How to store a Complex Nested JSON in Redis using

Question

As i am new to redis, i need some guidance on how we can store the below complex json in REDIS so that we can access the Elements of the JSON from REDIS -

"Reservations": [
        {
            "Instances": [
                {
                    "Monitoring": {
                        "State": "disabled"
                    },
                    "PublicDnsName": "",
                    "State": {
                        "Code": 16,
                        "Name": "running"
                    },
                    "EbsOptimized": "false",
                    "LaunchTime": "xxxxxxxxx",
                    "PrivateIpAddress": "x.x.x.x",
                    "ProductCodes": [],
                    "VpcId": "xxxxx",
                    "StateTransitionReason": "",
                    "InstanceId": "i-xxxxxxx",
                    "EnaSupport": "true",
                    "ImageId": "ami-xxxxx",
                    "PrivateDnsName": "ip-xxxxxx.ec2.internal",
                    "KeyName": "xxxxxxv",
                    "SecurityGroups": [
                        {
                            "GroupName": "xxx",
                            "GroupId": "sg-xxxx"
                        },
                        {
                            "GroupName": "xxxxxx",
                            "GroupId": "sg-xxxxx"
                        },
                        {
                            "GroupName": "xxxxx",
                            "GroupId": "sg-xxxxxx"
                        },
                        {
                            "GroupName": "xxxxx",
                            "GroupId": "sg-xxxxxx"
                        }
                    ],
                    "ClientToken": "xxxxx",
                    "SubnetId": "subnet-xxxxx",
                    "InstanceType": "t2.micro",
                    "NetworkInterfaces": [
                        {
                            "Status": "in-use",
                            "MacAddress": "xxxxxxxx",
                            "SourceDestCheck": "true",
                            "VpcId": "vpc-xxxxx",
                            "Description": "",
                            "NetworkInterfaceId": "eni-xxxxx",
                            "PrivateIpAddresses": [
                                {
                                    "PrivateDnsName": "ip-xx-ec2.internal",
                                    "Primary": "true",
                                    "PrivateIpAddress": "xxxxx"
                                }
                            ],
                            "PrivateDnsName": "ip-xxxx-xx.ec2.internal",
                            "Attachment": {
                                "Status": "attached",
                                "DeviceIndex": 0,
                                "DeleteOnTermination": "true",
                                "AttachmentId": "eni-attach-xxxxx",
                                "AttachTime": "2017-0xxxxx"
                            },
                            "Groups": [
                                {
                                    "GroupName": "xx",
                                    "GroupId": "sg-xxxx"
                                },
                                {
                                    "GroupName": "xxxx",
                                    "GroupId": "sg-xxx"
                                },
                                {
                                    "GroupName": "xxxx",
                                    "GroupId": "sg-xxx"
                                },
                                {
                                    "GroupName": "xxxx",
                                    "GroupId": "sg-xxxx"
                                }
                            ],
                            "Ipv6Addresses": [],
                            "OwnerId": "xxx",
                            "SubnetId": "subnet-xxxx",
                            "PrivateIpAddress": "1xxxx"
                        }
                    ],
                    "SourceDestCheck": "true",
                    "Placement": {
                        "Tenancy": "default",
                        "GroupName": "",
                        "AvailabilityZone": "us-xxxxxxx"
                    },
                    "Hypervisor": "xen",
                    "BlockDeviceMappings": [
                        {
                            "DeviceName": "/dev/xxxxxx",
                            "Ebs": {
                                "Status": "attached",
                                "DeleteOnTermination": "true",
                                "VolumeId": "vol-xxxxxx",
                                "AttachTime": "2017-xxxxxxx"
                            }
                        }
                    ],
                    "Architecture": "x86_64",
                    "RootDeviceType": "ebs",
                    "IamInstanceProfile": {
                        "Id": "xxxxxxxx",
                        "Arn": "arn:aws:iam::xxxxxxx"
                    },
                    "RootDeviceName": "/dev/xxxxx",
                    "VirtualizationType": "hvm",
                    "Tags": [
                        {
                            "Value": "xxxxxx",
                            "Key": "aws:cloudformation:stack-name"
                        },
                        {
                            "Value": "xxxxxxx",
                            "Key": "aws:cloudformation:logical-id"
                        },
                        {
                            "Value": "arn:aws:cloudformation:xxxxxx",
                            "Key": "aws:cloudformation:stack-id"
                        }
                    ],
                    "AmiLaunchIndex": 0
                }
            ],
            "ReservationId": "r-xxxxx",
            "RequesterId": "xxxxx",
            "Groups": [],
            "OwnerId": "xxxxxx"
        }
    ] 
}

I need to store this in such a way that i query the IP/Hostname/InstanceID to get all the elements that are present in the JSON.

I need some guidance on the above.

Answer 1

You can't directly do that, but luckily there is a new Redis module called ReJSON that does exactly what you need, and it has a nice Python binding as well. You need to use redis 4.0, then compile and install ReJSON and configure redis to load it, and it adds native commands for JSON manipulation.

It lets you store JSON documents in redis, and then either fetch or modify a specific element in the document tree, without retrieving (or internally even parsing) the document. Its Python client even lets you store python dicts and converts them to JSON automatically.

ReJSON module: http://rejson.io

Python client: https://pypi.python.org/pypi/rejson

Example:

from rejson import Client, Path

rj = Client(host='localhost', port=6379)

# Set the key `obj` to some object
obj = {
    'answer': 42,
    'arr': [None, True, 3.14],
    'truth': {
        'coord': 'out there'
    }
}
rj.jsonset('obj', Path.rootPath(), obj)

# Get something
print 'Is there anybody... {}?'.format(
    rj.jsonget('obj', Path('.truth.coord'))
)

Answer 2

You can use the pickle module incase you don't want to use reJson.

To set data in redis:

def store_dict_data_in_redis(redis_client, key, data, ex=0):
'''
store dict data in redis by pickle dumps
:param redis_client: redis client used to connect to obtain key value
:param key: key name
:param data: dict value
:param ex: expiry
:return: None
'''
    if ex > 0:
         redis_client.set(key, pickle.dumps(data), ex=ex)
    else:
         redis_client.set(key, pickle.dumps(data))

To obtain value from redis:

def get_dict_data_from_redis(redis_client, key):
'''
obtain dict data from redis
:param redis_client: redis client used to connect to obtain key value
:param key: key name
:return: dict data stored in redis
'''
    data = redis_client.get(key)
    if data:
       try:
          return pickle.loads(data)
       except:
          return eval(data.decode())
    return {}