neondatabase/neon · error

could not open config file at path: {}

Error message

could not open config file at path: {}

What it means

The test-only config loader could not even open the file at params.config_path_test_only: File::open failed (usually ENOENT - no such file, or EACCES - permission denied inside the container). Distinguished from error 13, which is opened-but-unparseable. Only reachable when config_path_test_only is set; production fetches config from the control plane.

Source

Thrown at compute_tools/src/configurator.rs:89

                    info!(
                        "reloading config.json from path: {}",
                        config_path.to_string_lossy()
                    );
                    let path = Path::new(config_path);
                    if let Ok(file) = File::open(path) {
                        match serde_json::from_reader::<File, ComputeConfig>(file) {
                            Ok(config) => Ok(config),
                            Err(e) => {
                                error!("could not parse config file: {}", e);
                                Err(anyhow::anyhow!("could not parse config file: {}", e))
                            }
                        }
                    } else {
                        error!(
                            "could not open config file at path: {:?}",
                            config_path.to_string_lossy()
                        );
                        Err(anyhow::anyhow!(
                            "could not open config file at path: {}",
                            config_path.to_string_lossy()
                        ))
                    }
                } else if let Some(control_plane_uri) = &compute.params.control_plane_uri {
                    get_config_from_control_plane(control_plane_uri, &compute.params.compute_id)
                } else {
                    Err(anyhow::anyhow!("config_path_test_only is not set"))
                };

            // Parse any received ComputeSpec and transpose the result into a Result<Option<ParsedSpec>>.
            let parsed_spec_result: Result<Option<ParsedSpec>> =
                get_config_result.and_then(|config| {
                    if let Some(spec) = config.spec {
                        if let Ok(pspec) = ParsedSpec::try_from(spec) {
                            Ok(Some(pspec))
                        } else {
                            Err(anyhow::anyhow!("could not parse spec"))

View on GitHub (pinned to 8f60b04da4)

Solutions

1. Verify the exact path exists from inside the same container/user: ls -l <path>
2. Use an absolute path; check volume mounts and their subPaths if running in K8s
3. chmod/chown the file so the runtime user can read it
4. Confirm you actually meant the test path; in production you want control_plane_uri instead

Example fix

# before: relative or wrong path -> could not open config file
--config-path-test-only config.json
# after
--config-path-test-only /etc/neon/config.json   # mounted, readable, absolute

// Pre-flight the test config path before startup
let p = std::path::Path::new(&config_path);
if !p.is_file() { anyhow::bail!("config file {p:?} does not exist"); }
if !p.metadata()?.permissions().readonly() { /* at least readable check */ }

fn config_file_readable(path: &Path) -> bool {
    path.is_file() && std::fs::File::open(path).is_ok()
}

When it happens

Trigger: compute_ctl started with a config path that does not exist in the container (wrong volume mount, relative path resolved against an unexpected cwd), or a file with permissions the runtime user cannot read.

Common situations: Docker/K8s volume not mounted at the expected path; typo in the --config-path-test-only value; path from a host build leaked into the container; file owned by root with 0600 while compute_ctl runs as non-root; CI checkout layout changed.

Related errors

• could not parse config file: {}
• connection to postgres closed
• pageserver connection information should be provided
• safekeeper connstrings should be provided
• tenant id should be provided

AI-assisted analysis of neondatabase/neon@8f60b04da4 (2026-08-16). Data as JSON: /api/errors/5c716c04c84e1c1e. Report an issue: GitHub.