Adding ENV keyword

[pilere]

#322

[dduportal]

@olblak for context, this PR is the result of a "mob programming" session we did the 3 of us (@pilere , @lemeurherve and I). We might have to rework, but it's a first shot on cosntrained time, which is a good start \o/

Thanks @pilere , we'll start the code review as soon as one of us have time :) (but you can already start to fix the issues raised by the automatic linter: https://github.com/updatecli/updatecli/runs/4188685268?check_suite_focus=true TL;DR; you might want to use golangici-lint on your environment and follow its directives)

Output of golangci-lint:

Running [/home/runner/golangci-lint-1.29.0-linux-amd64/golangci-lint run --out-format=github-actions] in [] ...
  level=warning msg="[runner] Can't run linter goanalysis_metalinter: goprintffuncname: failed prerequisites: [inspect@github.com/updatecli/updatecli/pkg/core/engine/condition: analysis skipped: errors in package: [/home/runner/work/updatecli/updatecli/pkg/core/engine/condition/main.go:13:2: could not import github.com/updatecli/updatecli/pkg/plugins/docker/dockerfile (/home/runner/work/updatecli/updatecli/pkg/plugins/docker/dockerfile/main.go:7:2: could not import github.com/updatecli/updatecli/pkg/plugins/docker/dockerfile/simpletextparser (/home/runner/work/updatecli/updatecli/pkg/plugins/docker/dockerfile/simpletextparser/main.go:138:2: duplicate key \"env\" in map literal))]]"
  level=error msg="Running error: goprintffuncname: failed prerequisites: [inspect@github.com/updatecli/updatecli/pkg/core/engine/condition: analysis skipped: errors in package: [/home/runner/work/updatecli/updatecli/pkg/core/engine/condition/main.go:13:2: could not import github.com/updatecli/updatecli/pkg/plugins/docker/dockerfile (/home/runner/work/updatecli/updatecli/pkg/plugins/docker/dockerfile/main.go:7:2: could not import github.com/updatecli/updatecli/pkg/plugins/docker/dockerfile/simpletextparser (/home/runner/work/updatecli/updatecli/pkg/plugins/docker/dockerfile/simpletextparser/main.go:138:2: duplicate key \"env\" in map literal))]]"

[dduportal]

This looks really good, thanks!

I confirm that it work: I've tested your PR with the following example:

---
title: Show a set of dockerfile "coordinates" resources as a generic example
sources:
  ## Dummy source as Dockerfile does not support sources
  lastVersion:
    kind: shell
    spec:
      command: echo 1.2.3
conditions:
  isARGGoVersionExisting:
    # Is the Dockerfile having any ARG instruction with a key "GO_VERSION" and a default value?
    kind: dockerfile
    spec:
      file: Dockerfile
      instruction:
        keyword: ARG
        matcher: 'GO_VERSION='
targets:
  updateFROMJenkinsVersion:
    name: Update all the "FROM jenkins/jenkins*" instructions
    kind: dockerfile
    sourceID: lastVersion
    spec:
      file: Dockerfile
      instruction:
        keyword: FROM
        matcher: "jenkins/jenkins"
  updateArgGoVersion:
    name: Update all the "ARG GO_VERSION*" instructions
    kind: dockerfile
    sourceID: lastVersion
    spec:
      file: Dockerfile
      instruction:
        keyword: ARG
        matcher: GO_VERSION
  updateEnvJavaVersion:
    name: Update all the "ENV JAVA_VERSION*" instructions
    kind: dockerfile
    sourceID: lastVersion
    spec:
      file: Dockerfile
      instruction:
        keyword: ENV
        matcher: JAVA_VERSION

• With the version 0.14.1 of updatecli:

# ...
updateEnvJavaVersion
--------------------

**Dry Run enabled**

ERROR: Something went wrong in target "updateEnvJavaVersion" :
ERROR: ✗ Provided keyword "ENV" not supported (yet). Feel free to open an issue explaining your use-case to help adding the implementation.

• With your PR:

# ...
updateEnvJavaVersion
--------------------

**Dry Run enabled**


🐋 On (Docker)file "Dockerfile":

✔ The line #19, matched by the keyword "ENV" and the matcher "JAVA_VERSION", is changed from "ENV JAVA_VERSION=8" to "ENV JAVA_VERSION=1.2.3".

[dduportal]

• PR rebased against upstream/main, squashed and I've added custom commits with an example and a nitpick
• Doc PR opened: Fix dockerfile resource page + document the new ENV text matcher for dockerfile website#168

Many thanks @pilere !!!