examples

Examples

• Examples
  • Printing "Hello World"
  • Executing Conditional Steps
  • Writing to a File
  • Passing Output to Next Step
  • Running a Docker Container
    • Configuring Container Volumes, Environment Variables, and More
    • Running Containers on the Host's Docker Environment
  • Executing Commands over SSH
  • Sending HTTP Requests
  • Querying JSON Data with jq
  • Formatting JSON Data with jq
  • Outputting Raw Values with jq
  • Sending Email Notifications
  • Sending Email
  • Customizing Signal Handling on Stop

Printing "Hello World"

This example demonstrates how to print "hello world" to the log.

name: hello world
steps:
  - name: "hello"
    command: echo hello world
  - name: "done"
    command: echo done!
    depends:
      - "1"

Executing Conditional Steps

This example demonstrates how to execute conditional steps.

params: foo
steps:
  - name: "step1"
    command: echo start
  - name: "foo"
    command: echo foo
    depends:
      - "step1"
    preconditions:
      - condition: "$1"
        expected: foo
  - name: "bar"
    command: echo bar
    depends:
      - "step1"
    preconditions:
      - condition: "$1"
        expected: bar

Writing to a File

This example demonstrates how to write text to a file.

steps:
  - name: write hello to '/tmp/hello.txt'
    command: echo hello
    stdout: /tmp/hello.txt

Passing Output to Next Step

This example demonstrates how to pass output from one step to the next. It will print "hello world" to the log.

steps:
  - name: pass 'hello'
    command: echo hello
    output: OUT1
  - name: output 'hello world'
    command: bash
    script: |
      echo $OUT1 world
    depends:
      - pass 'hello'

Running a Docker Container

This example demonstrates how to run a Docker container.

steps:
  - name: deno_hello_world
    executor: 
      type: docker
      config:
        image: "denoland/deno:1.10.3"
        host:
          autoRemove: true
    command: run https://examples.deno.land/hello-world.ts

Example log output:

You can configure the Docker host with the environment variable DOCKER_HOST.

For example:

env:
  - DOCKER_HOST : "tcp://XXX.XXX.XXX.XXX:2375"
steps:
  - name: deno_hello_world
    executor: 
      type: docker
      config:
        image: "denoland/deno:1.10.3"
        autoRemove: true
    command: run https://examples.deno.land/hello-world.ts

Configuring Container Volumes, Environment Variables, and More

You can config the Docker container (e.g., volumes, env, etc) by passing more detailed options.

For example:

steps:
  - name: deno_hello_world
    executor: 
      type: docker
      config:
        image: "denoland/deno:1.10.3"
        container:
          volumes:
            /app:/app:
          env:
            - FOO=BAR
        host:
          autoRemove: true
    command: run https://examples.deno.land/hello-world.ts

See the Docker's API documentation for all available options.

• For container, see ContainerConfig.
• For host, see HostConfig.

Running Containers on the Host's Docker Environment

If you are running dagu using a container, you need the setup below.

1. Run a socat conainer with the command below.

docker run -v /var/run/docker.sock:/var/run/docker.sock -p 2376:2375 bobrik/socat TCP4-LISTEN:2375,fork,reuseaddr UNIX-CONNECT:/var/run/docker.sock

2. Then you can set the DOCKER_HOST environment as follows.

env:
  - DOCKER_HOST : "tcp://host.docker.internal:2376"
steps:
  - name: deno_hello_world
    executor: 
      type: docker
      config:
        image: "denoland/deno:1.10.3"
        autoRemove: true
    command: run https://examples.deno.land/hello-world.ts

For more details, see this page.

Executing Commands over SSH

steps:
  - name: print ec2 instance id
    executor: 
      type: ssh
      config:
        user: ec2-user
        ip: "XXX.XXX.XXX.XXX"
        key: /Users/XXXXX/.ssh/prod-ec2instance-keypair.pem
        StrictHostKeyChecking: false
    command: ec2-metadata -i

Sending HTTP Requests

steps:
  - name: get fake json data
    executor: http
    command: GET https://jsonplaceholder.typicode.com/comments
    script: |
      {
        "timeout": 10,
        "headers": {},
        "query": {
          "postId": "1"
        },
        "body": ""
      }      

Querying JSON Data with jq

steps:
  - name: run query
    executor: jq
    command: '{(.id): .["10"].b}'
    script: |
      {"id": "sample", "10": {"b": 42}}

log output:

{
    "sample": 42
}

Formatting JSON Data with jq

steps:
  - name: format json
    executor: jq
    script: |
      {"id": "sample", "10": {"b": 42}}

log output:

{
    "10": {
        "b": 42
    },
    "id": "sample"
}

Outputting Raw Values with jq

steps:
  - name: output raw value
    executor:
      type: jq
      config:
        raw: true
    command: '.id'
    script: |
      {"id": "sample", "10": {"b": 42}}

log output:

sample

Sending Email Notifications

steps:
  - name: Sending Email on Finish or Error
    command: echo "hello world"

mailOn:
  failure: true
  success: true

smtp:
  host: "smtp.foo.bar"
  port: "587"
  username: "<username>"
  password: "<password>"
errorMail:
  from: "[email protected]"
  to: "[email protected]"
  prefix: "[Error]"
infoMail:
  from: "[email protected]"
  to: "[email protected]"
  prefix: "[Info]"

Sending Email

smtp:
  host: "smtp.foo.bar"
  port: "587"
  username: "<username>"
  password: "<password>"

steps:
  - name: step1
    executor:
      type: mail
      config:
        to: <to address>
        from: <from address>
        subject: "Urgent Request: Help Me Find My Sanity"
        message: |
          I'm in a bit of a pickle.
          I seem to have lost my sanity somewhere between my third cup of coffee and my fourth Zoom meeting of the day.
          
          If you see it lying around, please let me know.
          Thanks for your help!

          Best,

Customizing Signal Handling on Stop

steps:
  - name: step1
    command: bash
    script: |
      for s in {1..64}; do trap "echo trap $s" $s; done
      sleep 60
    signalOnStop: "SIGINT"

In the above example, the script waits indefinitely for a SIGINT signal, but a custom handler is defined to print a message and exit with code 130 when the signal is received. The signals section is used to configure dagu to send SIGINT signals when the user stops the pipeline.