are the results on a fresh Meteor 1.3.2.4 deployment.

_ METEOR_OPLOG_TOO_FAR_BEHIND npm_config_tmp

APPDATA METEOR_PACKAGE_SERVER_URL npm_config__underbar_env_thing

APP_ID METEOR_PACKAGE_STATS_SERVER_URL NPM_CONFIG_UPPERCASE_ENV_THING

APP_MONGO METEOR_PACKAGE_STATS_TEST_OUTPUT npm_config_userconfig

AUTOUPDATE_VERSION METEOR_PARENT_PID npm_config_x

BABEL_CACHE_DIR METEOR_PKG_SPIDERABLE_PHANTOMJS_ARGS npm_config_yes

BABEL_CACHE_PATH METEOR_PRETTY_OUTPUT npm_execpath

BABEL_DISABLE_CACHE METEOR_PRINT_ON_LISTEN npm_lifecycle_script

BABEL_ENV METEOR_PROGRESS_DEBUG npm_package_config_port

BIND_IP METEOR_SAVE_TMPDIRS npm_package_name

BLUEBIRD_DEBUG METEOR_SESSION_FILE npm_package_run_script_foo_var

CAFILE METEOR_SETTINGS npm_package_scripts_install

CMD METEOR_SHELL_DIR npm_run_script_foo_var

COMP_CWORD METEOR_SKIP_NPM_REBUILD NVM_IOJS_ORG_MIRROR

COMP_LINE METEOR_TEST_FAIL_RELEASE_DOWNLOAD NVM_NODEJS_ORG_MIRROR

COMP_POINT METEOR_TEST_FAKE_MONGOD_CONTROL_PORT OBJECT_IMPL

COMPUTERNAME METEOR_TEST_LATEST_RELEASE OSTYPE

comspec METEOR_TEST_MULTIPLE_MONGOD_REPLSET PACKAGE_DIRS

ComSpec METEOR_TEST_NO_PUBLISH path

CORDOVA_PLUGIN_ID METEOR_TEST_PRINT_LINKER_CACHE_DEBUG Path

DDP_DEFAULT_CONNECTION_URL METEOR_TEST_TMP PATH

DEBUG METEOR_TOOL_PATH PATHEXT

DEBUG_COLORS METEOR_WAREHOUSE_DIR PHANTOMJS_CDNURL

DEBUG_FD METEOR_WATCH_FORCE_POLLING PORT

DEBUG_MIME METEOR_WATCH_POLLING_INTERVAL_MS PREFIX

DEBUG_NOPT MOBILE_DDP_URL PROMPT

DEPLOY_DOMAIN MOBILE_ROOT_URL PS1

DEPLOY_HOSTNAME MONGO_OPLOG_URL PUMMEL

DESTDIR MONGO_URL PWD

DISABLE_WEBSOCKETS MSYSTEM PYTHON

DISCOVERY_PORT MW Q_DEBUG

EDITOR NODE_BINDINGS_ARROW random_env_var

EMACS NODE_BINDINGS_COMPILED_DIR ROOT_URL

EXPRESS_COV NODE_DEBUG RUN_ONCE_OUTCOME

FAST NODE_DISABLE_COLORS run_script_foo_var

GALAXY_MOCK_MODE NODE_ENV SAUCE_KEY

GALAXY_PASSWORD NODEJS_ORG_MIRROR SAUCE_PROJ

GALAXY_USERNAME NODE_NDEBUG SAUCE_USER

HOME NODE_OPTIONS SERVER_WEBSOCKET_COMPRESSION

HOSTNAME NODE_PATH SHELL

http_proxy NODE_PATHS STYLUS_COV

HTTP_PROXY NO_DEPRECATION SUDO_GID

https_proxy NODE_TLS_REJECT_UNAUTHORIZED SUDO_UID

HTTPS_PROXY NO_METEOR_PACKAGE SystemDrive

IOJS_ORG_MIRROR no_proxy SystemRoot

JOBS NO_PROXY TEMP

LANG NOPT_DEBUG TERM

LC_ALL npm_config_ TEST_COV

LC_CTYPE npm_config_argv TEST_GRACEFUL_FS_GLOBAL_PATCH

MAIL_URL npm_config__auth TEST_METADATA

MAKE npm_config__authCrypt TEST_PSEUDOMAP

METEOR_APP_PRELINK_CACHE_SIZE npm_config_cache TEST_REGEN

METEOR_BAD_PARENT_PID_FOR_TEST npm_config_depth THROW_FROM_PACKAGE

METEOR_BUILD_FARM_URL npm_config_global TIMEOUT_SCALE_FACTOR

METEOR_CATALOG_COMPRESS_RPCS npm_config_globalconfig TIMES

METEOR_COLOR npm_config_init_author_email TINYTEST_FILTER

METEOR_DEBUG_BUILD npm_config_init_author_name TMP

METEOR_DEBUG_SPRINGBOARD npm_config_init_author_url TMPDIR

METEOR_DEBUG_SQL npm_config_init_license TRACE_DEPRECATION

METEOR_DISABLE_BUILDER_IN_PLACE npm_config_init_version TRAVIS

METEOR_FORCE_PORTABLE npm_config_loglevel TRAVIS_BRANCH

METEOR_INSTALLATION npm_config_node_version TRAVIS_BUILD_NUMBER

METEOR_LINKER_CACHE_SIZE npm_config_other_env_thing TRAVIS_JOB_ID

METEOR_LOG npm_config__password TRAVIS_JOB_NUMBER

METEOR_NO_WORDWRAP npm_config_prefix TRAVIS_NODE_VERSION

METEOR_OFFLINE_CATALOG npm_config_proxy TRAVIS_PULL_REQUEST

TREE_HASH_DEBUG USERDOMAIN windir

UNLAZY USERNAME WRITE_RUNNER_JS

USE_JSESSIONID USERPROFILE YOUR_APP_ENV

Seriously ?