refactor: Fully type and validate config module set and get

We define the type for each config value, and validate the data when
retrieving and setting it.

Change-type: minor
Signed-off-by: Cameron Diver <cameron@balena.io>

package.json

@@ -64,7 +64,9 @@
     "event-stream": "3.3.4",
     "express": "^4.0.0",
     "fork-ts-checker-webpack-plugin": "^0.5.2",
+    "fp-ts": "^1.12.2",
     "husky": "^1.3.0",
+    "io-ts": "^1.5.1",
     "istanbul": "^0.4.5",
     "json-mask": "^0.3.8",
     "knex": "~0.15.2",

src/config/configJson.ts

@@ -3,8 +3,8 @@ import * as _ from 'lodash';
 import { fs } from 'mz';
 import * as path from 'path';
 
-import { ConfigSchema, ConfigValue } from '../lib/types';
 import { readLock, writeLock } from '../lib/update-lock';
+import * as Schema from './schema';
 
 import * as constants from '../lib/constants';
 import { writeAndSyncFile, writeFileAtomic } from '../lib/fs-utils';
@@ -15,11 +15,11 @@ export default class ConfigJsonConfigBackend {
 	private writeLockConfigJson: () => Promise.Disposer<() => void>;
 
 	private configPath?: string;
-	private cache: { [key: string]: ConfigValue } = {};
+	private cache: { [key: string]: unknown } = {};
 
-	private schema: ConfigSchema;
+	private schema: Schema.Schema;
 
-	public constructor(schema: ConfigSchema, configPath?: string) {
+	public constructor(schema: Schema.Schema, configPath?: string) {
 		this.configPath = configPath;
 		this.schema = schema;
 
@@ -35,10 +35,12 @@ export default class ConfigJsonConfigBackend {
 		});
 	}
 
-	public set(keyVals: { [key: string]: ConfigValue }): Promise<void> {
+	public set<T extends Schema.SchemaKey>(
+		keyVals: { [key in T]: unknown },
+	): Promise<void> {
 		let changed = false;
 		return Promise.using(this.writeLockConfigJson(), () => {
-			return Promise.mapSeries(_.keys(keyVals), (key: string) => {
+			return Promise.mapSeries(_.keys(keyVals) as T[], (key: T) => {
 				const value = keyVals[key];
 
 				if (this.cache[key] !== value) {
@@ -62,7 +64,7 @@ export default class ConfigJsonConfigBackend {
 		});
 	}
 
-	public get(key: string): Promise<ConfigValue> {
+	public get(key: string): Promise<unknown> {
 		return Promise.using(this.readLockConfigJson(), () => {
 			return Promise.resolve(this.cache[key]);
 		});

src/config/functions.ts

@@ -8,107 +8,100 @@ import Config from '.';
 import * as constants from '../lib/constants';
 import * as osRelease from '../lib/os-release';
 
-type ConfigProviderFunction = () => Bluebird<any>;
-
-export interface ConfigProviderFunctions {
-	[key: string]: ConfigProviderFunction;
-}
-
-export function createProviderFunctions(
-	config: Config,
-): ConfigProviderFunctions {
-	return {
-		version: () => {
-			return Bluebird.resolve(supervisorVersion);
-		},
-		currentApiKey: () => {
-			return config
-				.getMany(['apiKey', 'deviceApiKey'])
-				.then(({ apiKey, deviceApiKey }) => {
-					return apiKey || deviceApiKey;
-				});
-		},
-		provisioned: () => {
-			return config
-				.getMany(['uuid', 'apiEndpoint', 'registered_at', 'deviceId'])
-				.then(requiredValues => {
-					return _.every(_.values(requiredValues), Boolean);
-				});
-		},
-		osVersion: () => {
-			return osRelease.getOSVersion(constants.hostOSVersionPath);
-		},
-		osVariant: () => {
-			return osRelease.getOSVariant(constants.hostOSVersionPath);
-		},
-		provisioningOptions: () => {
-			return config
-				.getMany([
-					'uuid',
-					'userId',
-					'applicationId',
-					'apiKey',
-					'deviceApiKey',
-					'deviceType',
-					'apiEndpoint',
-					'apiTimeout',
-					'registered_at',
-					'deviceId',
-				])
-				.then(conf => {
-					return {
-						uuid: conf.uuid,
-						applicationId: conf.applicationId,
-						userId: conf.userId,
-						deviceType: conf.deviceType,
-						provisioningApiKey: conf.apiKey,
-						deviceApiKey: conf.deviceApiKey,
-						apiEndpoint: conf.apiEndpoint,
-						apiTimeout: conf.apiTimeout,
-						registered_at: conf.registered_at,
-						deviceId: conf.deviceId,
-					};
-				});
-		},
-		mixpanelHost: () => {
-			return config.get('apiEndpoint').then(apiEndpoint => {
-				if (!apiEndpoint) {
-					return null;
-				}
-				const url = new URL(apiEndpoint as string);
-				return { host: url.host, path: '/mixpanel' };
+export const fnSchema = {
+	version: () => {
+		return Bluebird.resolve(supervisorVersion);
+	},
+	currentApiKey: (config: Config) => {
+		return config
+			.getMany(['apiKey', 'deviceApiKey'])
+			.then(({ apiKey, deviceApiKey }) => {
+				return apiKey || deviceApiKey;
 			});
-		},
-		extendedEnvOptions: () => {
-			return config.getMany([
+	},
+	provisioned: (config: Config) => {
+		return config
+			.getMany(['uuid', 'apiEndpoint', 'registered_at', 'deviceId'])
+			.then(requiredValues => {
+				return _.every(_.values(requiredValues), Boolean);
+			});
+	},
+	osVersion: () => {
+		return osRelease.getOSVersion(constants.hostOSVersionPath);
+	},
+	osVariant: () => {
+		return osRelease.getOSVariant(constants.hostOSVersionPath);
+	},
+	provisioningOptions: (config: Config) => {
+		return config
+			.getMany([
 				'uuid',
-				'listenPort',
-				'name',
-				'apiSecret',
+				'userId',
+				'applicationId',
+				'apiKey',
 				'deviceApiKey',
-				'version',
 				'deviceType',
-				'osVersion',
-			]);
-		},
-		fetchOptions: () => {
-			return config.getMany([
-				'uuid',
-				'currentApiKey',
 				'apiEndpoint',
-				'deltaEndpoint',
-				'delta',
-				'deltaRequestTimeout',
-				'deltaApplyTimeout',
-				'deltaRetryCount',
-				'deltaRetryInterval',
-				'deltaVersion',
-			]);
-		},
-		unmanaged: () => {
-			return config.get('apiEndpoint').then(apiEndpoint => {
-				return !apiEndpoint;
+				'apiTimeout',
+				'registered_at',
+				'deviceId',
+			])
+			.then(conf => {
+				return {
+					uuid: conf.uuid,
+					applicationId: conf.applicationId,
+					userId: conf.userId,
+					deviceType: conf.deviceType,
+					provisioningApiKey: conf.apiKey,
+					deviceApiKey: conf.deviceApiKey,
+					apiEndpoint: conf.apiEndpoint,
+					apiTimeout: conf.apiTimeout,
+					registered_at: conf.registered_at,
+					deviceId: conf.deviceId,
+				};
 			});
-		},
-	};
-}
+	},
+	mixpanelHost: (config: Config) => {
+		return config.get('apiEndpoint').then(apiEndpoint => {
+			if (!apiEndpoint) {
+				return null;
+			}
+			const url = new URL(apiEndpoint);
+			return { host: url.host, path: '/mixpanel' };
+		});
+	},
+	extendedEnvOptions: (config: Config) => {
+		return config.getMany([
+			'uuid',
+			'listenPort',
+			'name',
+			'apiSecret',
+			'deviceApiKey',
+			'version',
+			'deviceType',
+			'osVersion',
+		]);
+	},
+	fetchOptions: (config: Config) => {
+		return config.getMany([
+			'uuid',
+			'currentApiKey',
+			'apiEndpoint',
+			'deltaEndpoint',
+			'delta',
+			'deltaRequestTimeout',
+			'deltaApplyTimeout',
+			'deltaRetryCount',
+			'deltaRetryInterval',
+			'deltaVersion',
+		]);
+	},
+	unmanaged: (config: Config) => {
+		return config.get('apiEndpoint').then(apiEndpoint => {
+			return !apiEndpoint;
+		});
+	},
+};
+
+export type FnSchema = typeof fnSchema;
+export type FnSchemaKey = keyof FnSchema;

src/config/index.ts

@@ -4,93 +4,39 @@ import { Transaction } from 'knex';
 import * as _ from 'lodash';
 import { generateUniqueKey } from 'resin-register-device';
 
+import { Either } from 'fp-ts/lib/Either';
+import * as t from 'io-ts';
+
 import ConfigJsonConfigBackend from './configJson';
 
-import * as constants from '../lib/constants';
-import { ConfigMap, ConfigSchema, ConfigValue } from '../lib/types';
-import { ConfigProviderFunctions, createProviderFunctions } from './functions';
+import * as FnSchema from './functions';
+import * as Schema from './schema';
+import { SchemaReturn, SchemaTypeKey, schemaTypes } from './schema-type';
 
 import DB from '../db';
+import {
+	ConfigurationValidationError,
+	InternalInconsistencyError,
+} from '../lib/errors';
 
 interface ConfigOpts {
 	db: DB;
 	configPath: string;
 }
 
+type ConfigMap<T extends SchemaTypeKey> = { [key in T]: SchemaReturn<key> };
+
 export class Config extends EventEmitter {
 	private db: DB;
 	private configJsonBackend: ConfigJsonConfigBackend;
-	private providerFunctions: ConfigProviderFunctions;
-
-	public schema: ConfigSchema = {
-		apiEndpoint: { source: 'config.json', default: '' },
-		apiTimeout: { source: 'config.json', default: 15 * 60 * 1000 },
-		listenPort: { source: 'config.json', default: 48484 },
-		deltaEndpoint: { source: 'config.json', default: 'https://delta.resin.io' },
-		uuid: { source: 'config.json', mutable: true },
-		apiKey: { source: 'config.json', mutable: true, removeIfNull: true },
-		deviceApiKey: { source: 'config.json', mutable: true, default: '' },
-		deviceType: { source: 'config.json', default: 'unknown' },
-		username: { source: 'config.json' },
-		userId: { source: 'config.json' },
-		deviceId: { source: 'config.json', mutable: true },
-		registered_at: { source: 'config.json', mutable: true },
-		applicationId: { source: 'config.json' },
-		appUpdatePollInterval: {
-			source: 'config.json',
-			mutable: true,
-			default: 60000,
-		},
-		mixpanelToken: {
-			source: 'config.json',
-			default: constants.defaultMixpanelToken,
-		},
-		bootstrapRetryDelay: { source: 'config.json', default: 30000 },
-		hostname: { source: 'config.json', mutable: true },
-		persistentLogging: { source: 'config.json', default: false, mutable: true },
-
-		version: { source: 'func' },
-		currentApiKey: { source: 'func' },
-		provisioned: { source: 'func' },
-		osVersion: { source: 'func' },
-		osVariant: { source: 'func' },
-		provisioningOptions: { source: 'func' },
-		mixpanelHost: { source: 'func' },
-		extendedEnvOptions: { source: 'func' },
-		fetchOptions: { source: 'func' },
-		unmanaged: { source: 'func' },
-
-		// NOTE: all 'db' values are stored and loaded as *strings*,
-		apiSecret: { source: 'db', mutable: true },
-		name: { source: 'db', mutable: true, default: 'local' },
-		initialConfigReported: { source: 'db', mutable: true, default: 'false' },
-		initialConfigSaved: { source: 'db', mutable: true, default: 'false' },
-		containersNormalised: { source: 'db', mutable: true, default: 'false' },
-		loggingEnabled: { source: 'db', mutable: true, default: 'true' },
-		connectivityCheckEnabled: { source: 'db', mutable: true, default: 'true' },
-		delta: { source: 'db', mutable: true, default: 'false' },
-		deltaRequestTimeout: { source: 'db', mutable: true, default: '30000' },
-		deltaApplyTimeout: { source: 'db', mutable: true, default: '' },
-		deltaRetryCount: { source: 'db', mutable: true, default: '30' },
-		deltaRetryInterval: { source: 'db', mutable: true, default: '10000' },
-		deltaVersion: { source: 'db', mutable: true, default: '2' },
-		lockOverride: { source: 'db', mutable: true, default: 'false' },
-		legacyAppsPresent: { source: 'db', mutable: true, default: 'false' },
-		// a JSON value, which is either null, or { app: number, commit: string }
-		pinDevice: { source: 'db', mutable: true, default: 'null' },
-		currentCommit: { source: 'db', mutable: true },
-		targetStateSet: { source: 'db', mutable: true, default: 'false' },
-		localMode: { source: 'db', mutable: true, default: 'false' },
-	};
 
 	public constructor({ db, configPath }: ConfigOpts) {
 		super();
 		this.db = db;
 		this.configJsonBackend = new ConfigJsonConfigBackend(
-			this.schema,
+			Schema.schema,
 			configPath,
 		);
-		this.providerFunctions = createProviderFunctions(this);
 	}
 
 	public init(): Bluebird<void> {
@@ -99,164 +45,155 @@ export class Config extends EventEmitter {
 		});
 	}
 
-	public get(key: string, trx?: Transaction): Bluebird<ConfigValue> {
+	public get<T extends SchemaTypeKey>(
+		key: T,
+		trx?: Transaction,
+	): Bluebird<SchemaReturn<T>> {
 		const db = trx || this.db.models.bind(this.db);
 
 		return Bluebird.try(() => {
-			if (this.schema[key] == null) {
+			if (Schema.schema.hasOwnProperty(key)) {
+				const schemaKey = key as Schema.SchemaKey;
+
+				return this.getSchema(schemaKey, db).then(value => {
+					if (value == null) {
+						const defaultValue = schemaTypes[key].default;
+						if (defaultValue instanceof t.Type) {
+							// The only reason that this would be the case in a non-function
+							// schema key is for the meta nullOrUndefined value. We check this
+							// by first decoding the value undefined with the default type, and
+							// then return undefined
+							const decoded = (defaultValue as t.Type<any>).decode(undefined);
+
+							this.checkValueDecode(decoded, key, undefined);
+							return decoded.value;
+						}
+						return defaultValue as SchemaReturn<T>;
+					}
+					const decoded = this.decodeSchema(schemaKey, value);
+
+					this.checkValueDecode(decoded, key, value);
+
+					return decoded.value;
+				});
+			} else if (FnSchema.fnSchema.hasOwnProperty(key)) {
+				const fnKey = key as FnSchema.FnSchemaKey;
+				// Cast the promise as something that produes an unknown, and this means that
+				// we can validate the output of the function as well, ensuring that the type matches
+				const promiseValue = FnSchema.fnSchema[fnKey](this) as Bluebird<
+					unknown
+				>;
+				return promiseValue.then((value: unknown) => {
+					const decoded = schemaTypes[key].type.decode(value);
+
+					this.checkValueDecode(decoded, key, value);
+
+					return decoded.value as SchemaReturn<T>;
+				});
+			} else {
 				throw new Error(`Unknown config value ${key}`);
 			}
-			switch (this.schema[key].source) {
-				case 'func':
-					return this.providerFunctions[key]().catch(e => {
-						console.error(`Error getting config value for ${key}`, e, e.stack);
-						return null;
-					});
-				case 'config.json':
-					return this.configJsonBackend.get(key);
-				case 'db':
-					return db('config')
-						.select('value')
-						.where({ key })
-						.then(([conf]: [{ value: string }]) => {
-							if (conf != null) {
-								return conf.value;
-							}
-							return;
-						});
-			}
-		}).then(value => {
-			const schemaEntry = this.schema[key];
-			if (value == null && schemaEntry != null && schemaEntry.default != null) {
-				return schemaEntry.default;
-			}
-			return value;
 		});
 	}
 
-	public getMany(keys: string[], trx?: Transaction): Bluebird<ConfigMap> {
-		return Bluebird.map(keys, (key: string) => this.get(key, trx)).then(
-			values => {
-				return _.zipObject(keys, values);
-			},
-		);
+	public getMany<T extends SchemaTypeKey>(
+		keys: T[],
+		trx?: Transaction,
+	): Bluebird<{ [key in T]: SchemaReturn<key> }> {
+		return Bluebird.map(keys, (key: T) => this.get(key, trx)).then(values => {
+			return _.zipObject(keys, values);
+		});
 	}
 
-	public set(keyValues: ConfigMap, trx?: Transaction): Bluebird<void> {
-		return Bluebird.try(() => {
-			// Split the values based on which storage backend they use
-			type SplitConfigBackend = {
-				configJsonVals: ConfigMap;
-				dbVals: ConfigMap;
-				fnVals: ConfigMap;
-			};
-			const { configJsonVals, dbVals, fnVals }: SplitConfigBackend = _.reduce(
-				keyValues,
-				(acc: SplitConfigBackend, val, key) => {
-					if (this.schema[key] == null || !this.schema[key].mutable) {
-						throw new Error(
-							`Config field ${key} not found or is immutable in config.set`,
-						);
-					}
-					if (this.schema[key].source === 'config.json') {
-						acc.configJsonVals[key] = val;
-					} else if (this.schema[key].source === 'db') {
-						acc.dbVals[key] = val;
-					} else {
-						throw new Error(
-							`Unknown config backend for key: ${key}, backend: ${
-								this.schema[key].source
-							}`,
-						);
-					}
-					return acc;
-				},
-				{ configJsonVals: {}, dbVals: {}, fnVals: {} },
-			);
+	public set<T extends SchemaTypeKey>(
+		keyValues: ConfigMap<T>,
+		trx?: Transaction,
+	): Bluebird<void> {
+		const setValuesInTransaction = (tx: Transaction) => {
+			const configJsonVals: Dictionary<unknown> = {};
+			const dbVals: Dictionary<unknown> = {};
 
-			// Set these values, taking into account the knex transaction
-			const setValuesInTransaction = (tx: Transaction): Bluebird<void> => {
-				const dbKeys = _.keys(dbVals);
-				return this.getMany(dbKeys, tx)
-					.then(oldValues => {
-						return Bluebird.map(dbKeys, (key: string) => {
-							const value = dbVals[key];
-							if (oldValues[key] !== value) {
-								return this.db.upsertModel(
-									'config',
-									{ key, value: (value || '').toString() },
-									{ key },
-									tx,
-								);
-							}
-						});
-					})
-					.then(() => {
-						return Bluebird.map(_.toPairs(fnVals), ([key, value]) => {
-							const fn = this.providerFunctions[key];
-							if (fn.set == null) {
-								throw new Error(
-									`Attempting to set provider function without set() method implemented - key: ${key}`,
-								);
-							}
-							return fn.set(value, tx);
-						});
-					})
-					.then(() => {
-						if (!_.isEmpty(configJsonVals)) {
-							return this.configJsonBackend.set(configJsonVals);
+			_.each(keyValues, (v, k: T) => {
+				const schemaKey = k as Schema.SchemaKey;
+				const source = Schema.schema[schemaKey].source;
+
+				switch (source) {
+					case 'config.json':
+						configJsonVals[schemaKey] = v;
+						break;
+					case 'db':
+						dbVals[schemaKey] = v;
+						break;
+					default:
+						throw new Error(
+							`Unknown configuration source: ${source} for config key: ${k}`,
+						);
+						break;
+				}
+			});
+
+			const dbKeys = _.keys(dbVals) as T[];
+			return this.getMany(dbKeys, tx)
+				.then(oldValues => {
+					return Bluebird.map(dbKeys, (key: T) => {
+						const value = dbVals[key];
+
+						// if we have anything other than a string, it must be converted to
+						// a string before being stored in the db
+						const strValue = Config.valueToString(value);
+
+						if (oldValues[key] !== value) {
+							return this.db.upsertModel(
+								'config',
+								{ key, value: strValue },
+								{ key },
+								tx,
+							);
 						}
 					});
-			};
+				})
+				.then(() => {
+					if (!_.isEmpty(configJsonVals)) {
+						return this.configJsonBackend.set(configJsonVals as {
+							[key in Schema.SchemaKey]: unknown
+						});
+					}
+				});
+		};
+
+		return Bluebird.try(() => {
+			// Firstly validate all of the types as they are being set
+			this.validateConfigMap(keyValues);
 
 			if (trx != null) {
 				return setValuesInTransaction(trx).return();
 			} else {
 				return this.db
-					.transaction((tx: Transaction) => {
-						return setValuesInTransaction(tx);
-					})
+					.transaction((tx: Transaction) => setValuesInTransaction(tx))
 					.return();
 			}
-		})
-			.then(() => {
-				return setImmediate(() => {
-					this.emit('change', keyValues);
-				});
-			})
-			.return();
+		}).then(() => {
+			this.emit('change', keyValues);
+		});
 	}
 
-	public remove(key: string): Bluebird<void> {
+	public remove<T extends Schema.SchemaKey>(key: T): Bluebird<void> {
 		return Bluebird.try(() => {
-			if (this.schema[key] == null || !this.schema[key].mutable) {
+			if (Schema.schema[key] == null || !Schema.schema[key].mutable) {
 				throw new Error(
 					`Attempt to delete non-existent or immutable key ${key}`,
 				);
 			}
-			if (this.schema[key].source === 'config.json') {
+			if (Schema.schema[key].source === 'config.json') {
 				return this.configJsonBackend.remove(key);
-			} else if (this.schema[key].source === 'db') {
+			} else if (Schema.schema[key].source === 'db') {
 				return this.db
 					.models('config')
 					.del()
 					.where({ key });
-			} else if (this.schema[key].source === 'func') {
-				const mutFn = this.providerFunctions[key];
-				if (mutFn == null) {
-					throw new Error(
-						`Could not find provider function for config ${key}!`,
-					);
-				}
-				if (mutFn.remove == null) {
-					throw new Error(
-						`Could not find removal provider function for config ${key}`,
-					);
-				}
-				return mutFn.remove();
 			} else {
 				throw new Error(
-					`Unknown or unsupported config backend: ${this.schema[key].source}`,
+					`Unknown or unsupported config backend: ${Schema.schema[key].source}`,
 				);
 			}
 		});
@@ -273,6 +210,72 @@ export class Config extends EventEmitter {
 		return generateUniqueKey();
 	}
 
+	private async getSchema<T extends Schema.SchemaKey>(
+		key: T,
+		db: Transaction,
+	): Promise<unknown> {
+		let value: unknown;
+		switch (Schema.schema[key].source) {
+			case 'config.json':
+				value = await this.configJsonBackend.get(key);
+				break;
+			case 'db':
+				value = await db('config')
+					.select('value')
+					.where({ key })
+					.then(([conf]: [{ value: string }]) => {
+						if (conf != null) {
+							return conf.value;
+						}
+						return;
+					});
+				break;
+		}
+
+		return value;
+	}
+
+	private decodeSchema<T extends Schema.SchemaKey>(
+		key: T,
+		value: unknown,
+	): Either<t.Errors, SchemaReturn<T>> {
+		return schemaTypes[key].type.decode(value);
+	}
+
+	private validateConfigMap<T extends SchemaTypeKey>(configMap: ConfigMap<T>) {
+		// Just loop over every value, run the decode function, and
+		// throw if any value fails verification
+		_.map(configMap, (value, key) => {
+			if (
+				!Schema.schema.hasOwnProperty(key) ||
+				!Schema.schema[key as Schema.SchemaKey].mutable
+			) {
+				throw new Error(
+					`Attempt to set value for non-mutable schema key: ${key}`,
+				);
+			}
+
+			// If the default entry in the schema is a type and not a value,
+			// use this in the validation of the value
+			const schemaTypesEntry = schemaTypes[key as SchemaTypeKey];
+			let type: t.Type<unknown>;
+			if (schemaTypesEntry.default instanceof t.Type) {
+				type = t.union([schemaTypesEntry.type, schemaTypesEntry.default]);
+			} else {
+				type = schemaTypesEntry.type;
+			}
+
+			const decoded = type.decode(value);
+			if (decoded.isLeft()) {
+				throw new Error(
+					`Cannot set value for ${key}, as value failed validation: ${
+						decoded.value
+					}`,
+				);
+			}
+		});
+	}
+
 	private generateRequiredFields() {
 		return this.getMany([
 			'uuid',
@@ -295,6 +298,31 @@ export class Config extends EventEmitter {
 			});
 		});
 	}
+
+	private static valueToString(value: unknown) {
+		switch (typeof value) {
+			case 'object':
+				return JSON.stringify(value);
+			case 'number':
+			case 'string':
+			case 'boolean':
+				return value.toString();
+			default:
+				throw new InternalInconsistencyError(
+					`Could not convert configuration value to string for storage, value: ${value}, type: ${typeof value}`,
+				);
+		}
+	}
+
+	private checkValueDecode(
+		decoded: Either<t.Errors, unknown>,
+		key: string,
+		value: unknown,
+	): void {
+		if (decoded.isLeft()) {
+			throw new ConfigurationValidationError(key, value);
+		}
+	}
 }
 
 export default Config;

src/config/schema-type.ts

@@ -0,0 +1,254 @@
+import * as t from 'io-ts';
+
+import * as constants from '../lib/constants';
+
+import {
+	NullOrUndefined,
+	PermissiveBoolean,
+	PermissiveNumber,
+	StringJSON,
+} from './types';
+
+export const schemaTypes = {
+	apiEndpoint: {
+		type: t.string,
+		default: '',
+	},
+	apiTimeout: {
+		type: PermissiveNumber,
+		default: 15 * 60 * 1000,
+	},
+	listenPort: {
+		type: PermissiveNumber,
+		default: 48484,
+	},
+	deltaEndpoint: {
+		type: t.string,
+		default: 'https://delta.resin.io',
+	},
+	uuid: {
+		type: t.string,
+		default: NullOrUndefined,
+	},
+	apiKey: {
+		type: t.string,
+		default: NullOrUndefined,
+	},
+	deviceApiKey: {
+		type: t.string,
+		default: '',
+	},
+	deviceType: {
+		type: t.string,
+		default: 'unknown',
+	},
+	username: {
+		type: t.string,
+		default: NullOrUndefined,
+	},
+	userId: {
+		type: PermissiveNumber,
+		default: NullOrUndefined,
+	},
+	deviceId: {
+		type: PermissiveNumber,
+		default: NullOrUndefined,
+	},
+	registered_at: {
+		type: PermissiveNumber,
+		default: NullOrUndefined,
+	},
+	applicationId: {
+		type: PermissiveNumber,
+		default: NullOrUndefined,
+	},
+	appUpdatePollInterval: {
+		type: PermissiveNumber,
+		default: 60000,
+	},
+	mixpanelToken: {
+		type: t.string,
+		default: constants.defaultMixpanelToken,
+	},
+	bootstrapRetryDelay: {
+		type: PermissiveNumber,
+		default: 30000,
+	},
+	hostname: {
+		type: t.string,
+		default: NullOrUndefined,
+	},
+	persistentLogging: {
+		type: PermissiveBoolean,
+		default: false,
+	},
+
+	// Database types
+	apiSecret: {
+		type: t.string,
+		default: NullOrUndefined,
+	},
+	name: {
+		type: t.string,
+		default: 'local',
+	},
+	initialConfigReported: {
+		type: t.string,
+		default: '',
+	},
+	initialConfigSaved: {
+		type: PermissiveBoolean,
+		default: false,
+	},
+	containersNormalised: {
+		type: PermissiveBoolean,
+		default: false,
+	},
+	loggingEnabled: {
+		type: PermissiveBoolean,
+		default: true,
+	},
+	connectivityCheckEnabled: {
+		type: PermissiveBoolean,
+		default: true,
+	},
+	delta: {
+		type: PermissiveBoolean,
+		default: false,
+	},
+	deltaRequestTimeout: {
+		type: PermissiveNumber,
+		default: 30000,
+	},
+	deltaApplyTimeout: {
+		type: PermissiveNumber,
+		default: NullOrUndefined,
+	},
+	deltaRetryCount: {
+		type: PermissiveNumber,
+		default: 30,
+	},
+	deltaRetryInterval: {
+		type: PermissiveNumber,
+		default: 10000,
+	},
+	deltaVersion: {
+		type: PermissiveNumber,
+		default: 2,
+	},
+	lockOverride: {
+		type: PermissiveBoolean,
+		default: false,
+	},
+	legacyAppsPresent: {
+		type: PermissiveBoolean,
+		default: false,
+	},
+	pinDevice: {
+		type: new StringJSON<{ app: number; commit: string }>(
+			t.interface({ app: t.number, commit: t.string }),
+		),
+		default: NullOrUndefined,
+	},
+	currentCommit: {
+		type: t.string,
+		default: NullOrUndefined,
+	},
+	targetStateSet: {
+		type: PermissiveBoolean,
+		default: false,
+	},
+	localMode: {
+		type: PermissiveBoolean,
+		default: false,
+	},
+
+	// Function schema types
+	// The type should be the value that the promise resolves
+	// to, not including the promise itself
+	// The type should be a union of every return type possible,
+	// and the default should be t.never always
+	version: {
+		type: t.string,
+		default: t.never,
+	},
+	currentApiKey: {
+		type: t.string,
+		default: t.never,
+	},
+	provisioned: {
+		type: t.boolean,
+		default: t.never,
+	},
+	osVersion: {
+		type: t.union([t.string, NullOrUndefined]),
+		default: t.never,
+	},
+	osVariant: {
+		type: t.union([t.string, NullOrUndefined]),
+		default: t.never,
+	},
+	provisioningOptions: {
+		type: t.interface({
+			// These types are taken from the types of the individual
+			// config values they're made from
+			// TODO: It would be nice if we could take the type values
+			// from the definitions above and still have the types work
+			uuid: t.union([t.string, NullOrUndefined]),
+			applicationId: t.union([PermissiveNumber, NullOrUndefined]),
+			userId: t.union([PermissiveNumber, NullOrUndefined]),
+			deviceType: t.string,
+			provisioningApiKey: t.union([t.string, NullOrUndefined]),
+			deviceApiKey: t.string,
+			apiEndpoint: t.string,
+			apiTimeout: PermissiveNumber,
+			registered_at: t.union([PermissiveNumber, NullOrUndefined]),
+			deviceId: t.union([PermissiveNumber, NullOrUndefined]),
+		}),
+		default: t.never,
+	},
+	mixpanelHost: {
+		type: t.union([t.null, t.interface({ host: t.string, path: t.string })]),
+		default: t.never,
+	},
+	extendedEnvOptions: {
+		type: t.interface({
+			uuid: t.union([t.string, NullOrUndefined]),
+			listenPort: PermissiveNumber,
+			name: t.string,
+			apiSecret: t.union([t.string, NullOrUndefined]),
+			deviceApiKey: t.string,
+			version: t.string,
+			deviceType: t.string,
+			osVersion: t.union([t.string, NullOrUndefined]),
+		}),
+		default: t.never,
+	},
+	fetchOptions: {
+		type: t.interface({
+			uuid: t.union([t.string, NullOrUndefined]),
+			currentApiKey: t.string,
+			apiEndpoint: t.string,
+			deltaEndpoint: t.string,
+			delta: PermissiveBoolean,
+			deltaRequestTimeout: PermissiveNumber,
+			deltaApplyTimeout: t.union([PermissiveNumber, NullOrUndefined]),
+			deltaRetryCount: PermissiveNumber,
+			deltaRetryInterval: PermissiveNumber,
+			deltaVersion: PermissiveNumber,
+		}),
+		default: t.never,
+	},
+	unmanaged: {
+		type: t.boolean,
+		default: t.never,
+	},
+};
+
+export type SchemaType = typeof schemaTypes;
+export type SchemaTypeKey = keyof SchemaType;
+
+export type RealType<T> = T extends t.Type<any> ? t.TypeOf<T> : T;
+export type SchemaReturn<T extends SchemaTypeKey> =
+	| t.TypeOf<SchemaType[T]['type']>
+	| RealType<SchemaType[T]['default']>;

src/config/schema.ts

@@ -0,0 +1,191 @@
+export const schema = {
+	apiEndpoint: {
+		source: 'config.json',
+		mutable: false,
+		removeIfNull: false,
+	},
+	apiTimeout: {
+		source: 'config.json',
+		mutable: false,
+		removeIfNull: false,
+	},
+	listenPort: {
+		source: 'config.json',
+		mutable: false,
+		removeIfNull: false,
+	},
+	deltaEndpoint: {
+		source: 'config.json',
+		mutable: false,
+		removeIfNull: false,
+	},
+	uuid: {
+		source: 'config.json',
+		mutable: true,
+		removeIfNull: false,
+	},
+	apiKey: {
+		source: 'config.json',
+		mutable: true,
+		removeIfNull: true,
+	},
+	deviceApiKey: {
+		source: 'config.json',
+		mutable: true,
+		removeIfNull: false,
+	},
+	deviceType: {
+		source: 'config.json',
+		mutable: false,
+		removeIfNull: false,
+	},
+	username: {
+		source: 'config.json',
+		mutable: false,
+		removeIfNull: false,
+	},
+	userId: {
+		source: 'config.json',
+		mutable: false,
+		removeIfNull: false,
+	},
+	deviceId: {
+		source: 'config.json',
+		mutable: true,
+		removeIfNull: false,
+	},
+	registered_at: {
+		source: 'config.json',
+		mutable: true,
+		removeIfNull: false,
+	},
+	applicationId: {
+		source: 'config.json',
+		mutable: false,
+		removeIfNull: false,
+	},
+	appUpdatePollInterval: {
+		source: 'config.json',
+		mutable: true,
+		removeIfNull: false,
+	},
+	mixpanelToken: {
+		source: 'config.json',
+		mutable: false,
+		removeIfNull: false,
+	},
+	bootstrapRetryDelay: {
+		source: 'config.json',
+		mutable: false,
+		removeIfNull: false,
+	},
+	hostname: {
+		source: 'config.json',
+		mutable: true,
+		removeIfNull: false,
+	},
+	persistentLogging: {
+		source: 'config.json',
+		mutable: true,
+		removeIfNull: false,
+	},
+
+	apiSecret: {
+		source: 'db',
+		mutable: true,
+		removeIfNull: false,
+	},
+	name: {
+		source: 'db',
+		mutable: true,
+		removeIfNull: false,
+	},
+	initialConfigReported: {
+		source: 'db',
+		mutable: true,
+		removeIfNull: false,
+	},
+	initialConfigSaved: {
+		source: 'db',
+		mutable: true,
+		removeIfNull: false,
+	},
+	containersNormalised: {
+		source: 'db',
+		mutable: true,
+		removeIfNull: false,
+	},
+	loggingEnabled: {
+		source: 'db',
+		mutable: true,
+		removeIfNull: false,
+	},
+	connectivityCheckEnabled: {
+		source: 'db',
+		mutable: true,
+		removeIfNull: false,
+	},
+	delta: {
+		source: 'db',
+		mutable: true,
+		removeIfNull: false,
+	},
+	deltaRequestTimeout: {
+		source: 'db',
+		mutable: true,
+		removeIfNull: false,
+	},
+	deltaApplyTimeout: {
+		source: 'db',
+		mutable: true,
+		removeIfNull: false,
+	},
+	deltaRetryCount: {
+		source: 'db',
+		mutable: true,
+		removeIfNull: false,
+	},
+	deltaRetryInterval: {
+		source: 'db',
+		mutable: true,
+		removeIfNull: false,
+	},
+	deltaVersion: {
+		source: 'db',
+		mutable: true,
+		removeIfNull: false,
+	},
+	lockOverride: {
+		source: 'db',
+		mutable: true,
+		removeIfNull: false,
+	},
+	legacyAppsPresent: {
+		source: 'db',
+		mutable: true,
+		removeIfNull: false,
+	},
+	pinDevice: {
+		source: 'db',
+		mutable: true,
+		removeIfNull: false,
+	},
+	currentCommit: {
+		source: 'db',
+		mutable: true,
+		removeIfNull: false,
+	},
+	targetStateSet: {
+		source: 'db',
+		mutable: true,
+		removeIfNull: false,
+	},
+	localMode: {
+		source: 'db',
+		mutable: true,
+		removeIfNull: false,
+	},
+};
+
+export type Schema = typeof schema;
+export type SchemaKey = keyof Schema;

src/config/types.ts

@@ -0,0 +1,114 @@
+import * as t from 'io-ts';
+import * as _ from 'lodash';
+
+import { InternalInconsistencyError } from '../lib/errors';
+import { checkTruthy } from '../lib/validation';
+
+const permissiveValue = t.union([
+	t.boolean,
+	t.string,
+	t.number,
+	t.null,
+	t.undefined,
+]);
+type PermissiveType = typeof permissiveValue;
+
+export const PermissiveBoolean = new t.Type<boolean, t.TypeOf<PermissiveType>>(
+	'PermissiveBoolean',
+	_.isBoolean,
+	(m, c) =>
+		permissiveValue.validate(m, c).chain(v => {
+			switch (typeof v) {
+				case 'boolean':
+				case 'string':
+				case 'number':
+					const val = checkTruthy(v);
+					if (val == null) {
+						return t.failure(v, c);
+					}
+					return t.success(val);
+				case 'undefined':
+					return t.success(false);
+				case 'object':
+					if (_.isNull(v)) {
+						return t.success(false);
+					} else {
+						return t.failure(v, c);
+					}
+				default:
+					return t.failure(v, c);
+			}
+		}),
+	() => {
+		throw new InternalInconsistencyError(
+			'Encode not defined for PermissiveBoolean',
+		);
+	},
+);
+
+export const PermissiveNumber = new t.Type<number, string | number>(
+	'PermissiveNumber',
+	_.isNumber,
+	(m, c) =>
+		t
+			.union([t.string, t.number])
+			.validate(m, c)
+			.chain(v => {
+				switch (typeof v) {
+					case 'number':
+						return t.success(v);
+					case 'string':
+						const i = parseInt(v, 10);
+						if (_.isNaN(i)) {
+							return t.failure(v, c);
+						}
+						return t.success(i);
+					default:
+						return t.failure(v, c);
+				}
+			}),
+	() => {
+		throw new InternalInconsistencyError(
+			'Encode not defined for PermissiveNumber',
+		);
+	},
+);
+
+// Define this differently, so that we can add a generic to it
+export class StringJSON<T> extends t.Type<T, string> {
+	readonly _tag: 'StringJSON' = 'StringJSON';
+	constructor(type: t.InterfaceType<any>) {
+		super(
+			'StringJSON',
+			(m): m is T => type.decode(m).isRight(),
+			(m, c) =>
+				// Accept either an object, or a string which represents the
+				// object
+				t
+					.union([t.string, type])
+					.validate(m, c)
+					.chain(v => {
+						let obj: T;
+						if (typeof v === 'string') {
+							obj = JSON.parse(v);
+						} else {
+							obj = v;
+						}
+						return type.decode(obj);
+					}),
+			() => {
+				throw new InternalInconsistencyError(
+					'Encode not defined for StringJSON',
+				);
+			},
+		);
+		// super(
+		// 	'string',
+		// 	(m): m is string => typeof m === 'string',
+		// 	(m, c) => (this.is(m) ? t.success(m) : t.failure(m, c)),
+		// 	t.identity,
+		// );
+	}
+}
+
+export const NullOrUndefined = t.union([t.undefined, t.null]);

src/lib/errors.ts

@@ -52,3 +52,11 @@ export function DuplicateUuidError(err: Error) {
 export class ExchangeKeyError extends TypedError {}
 
 export class InternalInconsistencyError extends TypedError {}
+
+export class ConfigurationValidationError extends TypedError {
+	public constructor(key: string, value: unknown) {
+		super(
+			`There was an error validating configuration input for key: ${key}, with value: ${value}`,
+		);
+	}
+}

test/05-device-state.spec.coffee

@@ -243,9 +243,8 @@ describe 'deviceState', ->
 			@deviceState.applications.images.save.restore()
 			@deviceState.deviceConfig.getCurrent.restore()
 
-			@config.get('pinDevice').then (pinnedString) ->
-				pinned = JSON.parse(pinnedString)
-				expect(pinned).to.have.property('app').that.equals('1234')
+			@config.get('pinDevice').then (pinned) ->
+				expect(pinned).to.have.property('app').that.equals(1234)
 				expect(pinned).to.have.property('commit').that.equals('abcdef')
 
 	it 'emits a change event when a new state is reported', ->