Add link to Linux Master application

README.md

@@ -160,6 +160,12 @@ Once you are familiar with the commands and feel comfortable enough to keep deep
   * Kernel
   * Virtulization
 
+#### Linux Master Application
+
+A completely free application for testing your knowledge on Linux
+
+<a href="https://play.google.com/store/apps/details?id=com.codingshell.linuxmaster"><img src="images/linux_master.jpeg"/></a>
+
 ### System Design
 
 System Design can be a complex topic. For that reason, I've created a separate repository for you to learn it properly.

resources/mongo.md

@@ -35,7 +35,66 @@ Name | Description
 #### Aggregations
 
 * Count the number of documents: `db.accounts.aggregate([ { "$count": "number of documents" }])`
-* Show only the sub element "attachment_uuids": `db.accounts.aggregate( [ {$project: {"hosts.attachment_uuids": 1, _id:0}} ] )`
+* Show only the sub element 'attachment_uuids': `db.accounts.aggregate( [ {$project: {"hosts.attachment_uuids": 1, _id:0}} ] )`
+
+#### Users
+
+* Display users:
+
+```
+use admin
+db.getUsers()
+```
+
+* Create administrative user
+
+```
+use admin
+db.createUser({user: "admin", pwd: "some_password", roles: ["root"]})
+```
+
+* Authentice: `db.auth(USERNAME, PASSWORD)`
+
+#### Roles
+
+* Display roles
+
+```
+use admin
+db.getRoles()
+```
+
+* Drop/Remove role: `db.dropRole("NAME_OF_THE_ROLE")`
+
+#### LDAP
+
+* Mongo Conf LDAP configuration
+
+```
+security:
+  # authorization: "enabled"
+  ldap:
+    servers: 'some.ldap.server.com'
+    userToDNMapping:
+         '[
+            {
+               match: "(.+)",
+               ldapQuery: "DC=X,DC=com??sub?(uid={0})"
+            }
+         ]'
+    authz:
+         queryTemplate: "{USER}?memberOf?base"
+setParameter:
+  authenticationMechanisms: 'PLAIN,SCRAM-SHA-1'
+```
+
+* Create role where the LDAP group "unicorns" has permissions to only run 'find' on "hosts" collection in 'test' db:
+
+```
+db.createRole({role:"cn=unicorns,ou=groups,dc=X,dc=com", privileges: [{ resource: {db: "", collection: "hosts"}, actions: ["find"]}], roles: [{ role: "read", db: "test"}]})
+```
+
+* Drop/Remove role from the previous example: `db.dropRole("cn=unicorns,ou=groups,dc=X,dc=com")`
 
 ### Mongo Python
 
@@ -64,3 +123,4 @@ mongo_client.update_one(
     {'_id': 1},
     {'$addToSet': {'some_list': { '$each': [1, 2, 3]} }}, upsert=True)
 ```
+