How to programmatically get current project id in Google cloud run api

Question

I have an API that is containerized and running inside cloud run. How can I get the current project ID where my cloud run is executing? I have tried:

• I see it in textpayload in logs but I am not sure how to read the textpayload inside the post function? The pub sub message I receive is missing this information.
• I have read up into querying the metadata api, but it is not very clear on how to do that again from within the api. Any links?

Is there any other way?

Edit:

After some comments below, I ended up with this code inside my .net API running inside Cloud Run.

        private string GetProjectid()
        {
            var projectid = string.Empty;
            try {
                var PATH = "http://metadata.google.internal/computeMetadata/v1/project/project-id";
                using (var client = new HttpClient())
                {
                    client.DefaultRequestHeaders.Add("Metadata-Flavor", "Google");
                    projectid = client.GetStringAsync(PATH).Result.ToString();
                }

                Console.WriteLine("PROJECT: " + projectid);
            }
            catch (Exception ex) {
                Console.WriteLine(ex.Message + " --- " + ex.ToString());
            }
            return projectid;
        }

Update, it works. My build pushes had been failing and I did not see. Thanks everyone.

Answer 1

You get the project ID by sending an GET request to http://metadata.google.internal/computeMetadata/v1/project/project-id with the Metadata-Flavor:Google header.

See this documentation

In Node.js for example:

index.js:

    const express = require('express');
    const axios = require('axios');
    const app = express();
    
    const axiosInstance = axios.create({
      baseURL: 'http://metadata.google.internal/',
      timeout: 1000,
      headers: {'Metadata-Flavor': 'Google'}
    });
    
    app.get('/', (req, res) => {
      let path = req.query.path || 'computeMetadata/v1/project/project-id';
      axiosInstance.get(path).then(response => {
        console.log(response.status)
        console.log(response.data);
        res.send(response.data);
      });
    });
    
    const port = process.env.PORT || 8080;
    app.listen(port, () => {
      console.log('Hello world listening on port', port);
    });

package.json:

    {
      "name": "metadata",
      "version": "1.0.0",
      "description": "Metadata server",
      "main": "app.js",
      "scripts": {
        "start": "node index.js"
      },
      "author": "",
      "license": "Apache-2.0",
      "dependencies": {
        "axios": "^0.18.0",
        "express": "^4.16.4"
      }
    }