fix(pi): docker image mcp env passthrough instead of literal expansion

[ricardoraposo]

Summary

Fixes docker-image MCP generation in the pi extension (buildPiMcpEntry, used by mcp-wiring.ts to write .pi/mcp.json).

The image branch always emitted every env var inline as -e KEY=value, so a reference like ${SIGNOZ_URL} was baked into the docker args literally. Docker never shell-expands its own args, so the container received the literal string ${SIGNOZ_URL} instead of the real value.

Change

New helper buildDockerEnvArgs splits env vars into two cases:

• Pure variable references (${VAR}) → emitted as bare -e VAR (docker passthrough) and collected into an env block so pi resolves the value into the docker process, which docker then forwards to the container.
• Literal values (e.g. LOG_LEVEL=info) → stay inline as -e KEY=value.

Only buildPiMcpEntry was touched. The Cursor / Kiro / Claude Code / OpenCode builders were intentionally left unchanged.

Before

{
  "command": "docker",
  "args": ["run","-i","--rm","-e","SIGNOZ_URL=${SIGNOZ_URL}","-e","SIGNOZ_API_KEY=${SIGNOZ_API_KEY}","-e","LOG_LEVEL=info","signoz/signoz-mcp-server:latest"]
}

After

{
  "command": "docker",
  "args": ["run","-i","--rm","-e","SIGNOZ_URL","-e","SIGNOZ_API_KEY","-e","LOG_LEVEL=info","signoz/signoz-mcp-server:latest"],
  "env": { "SIGNOZ_URL": "${SIGNOZ_URL}", "SIGNOZ_API_KEY": "${SIGNOZ_API_KEY}" }
}

Tested

• pnpm build and pnpm lint pass in packages/core.
• Verified generated output against the signoz MCP config matches the expected shape.

Bumps @arvoretech/hub-core to 0.26.1.

Summary by CodeRabbit

• Bug Fixes

  • Improved handling of Docker-based environment settings so variable references are passed through more reliably.
  • Updated container launches to better preserve existing environment values when they are referenced indirectly.

• Chores

  • Bumped the core package version to 0.26.1.

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[coderabbitai]

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Review failed

The pull request is closed.

ℹ️ Recent review info

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Configuration used: defaults

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Run ID: 244d6126-fd08-4a30-85d2-049b043c7b9d

📥 Commits

Reviewing files that changed from the base of the PR and between bcbe29a and 7459d87.

📒 Files selected for processing (2)

• packages/core/package.json
• packages/core/src/prompt-builders.ts

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---

📝 Walkthrough

Walkthrough

Adds an internal buildDockerEnvArgs helper in the core package's prompt builders that converts env maps into Docker -e CLI arguments, treating ${...}-style placeholder values specially by passing only the key and collecting the value into a passthroughEnv object. buildPiMcpEntry now uses this helper and conditionally attaches env. The core package version was bumped from 0.26.0 to 0.26.1.

Changes

Docker Env Passthrough

Layer / File(s)	Summary
Docker env args helper and integration packages/core/src/prompt-builders.ts	New buildDockerEnvArgs helper builds -e CLI arguments and detects ${word}-only placeholder values, routing them into a passthroughEnv map; buildPiMcpEntry's Docker branch now uses this helper and conditionally includes env in the returned config.
Package version bump packages/core/package.json	Version bumped from 0.26.0 to 0.26.1.

Estimated code review effort: 2 (Simple) | ~10 minutes

Sequence Diagram(s)

sequenceDiagram
  participant buildPiMcpEntry
  participant buildDockerEnvArgs
  participant DockerConfig

  buildPiMcpEntry->>buildDockerEnvArgs: pass env map
  buildDockerEnvArgs->>buildDockerEnvArgs: detect ${...} placeholder values
  buildDockerEnvArgs-->>buildPiMcpEntry: return args and passthroughEnv
  buildPiMcpEntry->>DockerConfig: attach args
  buildPiMcpEntry->>DockerConfig: attach env when passthroughEnv present

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✨ Finishing Touches

📝 Generate docstrings

• Create stacked PR
• Commit on current branch

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch ricardo-/-fix-pi-docker-mcp-env-passthrough

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