Web Console local OTLP

Hosted Web Console origin https://cdn.web-ide.platform.salesforce.com POSTs to http://localhost:4318/v1/traces when salesforcedx-vscode-salesforcedx.enableLocalTraces is on (OTLPTraceExporter default in spansWeb.ts). Two independent blocks; LNA first.

Canonical docker overlay: observability README.

1. Chrome Local Network Access

Error: Permission was denied for this request to access the loopback address space.

Chrome 142+ Local Network Access gates public origin → loopback before CORS headers apply.

Web Console often has no extension toolbar and may iframe the CDN origin, so site-settings / CORS extensions fail. Disable the check in a normal Chrome tab, same profile:

1. chrome://flags/#local-network-access-check → Disabled
2. Relaunch Chrome
3. Reload Web Console

Done when: console no longer mentions loopback / address space. Remaining errors are collector CORS.

2. otel-lgtm HTTPS CORS

Image grafana/otel-lgtm allowlists http://* only (v0.33.0 config). HTTPS Salesforce origin does not match.

Overlay file (any path; example ~/.otel-lgtm/otelcol-cors.yaml):

receivers:
  otlp:
    protocols:
      http:
        cors:
          allowed_origins:
            - http://*
            - https://cdn.web-ide.platform.salesforce.com
          allowed_headers:
            - "*"

Restart collector with the overlay (image config paths):

docker run -d --rm --name otel-lgtm \
  -p 3000:3000 -p 4317:4317 -p 4318:4318 \
  -v "$HOME/.otel-lgtm/otelcol-cors.yaml:/otel-lgtm/otelcol-cors.yaml:ro" \
  -e OTELCOL_EXTRA_ARGS='--config=file:/otel-lgtm/otelcol-cors.yaml' \
  docker.io/grafana/otel-lgtm

Done when:

curl -si -X OPTIONS http://localhost:4318/v1/traces \
  -H 'Origin: https://cdn.web-ide.platform.salesforce.com' \
  -H 'Access-Control-Request-Method: POST' \
  -H 'Access-Control-Request-Headers: content-type'

returns access-control-allow-origin: https://cdn.web-ide.platform.salesforce.com.

Plain ["*"] origin is rejected when credentials are on (collector HTTP CORS).

3. Enable the setting

Web Console Settings → salesforcedx-vscode-salesforcedx.enableLocalTraces = true. Reload. Grafana: http://localhost:3000 (admin/admin).

File traces (enableFileTraces → ~/.sf/vscode-spans/) are a different sink — see span-file-export. Hosted Web Console cannot write that dir; use this OTLP path.