This guide shows you workflow examples that configure a service container using the Docker Hub
redis
image. The workflow runs a script to create a Redis client and populate the client with data. To test that the workflow creates and populates the Redis client, the script prints the client's data to the console.
Note:
If your workflows use Docker container actions, job containers, or service containers, then you must use a Linux runner:
- If you are using GitHub-hosted runners, you must use an Ubuntu runner.
- If you are using self-hosted runners, you must use a Linux machine as your runner and Docker must be installed.
You should be familiar with how service containers work with GitHub Actions and the networking differences between running jobs directly on the runner or in a container. For more information, see "
About service containers
."
You may also find it helpful to have a basic understanding of YAML, the syntax for GitHub Actions, and Redis. For more information, see:
Configuring jobs to run in a container simplifies networking configurations between the job and the service containers. Docker containers on the same user-defined bridge network expose all ports to each other, so you don't need to map any of the service container ports to the Docker host. You can access the service container from the job container using the label you configure in the workflow.
You can copy this workflow file to the
.github/workflows
directory of your repository and modify it as needed.
YAML
name: Redis container example
on: push
jobs:
# Label of the container job
container-job:
# Containers must run in Linux based operating systems
runs-on: ubuntu-latest
# Docker Hub image that `container-job` executes in
container: node:10.18-jessie
# Service containers to run with `container-job`
services:
# Label used to access the service container
redis:
# Docker Hub image
image: redis
# Set health checks to wait until redis has started
options: >-
--health-cmd "redis-cli ping"
--health-interval 10s
--health-timeout 5s
--health-retries 5
steps:
# Downloads a copy of the code in your repository before running CI tests
- name: Check out repository code
uses: actions/checkout@v4
# Performs a clean installation of all dependencies in the `package.json` file
# For more information, see https://docs.npmjs.com/cli/ci.html
- name: Install dependencies
run: npm ci
- name: Connect to Redis
# Runs a script that creates a Redis client, populates
# the client with data, and retrieves data
run: node client.js
# Environment variable used by the `client.js` script to create a new Redis client.
env:
# The hostname used to communicate with the Redis service container
REDIS_HOST: redis
# The default Redis port
REDIS_PORT: 6379
name:
Redis
container
example
on:
push
jobs:
container-job:
runs-on:
ubuntu-latest
container:
node:10.18-jessie
services:
redis:
image:
redis
options:
>-
--health-cmd "redis-cli ping"
--health-interval 10s
--health-timeout 5s
--health-retries 5
steps:
-
name:
Check
out
repository
code
uses:
actions/checkout@v4
-
name:
Install
dependencies
run:
npm
ci
-
name:
Connect
to
Redis
run:
node
client.js
env:
REDIS_HOST:
redis
REDIS_PORT:
6379
This workflow configures a job that runs in the
node:10.18-jessie
container and uses the
ubuntu-latest
GitHub-hosted runner as the Docker host for the container. For more information about the
node:10.18-jessie
container, see the
node image
on Docker Hub.
The workflow configures a service container with the label
redis
. All services must run in a container, so each service requires that you specify the container
image
. This example uses the
redis
container image, and includes health check options to make sure the service is running. Append a tag to the image name to specify a version, e.g.
redis:6
. For more information, see the
redis image
on Docker Hub.
YAML
jobs:
# Label of the container job
container-job:
# Containers must run in Linux based operating systems
runs-on: ubuntu-latest
# Docker Hub image that `container-job` executes in
container: node:10.18-jessie
# Service containers to run with `container-job`
services:
# Label used to access the service container
redis:
# Docker Hub image
image: redis
# Set health checks to wait until redis has started
options: >-
--health-cmd "redis-cli ping"
--health-interval 10s
--health-timeout 5s
--health-retries 5
jobs:
container-job:
runs-on:
ubuntu-latest
container:
node:10.18-jessie
services:
redis:
image:
redis
options:
>-
--health-cmd "redis-cli ping"
--health-interval 10s
--health-timeout 5s
--health-retries 5
The workflow performs the following steps:
- Checks out the repository on the runner
- Installs dependencies
- Runs a script to create a client
YAML
steps:
# Downloads a copy of the code in your repository before running CI tests
- name: Check out repository code
uses: actions/checkout@v4
# Performs a clean installation of all dependencies in the `package.json` file
# For more information, see https://docs.npmjs.com/cli/ci.html
- name: Install dependencies
run: npm ci
- name: Connect to Redis
# Runs a script that creates a Redis client, populates
# the client with data, and retrieves data
run: node client.js
# Environment variable used by the `client.js` script to create a new Redis client.
env:
# The hostname used to communicate with the Redis service container
REDIS_HOST: redis
# The default Redis port
REDIS_PORT: 6379
steps:
-
name:
Check
out
repository
code
uses:
actions/checkout@v4
-
name:
Install
dependencies
run:
npm
ci
-
name:
Connect
to
Redis
run:
node
client.js
env:
REDIS_HOST:
redis
REDIS_PORT:
6379
The
client.js
script looks for the
REDIS_HOST
and
REDIS_PORT
environment variables to create the client. The workflow sets those two environment variables as part of the "Connect to Redis" step to make them available to the
client.js
script. For more information about the script, see "
Testing the Redis service container
."
The hostname of the Redis service is the label you configured in your workflow, in this case,
redis
. Because Docker containers on the same user-defined bridge network open all ports by default, you'll be able to access the service container on the default Redis port 6379.
When you run a job directly on the runner machine, you'll need to map the ports on the service container to ports on the Docker host. You can access service containers from the Docker host using
localhost
and the Docker host port number.
You can copy this workflow file to the
.github/workflows
directory of your repository and modify it as needed.
YAML
name: Redis runner example
on: push
jobs:
# Label of the runner job
runner-job:
# You must use a Linux environment when using service containers or container jobs
runs-on: ubuntu-latest
# Service containers to run with `runner-job`
services:
# Label used to access the service container
redis:
# Docker Hub image
image: redis
# Set health checks to wait until redis has started
options: >-
--health-cmd "redis-cli ping"
--health-interval 10s
--health-timeout 5s
--health-retries 5
ports:
# Maps port 6379 on service container to the host
- 6379:6379
steps:
# Downloads a copy of the code in your repository before running CI tests
- name: Check out repository code
uses: actions/checkout@v4
# Performs a clean installation of all dependencies in the `package.json` file
# For more information, see https://docs.npmjs.com/cli/ci.html
- name: Install dependencies
run: npm ci
- name: Connect to Redis
# Runs a script that creates a Redis client, populates
# the client with data, and retrieves data
run: node client.js
# Environment variable used by the `client.js` script to create
# a new Redis client.
env:
# The hostname used to communicate with the Redis service container
REDIS_HOST: localhost
# The default Redis port
REDIS_PORT: 6379
name:
Redis
runner
example
on:
push
jobs:
runner-job:
runs-on:
ubuntu-latest
services:
redis:
image:
redis
options:
>-
--health-cmd "redis-cli ping"
--health-interval 10s
--health-timeout 5s
--health-retries 5
ports:
-
6379
:6379
steps:
-
name:
Check
out
repository
code
uses:
actions/checkout@v4
-
name:
Install
dependencies
run:
npm
ci
-
name:
Connect
to
Redis
run:
node
client.js
env:
REDIS_HOST:
localhost
REDIS_PORT:
6379
The example uses the
ubuntu-latest
GitHub-hosted runner as the Docker host.
The workflow configures a service container with the label
redis
. All services must run in a container, so each service requires that you specify the container
image
. This example uses the
redis
container image, and includes health check options to make sure the service is running. Append a tag to the image name to specify a version, e.g.
redis:6
. For more information, see the
redis image
on Docker Hub.
The workflow maps port 6379 on the Redis service container to the Docker host. For more information about the
ports
keyword, see "
About service containers
."
YAML
jobs:
# Label of the runner job
runner-job:
# You must use a Linux environment when using service containers or container jobs
runs-on: ubuntu-latest
# Service containers to run with `runner-job`
services:
# Label used to access the service container
redis:
# Docker Hub image
image: redis
# Set health checks to wait until redis has started
options: >-
--health-cmd "redis-cli ping"
--health-interval 10s
--health-timeout 5s
--health-retries 5
ports:
# Maps port 6379 on service container to the host
- 6379:6379
jobs:
runner-job:
runs-on:
ubuntu-latest
services:
redis:
image:
redis
options:
>-
--health-cmd "redis-cli ping"
--health-interval 10s
--health-timeout 5s
--health-retries 5
ports:
-
6379
:6379
The workflow performs the following steps:
- Checks out the repository on the runner
- Installs dependencies
- Runs a script to create a client
YAML
steps:
# Downloads a copy of the code in your repository before running CI tests
- name: Check out repository code
uses: actions/checkout@v4
# Performs a clean installation of all dependencies in the `package.json` file
# For more information, see https://docs.npmjs.com/cli/ci.html
- name: Install dependencies
run: npm ci
- name: Connect to Redis
# Runs a script that creates a Redis client, populates
# the client with data, and retrieves data
run: node client.js
# Environment variable used by the `client.js` script to create
# a new Redis client.
env:
# The hostname used to communicate with the Redis service container
REDIS_HOST: localhost
# The default Redis port
REDIS_PORT: 6379
steps:
-
name:
Check
out
repository
code
uses:
actions/checkout@v4
-
name:
Install
dependencies
run:
npm
ci
-
name:
Connect
to
Redis
run:
node
client.js
env:
REDIS_HOST:
localhost
REDIS_PORT:
6379
The
client.js
script looks for the
REDIS_HOST
and
REDIS_PORT
environment variables to create the client. The workflow sets those two environment variables as part of the "Connect to Redis" step to make them available to the
client.js
script. For more information about the script, see "
Testing the Redis service container
."
The hostname is
localhost
or
127.0.0.1
.
You can test your workflow using the following script, which creates a Redis client and populates the client with some placeholder data. The script then prints the values stored in the Redis client to the terminal. Your script can use any language you'd like, but this example uses Node.js and the
redis
npm module. For more information, see the
npm redis module
.
You can modify
client.js
to include any Redis operations needed by your workflow. In this example, the script creates the Redis client instance, adds placeholder data, then retrieves the data.
Add a new file called
client.js
to your repository with the following code.
JavaScript
const redis = require("redis");
// Creates a new Redis client
// If REDIS_HOST is not set, the default host is localhost
// If REDIS_PORT is not set, the default port is 6379
const redisClient = redis.createClient({
url: `redis://${process.env.REDIS_HOST}:${process.env.REDIS_PORT}`
});
redisClient.on("error", (err) => console.log("Error", err));
(async () => {
await redisClient.connect();
// Sets the key "octocat" to a value of "Mona the octocat"
const setKeyReply = await redisClient.set("octocat", "Mona the Octocat");
console.log("Reply: " + setKeyReply);
// Sets a key to "species", field to "octocat", and "value" to "Cat and Octopus"
const SetFieldOctocatReply = await redisClient.hSet("species", "octocat", "Cat and Octopus");
console.log("Reply: " + SetFieldOctocatReply);
// Sets a key to "species", field to "dinotocat", and "value" to "Dinosaur and Octopus"
const SetFieldDinotocatReply = await redisClient.hSet("species", "dinotocat", "Dinosaur and Octopus");
console.log("Reply: " + SetFieldDinotocatReply);
// Sets a key to "species", field to "robotocat", and "value" to "Cat and Robot"
const SetFieldRobotocatReply = await redisClient.hSet("species", "robotocat", "Cat and Robot");
console.log("Reply: " + SetFieldRobotocatReply);
try {
// Gets all fields in "species" key
const replies = await redisClient.hKeys("species");
console.log(replies.length + " replies:");
replies.forEach((reply, i) => {
console.log(" " + i + ": " + reply);
});
await redisClient.quit();
}
catch (err) {
// statements to handle any exceptions
}
})();
const
redis =
require
(
"redis"
);
const
redisClient = redis.
createClient
({
url
:
`redis://
${process.env.REDIS_HOST}
:
${process.env.REDIS_PORT}
`
});
redisClient.
on
(
"error"
,
(
err
) =>
console
.
log
(
"Error"
, err));
(
async
() => {
await
redisClient.
connect
();
const
setKeyReply =
await
redisClient.
set
(
"octocat"
,
"Mona the Octocat"
);
console
.
log
(
"Reply: "
+ setKeyReply);
const
SetFieldOctocatReply
=
await
redisClient.
hSet
(
"species"
,
"octocat"
,
"Cat and Octopus"
);
console
.
log
(
"Reply: "
+
SetFieldOctocatReply
);
const
SetFieldDinotocatReply
=
await
redisClient.
hSet
(
"species"
,
"dinotocat"
,
"Dinosaur and Octopus"
);
console
.
log
(
"Reply: "
+
SetFieldDinotocatReply
);
const
SetFieldRobotocatReply
=
await
redisClient.
hSet
(
"species"
,
"robotocat"
,
"Cat and Robot"
);
console
.
log
(
"Reply: "
+
SetFieldRobotocatReply
);
try
{
const
replies =
await
redisClient.
hKeys
(
"species"
);
console
.
log
(replies.
length
+
" replies:"
);
replies.
forEach
(
(
reply, i
) =>
{
console
.
log
(
" "
+ i +
": "
+ reply);
});
await
redisClient.
quit
();
}
catch
(err) {
}
})();
The script creates a new Redis client using the
createClient
method, which accepts a
host
and
port
parameter. The script uses the
REDIS_HOST
and
REDIS_PORT
environment variables to set the client's IP address and port. If
host
and
port
are not defined, the default host is
localhost
and the default port is 6379.
The script uses the
set
and
hset
methods to populate the database with some keys, fields, and values. To confirm that the Redis client contains the data, the script prints the contents of the database to the console log.
When you run this workflow, you should see the following output in the "Connect to Redis" step confirming you created the Redis client and added data:
Reply: OK
Reply: 1
Reply: 1
Reply: 1
3 replies:
0: octocat
1: dinotocat
2: robotocat
