Feat/app env vars (#430)

* initial changes for env var support

* WIP

* Update applications.js

* JSON stringify before encrypting

* use call_hook.url

* env vars working

GET /v1/AppEnv?url=[URL] to trigger options request to URL and return app-schema
POST /v1/Applications with {env_vars: [OBJECT} to create app with env vars
PUT /v1/Applications/[SID] with {env_vars: [OBJECT} to change env vars
GET returns env vars

POST and PUT will also trigger an OPTIONS request to the call_hook url to get schema and then validate the env_vars against it

* update appenv cannot finish request.

* wip

* wip

* wip

* wip

---------

Co-authored-by: Dave Horton <daveh@beachdognet.com>
Co-authored-by: Quan HL <quan.luuhoang8@gmail.com>
Co-authored-by: Hoan Luu Huu <110280845+xquanluu@users.noreply.github.com>

lib/utils/appenv_utils.js

@@ -0,0 +1,70 @@
+const Ajv = require('ajv');
+const assert = require('assert');
+
+const ajv = new Ajv();
+const schemaSchema = require('./appenv_schemaSchema.json');
+
+
+const validateAppEnvSchema = (schema) => {
+  const validate = ajv.compile(schemaSchema);
+  return validate(schema);
+};
+
+//Currently this request is not signed with the webhook secret as it is outside an account
+const fetchAppEnvSchema = async(logger, url) => {
+  try {
+    const response = await fetch(url, {
+      method: 'OPTIONS',
+      headers: {
+        Accept: 'application/json'
+      }
+    });
+    if (!response.ok) {
+      logger.info(`Failure to fetch app env schema ${response.status} ${response.statusText}`);
+      return false;
+    }
+    const schema = await response.json();
+    return schema;
+  }
+  catch (e) {
+    logger.info(`Failure to fetch app env schema ${e}`);
+    return false;
+  }
+};
+
+const validateAppEnvData = async(schema, data) => {
+  const schemaKeys = Object.keys(schema);
+  const dataKeys = Object.keys(data);
+  let errorMsg = false;
+  // Check for required keys
+  schemaKeys.forEach((k) => {
+    if (schema[k].required) {
+      if (!dataKeys.includes(k)) {
+        errorMsg = `Missing required value env_vars.${k}`;
+        console.log(errorMsg);
+      }
+    }
+  });
+  //Validate the values
+  dataKeys.forEach((k) => {
+    if (schemaKeys.includes(k)) {
+      try {
+        // Check value is correct type
+        assert(typeof data[k] == schema[k].type);
+        // if enum check value is valid
+        if (schema[k].enum) {
+          assert(schema[k].enum.includes(data[k]));
+        }
+      } catch (error) {
+        errorMsg = `Invalid value/type for env_vars.${k}`;
+      }
+    }
+  });
+  return errorMsg;
+};
+
+module.exports = {
+  validateAppEnvSchema,
+  fetchAppEnvSchema,
+  validateAppEnvData
+};