$ in command is to aggressively replaced with $()

[mihaichitic]

Expected Behavior

it should translate to:

spec:
      containers:
        - args:
            - /bin/sh
            - -c
            - |
              echo '$$variable'
              echo $${VAR:+--flag "$$VAR"}
          env:
            - name: VAR
              value: flagValue
            - name: variable
              value: 'should not be interpolated'
          image: alpine
          name: app

which results in kubernetes the following output:

$variable
--flag flagValue

Actual Behavior

it translates to

spec:
      containers:
        - args:
            - /bin/sh
            - -c
            - |
              echo '$()$(variable)'
              echo $()$(){VAR:+--flag "$()$(VAR)"}
          env:
            - name: VAR
              value: flagValue
            - name: variable
              value: 'should not be interpolated'
          image: alpine
          name: app

which in kubernetes will result the following output

$()should not be interpolated
{VAR:+--flag flagValue}

Steps To Reproduce

No response

Kompose Version

1.28

Docker-Compose file

services:
  app:
    image: alpine
    command:
        - /bin/sh
        - -c
        - |
          echo '$$variable'
          echo $${VAR:+--flag "$$VAR"}
    environment:
        variable: 'should not be interpolated'
        VAR: 'flagValue'

Anything else?

No response

[SBD580]

Also, seems like underscores are not treated property: $A_B -> $(A)_B

[sfdumi]

I'm not sure escaping variables for bash is the best way to handle the initial issue presented here: https://github.com/kubernetes/kompose/issues/1497

One of the many possible counter-examples is to use a script / config file from command args, in a language other than bash/sh.

In this case, the code to be executed (PHP, but it can be any language) must remain unchanged.

services:
  php:
    image: php:8-cli
    command:
      - -r
      - |
       var_dump($$_ENV['FILE']);
       $$file = $$_ENV['FILE'];
       echo file_get_contents($$_ENV['FILE']);
       echo file_get_contents($$file);
    environment:
      FILE: /usr/local/bin/docker-php-entrypoint

However, I get the initial simple case that led to this change, it is fairly common.

If escaping must remain in place, at least the regex should be changed to allow more complex cases:

• to include underscores (as @SBD580 pointed out), and also
• curly branches and handle more complex expressions, as the one already provided by @mihaichitic .

I think it should be somewhere along the lines of \$(\{?([a-zA-Z0-9_]+)(:[+-]?[^}]*)?\}?).

• \$(\{? matches a dollar sign followed by an optional opening brace.
• ([a-zA-Z0-9_]+) matches one or more alphanumeric characters or underscores. This is the variable name.
• (:[+-]?[^}]*)? matches an optional colon, followed by an optional plus or minus sign, followed by any number of characters that are not a closing brace. This is the optional modifier and value in expressions like ${VAR:+--flag "$VAR”}.
• \}?) matches an optional closing brace.

I will try to open a PR in the coming period, as soon as I can test the changes.

[AhmedGrati]

@sfdumi I can assign it to you if you want to open a PR for this issue.

[sfdumi]

Sure.

[AhmedGrati]

/assign sfdumi

[k8s-triage-robot]

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/lifecycle stale

[k8s-triage-robot]

The Kubernetes project currently lacks enough active contributors to adequately respond to all issues.

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/lifecycle rotten

[k8s-triage-robot]

The Kubernetes project currently lacks enough active contributors to adequately respond to all issues and PRs.

This bot triages issues according to the following rules:

• After 90d of inactivity, lifecycle/stale is applied
• After 30d of inactivity since lifecycle/stale was applied, lifecycle/rotten is applied
• After 30d of inactivity since lifecycle/rotten was applied, the issue is closed

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/close not-planned

[k8s-ci-robot]

@k8s-triage-robot: Closing this issue, marking it as "Not Planned".

In response to this:

The Kubernetes project currently lacks enough active contributors to adequately respond to all issues and PRs.

This bot triages issues according to the following rules:

• After 90d of inactivity, lifecycle/stale is applied
• After 30d of inactivity since lifecycle/stale was applied, lifecycle/rotten is applied
• After 30d of inactivity since lifecycle/rotten was applied, the issue is closed

You can:

• Reopen this issue with /reopen
• Mark this issue as fresh with /remove-lifecycle rotten
• Offer to help out with Issue Triage

Please send feedback to sig-contributor-experience at kubernetes/community.

/close not-planned

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[fresh2dev]

The docker-compose CLI offers this flag:

--no-interpolate          Don't interpolate environment variables

The user could work around this issue if kompose offered the same.

[k8s-triage-robot]

The Kubernetes project currently lacks enough active contributors to adequately respond to all issues and PRs.

This bot triages issues according to the following rules:

• After 90d of inactivity, lifecycle/stale is applied
• After 30d of inactivity since lifecycle/stale was applied, lifecycle/rotten is applied
• After 30d of inactivity since lifecycle/rotten was applied, the issue is closed

You can:

• Reopen this issue with /reopen
• Mark this issue as fresh with /remove-lifecycle rotten
• Offer to help out with Issue Triage

Please send feedback to sig-contributor-experience at kubernetes/community.

/close not-planned

[k8s-ci-robot]

@k8s-triage-robot: Closing this issue, marking it as "Not Planned".

In response to this:

The Kubernetes project currently lacks enough active contributors to adequately respond to all issues and PRs.

This bot triages issues according to the following rules:

• After 90d of inactivity, lifecycle/stale is applied
• After 30d of inactivity since lifecycle/stale was applied, lifecycle/rotten is applied
• After 30d of inactivity since lifecycle/rotten was applied, the issue is closed

You can:

• Reopen this issue with /reopen
• Mark this issue as fresh with /remove-lifecycle rotten
• Offer to help out with Issue Triage

Please send feedback to sig-contributor-experience at kubernetes/community.

/close not-planned

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