debug-app.ts

/**
 * Copyright (c) 2021 Gitpod GmbH. All rights reserved.
 * Licensed under the GNU Affero General Public License (AGPL).
 * See License.AGPL.txt in the project root for license information.
 */

import * as http from "http";
import express from "express";
import { injectable, postConstruct } from "inversify";
import { log, LogrusLogLevel } from "./logging";

export interface SetLogLevelRequest {
    level: LogrusLogLevel;
}
export namespace SetLogLevelRequest {
    export function is(o: any): o is SetLogLevelRequest {
        return typeof o === "object" && "level" in o;
    }
}

@injectable()
export class DebugApp {
    protected _app: express.Application;
    protected httpServer: http.Server | undefined = undefined;

    @postConstruct()
    public ctor() {
        this._app = this.create();
    }

    create(): express.Application {
        const app = express();

        app.use(express.json());
        app.use(express.urlencoded({ extended: true }));

        app.post("/debug/logging", (req, res) => {
            try {
                const levelRequest = req.body;
                if (!SetLogLevelRequest.is(levelRequest)) {
                    res.status(400).end("not a SetLogLevelRequest");
                    return;
                }

                const newLogLevel = levelRequest.level;
                log.setLogLevel(newLogLevel);
                log.info("set log level", { newLogLevel });
                res.status(200).end(JSON.stringify(levelRequest));
            } catch (err) {
                res.status(500).end(err);
            }
        });
        return app;
    }

    public start(port: number = 6060) {
        this.httpServer = this._app.listen(port, "localhost", () => {
            log.info(`debug server listening on port: ${port}`);
        });
    }

    public async stop() {
        const server = this.httpServer;
        if (!server) {
            return;
        }
        return new Promise<void>((resolve) =>
            server.close((err: any) => {
                if (err) {
                    log.warn(`error while closing http server`, { err });
                }
                this.httpServer = undefined;
                resolve();
            }),
        );
    }

    public get app(): express.Application {
        return this._app;
    }
}