linera-io/linera-protocol · critical

Fail to read server config

Error message

Fail to read server config

What it means

The validator proxy's run() loads its ValidatorServerConfig with util::read_json(&self.config_path).expect("Fail to read server config"). The panic fires when the config file cannot be opened or its JSON cannot be deserialized into ValidatorServerConfig, before the proxy starts serving.

Source

Thrown at linera-service/src/proxy/main.rs:619

        if let Some(threads) = options.tokio_threads {
            builder.worker_threads(threads);
        }

        builder
    };

    if let Some(blocking_threads) = options.tokio_blocking_threads {
        runtime.max_blocking_threads(blocking_threads);
    }

    runtime.enable_all().build()?.block_on(options.run())
}

impl ProxyOptions {
    async fn run(&self) -> Result<()> {
        let server_config: ValidatorServerConfig =
            util::read_json(&self.config_path).expect("Fail to read server config");
        let public_key = &server_config.validator.public_key;
        linera_service::tracing::opentelemetry::init(
            &format!("validator-{public_key}-proxy"),
            self.otlp_exporter_endpoint.as_deref(),
        );

        let store_config = self
            .storage_config
            .add_common_storage_options(&self.common_storage_options)?;
        let cache_sizes = self.common_storage_options.storage_cache_config();
        // Proxies are part of validator infrastructure and should not output contract logs.
        let allow_application_logs = false;
        store_config
            .run_with_storage(
                None,
                allow_application_logs,
                cache_sizes,
                ProxyContext::from_options(self)?,

View on GitHub (pinned to 6c226ddcb3)

Solutions

1. Confirm the file exists and is readable at the exact path passed to the proxy (use absolute paths in systemd units)
2. Validate the JSON (jq . config.json) and diff its structure against a freshly generated ValidatorServerConfig for your version
3. Regenerate the server config with the proxy's generate/setup flow for the current version rather than hand-editing an old file
4. Check file permissions/ownership for the service user running the proxy

Example fix

# before
linera-proxy --config config.json   # relative path, wrong cwd

# after
jq . /etc/linera/proxy/server.json   # valid JSON + schema
linera-proxy --config /etc/linera/proxy/server.json

# Systemd-style pre-flight for the proxy config.
ExecStartPre=/bin/sh -c 'test -r /etc/linera/proxy/server.json && jq -e .validator.public_key /etc/linera/proxy/server.json > /dev/null'

When it happens

Trigger: Launching linera-proxy with a --config path that does not exist, is not readable, contains invalid JSON, or has a ValidatorServerConfig schema mismatch (missing validator section, wrong key names for the installed version).

Common situations: First-time proxy deployment where the config was never generated; path typos or running from a different working directory with a relative path; config written for an older/newer Linera version after upgrade; file ownership issues under systemd/container users.

Related errors

• Failed to read server config
• Unable to read committee config file
• Invalid options file format: \n {options_string}
• Failed to deserialize service response
• Application parameters must be deserializable

AI-assisted analysis of linera-io/linera-protocol@6c226ddcb3 (2026-08-22). Data as JSON: /api/errors/2fb61269df14dc94. Report an issue: GitHub.