Add a network magic config field for custom testnets

zebra-network/src/config.rs

@@ -16,7 +16,7 @@ use tracing::Span;
 
 use zebra_chain::parameters::{
     testnet::{self, ConfiguredActivationHeights},
-    Network, NetworkKind,
+    Magic, Network, NetworkKind,
 };
 
 use crate::{
@@ -636,6 +636,7 @@ impl<'de> Deserialize<'de> for Config {
     {
         #[derive(Deserialize)]
         struct DTestnetParameters {
+            network_magic: Option<[u8; 4]>,
             network_name: Option<String>,
             activation_heights: Option<ConfiguredActivationHeights>,
         }
@@ -718,26 +719,34 @@ impl<'de> Deserialize<'de> for Config {
                 NetworkKind::Testnet,
                 Some(DTestnetParameters {
                     network_name,
+                    network_magic,
                     activation_heights,
                 }),
             ) => {
                 let mut params_builder = testnet::Parameters::build();
+                let should_avoid_default_peers =
+                    network_magic.is_some() || activation_heights.is_some();
+
+                // Return an error if the initial testnet peers includes any of the default initial Mainnet or Testnet
+                // peers while activation heights or a custom network magic is configured.
+                if should_avoid_default_peers
+                    && contains_default_initial_peers(&initial_testnet_peers)
+                {
+                    return Err(de::Error::custom(
+                        "cannot use default initials peers with incompatible testnet",
+                    ));
+                }
 
                 if let Some(network_name) = network_name {
                     params_builder = params_builder.with_network_name(network_name)
                 }
 
+                if let Some(network_magic) = network_magic {
+                    params_builder = params_builder.with_network_magic(Magic(network_magic));
+                }
+
                 // Retain default Testnet activation heights unless there's an empty [testnet_parameters.activation_heights] section.
                 if let Some(activation_heights) = activation_heights {
-                    // Return an error if the initial testnet peers includes any of the default initial Mainnet or Testnet
-                    // peers while activation heights are configured.
-                    // TODO: Check that the network magic is different from the default Mainnet/Testnet network magic too?
-                    if contains_default_initial_peers(&initial_testnet_peers) {
-                        return Err(de::Error::custom(
-                            "cannot use default initial testnet peers with configured activation heights",
-                        ));
-                    }
-
                     params_builder = params_builder.with_activation_heights(activation_heights)
                 }
 

zebrad/tests/common/configs/v1.8.0.toml

@@ -0,0 +1,91 @@
+# Default configuration for zebrad.
+#
+# This file can be used as a skeleton for custom configs.
+#
+# Unspecified fields use default values. Optional fields are Some(field) if the
+# field is present and None if it is absent.
+#
+# This file is generated as an example using zebrad's current defaults.
+# You should set only the config options you want to keep, and delete the rest.
+# Only a subset of fields are present in the skeleton, since optional values
+# whose default is None are omitted.
+#
+# The config format (including a complete list of sections and fields) is
+# documented here:
+# https://docs.rs/zebrad/latest/zebrad/config/struct.ZebradConfig.html
+#
+# zebrad attempts to load configs in the following order:
+#
+# 1. The -c flag on the command line, e.g., `zebrad -c myconfig.toml start`;
+# 2. The file `zebrad.toml` in the users's preference directory (platform-dependent);
+# 3. The default config.
+#
+# The user's preference directory and the default path to the `zebrad` config are platform dependent,
+# based on `dirs::preference_dir`, see https://docs.rs/dirs/latest/dirs/fn.preference_dir.html :
+#
+# | Platform | Value                                 | Example                                        |
+# | -------- | ------------------------------------- | ---------------------------------------------- |
+# | Linux    | `$XDG_CONFIG_HOME` or `$HOME/.config` | `/home/alice/.config/zebrad.toml`              |
+# | macOS    | `$HOME/Library/Preferences`           | `/Users/Alice/Library/Preferences/zebrad.toml` |
+# | Windows  | `{FOLDERID_RoamingAppData}`           | `C:\Users\Alice\AppData\Local\zebrad.toml`     |
+
+[consensus]
+checkpoint_sync = true
+
+[mempool]
+eviction_memory_time = "1h"
+tx_cost_limit = 80000000
+
+[metrics]
+
+[mining]
+debug_like_zcashd = true
+
+[network]
+cache_dir = true
+crawl_new_peer_interval = "1m 1s"
+initial_mainnet_peers = [
+    "dnsseed.z.cash:8233",
+    "dnsseed.str4d.xyz:8233",
+    "mainnet.seeder.zfnd.org:8233",
+    "mainnet.is.yolo.money:8233",
+]
+initial_testnet_peers = []
+listen_addr = "0.0.0.0:8233"
+max_connections_per_ip = 1
+network = "Testnet"
+peerset_initial_target_size = 25
+
+[network.testnet_parameters]
+network_name = "ConfiguredTestnet_1"
+network_magic = [0, 0, 0, 0]
+
+[network.testnet_parameters.activation_heights]
+BeforeOverwinter = 1
+Overwinter = 207_500
+Sapling = 280_000
+Blossom = 584_000
+Heartwood = 903_800
+Canopy = 1_028_500
+NU5 = 1_842_420
+
+[rpc]
+debug_force_finished_sync = false
+parallel_cpu_threads = 0
+
+[state]
+cache_dir = "cache_dir"
+delete_old_database = true
+ephemeral = false
+
+[sync]
+checkpoint_verify_concurrency_limit = 1000
+download_concurrency_limit = 50
+full_verify_concurrency_limit = 20
+parallel_cpu_threads = 0
+
+[tracing]
+buffer_limit = 128000
+force_use_color = false
+use_color = true
+use_journald = false