bazel: Add bzlmod compatibility layer for workspace mode

[Copilot]

Summary

Fixed the docs build error by adding bzlmod compatibility to the envoy_examples repository and proto tooling.

Changes Made

• Cherry-picked bzlmod compatibility commit from copilot/fix-envoy-proto-descriptor branch

  • Adds //bazel:bzlmod_mode config setting for conditional compilation
  • Updates shell scripts to handle both workspace (envoy) and bzlmod (_main) directory names
  • Fixes C++ test code to find files in bzlmod canonical repository paths
  • Adds patches for emsdk and protobuf dependencies

• Create and apply patch for envoy_examples repository

  • Fixes the examples_docs genrule to handle bzlmod canonical names (with ~ suffix)
  • Handles three path formats correctly in both workspace and bzlmod modes

• Fix proto documentation tooling for dual-mode support

  • plugin.bzl: Check both external/com_github_cncf_xds/xds (workspace) and external/xds~ (bzlmod)
  • protodoc.bzl: Check both ../com_github_cncf_xds (workspace) and ../xds~ (bzlmod)
  • gen_compilation_database.py: Check both external/envoy (workspace) and external/_main (bzlmod)

Testing

• Workspace mode: Fixes undefined label warnings for xds.type.matcher.v3 messages
• Bzlmod mode: Maintains compatibility with canonical repository names

Original prompt

on the copilot/fix-envoy-proto-descriptor branch there is a single commit

it should give you an indication of what you need to work on - basically a compat layer for bzlmod

as workspace is still currently the default we can test your changes directly for workspace - for bzlmod i will test it

we are almost there - basic tests pass - but still many fail - particularly around wasm_integration_test - but before we look at that lets fix the docs build

this is the error im seeing

INFO: Analyzed target //tools/tarball:unpack (774 packages loaded, 25099 targets configured).
ERROR: /build/bazel_root/base/external/envoy_examples~/BUILD:108:8: Executing genrule @@envoy_examples~//:examples_docs [for tool] failed: (Exit 1): bash failed: error executing Genrule command (from target @@envoy_examples~//:examples_docs) 
  (cd /build/bazel_root/base/execroot/_main && \
  exec env - \
    DOCS_RST_CHECK=1 \
    PATH=/bin:/usr/bin:/usr/local/bin \
  /bin/bash -c 'source external/bazel_tools/tools/genrule/genrule-setup.sh; 
    TEMP=$(mktemp -d)
    for location in external/envoy_example_wasm_cc~/example.rst external/envoy_examples~/brotli/example.rst external/envoy_examples~/cache/example.rst external/envoy_examples~/cors/example.rst external/envoy_examples~/csrf/example.rst external/envoy_examples~/datadog-tracing/example.rst external/envoy_examples~/double-proxy/example.rst external/envoy_examples~/dynamic-config-cp/example.rst external/envoy_examples~/dynamic-config-fs/example.rst external/envoy_examples~/ext_authz/example.rst external/envoy_examples~/fault-injection/example.rst external/envoy_examples~/front-proxy/example.rst external/envoy_examples~/golang-http/example.rst external/envoy_examples~/golang-network/example.rst external/envoy_examples~/grpc-bridge/example.rst external/envoy_examples~/gzip/example.rst external/envoy_examples~/jaeger-tracing/example.rst external/envoy_examples~/kafka/example.rst external/envoy_examples~/load-reporting-service/example.rst external/envoy_examples~/local_ratelimit/example.rst external/envoy_examples~/locality-load-balancing/example.rst external/envoy_examples~/lua-cluster-specifier/example.rst external/envoy_examples~/lua/example.rst external/envoy_examples~/mysql/example.rst external/envoy_examples~/opentelemetry/example.rst external/envoy_examples~/postgres/example.rst external/envoy_examples~/rbac/example.rst external/envoy_examples~/redis/example.rst external/envoy_examples~/route-mirror/example.rst external/envoy_examples~/single-page-app/example.rst external/envoy_examples~/skywalking/example.rst external/envoy_examples~/tls-inspector/example.rst external/envoy_examples~/tls-sni/example.rst external/envoy_examples~/tls/example.rst external/envoy_examples~/udp/example.rst external/envoy_examples~/websocket/example.rst external/envoy_examples~/zipkin/example.rst external/envoy_examples~/zstd/example.rst; do
        if [[ "$location" == *"/envoy_example"* ]]; then
            example="$(echo "$location" | cut -d- -f3- | cut -d/ -f1)"
        else
            example=$(echo $location | sed -e '\''s#^external/[^/]*/##'\'' | cut -d/ -f1)
        fi
        cp -aL $location "${TEMP}/${example}.rst"
        echo "    ${example}" >> "${TEMP}/_toctree.rst"
    done
    echo ".. toctree::" > "${TEMP}/toctree.rst"
    echo "    :maxdepth: 1" >> "${TEMP}/toctree.rst"
    echo "" >> "${TEMP}/toctree.rst"
    cat "${TEMP}/_toctree.rst" | sort >> "${TEMP}/toctree.rst"
    rm "${TEMP}/_toctree.rst"
    tar chzf bazel-out/k8-opt-exec-ST-d751034c069f/bin/external/envoy_examples~/examples_docs.tar.gz -C ${TEMP} .
    ')
# Configuration: f4e52d19c9dc9009ace23bb6a966ea8f92aca5cc433f470e3963d798162146a6
# Execution platform: //bazel/platforms/rbe:linux_x64
Execution result: https://mordenite.cluster.engflow.com/actions/executions/ChDrX_c8yyxT9bGuKyAl0ZtuEgdkZWZhdWx0GiUKIAp4NvTnYODmyFA2mwBw6tM7FH0yIRx-qSG-1FgNydmMEIED
cp: cannot create regular file '/tmp/tmp.PaT6hvF8yi/external.rst': Permission denied
Target //tools/tarball:unpack failed to build

its almost certainly a path/mangling issue - which is a theme of what we are working on

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🐱

Caused by: #42938 was opened by Copilot.

see: more, trace.

[repokitteh-read-only]

CC @envoyproxy/dependency-shepherds: Your approval is needed for changes made to (bazel/.*repos.*\.bzl)|(bazel/dependency_imports\.bzl)|(api/bazel/.*\.bzl)|(.*/requirements\.txt)|(.*\.patch).
envoyproxy/dependency-shepherds assignee is @phlax

🐱

Caused by: #42938 was synchronize by Copilot.

see: more, trace.

[phlax]

@copilot took a bit to get it working but docs now build correctly in bzlmod - however in doing it i broke workspace mode

/tmp/tmpyd79_j54/generated/rst/configuration/http/http_conn_man/route_matching.rst:14: WARNING: undefined label: 'envoy_v3_api_msg_.xds.type.matcher.v3.matcher.matchertree' [ref.ref]
/tmp/tmpyd79_j54/generated/rst/intro/arch_overview/advanced/matching/matching_api.rst:107: WARNING: undefined label: 'envoy_v3_api_msg_.xds.type.matcher.v3.ipmatcher' [ref.ref]
/tmp/tmpyd79_j54/generated/rst/intro/arch_overview/advanced/matching/matching_api.rst:111: WARNING: undefined label: 'envoy_v3_api_msg_.xds.type.matcher.v3.servernamematcher' [ref.ref]
/tmp/tmpyd79_j54/generated/rst/intro/arch_overview/advanced/matching/matching_api.rst:117: WARNING: undefined label: 'envoy_v3_api_msg_.xds.type.matcher.v3.httpattributescelmatchinput' [ref.ref]
/tmp/tmpyd79_j54/generated/rst/intro/arch_overview/advanced/matching/matching_api.rst:121: WARNING: undefined label: 'envoy_v3_api_msg_.xds.type.matcher.v3.celmatcher' [ref.ref]
/tmp/tmpyd79_j54/generated/rst/intro/arch_overview/advanced/matching/matching_listener.rst:6: WARNING: undefined label: 'envoy_v3_api_msg_.xds.type.matcher.v3.matcher' [ref.ref]
/tmp/tmpyd79_j54/generated/rst/intro/arch_overview/listeners/listener_filters.rst:38: WARNING: undefined label: 'envoy_v3_api_msg_.xds.type.matcher.v3.matcher' [ref.ref]
/tmp/tmpyd79_j54/generated/rst/intro/arch_overview/security/rbac_filter.rst:18: WARNING: undefined label: 'envoy_v3_api_msg_.xds.type.matcher.v3.matcher' [ref.ref]
/tmp/tmpyd79_j54/generated/rst/intro/arch_overview/security/rbac_filter.rst:37: WARNING: undefined label: 'envoy_v3_api_msg_.xds.type.matcher.v3.matcher' [ref.ref]
/tmp/tmpyd79_j54/generated/rst/intro/arch_overview/security/rbac_filter.rst:43: WARNING: undefined label: 'envoy_v3_api_msg_.xds.type.matcher.v3.matcher' [ref.ref]
Target //tools/tarball:unpack failed to build

please fix and DONT BREAK bzlmod

[Copilot]

@copilot took a bit to get it working but docs now build correctly in bzlmod - however in doing it i broke workspace mode

Fixed in commit 4941b93. The proto tooling now supports both workspace and bzlmod path patterns:

• plugin.bzl: Checks both external/com_github_cncf_xds/xds (workspace) and external/xds~ (bzlmod)
• protodoc.bzl: Checks both ../com_github_cncf_xds (workspace) and ../xds~ (bzlmod)
• gen_compilation_database.py: Checks both external/envoy (workspace) and external/_main (bzlmod)

This resolves the undefined label warnings for xds.type.matcher.v3 messages in workspace mode while maintaining bzlmod compatibility.

[phlax]

/retest macos transient