Document environment variables in help

Available environment variables should be documented in --help or something like that.

It should also be documented that any additional envvar should be added to the list.

changed milestone to %Ğ1 fake migration

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@tuxmain I've found only one relevant environment variable in the source code, excluding those related to the toolchain or to the test suite:

• DUNITER_GENESIS_CONFIG

Is there any other you were thinking about when filing this issue?

I don't know, maybe some are used only in Substrate code. Another option would be to replace them with CLI arguments. @HugoTrentesaux ?

I've searched through duniter-v2s and substrate source code for environment variables.

Environment variables found in substrate code:

$ find . -name .git -prune -o -type f -exec grep -Eo 'env::var\([^)]*)' {} \; | sed -E 's/^env::var\(//;s/\)$//' | sort -u
"CARGO"
"CARGO_CFG_TARGET_ARCH"
"CARGO_CFG_TARGET_ENV"
"CARGO_CFG_TARGET_OS"
"CARGO_MANIFEST_DIR"
"CARGO_PKG_NAME"
"CARGO_PKG_VERSION"
crate::SKIP_BUILD_ENV
crate::WASM_BUILD_NO_COLOR
crate::WASM_BUILD_RUSTFLAGS_ENV
crate::WASM_BUILD_TYPE_ENV
crate::WASM_BUILD_WORKSPACE_HINT
crate::WASM_TARGET_DIRECTORY
"ENABLE_LOGGING"
format!("CARGO_FEATURE_{}", feature_env
generate_crate_skip_build_env_name(
"HOST"
OFFLINE
"OPT_LEVEL"
"OUT_DIR"
"PRINT_MAX_LOG_LEVEL"
PRINT_PALLET_UPGRADE
"PROFILE"
"RUN_CUSTOM_FORMAT_TEST"
"RUN_FORKED_TEST"
"RUN_TEST"
"RUN_TEST_PARENT_ID_WITH_THREADS"
"RUN_UI_TESTS"
"RUSTC"
"RUSTC_BOOTSTRAP"
"RUST_LOG"
"SUBSTRATE_CLI_GIT_COMMIT_HASH"
"SUBSTRATE_TEST_TIMEOUT"
"TEST_LOG_FILTER"
"TRACING_TARGETS"
version_env
WASM_BUILD_TOOLCHAIN

Environment variables found in duniter-v2s code:

$ find . -name .git -prune -o -type f -exec grep -Eo 'env::var\([^)]*)' {} \; | sed -E 's/^env::var\(//;s/\)$//' | sort -u
"AT_BLOCK_NUMBER"
"DUNITER_BINARY_PATH"
"DUNITER_END2END_TESTS_SPAWN_NODE_TIMEOUT"
"DUNITER_GENESIS_CONFIG"
"DUNITER_GENESIS_TIMESTAMP"
env_var_name
"GITLAB_TOKEN"
"WS_RPC_ENDPOINT"

Chainspec related environment variables:

$ find . -name .git -prune -o -type f -exec grep -w get_env_u32 {} \; -print
    let babe_epoch_duration = get_env_u32("DUNITER_BABE_EPOCH_DURATION", 30) as u64;
    let cert_validity_period = get_env_u32("DUNITER_CERT_VALIDITY_PERIOD", 1_000);
    let membership_period = get_env_u32("DUNITER_MEMBERSHIP_PERIOD", 1_000);
    let smith_cert_validity_period = get_env_u32("DUNITER_SMITH_CERT_VALIDITY_PERIOD", 1_000);
    let smith_membership_period = get_env_u32("DUNITER_SMITH_MEMBERSHIP_PERIOD", 1_000);
    let ud_creation_period = get_env_u32("DUNITER_UD_CREATION_PERIOD", 10);
    let ud_reeval_period = get_env_u32("DUNITER_UD_REEEVAL_PERIOD", 200);

Remaining after ruling out build, test and chainspec related variables:

substrate

None (IMHO).

duniter

"DUNITER_GENESIS_CONFIG"
"DUNITER_GENESIS_TIMESTAMP"

These variables are related to the chainspec (chain spec generation or bootnode startup).

Pini is right, the only environment variables are related to chainspec generation. I guess it is for convenience, and they are only needed for developers. Only documenting them in the developer documentation is enough in my opinion.

I think we should focus on documenting things that people will use or need to understand, and keep the rest for specific tutorials.

added P9-somedaymaybe label and removed P7-nicetohave label

changed milestone to %Horizon

removed milestone %Horizon