rococo-runtime: RococoGenesisExt removed (#1490)

[`RococoGenesisExt`](https://github.com/paritytech/polkadot-sdk/blob/a414ea7515c9cdc81f1d12410e646afc148250e8/polkadot/node/service/src/chain_spec.rs#L152-L171)
is removed. It was the hack to allow overwriting
`EpochDurationInBlocks`. Removal of `RococGenesisExt` prevents from
manipulating the state to change the runtime constants.

Changes:
- Environment variable which controls the `time::EpochDurationInBlocks`
value was added: `ROCOCO_EPOCH_DURATION` (epoch duration will be set to
the value of env),
- `10,100,600` versions of rococo-runtime are built in CI and put into `polkadot-debug` docker image.

`rococo-runtime` building examples:
- to build runtime for `versi_staging_testnet` which had
EpochDurationInBlocks set to 100:
  ```
ROCOCO_EPOCH_DURATION=100 cargo build --features=fast-runtime -p
rococo-runtime
  ```
- to build runtime for `wococo_development`
  ```
ROCOCO_EPOCH_DURATION=10 cargo build --features=fast-runtime -p
rococo-runtime
  ```
- to build `versi-staging` chain spec:
  ```
ROCOCO_EPOCH_DURATION=100 cargo run -p polkadot --features=fast-runtime
-- build-spec --chain versi-staging --raw
  ```
- to build `wococo-dev` chain spec:
  ```
ROCOCO_EPOCH_DURATION=10 cargo run -p polkadot --features=fast-runtime
-- build-spec --chain wococo-dev --raw
  ```

It is also possible to change the epoch duration by replacing the `code` field in the chain spec with the hex dump of pre-built runtime wasm blob (because the epoch duration is hard-coded into wasm blob).

---------

Co-authored-by: Bastian Köcher <git@kchr.de>

.gitlab/pipeline/build.yml

@@ -19,12 +19,18 @@ build-linux-stable:
     RUN_UI_TESTS: 1
   script:
     - time cargo build --locked --profile testnet --features pyroscope,fast-runtime --bin polkadot --bin polkadot-prepare-worker --bin polkadot-execute-worker
+    - time ROCOCO_EPOCH_DURATION=10  ./polkadot/scripts/build-only-wasm.sh rococo-runtime $(pwd)/runtimes/rococo-runtime-10/
+    - time ROCOCO_EPOCH_DURATION=100 ./polkadot/scripts/build-only-wasm.sh rococo-runtime $(pwd)/runtimes/rococo-runtime-100/
+    - time ROCOCO_EPOCH_DURATION=600 ./polkadot/scripts/build-only-wasm.sh rococo-runtime $(pwd)/runtimes/rococo-runtime-600/
+    - pwd
+    - ls -alR runtimes
     # pack artifacts
     - mkdir -p ./artifacts
     - VERSION="${CI_COMMIT_REF_NAME}" # will be tag or branch name
     - mv ./target/testnet/polkadot ./artifacts/.
     - mv ./target/testnet/polkadot-prepare-worker ./artifacts/.
     - mv ./target/testnet/polkadot-execute-worker ./artifacts/.
+    - mv ./runtimes/ ./artifacts/.
     - pushd artifacts
     - sha256sum polkadot | tee polkadot.sha256
     - shasum -c polkadot.sha256

docker/dockerfiles/polkadot/polkadot_injected_debug.Dockerfile

@@ -28,13 +28,16 @@ RUN apt-get update && \
 	find /var/lib/apt/lists/ -type f -not -name lock -delete; \
 	# add user and link ~/.local/share/polkadot to /data
 	useradd -m -u 1000 -U -s /bin/sh -d /polkadot polkadot && \
-	mkdir -p /data /polkadot/.local/share && \
+	mkdir -p /data /polkadot/.local/share /polkdot/runtimes && \
 	chown -R polkadot:polkadot /data && \
 	ln -s /data /polkadot/.local/share/polkadot
 
 # add polkadot binaries to docker image
 COPY ./artifacts/polkadot ./artifacts/polkadot-execute-worker ./artifacts/polkadot-prepare-worker /usr/local/bin
 
+# add runtime binaries to docker image
+COPY ./artifacts/runtimes /polkadot/runtimes/
+
 USER polkadot
 
 # check if executable works in this container

polkadot/node/service/src/chain_spec.rs

@@ -84,7 +84,7 @@ pub type WestendChainSpec = GenericChainSpec;
 
 /// The `ChainSpec` parameterized for the rococo runtime.
 #[cfg(feature = "rococo-native")]
-pub type RococoChainSpec = service::GenericChainSpec<RococoGenesisExt, Extensions>;
+pub type RococoChainSpec = service::GenericChainSpec<rococo::RuntimeGenesisConfig, Extensions>;
 
 /// The `ChainSpec` parameterized for the `versi` runtime.
 ///
@@ -96,30 +96,6 @@ pub type VersiChainSpec = RococoChainSpec;
 #[cfg(not(feature = "rococo-native"))]
 pub type RococoChainSpec = GenericChainSpec;
 
-/// Extension for the Rococo genesis config to support a custom changes to the genesis state.
-#[derive(serde::Serialize, serde::Deserialize)]
-#[cfg(feature = "rococo-native")]
-pub struct RococoGenesisExt {
-	/// The runtime genesis config.
-	runtime_genesis_config: rococo::RuntimeGenesisConfig,
-	/// The session length in blocks.
-	///
-	/// If `None` is supplied, the default value is used.
-	session_length_in_blocks: Option<u32>,
-}
-
-#[cfg(feature = "rococo-native")]
-impl sp_runtime::BuildStorage for RococoGenesisExt {
-	fn assimilate_storage(&self, storage: &mut sp_core::storage::Storage) -> Result<(), String> {
-		sp_state_machine::BasicExternalities::execute_with_storage(storage, || {
-			if let Some(length) = self.session_length_in_blocks.as_ref() {
-				rococo_runtime_constants::time::EpochDurationInBlocks::set(length);
-			}
-		});
-		self.runtime_genesis_config.assimilate_storage(storage)
-	}
-}
-
 pub fn polkadot_config() -> Result<GenericChainSpec, String> {
 	GenericChainSpec::from_json_bytes(&include_bytes!("../chain-specs/polkadot.json")[..])
 }
@@ -780,10 +756,7 @@ pub fn rococo_staging_testnet_config() -> Result<RococoChainSpec, String> {
 		"Rococo Staging Testnet",
 		"rococo_staging_testnet",
 		ChainType::Live,
-		move || RococoGenesisExt {
-			runtime_genesis_config: rococo_staging_testnet_config_genesis(wasm_binary),
-			session_length_in_blocks: None,
-		},
+		move || rococo_staging_testnet_config_genesis(wasm_binary),
 		boot_nodes,
 		Some(
 			TelemetryEndpoints::new(vec![(ROCOCO_STAGING_TELEMETRY_URL.to_string(), 0)])
@@ -817,10 +790,7 @@ pub fn versi_staging_testnet_config() -> Result<RococoChainSpec, String> {
 		"Versi Staging Testnet",
 		"versi_staging_testnet",
 		ChainType::Live,
-		move || RococoGenesisExt {
-			runtime_genesis_config: rococo_staging_testnet_config_genesis(wasm_binary),
-			session_length_in_blocks: Some(100),
-		},
+		move || rococo_staging_testnet_config_genesis(wasm_binary),
 		boot_nodes,
 		Some(
 			TelemetryEndpoints::new(vec![(VERSI_STAGING_TELEMETRY_URL.to_string(), 0)])
@@ -1130,11 +1100,7 @@ pub fn rococo_development_config() -> Result<RococoChainSpec, String> {
 		"Development",
 		"rococo_dev",
 		ChainType::Development,
-		move || RococoGenesisExt {
-			runtime_genesis_config: rococo_development_config_genesis(wasm_binary),
-			// Use 1 minute session length.
-			session_length_in_blocks: Some(10),
-		},
+		move || rococo_development_config_genesis(wasm_binary),
 		vec![],
 		None,
 		Some(DEFAULT_PROTOCOL_ID),
@@ -1153,11 +1119,7 @@ pub fn versi_development_config() -> Result<RococoChainSpec, String> {
 		"Development",
 		"versi_dev",
 		ChainType::Development,
-		move || RococoGenesisExt {
-			runtime_genesis_config: rococo_development_config_genesis(wasm_binary),
-			// Use 1 minute session length.
-			session_length_in_blocks: Some(10),
-		},
+		move || rococo_development_config_genesis(wasm_binary),
 		vec![],
 		None,
 		Some("versi"),
@@ -1177,11 +1139,7 @@ pub fn wococo_development_config() -> Result<RococoChainSpec, String> {
 		"Development",
 		"wococo_dev",
 		ChainType::Development,
-		move || RococoGenesisExt {
-			runtime_genesis_config: rococo_development_config_genesis(wasm_binary),
-			// Use 1 minute session length.
-			session_length_in_blocks: Some(10),
-		},
+		move || rococo_development_config_genesis(wasm_binary),
 		vec![],
 		None,
 		Some(WOCOCO_DEV_PROTOCOL_ID),
@@ -1239,11 +1197,7 @@ pub fn rococo_local_testnet_config() -> Result<RococoChainSpec, String> {
 		"Rococo Local Testnet",
 		"rococo_local_testnet",
 		ChainType::Local,
-		move || RococoGenesisExt {
-			runtime_genesis_config: rococo_local_testnet_genesis(wasm_binary),
-			// Use 1 minute session length.
-			session_length_in_blocks: Some(10),
-		},
+		move || rococo_local_testnet_genesis(wasm_binary),
 		vec![],
 		None,
 		Some(DEFAULT_PROTOCOL_ID),
@@ -1278,11 +1232,7 @@ pub fn wococo_local_testnet_config() -> Result<RococoChainSpec, String> {
 		"Wococo Local Testnet",
 		"wococo_local_testnet",
 		ChainType::Local,
-		move || RococoGenesisExt {
-			runtime_genesis_config: wococo_local_testnet_genesis(wasm_binary),
-			// Use 1 minute session length.
-			session_length_in_blocks: Some(10),
-		},
+		move || wococo_local_testnet_genesis(wasm_binary),
 		vec![],
 		None,
 		Some(DEFAULT_PROTOCOL_ID),
@@ -1317,11 +1267,7 @@ pub fn versi_local_testnet_config() -> Result<RococoChainSpec, String> {
 		"Versi Local Testnet",
 		"versi_local_testnet",
 		ChainType::Local,
-		move || RococoGenesisExt {
-			runtime_genesis_config: versi_local_testnet_genesis(wasm_binary),
-			// Use 1 minute session length.
-			session_length_in_blocks: Some(10),
-		},
+		move || versi_local_testnet_genesis(wasm_binary),
 		vec![],
 		None,
 		Some("versi"),

polkadot/runtime/rococo/Cargo.toml

@@ -110,7 +110,7 @@ sp-tracing = { path = "../../../substrate/primitives/tracing", default-features
 tokio = { version = "1.24.2", features = ["macros"] }
 
 [build-dependencies]
-substrate-wasm-builder = { path = "../../../substrate/utils/wasm-builder" }
+substrate-wasm-builder = { path = "../../../substrate/utils/wasm-builder", optional = true }
 
 [features]
 default = [ "std" ]
@@ -196,6 +196,7 @@ std = [
 	"sp-storage/std",
 	"sp-tracing/std",
 	"sp-version/std",
+	"substrate-wasm-builder",
 	"tx-pool-api/std",
 	"xcm-builder/std",
 	"xcm-executor/std",

polkadot/runtime/rococo/README.md

@@ -2,6 +2,13 @@
 
 Rococo is a testnet runtime with no stability guarantees.
 
+## How to build `rococo` runtime
+`EpochDurationInBlocks` parameter is configurable via `ROCOCO_EPOCH_DURATION` environment variable. To build wasm
+runtime blob with customized epoch duration the following command shall be exectuted:
+```bash
+ROCOCO_EPOCH_DURATION=10 ./polkadot/scripts/build-only-wasm.sh rococo-runtime /path/to/output/directory/
+```
+
 ## How to run `rococo-local`
 
 The [Cumulus Tutorial](https://docs.substrate.io/tutorials/v3/cumulus/start-relay/) details building, starting, and

polkadot/runtime/rococo/build.rs

@@ -14,12 +14,19 @@
 // You should have received a copy of the GNU General Public License
 // along with Substrate.  If not, see <http://www.gnu.org/licenses/>.
 
-use substrate_wasm_builder::WasmBuilder;
-
+#[cfg(feature = "std")]
 fn main() {
-	WasmBuilder::new()
+	// note: needs to be synced with rococo-runtime-constants::time hard-coded string literal
+	const ROCOCO_EPOCH_DURATION_ENV: &str = "ROCOCO_EPOCH_DURATION";
+
+	substrate_wasm_builder::WasmBuilder::new()
 		.with_current_project()
 		.import_memory()
 		.export_heap_base()
-		.build()
+		.build();
+
+	println!("cargo:rerun-if-env-changed={}", ROCOCO_EPOCH_DURATION_ENV);
 }
+
+#[cfg(not(feature = "std"))]
+fn main() {}

polkadot/runtime/rococo/constants/src/lib.rs

@@ -38,12 +38,13 @@ pub mod currency {
 /// Time and blocks.
 pub mod time {
 	use primitives::{BlockNumber, Moment};
-	use runtime_common::prod_or_fast;
 	pub const MILLISECS_PER_BLOCK: Moment = 6000;
 	pub const SLOT_DURATION: Moment = MILLISECS_PER_BLOCK;
-	pub const DEFAULT_EPOCH_DURATION: BlockNumber = prod_or_fast!(1 * HOURS, 1 * MINUTES);
+
 	frame_support::parameter_types! {
-		pub storage EpochDurationInBlocks: BlockNumber = DEFAULT_EPOCH_DURATION;
+		pub storage EpochDurationInBlocks: BlockNumber = option_env!("ROCOCO_EPOCH_DURATION")
+			.map(|s| s.parse().expect("`ROCOCO_EPOCH_DURATION` is not a valid `BlockNumber`"))
+			.unwrap_or(1 * MINUTES);
 	}
 
 	// These time units are defined in number of blocks.

polkadot/zombienet_tests/functional/0002-parachains-disputes.toml

@@ -1,7 +1,7 @@
 [settings]
 timeout = 1000
 
-[relaychain.genesis.runtime.runtime_genesis_config.configuration.config]
+[relaychain.genesis.runtime.configuration.config]
   max_validators_per_core = 5
   needed_approvals = 8
 

polkadot/zombienet_tests/functional/0004-parachains-garbage-candidate.toml

@@ -2,7 +2,7 @@
 timeout = 1000
 bootnode = true
 
-[relaychain.genesis.runtime.runtime_genesis_config.configuration.config]
+[relaychain.genesis.runtime.configuration.config]
   max_validators_per_core = 1
   needed_approvals = 2
 

polkadot/zombienet_tests/misc/0001-paritydb.toml

@@ -2,7 +2,7 @@
 timeout = 1000
 bootnode = true
 
-[relaychain.genesis.runtime.runtime_genesis_config.configuration.config]
+[relaychain.genesis.runtime.configuration.config]
   max_validators_per_core = 1
   needed_approvals = 3