Add entrypoint and mounts fields to MCP server configs (breaking change)

[Copilot]

The MCP gateway spec had two bugs: missing optional entrypoint field for container entrypoint overrides, and mounts configured at gateway level instead of per-server.

Changes

Schema & Types

• Added entrypoint (string) and mounts (array) fields to BaseMCPServerConfig
• Updated mcp_config_schema.json with new field definitions and validation patterns
• Removed mounts field from MCPGatewayRuntimeConfig (breaking change)

Parsing & Transformation

• Enhanced parser.ParseMCPConfig and workflow.ParseMCPConfigFromMap to parse new fields
• Transform entrypoint → docker run --entrypoint <value>
• Transform mounts → docker run -v <source>:<dest>:<mode> (sorted for deterministic output)
• Removed all gateway-level mounts extraction, validation, and docker command generation

Breaking Change

• Gateway-level mounts configuration is no longer supported
• Users must migrate to per-server mounts configuration
• Migration: Move sandbox.mcp.mounts to tools.<server-name>.mounts

Example

tools:
  custom-mcp:
    container: ghcr.io/org/server:latest
    entrypoint: /custom/entrypoint.sh
    entrypointArgs: ["--config", "/app/config.json"]
    mounts:
      - "/host/data:/data:ro"
      - "/host/cache:/cache:rw"

Generates: docker run --rm -i -v /host/cache:/cache:rw -v /host/data:/data:ro --entrypoint /custom/entrypoint.sh ghcr.io/org/server:latest --config /app/config.json

Original prompt

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This section details on the original issue you should resolve

<issue_title>Bug in mcp gateway spec</issue_title>
<issue_description>The current mcp gateway spec has two bugs

• while mcp servers can be configured with "entrypointArgs" it needs an optional "entrypoint" option too
• the "mounts" option should not be part of the "gateway" object, but should be an option for individual mcp server configurations under "mcpServers"</issue_description>

<agent_instructions>Please update the spec and make sure that all tests reflect the changes.</agent_instructions>

Comments on the Issue (you are @copilot in this section)

• Fixes Bug in mcp gateway spec #9404

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[pelikhan]

@copilot do not care about backward compatibility. Match the spec as it is.

Remove deprecated Gateway-level mounts marked deprecated

[Copilot]

@copilot do not care about backward compatibility. Match the spec as it is.

Remove deprecated Gateway-level mounts marked deprecated

Removed all backward compatibility for gateway-level mounts. The mounts field has been completely removed from the gateway configuration and is now only supported on individual MCP server configurations.

Changes in commit 1460127:

• Removed Mounts field from MCPGatewayRuntimeConfig
• Removed gateway mounts extraction, validation, and docker command generation
• Deleted tests for deprecated feature
• Updated schema and documentation to match the spec

The example file now demonstrates per-server mounts configuration instead of gateway-level mounts.