Middleware "strapi::session": App keys are required. Please set app.keys in config/server.js (ex: keys: ['myKeyA', 'myKeyB'])

Question

Trying to set up strapi and cloudinary I watched two videos and they are all OK, but I have an error, tell me why?

Middleware "strapi::session": App keys are required. Please set app.keys in config/server.js (ex: keys: ['myKeyA', 'myKeyB'])

plugins.js

module.exports = ({ env }) => ({
  // ...
  upload: {
    config: {
      provider: 'cloudinary',
      providerOptions: {
        cloud_name: env('CLOUDINARY_NAME'),
        api_key: env('CLOUDINARY_KEY'),
        api_secret: env('CLOUDINARY_SECRET'),
      },
      actionOptions: {
        upload: {},
        delete: {},
      },
    },
  },
  // ...
});

.env

HOST=0.0.0.0
PORT=1337
CLOUDINARY_NAME="my data"
CLOUDINARY_KEY="my data"
CLOUDINARY_SECRET="my data"
JWT_SECRET=my data

server.js

module.exports = ({ env }) => ({
  host: env('HOST', '0.0.0.0'),
  port: env.int('PORT', 1337),
  app: {
    keys: env.array('APP_KEYS'),
  },
});

middlewares.js

module.exports = [
  'strapi::errors',
  'strapi::security',
  'strapi::cors',
  'strapi::poweredBy',
  'strapi::logger',
  'strapi::query',
  'strapi::body',
  'strapi::session',
  'strapi::favicon',
  'strapi::public',
];

admin.js

module.exports = ({ env }) => ({
  auth: {
    secret: env('ADMIN_JWT_SECRET'),
  },
  apiToken: {
    salt: env('API_TOKEN_SALT'),
  },
});

Answer 1

It looks like you don't have APP_KEYS defined in your .env file (assuming you're sharing the full file), as well as some other env variables you're accessing using strapi's built in env utility.

In your .env you should have a value for the following that should follow this format:

APP_KEYS=['key1','key2']

You can read more about environment config from Strapi's development docs: https://docs.strapi.io/developer-docs/latest/setup-deployment-guides/configurations/optional/environment.html#strapi-s-environment-variables