exec mixin

Run a command or script.

✅ Learn how to use the exec mixin with our Exec Mixin Best Practice Guide

Source: https://porter.sh/src/pkg/exec

Install or Upgrade

porter mixin install exec

Mixin Syntax

exec:
  description: "Description of the command"
  command: cmd
  arguments:
  - arg1
  - arg2
  flags:
    a: flag-value
    long-flag: true
    repeated-flag:
    - flag-value1
    - flag-value2
  suffix-arguments:
  - suffix-arg1
  suppress-output: false
  outputs:
  - name: NAME
    jsonPath: JSONPATH
  - name: NAME
    regex: GOLANG_REGULAR_EXPRESSION
  - name: NAME
    path: FILEPATH

This is executed as:

$ cmd arg1 arg2 -a flag-value --long-flag true --repeated-flag flag-value1 --repeated-flag flag-value2 suffix-arg1

Suppress Output

The suppress-output field controls whether output from the mixin should be prevented from printing to the console. By default this value is false, using Porter’s default behavior of hiding known sensitive values. When suppress-output: true all output from the mixin (stderr and stdout) are hidden.

Step outputs (below) are still collected when output is suppressed. This allows you to prevent sensitive data from being exposed while still collecting it from a command and using it in your bundle.

Outputs

The mixin supports outputs of various types:

• JSON Path
• Regular Expressions
• File Paths

JSON Path

The jsonPath output treats stdout like a json document and applies the expression, saving the result to the output.

outputs:
- name: NAME
  jsonPath: JSONPATH

For example, if the jsonPath expression was $[*].id and the command sent the following to stdout:

[
  {
    "id": "1085517466897181794",
    "name": "my-vm"
  }
]

Then then output would have the following contents:

["1085517466897181794"]

When you are developing your jsonPath expression, you can specify the –debug flag and the full json document with your query are printed to stderr so that you can troubleshoot and improve your query based on the real result of the mixin’s execution.

Regular Expressions

The regex output applies a Go-syntax regular expression to stdout and saves every capture group, one per line, to the output.

outputs:
- name: NAME
  regex: GOLANG_REGULAR_EXPRESSION

For example, if the regex expression was --- FAIL: (.*) \(.*\) and the command send the following to stdout:

--- FAIL: TestMixin_Install (0.00s)
stuff
things
--- FAIL: TestMixin_Upgrade (0.00s)
more
logs

Then the output would have the following contents:

TestMixin_Install
TestMixin_Upgrade

File Paths

The path output saves the content of the specified file path to an output.

outputs:
- name: kubeconfig
  path: /root/.kube/config

---

Examples

See exec outputs for a full working example.

Run a command

install:
- exec:
    description: "Install Hello World"
    command: make
    arguments:
    - install

Run a script

install:
- exec:
    description: "Install Hello World"
    command: ./install-world.sh

FAQ

How do I use pipes?

If you have a command that pipes, place the command in a script file and then use the exec mixin to invoke that script passing in any parameters that the script requires as arguments.