How to change docker image via CI/CD ?

[Qbason]

Hello!

What is the easiest way to change the Docker image in an application via CI/CD?

Here’s the case:
I want to build a Docker image through CI/CD, but I don’t want to publish it as latest. Instead, I want to deploy using a specific Docker image tag. This approach helps distinguish versions and makes rollbacks easier in case of a failure.

[Qbason]

This might be useful for someone who prefers to handle CI separately from CD :)

const apikey = process.env.DOKPLOY_API_KEY;
const url = process.env.DOKPLOY_URL;
const applicationId = process.env.DOKPLOY_APPLICATION_ID;
const newDockerImage = process.env.NEW_DOCKER_IMAGE;

if (!apikey){
    throw new Error("DOKPLOY_API_KEY is not set");
}
if (!url){
    throw new Error("DOKPLOY_URL is not set");
}
if (!applicationId){
    throw new Error("DOKPLOY_APPLICATION_ID is not set");
}
if (!newDockerImage){
    throw new Error("NEW_DOCKER_IMAGE is not set");
}


const checkIfApplicationExists = async (applicationId) => {

    const response = await fetch(`${url}/application.one?applicationId=${applicationId}`, {
        method: "GET",
        headers: {
            "x-api-key": apikey,
            "Content-Type": "application/json"
        }
    });

    if (!response.ok) {
        throw new Error(`Error fetching application: ${response.statusText}`);
    }

    console.log(`Application ${applicationId} exists.`);
}

const changeDockerImage = async (applicationId, newDockerImage) => {

    const response = await fetch(`${url}/application.update`, {
        method: "POST",
        headers: {
            "x-api-key": apikey,
            "Content-Type": "application/json"
        },
        body: JSON.stringify({
            applicationId: applicationId,
            dockerImage: newDockerImage
        })
    });

    if (!response.ok) {
        throw new Error(`Error updating application: ${response.statusText}`);
    }
    console.log(`Application ${applicationId} updated to use Docker image ${newDockerImage}.`);

}

const deployApplication = async (applicationId) => {

    const response = await fetch(`${url}/application.deploy`, {
        method: "POST",
        headers: {
            "x-api-key": apikey,
            "Content-Type": "application/json"
        },
        body: JSON.stringify({
            applicationId: applicationId,
            title: "Automated deployment via CI/CD"
        })
    });

    if (!response.ok) {
        throw new Error(`Error deploying application: ${response.statusText}`);
    }
    console.log(`Application ${applicationId} deployment triggered.`);

}

const checkIfDeploymentSucceeded = async (applicationId) => {

    let status = "running";

    while(status === "running") {

        const response = await fetch(`${url}/deployment.all?applicationId=${applicationId}`, {
            method: "GET",
            headers: {
                "x-api-key": apikey,
                "Content-Type": "application/json"
            }
        });

        if (!response.ok) {
            throw new Error(`Error fetching deployments: ${response.statusText}`);
        }

        const deployments = await response.json();
        
        const latestDeployment = deployments[0];
        status = latestDeployment.status;
        console.log(`Current deployment status: ${status}`);
        if(status === "error"){
            throw new Error(`Deployment failed: ${latestDeployment.errorMessage}`);
        }
        await new Promise(resolve => setTimeout(resolve, 5000)); 
    }
    console.log(`Application ${applicationId} deployed successfully.`);
}

const main = async () => {
    await checkIfApplicationExists(applicationId);
    await changeDockerImage(applicationId, newDockerImage);
    await deployApplication(applicationId);
    await checkIfDeploymentSucceeded(applicationId);
}

main();