Granting External Group Access to Specific Containers with Podman: An Easy Guide

Podman, an open-source container application for Linux, is gaining popularity due to its ease of use and simplicity. It provides an alternative to Docker, allowing users to manage containers without the need for a daemon. However, Podman users may encounter issues when trying to grant external group access to specific containers. In this article, we will discuss how to grant external group access to containers using Podman.

Prerequisites

Before we begin, ensure the following prerequisites are met:

• A Linux system with Podman installed.
• A user with sudo privileges.
• An LDAP server running and accessible from the system.

Setting Up the LDAP Server

Before we can grant external group access to containers, we need to set up our LDAP server. Here's a brief overview of the steps:

1. Install the necessary packages:

sudo apt-get update
 sudo apt-get install openldap-utils openldap-server openldap-client

2. Configure the LDAP server:

Edit the /etc/ldap/slapd.d/ directory and create a new file, e.g., cn=config.

sudo nano /etc/ldap/slapd.d/cn=config.ldif

Add the following configuration:

dn: cn=config
 objectClass: olcDatabaseConfig
 olcDatabase: hdb
 olcSuffix: "dc=example,dc=com"
 olcRootDN: "cn=admin,dc=example,dc=com"
 olcRootPW: {SSHA}your_password

3. Start the LDAP server:

sudo systemctl start slapd

Creating an LDAP Group

Next, we need to create an LDAP group. Here's how:

1. Log in as the root user:

sudo su

2. Create a new group:

ldapadd -x -D "cn=admin,dc=example,dc=com" -w your_password -f group.ldif

Create a file named group.ldif with the following content:

dn: cn=groupname,ou=Groups,dc=example,dc=com
 objectClass: posixGroup
 cn: groupname
 gidNumber: 1001

Creating an LDAP User

Now, we need to create an LDAP user:

1. Create a new user:

ldapadd -x -D "cn=admin,dc=example,dc=com" -w your_password -f user.ldif

Create a file named user.ldif with the following content:

dn: cn=username,ou=Users,dc=example,dc=com
 objectClass: posixAccount
 objectClass: inetOrgPerson
 cn: username
 uid: username
 gidNumber: 1001
 userPassword: {SSHA}user_password

Granting External Group Access to a Container

Now, we can grant external group access to a container:

1. Create a new Podman image:

podman create --group-add groupname myimage

2. Tag the image:

podman tag myimage:latest your_registry/myimage:latest

3. Pull the image:

podman pull your_registry/myimage:latest

4. Run the container:

podman run --group-add groupname your_registry/myimage:latest

In this article, we discussed how to grant external group access to specific containers using Podman. We covered setting up an LDAP server, creating an LDAP group and user, and granting external group access to a container. For further reading, check out the following resources:

• Podman Documentation
• LDAP.com