# Installing MongoDB and Mongosh#
## Deploying MongoDB on Ubuntu#
### Download the tar package from the official website#
Copy the download link of the tar package from the official website
### Installation on Ubuntu#
Execute the command to download the tar package
wget https://fastdl.mongodb.org/linux/mongodb-linux-x86_64-ubuntu2004-6.0.7.tgz
Unzip the package
tar -zxvf mongodb-linux-x86_64-ubuntu2204-6.0.7.tgz
Rename the extracted files and move them to /usr/local/mongodb
mv mongodb-linux-x86_64-ubuntu2204-6.0.7/ mongodb/
### Configuration#
Create the logs and data folders in the directory
mkdir logs
mkdir data
Execute the following command in the logs folder
touch mongodb.log
Then go to the bin directory
Create a new configuration file called mongodb.conf
# Directory for data files
dbpath = /usr/local/mongodb/data
# Directory for log files
logpath = /usr/local/mongodb/logs/mongodb.log
logappend=true
# Port
port = 27017
# Enable as a daemon, running in the background
fork = false
# Authentication mode
auth=true
# Remote connection
bind_ip=0.0.0.0
### Starting in the bin directory#
Execute the startup command
./mongod -f mongodb.conf
To start in the background, add --fork
./mongod --fork -f mongodb.conf
## Installing MongoDB Shell#
Download the compressed package
wget https://downloads.mongodb.com/compass/mongosh-1.6.0-linux-x64.tgz
Unzip the package
tar -zxvf mongosh-1.6.0-linux-x64.tgz
Rename the extracted files
mv mongosh-1.6.0-linux-x64 mongosh
The mongosh/bin directory provides the mongosh command to connect to the MongoDB database service.
## Adding the bin directory to the PATH environment variable#
Currently, the mongod command is located in the mongodb/bin directory, and the mongosh command is located in the mongosh/bin directory. These two paths need to be added to the Path environment variable.
Execute the command to edit the environment variable
vi ~/.bashrc
Add the following line at the end of the file
PATH=$PATH:$HOME/bin:/usr/local/mongodb/bin:/usr/local/mongosh/bin
Save the file and execute the command to make the configuration effective
source ~/.bashrc
## Starting#
MongoDB can be started using
mongodb --fork -f mongodb.conf
To start mongosh directly
mongosh
mongosh connects to mongodb:localhost:27017 by default
## Troubleshooting#
### Permission issues#
However, when inserting data as a regular user (or even as a root user), an error occurs. This is because in the previous configuration file, the auth verification was set to true.
To resolve this, auth needs to be changed to false first, and then restart the process.
ps -ef | grep mongodb
kill -9 port_number
After starting, create a super administrator account in the admin collection. Once created, change the auth setting in the configuration file to true and restart the mongo process.
#### Creating a super user#
>use admin
>db.createUser({user:"root",pwd:"XXXXXX",roles:[{role:"userAdminAnyDatabase",db:"admin"},{role:"readWriteAnyDatabase",db:"admin"}]})
After creating the user, restart MongoDB and reconnect with mongosh.
# Users and Roles#
## Roles#
Built-In Roles
Database User Roles: read, readWrite;
Database Management Roles: dbAdmin, dbOwner, userAdmin;
Cluster Administration Roles: clusterAdmin, clusterManager, clusterMonitor, hostManager;
Backup and Restoration Roles: backup, restore;
All Database Roles: readAnyDatabase, readWriteAnyDatabase, userAdminAnyDatabase, dbAdminAnyDatabase;
Superuser Role: root
// Several roles indirectly or directly provide access to the system superuser (dbOwner, userAdmin, userAdminAnyDatabase)
Internal Role: __system
Functionality of Specific Roles
Read: Allows users to read from a specified database
readWrite: Allows users to read and write to a specified database
dbAdmin: Allows users to perform administrative functions in a specified database, such as creating and deleting indexes, viewing statistics, or accessing system.profile
userAdmin: Allows users to write to the system.users collection, enabling them to create, delete, and manage users in a specified database
clusterAdmin: Only available in the admin database, grants users administrative privileges for all sharding and replication-related functions
readAnyDatabase: Only available in the admin database, grants users read access to all databases
readWriteAnyDatabase: Only available in the admin database, grants users read and write access to all databases
userAdminAnyDatabase: Only available in the admin database, grants users userAdmin privileges for all databases
dbAdminAnyDatabase: Only available in the admin database, grants users dbAdmin privileges for all databases
root: Only available in the admin database, superuser account with superuser privileges
## Users#
### Creating a Regular User#
// Switch to the admin database
use admin
// Perform auth authentication, returns 1 if successful
db.auth("root","password")
// Switch or create a database, e.g. test
use test
db.createUser({user:"user",pwd:"123456",roles:[{role:"readWrite",db:"test"}]})
db.createUser({user:"testadmin",pwd:"123456",roles:[{role:"dbAdmin",db:"test_data"},{role:"readWrite",db:"test_data"},{role:"userAdmin",db:"test_data"}]})
### Viewing and Deleting Users#
# Switch to the admin database
use admin
# View all users
db.system.users.find()
# Delete a user. Switch to the database where the account is located before deleting.
db.system.users.remove({user:"testadmin"})
The super administrator may not have the permission to delete. Check if the role includes the permission to delete the user.
