# Work with security groups in Amazon EC2
<a name="examples-ec2-security-groups"></a>

## Create a security group
<a name="create-a-security-group"></a>

To create a security group, call the Ec2Client’s `createSecurityGroup` method with a [CreateSecurityGroupRequest](https://sdk.amazonaws.com/java/api/latest/software/amazon/awssdk/services/ec2/model/CreateSecurityGroupRequest.html) that contains the key’s name.

 **Imports** 

```
import software.amazon.awssdk.regions.Region;
import software.amazon.awssdk.services.ec2.Ec2Client;
import software.amazon.awssdk.services.ec2.model.CreateSecurityGroupRequest;
import software.amazon.awssdk.services.ec2.model.AuthorizeSecurityGroupIngressRequest;
import software.amazon.awssdk.services.ec2.model.AuthorizeSecurityGroupIngressResponse;
import software.amazon.awssdk.services.ec2.model.Ec2Exception;
import software.amazon.awssdk.services.ec2.model.IpPermission;
import software.amazon.awssdk.services.ec2.model.CreateSecurityGroupResponse;
import software.amazon.awssdk.services.ec2.model.IpRange;
```

 **Code** 

```
            CreateSecurityGroupRequest createRequest = CreateSecurityGroupRequest.builder()
                .groupName(groupName)
                .description(groupDesc)
                .vpcId(vpcId)
                .build();

            CreateSecurityGroupResponse resp= ec2.createSecurityGroup(createRequest);
```

See the [complete example](https://github.com/awsdocs/aws-doc-sdk-examples/blob/0b1785e42949ebf959eaa0f0da4dc2a48f92ea25/javav2/example_code/ec2/src/main/java/com/example/ec2/CreateSecurityGroup.java) on GitHub.

## Configure a security group
<a name="configure-a-security-group"></a>

A security group can control both inbound (ingress) and outbound (egress) traffic to your Amazon EC2 instances.

To add ingress rules to your security group, use the Ec2Client’s `authorizeSecurityGroupIngress` method, providing the name of the security group and the access rules ([IpPermission](https://sdk.amazonaws.com/java/api/latest/software/amazon/awssdk/services/ec2/model/IpPermission.html)) you want to assign to it within an [AuthorizeSecurityGroupIngressRequest](https://sdk.amazonaws.com/java/api/latest/software/amazon/awssdk/services/ec2/model/AuthorizeSecurityGroupIngressRequest.html) object. The following example shows how to add IP permissions to a security group.

 **Imports** 

```
import software.amazon.awssdk.regions.Region;
import software.amazon.awssdk.services.ec2.Ec2Client;
import software.amazon.awssdk.services.ec2.model.CreateSecurityGroupRequest;
import software.amazon.awssdk.services.ec2.model.AuthorizeSecurityGroupIngressRequest;
import software.amazon.awssdk.services.ec2.model.AuthorizeSecurityGroupIngressResponse;
import software.amazon.awssdk.services.ec2.model.Ec2Exception;
import software.amazon.awssdk.services.ec2.model.IpPermission;
import software.amazon.awssdk.services.ec2.model.CreateSecurityGroupResponse;
import software.amazon.awssdk.services.ec2.model.IpRange;
```

 **Code** 

First, create an Ec2Client

```
        Region region = Region.US_WEST_2;
        Ec2Client ec2 = Ec2Client.builder()
                .region(region)
                .build();
```

Then use the Ec2Client’s `authorizeSecurityGroupIngress` method,

```
            IpRange ipRange = IpRange.builder()
                .cidrIp("0.0.0.0/0").build();

            IpPermission ipPerm = IpPermission.builder()
                .ipProtocol("tcp")
                .toPort(80)
                .fromPort(80)
                .ipRanges(ipRange)
                .build();

            IpPermission ipPerm2 = IpPermission.builder()
                .ipProtocol("tcp")
                .toPort(22)
                .fromPort(22)
                .ipRanges(ipRange)
                .build();

            AuthorizeSecurityGroupIngressRequest authRequest =
                AuthorizeSecurityGroupIngressRequest.builder()
                        .groupName(groupName)
                        .ipPermissions(ipPerm, ipPerm2)
                        .build();

            AuthorizeSecurityGroupIngressResponse authResponse =
            ec2.authorizeSecurityGroupIngress(authRequest);

            System.out.printf(
                "Successfully added ingress policy to Security Group %s",
                groupName);

            return resp.groupId();

        } catch (Ec2Exception e) {
            System.err.println(e.awsErrorDetails().errorMessage());
            System.exit(1);
        }
        return "";
    }
```

To add an egress rule to the security group, provide similar data in an [AuthorizeSecurityGroupEgressRequest](https://sdk.amazonaws.com/java/api/latest/software/amazon/awssdk/services/ec2/model/AuthorizeSecurityGroupEgressRequest.html) to the Ec2Client’s `authorizeSecurityGroupEgress` method.

See the [complete example](https://github.com/awsdocs/aws-doc-sdk-examples/blob/0b1785e42949ebf959eaa0f0da4dc2a48f92ea25/javav2/example_code/ec2/src/main/java/com/example/ec2/CreateSecurityGroup.java) on GitHub.

## Describe security groups
<a name="describe-security-groups"></a>

To describe your security groups or get information about them, call the Ec2Client’s `describeSecurityGroups` method. It returns a [DescribeSecurityGroupsResponse](https://sdk.amazonaws.com/java/api/latest/software/amazon/awssdk/services/ec2/model/DescribeSecurityGroupsResponse.html) that you can use to access the list of security groups by calling its `securityGroups` method, which returns a list of [SecurityGroup](https://sdk.amazonaws.com/java/api/latest/software/amazon/awssdk/services/ec2/model/SecurityGroup.html) objects.

 **Imports** 

```
import software.amazon.awssdk.regions.Region;
import software.amazon.awssdk.services.ec2.Ec2Client;
import software.amazon.awssdk.services.ec2.model.DescribeSecurityGroupsRequest;
import software.amazon.awssdk.services.ec2.model.DescribeSecurityGroupsResponse;
import software.amazon.awssdk.services.ec2.model.SecurityGroup;
import software.amazon.awssdk.services.ec2.model.Ec2Exception;
```

 **Code** 

```
     public static void describeEC2SecurityGroups(Ec2Client ec2, String groupId) {

        try {
            DescribeSecurityGroupsRequest request =
                DescribeSecurityGroupsRequest.builder()
                        .groupIds(groupId).build();

            DescribeSecurityGroupsResponse response =
                ec2.describeSecurityGroups(request);

             for(SecurityGroup group : response.securityGroups()) {
                System.out.printf(
                    "Found Security Group with id %s, " +
                            "vpc id %s " +
                            "and description %s",
                    group.groupId(),
                    group.vpcId(),
                    group.description());
            }
        } catch (Ec2Exception e) {
            System.err.println(e.awsErrorDetails().errorMessage());
            System.exit(1);
        }
    }
```

See the [complete example](https://github.com/awsdocs/aws-doc-sdk-examples/blob/0b1785e42949ebf959eaa0f0da4dc2a48f92ea25/javav2/example_code/ec2/src/main/java/com/example/ec2/DescribeSecurityGroups.java) on GitHub.

## Delete a security group
<a name="delete-a-security-group"></a>

To delete a security group, call the Ec2Client’s `deleteSecurityGroup` method, passing it a [DeleteSecurityGroupRequest](https://sdk.amazonaws.com/java/api/latest/software/amazon/awssdk/services/ec2/model/DeleteSecurityGroupRequest.html) that contains the ID of the security group to delete.

 **Imports** 

```
import software.amazon.awssdk.regions.Region;
import software.amazon.awssdk.services.ec2.Ec2Client;
import software.amazon.awssdk.services.ec2.model.DeleteSecurityGroupRequest;
import software.amazon.awssdk.services.ec2.model.Ec2Exception;
```

 **Code** 

```
    public static void deleteEC2SecGroup(Ec2Client ec2,String groupId) {

        try {
            DeleteSecurityGroupRequest request = DeleteSecurityGroupRequest.builder()
                .groupId(groupId)
                .build();

            ec2.deleteSecurityGroup(request);
            System.out.printf(
                "Successfully deleted Security Group with id %s", groupId);

        } catch (Ec2Exception e) {
            System.err.println(e.awsErrorDetails().errorMessage());
            System.exit(1);
        }
     }
```

See the [complete example](https://github.com/awsdocs/aws-doc-sdk-examples/blob/0b1785e42949ebf959eaa0f0da4dc2a48f92ea25/javav2/example_code/ec2/src/main/java/com/example/ec2/DeleteSecurityGroup.java) on GitHub.

## More information
<a name="more-information"></a>
+  [Amazon EC2 Security Groups](https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/ec2-security-groups.html) in the Amazon EC2 User Guide for Linux Instances
+  [Authorize inbound traffic for Your Linux Instances](https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/authorizing-access-to-an-instance.html) in the Amazon EC2 User Guide for Linux Instances
+  [CreateSecurityGroup](https://docs.aws.amazon.com/AWSEC2/latest/APIReference/API_CreateSecurityGroup.html) in the Amazon EC2 API Reference
+  [DescribeSecurityGroups](https://docs.aws.amazon.com/AWSEC2/latest/APIReference/API_DescribeSecurityGroups.html) in the Amazon EC2 API Reference
+  [DeleteSecurityGroup](https://docs.aws.amazon.com/AWSEC2/latest/APIReference/API_DeleteSecurityGroup.html) in the Amazon EC2 API Reference
+  [AuthorizeSecurityGroupIngress](https://docs.aws.amazon.com/AWSEC2/latest/APIReference/API_AuthorizeSecurityGroupIngress.html) in the Amazon EC2 API Reference