CONCOURSE RESOURCE TEMPLATE

Can be used as a template for developing a concourse resource.

Table of Contents

• OVERVIEW
  • CHECK
  • IN
  • OUT
• BUILD AND PUSH THE RESOURCE
• TEST THIS RESOURCE

Documentation and Reference

• concourse-resource-template docker image on DockerHub
• This repos github webpage built with concourse

OVERVIEW

A concourse resource is a docker image.

It requires 3 kinds of scripts or executables,

• check - Detecting new versions of the STUFF (e.g. git version)
• in - GET STUFF
• out - PUT STUFF

You build your resource with a Dockerfile by using the concourse docker base image and adding your scripts/executables to /opt/resource.

The three scripts/executables can be written with bash, go, etc.

• My go is build is located in /build-resource-using-go (In development)
• My bash build is located in /build-resource-using-bash

---

CHECK

check is performed before anything can use the resource. It is used to determine if the STUFF has changed (checks version of STUFF).

PART 1 - Input

Concourse will send stdin for check to parse, where the source and comes from the pipeline and the version comes from the check.

{
  "source": {
    "source1": "source1 info",
    "source2": "source2 info",
    "source3": "source3 info"
  },
  "version": {
    "ref": "null"
  }
}

PART 2 - Check/Update Version

In this example, I will mimic a getting a new version and increment until version 5.

PART 3 - Output

Check will send stdout that will be used in the next step in the pipeline.

[
  {
    "ref": "1"
  }
]

---

IN

The in is performed after a check has confirmed there is something there. For my resource, in will mimic fetching STUFF and place a file in the working directory.

PART 1 - Input

Concourse will send stdin for in to parse, where the source and params come from the pipeline and the version comes from the check.

{
  "params": {
    "param1": "get param1",
    "param2": "get param2",
    "param3": "get param3"
  },
  "source": {
    "source1": "source1 info",
    "source2": "source2 info",
    "source3": "source3 info"
  },
  "version": {
    "ref": "1"
  }
}

PART 2 - GET Something

In this example, I will mimic a fetch some STUFF and place a file get_fetch.json in the working directory.

PART 3 - Output

Input will send stdout that will be used in the next step in the pipeline.

{
  "version": {
    "ref": "1"
  },
  "metadata": [
    { "name": "author", "value": "Jeff DeCola"},
    { "name": "author_date", "value": "March 2023"},
    { "name": "executable", "value": "in"},
    { "name": "version", "value": "1" }
  ]
}

---

OUT

The out will mimic updating STUFF and is performed after the task.

PART 1 - Input

Concourse will send stdin for out to parse, where the source and params come from the pipeline.

{
  "params": {
    "param1": "put param1",
    "param2": "put param2",
    "param3": "put param3"
  },
  "source": {
    "source1": "source1 info",
    "source2": "source2 info",
    "source3": "source3 info"
  }
}

PART 2 - PUT Something

In this example, I will mimic a push/deploy to STUFF and place a file put_fetch.json in the working directory.

It is important you must recheck version here. So you must get the version.

PART 3 - Output

You send stdout that will be used in the next step in the pipeline.

{
  "version": {
    "ref": "1"
  },
  "metadata": [
    { "name": "author", "value": "Addie DeCola"},
    { "name": "author_date", "value": "April 2021"},
    { "name": "executable", "value": "out"},
    { "name": "version", "value": "1" }
  ]
}

BUILD AND PUSH THE RESOURCE

I am using bash shell scripts to build the resource docker image. Using go is still in development.

To build.sh using the Dockerfile,

cd build-resource-using-bash/build
sh build-resource.sh

Note how a concourse base image is used to build the resource.

To push.sh the resource docker image to dockerhub,

cd build-resource-using-bash/push
sh push.sh

You can check this docker image,

docker images jeffdecola/concourse-resource-template
docker run --name concourse-resource-template -dit jeffdecola/concourse-resource-template
docker exec -i -t concourse-resource-template /bin/bash
cd /opt/resource
tree
docker logs concourse-resource-template
docker rm -f concourse-resource-template

TEST THIS RESOURCE

Now we can test the resource in a concourse pipeline.

To set-pipeline.sh for concourse,

cd test-this-resource
sh set-pipeline.sh.

Where the pipeline.yml,

#------------------------------------------------------------------------------------------
jobs:

#**********************************************
- name: job-test-concourse-resource-template
#**********************************************
  plan:

    # GET REPO FROM GITHUB
    - get: concourse-resource-template
      trigger: true

    # CONCOURSE RESOURCE TEMPLATE
    - get: concourse-resource-template-test
      params:
        param1: "get param1"
        param2: "get param2"
        param3: "get param3"

    # RUN TASK IN REPO USING ALPINE DOCKER IMAGE
    - task: task-test-concourse-resource-template
      file: concourse-resource-template/test-this-resource/tasks/task-test-concourse-resource-template.yml

      # TASK SUCCESS
      on_success:
        do:
          # CONCOURSE RESOURCE TEMPLATE
          - put: concourse-resource-template-test
            params:
              param1: "put param1"
              param2: "put param2"
              param3: "put param3"

#------------------------------------------------------------------------------------------
resource_types:

  - name: jeffs-resource
    type: docker-image
    source:
      repository: jeffdecola/concourse-resource-template
      tag: latest

#------------------------------------------------------------------------------------------
resources:

  - name: concourse-resource-template
    type: git
    icon: github
    source:
      uri: git@github.com:jeffdecola/concourse-resource-template.git
      branch: master
      private_key: ((git_private_key))

  - name: concourse-resource-template-test
    type: jeffs-resource
    source:
      source1: "source1 info"
      source2: "source2 info"
      source3: "source3 info"

Note: You will need to put your ((git_private_key)) in a .credentials file in the root of this repo.