mu-auth-sudo

NPM package for a SPARQL client for mu.semte.ch that overrules access rights in queries through a mu-auth-sudo header.

Usage

``bash
npm install @lblod/mu-auth-sudo
`

Include the following in your code
`js
import { querySudo as query, updateSudo as update } from '@lblod/mu-auth-sudo';


//Examples

// To run a regular query

const queryString = SELECT * FROM { GRAPH ?g { ?s ?p ?o. } } LIMIT 1;
await query(queryString);

// To pass extra headers

const updateString = INSERT DATA { GRAPH { . } };
const extraHeaders = { 'mu-call-scope-id': 'http://foo/bar', 'other-info'; 'hello' };
await update(updateString, extraHeaders);

// With custom connection options (this should be exceptional, make sure you know what you're doing)

const connectionOptions = { sparqlEndpoint: 'http://the.custom.endpoint/sparql', mayRetry: true, };

await update(updateString, extraHeaders, connectionOptions);

// Authentication via digest or basic auth
const connectionOptions = {
sparqlEndpoint: 'http://the.custom.endpoint/sparql',
authUser: "dba",
authPassword: "mypass",
authType: "digest"
};

await update(updateString, extraHeaders, connectionOptions);

`

Typescript usage

The query method allows for specifying the resulting bindings you expect to receive. Additionally, there are special return types for
ASK, CONSTRUCT and DESCRIBE queries.

`ts

const queryString = SELECT * FROM { GRAPH ?g { ?s ?p ?o. } } LIMIT 1;
// for SELECT queries, list the variable bindings you ask for in the select as an array of strings
const result = await querySudo<['g', 's', 'p', 'o']>(queryString);
// result shape and bindings are now typed, and will fully autocomplete
result.results.bindins[0].g.value

const queryString = ASK {?something ?exists "with this value"}
// for ASK queries, simply specify the literal 'ask' as the generic
const result = await querySudo<'ask'>(queryString)
// result shape is typed
result.boolean

const queryString = DESCRIBE
// for DESCRIBE queries, simply specify the literal 'describe' as the generic
// note, this is fully equivalent to querySudo<['s', 'p', 'v']>
const result = await querySudo<'describe'>(queryString)
// result shape is typed
result.results.bindings[0].s.value

const queryString = CONSTRUCT {?my ?triple ?pattern. } WHERE {?my ?triple ?pattern .}
// for CONSTRUCT queries, simply specify the literal 'construct' as the generic
// note, this is fully equivalent to querySudo<['s', 'p', 'v']>
const result = await querySudo<'construct'>(queryString)
// result shape is typed
result.results.bindings[0].s.value
`

If you don't care or don't know the result shape, you can simply leave out the generic. It defaults to string[], which means
everything except the specific binding names will still be typed, e.g:

`ts

const queryString = SELECT * FROM { GRAPH ?g { ?s ?p ?o. } } LIMIT 1;
const result = querySudo(queryString);

// still fully typed
const firstBinding = result.results.bindings[0]

// won't complain, since we haven't specified the precise binding names
const hmmm = firstBinding.banana

// however, the shape of the binding is still typed
const {value, type} = hmmm

`

Logging

The verbosity of logging can be configured as in the javascript template through following environment variables:

- LOG_SPARQL_ALL: Logging of all executed SPARQL queries, read as well as update (default true)
- LOG_SPARQL_QUERIES: Logging of executed SPARQL read queries (default: undefined). Overrules LOG_SPARQL_ALL.
- LOG_SPARQL_UPDATES: Logging of executed SPARQL update queries (default undefined). Overrules LOG_SPARQL_ALL.
- DEBUG_AUTH_HEADERS: Debugging of mu-authorization access-control related headers (default true)

Following values are considered true: ["true", "TRUE", "1"].

Retrying

You can tweak system-wide retry parameters. These should be considered internal, but tweaking them may help in extreme scenarios. Use with extreme caution.

- SUDO_QUERY_RETRY: System-wide configuration to enable the retry-mechanism (default 'false').
Warning: this overules eventual source-code specifications (i.e. connectionOptions = { mayRetry: false }), so make sure you know what you're doing.
- SUDO_QUERY_RETRY_MAX_ATTEMPTS: Specfiy the number of max retry attempts (default: 5)
- SUDO_QUERY_RETRY_FOR_HTTP_STATUS_CODES: Specify what returned HTTP status from the database are allowed for retry. (default: ''). Overriding this list should be considered case by case.
- SUDO_QUERY_RETRY_FOR_CONNECTION_ERRORS: Specify what connection errors are allowed for retry. (default: 'ECONNRESET,ETIMEDOUT,EAI_AGAIN')
- SUDO_QUERY_RETRY_TIMEOUT_INCREMENT_FACTOR: Specify the factor applied to the timeout before the next attempt. Check implementation to see how it is calculated. (default: '0.3'`)