Connecting to a Redis instance

This page describes how to connect to your Redis instance using Compute Engine and Google Kubernetes Engine. It also provides instructions for testing basic Redis commands with Telnet.

For a list of Google Cloud environments that Memorystore for Redis supports, see Supported environments. Some serverless environments that Memorystore supports require a Serverless VPC Access connector. See Serverless VPC Access connector requirement for more details.

Connecting to a Redis instance from a Compute Engine VM using telnet

You can connect to the Redis instance from any Compute Engine VM instance located within the same project, region and network as the Redis instance.

If you don't already have a Compute Engine VM in the same project, region, and network as your Redis instance, create one and connect to it by following Quickstart using a Linux VM.
Install telnet using apt-get:
```
sudo apt-get install telnet
```
From the terminal, telnet to the IP address of the Redis instance, replacing variables with appropriate values.
```
telnet instance-ip-address 6379
```
If successful, the command will return this result:
```
Trying instance-ip-address…
Connected to instance-ip-address
```
In the telnet session, enter some Redis commands:

Enter:
```
PING
```
Result:
```
PONG
```
Enter
```
SET HELLO WORLD
```
Result:
```
+OK
```
Enter:
```
GET HELLO
```
Result:
```
$5
WORLD
```

Connecting to a Redis instance from a Compute Engine VM using `redis-cli`

You can connect to the Redis instance from any Compute Engine VM instance located within the same project, region, and network as the Redis instance.

If you don't already have a Compute Engine VM in the same project, region, and network as your Redis instance, create one and connect to it by following Quickstart Using a Linux VM.
Install redis-cli on the Compute Engine VM by running the following command from the Compute Engine SSH terminal:
```
sudo apt-get install redis-server
```
Run the following command in the Compute Engine terminal, replacing variables with appropriate values.
```
redis-cli -h redis-instance-ip-address
```
You are now connected to your Redis instance using redis-cli.
Once you are done testing your connection to the Redis instance, you should consider deleting the Compute Engine VM you used to connect to the Redis instance. Doing so helps you avoid incurring charges to your Cloud Billing account.

Connecting to a Redis instance that uses AUTH

This section describes how to connect to a Redis instance that has the AUTH feature enabled.

If you don't already have a Compute Engine VM in the same project, region, and network as your Redis instance, create one and connect to it by following Quickstart Using a Linux VM.
Install redis-cli on the Compute Engine VM by running the following command from the Compute Engine SSH terminal:
```
sudo apt-get install redis-server
```
Get your instance's AUTH string
Run the following command to use redis-cli to authenticate and connect to your instance, replacing variables with appropriate values:
```
redis-cli -h instance-ip-address -a auth-string
```
Or:
```
redis-cli -h instance-ip-address
AUTH auth-string
```
Run a Redis SET and GET command to verify that you have established an authenticated connection to your instance.
Once you are done testing your connection to the Redis instance, you should consider deleting the Compute Engine VM you used to connect to the Redis instance. Doing so helps you avoid incurring charges to your Cloud Billing account.

Securely connecting to a Redis instance using Stunnel and telnet

This section provides an example of how to connect to a Redis instance that has TLS enabled using Stunnel.

If you don't already have a Redis instance that has TLS enabled, create one by following Creating a Redis instance with TLS.
If you don't already have a Compute Engine VM in the same region, project, and network as the Redis instance from the previous step, create one and connect to it by following Quickstart using a Linux VM.
1. Install the necessary tools for this guide by running the following commands:
```
sudo apt-get install stunnel4
```
```
sudo apt-get install telnet
```
Note: The remaining steps in this guide occur in the SSH terminal of the Compute Engine VM you created and connected to, unless otherwise specified.
Configure your Compute Engine VM for use with Stunnel:
1. Make a new file in which to put your Certificate Authority (CA) by running the following command:
```
sudo vim /tmp/server_ca.pem
```
2. View your Redis instance's Certificate Authority(s) by running the following command in the standard terminal you use to manage Google Cloud resources (not the Compute Engine terminal):
```
gcloud beta redis instances describe instance-id --region=region
```
  There may be up to three CAs.
3. Copy all of the visible Certificate Authorities including the -----BEGIN CERTIFICATE----- line and the -----END CERTIFICATE----- lines, and paste and save it the server_ca.pem file you previously created.
  
  Note: Make sure that the text of the Certificate Authority is completely left justified. There should be no leading whitespace on any line of the CA.
4. Make a new file in which to put Stunnel configuration information by running the following command:
```
sudo vim /etc/stunnel/redis-client.conf
```
  Paste the following text in the file, replacing redis-instance-ip with the Redis instance's IP address:
```
output=/tmp/stunnel.log
CAfile=/tmp/server_ca.pem
client=yes
pid=/var/run/stunnel.pid
verifyChain=yes
sslVersion=TLSv1.2
[redis]
accept=127.0.0.1:6378
connect=redis-instance-ip:6378
```
5. Restart Stunnel by running the following commands:
```
sudo stunnel /etc/stunnel/redis-client.conf
```
```
sudo systemctl restart stunnel4
```
To connect to your Redis instance using Telnet, run the following command:
```
telnet localhost 6378
```
In the Telnet session, ping the Redis instance:

Enter:
```
PING
```
Result:
```
PONG
```

Connecting to a Redis instance from a Google Kubernetes Engine cluster

You can connect to your Redis instances from Google Kubernetes Engine clusters that are in the same region and use the same network as your instance.

Connecting from a pod running a bash shell

Go to the GKE page in the Cloud Console.
GKE
Click on the GKE cluster you'd like to connect from. If you don't already have a cluster, create one in the same zone and region as your Redis instance with IP aliases enabled. For instructions on how to create a cluster with IP aliases enabled, see the IP aliases documentation.
Click the Connect button to the right of your cluster's name, then click the Run in Cloud Shell button in the window that appears.
Configure kubectl command line access by running the following command:
```
gcloud container clusters get-credentials CLUSTER_NAME --zone=CLUSTER_ZONE --project=PROJECT_ID
```
- CLUSTER_NAME is the name of your cluster.
- CLUSTER_ZONE is the zone your cluster is in. Must also be the zone your Redis instance is in.
- PROJECT_ID is the project where your cluster and your Redis instances exist.
You should get the success message: kubeconfig generated for CLUSTER_NAME
If your cluster is version 1.8 or higher and has IP aliases enabled, skip this step. If your cluster is version 1.7 or lower, or your version 1.8 or higher cluster doesn't have IP aliases enabled, follow these workaround steps before trying to connect to your instance:
Workaround

Run these three commands, replacing RESERVED_IP_RANGE with the reserved IP range of your instance:
```
git clone https://github.com/bowei/k8s-custom-iptables.git
```
```
cd k8s-custom-iptables/
```
```
TARGETS="RESERVED_IP_RANGE" ./install.sh
```
If you don't know the reserved IP range of your instance, you can find out by entering this command: gcloud redis instances describe INSTANCE_ID --region=REGION
For more information about IP aliases, including how to create a cluster with this setting enabled, see the IP aliases documentation.
Use the following command to connect to a bash shell:
```
kubectl run -i --tty busybox --image=busybox -- sh
```
Telnet to your Redis instance using the host address and port number:
```
telnet HOST-IP PORT
```
Enter a basic Redis command to verify the connection:
```
PING
+PONG
```
To close the telnet connection, press Control+C (or Command+C on Mac). To exit the bash shell in your pod, enter return. If you are done and no longer need to connect to Redis, run the following command from the /k8s-custom-iptables/ directory:
```
./uninstall.sh
```

Connecting to a Redis instance from a Google Kubernetes Engine pod

Before you begin, you need a GKE cluster. If you don't already have a cluster, create one in the same zone and region as your Redis instance with IP aliases enabled. For instructions on how to create a cluster with IP aliases enabled, see the IP Aliases documentation.

From the top-right corner of the console, click the Activate Cloud Shell button.
Configure kubectl command line access by running the following command:
```
gcloud container clusters get-credentials CLUSTER_NAME --zone CLUSTER_ZONE --project PROJECT_ID
```
- CLUSTER_NAME is the name of your cluster.
- CLUSTER_ZONE is the zone your cluster is in. Must also be the zone your Redis instance is in.
- PROJECT_ID is the project where your cluster and your Redis instances exist.
You should get the success message: kubeconfig generated for CLUSTER_NAME
If your cluster is version 1.8 or higher and has IP aliases enabled, skip this step. If your cluster is version 1.7 or lower, or your version 1.8 or higher cluster doesn't have IP aliases enabled, follow these workaround steps before trying to connect to your instance:
Workaround

Run these three commands, replacing RESERVED_IP_RANGE with the reserved IP range of your instance:
```
git clone https://github.com/bowei/k8s-custom-iptables.git
```
```
cd k8s-custom-iptables/
```
```
TARGETS="RESERVED_IP_RANGE" ./install.sh
```
If you don't know the reserved IP range of your instance, you can find out by entering this command: gcloud redis instances describe INSTANCE_ID --region [REGION]
For more information about IP aliases, including how to create a cluster with this setting enabled, see the IP aliases documentation.

Use the following command to start a Redis pod running the redis-cli:

kubectl run -i --tty redisbox --image=gcr.io/google_containers/redis:v1 -- sh

Run a redis-cli command, replacing HOST-IP with the host IP address of your Redis instance:
```
redis-cli -h HOST-IP info
```

Optionally, run a Redis benchmark command, again replacing HOST-IP with the host IP address of your Redis instance:

redis-benchmark -c 100 -n 100000 -d 1024 -r 100000 -t PING,SET,GET,INCR,LPUSH,RPUSH,LPOP,RPOP,SADD,SPOP,MSET -h HOST-IP -q

To exit the Redis pod, enter return. If you are done and no longer need to connect to Redis, run the following command from the /k8s-custom-iptables/ directory:
```
./uninstall.sh
```

What's next

Connect to your Redis instance using a sample application that runs on: