I need to know in which file the default password which is "admin" for the default user "admin" is stored on the ambari-server?
I'm not sure if it stores the password in a file. If you are looking for the storage in database, it is stored in ambari database and users table. To check password from postgres you can use
psql -U ambari -d ambari
password : bigdata( default)
ambari=> select user_password from users where user_name='admin';
This will be a salted value
Ambari apsswords are not stored in a file by default. It uses DB store by default (if you have not set the LDAP/AD authentication)
ambari=> update ambari.users set user_password='538916f8943ec225d97a9a86a2c6ec0818c1cd400e09e03b660fdaaec4af29ddbb6f2b1033b81b00' where user_name='admin'
You can use the above SQL query in abari Database to reset the "admin" user to default password "admin"
The above password is stored in ambari DB in encoded form.
However the Encoded String "538916f8943ec225d97a9a86a2c6ec0818c1cd400e09e03b660fdaaec4af29ddbb6f2b1033b81b00" means "admin".