[PAN-3126] add an override facility for genesis configs

config/src/main/java/tech/pegasys/pantheon/config/GenesisConfigFile.java

@@ -16,6 +16,8 @@
 import static tech.pegasys.pantheon.config.JsonUtil.normalizeKeys;
 
 import java.io.IOException;
+import java.util.Collections;
+import java.util.Map;
 import java.util.Optional;
 import java.util.stream.Stream;
 
@@ -82,9 +84,13 @@ public static GenesisConfigFile fromConfig(final ObjectNode config) {
   }
 
   public GenesisConfigOptions getConfigOptions() {
+    return getConfigOptions(Collections.emptyMap());
+  }
+
+  public GenesisConfigOptions getConfigOptions(final Map<String, String> overrides) {
     ObjectNode config =
         JsonUtil.getObjectNode(configRoot, "config").orElse(JsonUtil.createEmptyObjectNode());
-    return new JsonGenesisConfigOptions(config);
+    return new JsonGenesisConfigOptions(config, overrides);
   }
 
   public Stream<GenesisAllocation> streamAllocations() {

config/src/main/java/tech/pegasys/pantheon/config/JsonGenesisConfigOptions.java

@@ -15,10 +15,12 @@
 import static java.util.Objects.isNull;
 
 import java.math.BigInteger;
+import java.util.Collections;
 import java.util.Map;
 import java.util.Optional;
 import java.util.OptionalInt;
 import java.util.OptionalLong;
+import java.util.TreeMap;
 
 import com.fasterxml.jackson.databind.node.ObjectNode;
 import com.google.common.collect.ImmutableMap;
@@ -30,13 +32,22 @@ public class JsonGenesisConfigOptions implements GenesisConfigOptions {
   private static final String IBFT2_CONFIG_KEY = "ibft2";
   private static final String CLIQUE_CONFIG_KEY = "clique";
   private final ObjectNode configRoot;
+  private final Map<String, String> configOverrides = new TreeMap<>(String.CASE_INSENSITIVE_ORDER);
 
   public static JsonGenesisConfigOptions fromJsonObject(final ObjectNode configRoot) {
     return new JsonGenesisConfigOptions(configRoot);
   }
 
-  JsonGenesisConfigOptions(final ObjectNode maybeConfig) {
+  private JsonGenesisConfigOptions(final ObjectNode maybeConfig) {
+    this(maybeConfig, Collections.emptyMap());
+  }
+
+  JsonGenesisConfigOptions(
+      final ObjectNode maybeConfig, final Map<String, String> configOverrides) {
     this.configRoot = isNull(maybeConfig) ? JsonUtil.createEmptyObjectNode() : maybeConfig;
+    if (configOverrides != null) {
+      this.configOverrides.putAll(configOverrides);
+    }
   }
 
   @Override
@@ -148,17 +159,17 @@ public OptionalLong getIstanbulBlockNumber() {
 
   @Override
   public Optional<BigInteger> getChainId() {
-    return JsonUtil.getValueAsString(configRoot, "chainid").map(BigInteger::new);
+    return getOptionalBigInteger("chainid");
   }
 
   @Override
   public OptionalInt getContractSizeLimit() {
-    return JsonUtil.getInt(configRoot, "contractsizelimit");
+    return getOptionalInt("contractsizelimit");
   }
 
   @Override
   public OptionalInt getEvmStackSize() {
-    return JsonUtil.getInt(configRoot, "evmstacksize");
+    return getOptionalInt("evmstacksize");
   }
 
   @Override
@@ -176,9 +187,8 @@ public Map<String, Object> asMap() {
         .ifPresent(
             l -> {
               builder.put("eip150Block", l);
-              if (configRoot.has("eip150hash")) {
-                builder.put("eip150Hash", configRoot.get("eip150hash").asText());
-              }
+              getOptionalString("eip150hash")
+                  .ifPresent(eip150hash -> builder.put("eip150Hash", eip150hash));
             });
     getSpuriousDragonBlockNumber()
         .ifPresent(
@@ -207,7 +217,45 @@ public Map<String, Object> asMap() {
     return builder.build();
   }
 
+  private Optional<String> getOptionalString(final String key) {
+    if (configOverrides.containsKey(key)) {
+      final String value = configOverrides.get(key);
+      return value == null || value.isEmpty() ? Optional.empty() : Optional.of(value);
+    } else {
+      return JsonUtil.getString(configRoot, key);
+    }
+  }
+
   private OptionalLong getOptionalLong(final String key) {
-    return JsonUtil.getLong(configRoot, key);
+    if (configOverrides.containsKey(key)) {
+      final String value = configOverrides.get(key);
+      return value == null || value.isEmpty()
+          ? OptionalLong.empty()
+          : OptionalLong.of(Long.valueOf(configOverrides.get(key)));
+    } else {
+      return JsonUtil.getLong(configRoot, key);
+    }
+  }
+
+  private OptionalInt getOptionalInt(final String key) {
+    if (configOverrides.containsKey(key)) {
+      final String value = configOverrides.get(key);
+      return value == null || value.isEmpty()
+          ? OptionalInt.empty()
+          : OptionalInt.of(Integer.valueOf(configOverrides.get(key)));
+    } else {
+      return JsonUtil.getInt(configRoot, key);
+    }
+  }
+
+  private Optional<BigInteger> getOptionalBigInteger(final String key) {
+    if (configOverrides.containsKey(key)) {
+      final String value = configOverrides.get(key);
+      return value == null || value.isEmpty()
+          ? Optional.empty()
+          : Optional.of(new BigInteger(value));
+    } else {
+      return JsonUtil.getValueAsString(configRoot, key).map(BigInteger::new);
+    }
   }
 }

config/src/test/java/tech/pegasys/pantheon/config/GenesisConfigFileTest.java

@@ -17,6 +17,7 @@
 
 import java.math.BigInteger;
 import java.util.Map;
+import java.util.TreeMap;
 import java.util.function.Function;
 import java.util.stream.Collectors;
 
@@ -214,6 +215,59 @@ public void acceptComments() {
     // Unfortunately there is no good (non-flakey) way to assert logs.
   }
 
+  @Test
+  public void testOverridePresent() {
+    final GenesisConfigFile config = GenesisConfigFile.development();
+    final int bigBlock = 999_999_999;
+    final String bigBlockString = Integer.toString(bigBlock);
+    final Map<String, String> override = new TreeMap<>(String.CASE_INSENSITIVE_ORDER);
+    override.put("istanbulBlock", bigBlockString);
+    override.put("chainId", bigBlockString);
+    override.put("contractSizeLimit", bigBlockString);
+
+    assertThat(config.getConfigOptions(override).getIstanbulBlockNumber()).hasValue(bigBlock);
+    assertThat(config.getConfigOptions(override).getChainId())
+        .hasValue(BigInteger.valueOf(bigBlock));
+    assertThat(config.getConfigOptions(override).getContractSizeLimit()).hasValue(bigBlock);
+  }
+
+  @Test
+  public void testOverrideNull() {
+    final GenesisConfigFile config = GenesisConfigFile.development();
+    final Map<String, String> override = new TreeMap<>(String.CASE_INSENSITIVE_ORDER);
+    override.put("istanbulBlock", null);
+    override.put("chainId", null);
+    override.put("contractSizeLimit", null);
+
+    assertThat(config.getConfigOptions(override).getIstanbulBlockNumber()).isNotPresent();
+    assertThat(config.getConfigOptions(override).getChainId()).isNotPresent();
+    assertThat(config.getConfigOptions(override).getContractSizeLimit()).isNotPresent();
+  }
+
+  @Test
+  public void testOverrideEmptyString() {
+    final GenesisConfigFile config = GenesisConfigFile.development();
+    final Map<String, String> override = new TreeMap<>(String.CASE_INSENSITIVE_ORDER);
+    override.put("istanbulBlock", "");
+    override.put("chainId", "");
+    override.put("contractSizeLimit", "");
+
+    assertThat(config.getConfigOptions(override).getIstanbulBlockNumber()).isNotPresent();
+    assertThat(config.getConfigOptions(override).getChainId()).isNotPresent();
+    assertThat(config.getConfigOptions(override).getContractSizeLimit()).isNotPresent();
+  }
+
+  @Test
+  public void testNoOverride() {
+    final GenesisConfigFile config = GenesisConfigFile.development();
+
+    assertThat(config.getConfigOptions().getConstantinopleFixBlockNumber()).hasValue(0);
+    assertThat(config.getConfigOptions().getIstanbulBlockNumber()).isNotPresent();
+    assertThat(config.getConfigOptions().getChainId()).hasValue(BigInteger.valueOf(2018));
+    assertThat(config.getConfigOptions().getContractSizeLimit()).hasValue(2147483647);
+    assertThat(config.getConfigOptions().getEvmStackSize()).isNotPresent();
+  }
+
   private GenesisConfigFile configWithProperty(final String key, final String value) {
     return GenesisConfigFile.fromConfig("{\"" + key + "\":\"" + value + "\"}");
   }

pantheon/src/main/java/tech/pegasys/pantheon/cli/PantheonCommand.java

@@ -118,6 +118,7 @@
 import java.util.Map;
 import java.util.Optional;
 import java.util.Set;
+import java.util.TreeMap;
 import java.util.function.Supplier;
 import java.util.stream.Collectors;
 
@@ -650,6 +651,16 @@ void setBannedNodeIds(final List<String> values) {
   private final Integer pendingTxRetentionPeriod =
       TransactionPoolConfiguration.DEFAULT_TX_RETENTION_HOURS;
 
+  @Option(
+      names = {"--override-genesis-config"},
+      paramLabel = "NAME=VALUE",
+      description = "Overrides configuration values in the genesis file.  Use with care.",
+      arity = "*",
+      hidden = true,
+      split = ",")
+  private final Map<String, String> genesisConfigOverrides =
+      new TreeMap<>(String.CASE_INSENSITIVE_ORDER);
+
   private EthNetworkConfig ethNetworkConfig;
   private JsonRpcConfiguration jsonRpcConfiguration;
   private GraphQLConfiguration graphQLConfiguration;
@@ -932,7 +943,7 @@ public PantheonController<?> buildController() {
   public PantheonControllerBuilder<?> getControllerBuilder() {
     try {
       return controllerBuilderFactory
-          .fromEthNetworkConfig(updateNetworkConfig(getNetwork()))
+          .fromEthNetworkConfig(updateNetworkConfig(getNetwork()), genesisConfigOverrides)
           .synchronizerConfiguration(buildSyncConfig())
           .ethProtocolConfiguration(ethProtocolOptions.toDomainObject())
           .rocksDbConfiguration(buildRocksDbConfiguration())
@@ -946,7 +957,8 @@ public PantheonControllerBuilder<?> getControllerBuilder() {
           .clock(Clock.systemUTC())
           .isRevertReasonEnabled(isRevertReasonEnabled)
           .isPruningEnabled(isPruningEnabled)
-          .pruningConfiguration(buildPruningConfiguration());
+          .pruningConfiguration(buildPruningConfiguration())
+          .genesisConfigOverrides(genesisConfigOverrides);
     } catch (final IOException e) {
       throw new ExecutionException(this.commandLine, "Invalid path", e);
     }
@@ -1351,7 +1363,7 @@ private EthNetworkConfig updateNetworkConfig(final NetworkName network) {
           final GenesisConfigFile genesisConfigFile = GenesisConfigFile.fromConfig(genesisConfig());
           builder.setNetworkId(
               genesisConfigFile
-                  .getConfigOptions()
+                  .getConfigOptions(genesisConfigOverrides)
                   .getChainId()
                   .orElse(EthNetworkConfig.getNetworkConfig(MAINNET).getNetworkId()));
         } catch (final DecodeException e) {

pantheon/src/main/java/tech/pegasys/pantheon/controller/CliquePantheonControllerBuilder.java

@@ -59,7 +59,7 @@ public class CliquePantheonControllerBuilder extends PantheonControllerBuilder<C
   protected void prepForBuild() {
     localAddress = Util.publicKeyToAddress(nodeKeys.getPublicKey());
     final CliqueConfigOptions cliqueConfig =
-        genesisConfig.getConfigOptions().getCliqueConfigOptions();
+        genesisConfig.getConfigOptions(genesisConfigOverrides).getCliqueConfigOptions();
     final long blocksPerEpoch = cliqueConfig.getEpochLength();
     secondsBetweenBlocks = cliqueConfig.getBlockPeriodSeconds();
 
@@ -121,7 +121,10 @@ protected MiningCoordinator createMiningCoordinator(
   @Override
   protected ProtocolSchedule<CliqueContext> createProtocolSchedule() {
     return CliqueProtocolSchedule.create(
-        genesisConfig.getConfigOptions(), nodeKeys, privacyParameters, isRevertReasonEnabled);
+        genesisConfig.getConfigOptions(genesisConfigOverrides),
+        nodeKeys,
+        privacyParameters,
+        isRevertReasonEnabled);
   }
 
   @Override

pantheon/src/main/java/tech/pegasys/pantheon/controller/IbftLegacyPantheonControllerBuilder.java

@@ -64,14 +64,16 @@ protected MiningCoordinator createMiningCoordinator(
   @Override
   protected ProtocolSchedule<IbftContext> createProtocolSchedule() {
     return IbftProtocolSchedule.create(
-        genesisConfig.getConfigOptions(), privacyParameters, isRevertReasonEnabled);
+        genesisConfig.getConfigOptions(genesisConfigOverrides),
+        privacyParameters,
+        isRevertReasonEnabled);
   }
 
   @Override
   protected IbftContext createConsensusContext(
       final Blockchain blockchain, final WorldStateArchive worldStateArchive) {
     final IbftConfigOptions ibftConfig =
-        genesisConfig.getConfigOptions().getIbftLegacyConfigOptions();
+        genesisConfig.getConfigOptions(genesisConfigOverrides).getIbftLegacyConfigOptions();
     final EpochManager epochManager = new EpochManager(ibftConfig.getEpochLength());
     final VoteTallyCache voteTallyCache =
         new VoteTallyCache(

pantheon/src/main/java/tech/pegasys/pantheon/controller/IbftPantheonControllerBuilder.java

@@ -81,7 +81,7 @@ public class IbftPantheonControllerBuilder extends PantheonControllerBuilder<Ibf
 
   @Override
   protected void prepForBuild() {
-    ibftConfig = genesisConfig.getConfigOptions().getIbft2ConfigOptions();
+    ibftConfig = genesisConfig.getConfigOptions(genesisConfigOverrides).getIbft2ConfigOptions();
     ibftEventQueue = new IbftEventQueue(ibftConfig.getMessageQueueLimit());
   }
 
@@ -211,7 +211,9 @@ protected MiningCoordinator createMiningCoordinator(
   @Override
   protected ProtocolSchedule<IbftContext> createProtocolSchedule() {
     return IbftProtocolSchedule.create(
-        genesisConfig.getConfigOptions(), privacyParameters, isRevertReasonEnabled);
+        genesisConfig.getConfigOptions(genesisConfigOverrides),
+        privacyParameters,
+        isRevertReasonEnabled);
   }
 
   @Override
@@ -226,7 +228,8 @@ protected void validateContext(final ProtocolContext<IbftContext> context) {
   @Override
   protected IbftContext createConsensusContext(
       final Blockchain blockchain, final WorldStateArchive worldStateArchive) {
-    final IbftConfigOptions ibftConfig = genesisConfig.getConfigOptions().getIbft2ConfigOptions();
+    final IbftConfigOptions ibftConfig =
+        genesisConfig.getConfigOptions(genesisConfigOverrides).getIbft2ConfigOptions();
     final EpochManager epochManager = new EpochManager(ibftConfig.getEpochLength());
     return new IbftContext(
         new VoteTallyCache(

pantheon/src/main/java/tech/pegasys/pantheon/controller/MainnetPantheonControllerBuilder.java

@@ -86,6 +86,8 @@ protected Void createConsensusContext(
   @Override
   protected ProtocolSchedule<Void> createProtocolSchedule() {
     return MainnetProtocolSchedule.fromConfig(
-        genesisConfig.getConfigOptions(), privacyParameters, isRevertReasonEnabled);
+        genesisConfig.getConfigOptions(genesisConfigOverrides),
+        privacyParameters,
+        isRevertReasonEnabled);
   }
 }

pantheon/src/main/java/tech/pegasys/pantheon/controller/PantheonController.java

@@ -29,6 +29,7 @@
 import tech.pegasys.pantheon.ethereum.p2p.config.SubProtocolConfiguration;
 
 import java.util.Collection;
+import java.util.Collections;
 import java.util.Map;
 
 public class PantheonController<C> implements java.io.Closeable {
@@ -129,12 +130,25 @@ public static class Builder {
 
     public PantheonControllerBuilder<?> fromEthNetworkConfig(
         final EthNetworkConfig ethNetworkConfig) {
-      return fromGenesisConfig(GenesisConfigFile.fromConfig(ethNetworkConfig.getGenesisConfig()))
+      return fromEthNetworkConfig(ethNetworkConfig, Collections.emptyMap());
+    }
+
+    public PantheonControllerBuilder<?> fromEthNetworkConfig(
+        final EthNetworkConfig ethNetworkConfig, final Map<String, String> genesisConfigOverrides) {
+      return fromGenesisConfig(
+              GenesisConfigFile.fromConfig(ethNetworkConfig.getGenesisConfig()),
+              genesisConfigOverrides)
           .networkId(ethNetworkConfig.getNetworkId());
     }
 
     public PantheonControllerBuilder<?> fromGenesisConfig(final GenesisConfigFile genesisConfig) {
-      final GenesisConfigOptions configOptions = genesisConfig.getConfigOptions();
+      return fromGenesisConfig(genesisConfig, Collections.emptyMap());
+    }
+
+    public PantheonControllerBuilder<?> fromGenesisConfig(
+        final GenesisConfigFile genesisConfig, final Map<String, String> genesisConfigOverrides) {
+      final GenesisConfigOptions configOptions =
+          genesisConfig.getConfigOptions(genesisConfigOverrides);
       final PantheonControllerBuilder<?> builder;
 
       if (configOptions.isEthHash()) {