GreenGrass IoT - Deploy docker-compose along with it's dependencies as a different component

Question

Hello, I'm trying to deploy docker-compose dependencies and prerequisites on my IoT ubuntu based edge device, then run my custom docker-compose.yaml component. When trying to deploy only the docker-compose dependencies component, and then the custom docker-compose.yaml component, everything works fine. Although, when I'm connecting the two of them into one deployment, and putting the docker-compose-dependencies as a dependency component in my recipe, it seems to ignore the docker-compose-dependency (even though it is appearing in the dependency resolver in GreenGrass logs).

My docker-compose-dependency recipe:

{
  "RecipeFormatVersion": "2020-01-25",
  "ComponentName": "docker-compose-dependency",
  "ComponentVersion": "1.0.9",
  "ComponentType": "aws.greengrass.generic",
  "ComponentDescription": "My first Greengrass component.",
  "ComponentPublisher": "Me",
  "ComponentConfiguration": {
    "DefaultConfiguration": {
      "Message": "world"
    }
  },
  "Manifests": [
    {
      "Platform": {
        "os": "linux"
      },
      "Name": "Linux",
      "Lifecycle": {
        "Run": {
          "Script": "install -m 0755 -d /etc/apt/keyrings && curl -fsSL https://download.docker.com/linux/ubuntu/gpg | sudo gpg --dearmor -o /etc/apt/keyrings/docker.gpg && chmod a+r /etc/apt/keyrings/docker.gpg && echo deb [arch=arm64 signed-by=/etc/apt/keyrings/docker.gpg] https://download.docker.com/linux/ubuntu   focal stable > /etc/apt/sources.list.d/docker.list && apt-get update && apt-get install docker-ce docker-ce-cli containerd.io -y && curl -L https://github.com/ubiquiti/docker-compose-aarch64/releases/download/1.22.0/docker-compose-Linux-aarch64 -o /usr/local/bin/docker-compose && chmod +x /usr/local/bin/docker-compose",
          "RequiresPrivilege": "true"
        }
      },
      "Artifacts": []
    }
  ],
  "Lifecycle": {}
}

My docker-compose-yaml recipe:

{
  "RecipeFormatVersion": "2020-01-25",
  "ComponentName": "docker-compose-yaml",
  "ComponentVersion": "1.0.31",
  "ComponentType": "aws.greengrass.generic",
  "ComponentDescription": "A component that uses Docker Compose to run images from our private ecr.",
  "ComponentPublisher": "Amazon",
  "ComponentDependencies": {
    "aws.greengrass.DockerApplicationManager": {
      "VersionRequirement": ">=2.0.0 <2.1.0",
      "DependencyType": "HARD"
    },
    "aws.greengrass.TokenExchangeService": {
      "VersionRequirement": ">=2.0.0 <2.1.0",
      "DependencyType": "HARD"
    },
    "docker-compose-dependency": {
      "VersionRequirement": ">1.0.0",
      "DependencyType": "HARD"
    }
  },
  "Manifests": [
    {
      "Platform": {
        "os": "all"
      },
      "Lifecycle": {
        "run": "docker-compose -f {artifacts:path}/docker-compose.yaml up"
      },
      "Artifacts": [
        {
          "Uri": "docker:****************.dkr.ecr.eu-central-1.amazonaws.com/my-test-image:******",
          "Unarchive": "NONE",
          "Permission": {
            "Read": "OWNER",
            "Execute": "NONE"
          }
        },       
        {
          "Uri": "docker:traefik:v2.10",
          "Unarchive": "NONE",
          "Permission": {
            "Read": "OWNER",
            "Execute": "NONE"
          }
        },
        {
          "Uri": "s3://*********/docker-compose.yaml",
          "Digest": "***********************************************",
          "Algorithm": "SHA-256",
          "Unarchive": "NONE",
          "Permission": {
            "Read": "OWNER",
            "Execute": "NONE"
          }
        }
      ]
    }
  ],
  "Lifecycle": {}
}

I tried to create a deployment once with only the docker-compose-yaml component to be installed, and once with both of them to be installed, but ended up with the same result.

Thanks!

MassimilianoAWS · Answer

The issue is that `docker` is a pre-requisite of  `aws.greengrass.DockerApplication`, while in your case you are installing `docker` via the `docker-compose-dependencies` component which is only a dependency of your `docker-compose-yaml` component. When Greenrass tried to pull the `docker:` container images artifacts, it fails since docker is not yet installed.

While I would recommend to install dependencies such as docker, language run-times, etc, as part of the device system image, you can:

1. Replace the `docker:` artifacts with `s3:` artifacts, storing the container images in S3 and loading them up in your recipe `Run:` lifecycle via `docker load {artifacts:path}/image.tar.gz`. The advantage of this approach is that the image is downloaded before your current component is stopped, thus limiting the downtime

2. Remove the container images from the artifacts section and perform a `docker pull <img>` in your recipe `Run:` lifecycle. This allows you to leverage the container registry and not have to export the image to S3, but will cause a longer downtime, since your current component will be stopped before the new image gets pulled from the registry.

3. Install docker on the system, and only keep `curl -L https://github.com/ubiquiti/docker-compose-aarch64/releases/download/1.22.0/docker-compose-Linux-aarch64 -o /usr/local/bin/docker-compose && chmod +x /usr/local/bin/docker-compose"` as part of your `docker-compose-dependencies` component.

4. Ensure `docker-compose-dependencies` is deployed to the device before deploying the `docker-compose-yaml` component (or any other component depending on `aws.greengrass.DockerApplication`.

GreenGrass IoT - Deploy docker-compose along with it's dependencies as a different component

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