Skill: golang-echo-otel-middleware

Use this skill when adding or configuring github.com/adlandh/echo-otel-middleware/v2 in a Go Echo application, or when writing examples for this middleware.

Essentials

• Import path must include /v2: github.com/adlandh/echo-otel-middleware/v2.
• Alias examples as echootelmiddleware to match the package name and README.
• This middleware targets Echo v5: use github.com/labstack/echo/v5 and handler signatures with *echo.Context.
• Middleware() uses global OpenTelemetry tracer provider and propagator; use MiddlewareWithConfig when the app owns explicit OTel setup.

Basic Usage

app := echo.New()
app.Use(echootelmiddleware.Middleware())

Use explicit config when a tracer provider or propagator is constructed by the application:

app.Use(echootelmiddleware.MiddlewareWithConfig(echootelmiddleware.OtelConfig{
	TracerProvider: tp,
	Propagator:     otel.GetTextMapPropagator(),
}))

Config Defaults

• TracerProvider: otel.GetTracerProvider().
• Propagator: otel.GetTextMapPropagator().
• Skipper: Echo middleware.DefaultSkipper.
• BodySkipper: no-op, returns false, false.
• AreHeadersDump: true.
• IsBodyDump: false.
• RemoveNewLines: false.
• LimitNameSize and LimitValueSize: 0, meaning unlimited.

Safe Body Dumping

• Body dumping is opt-in with IsBodyDump: true because it can capture PII, tokens, and secrets.
• Prefer BodySkipper to exclude sensitive endpoints, compressed bodies, uploads, auth payloads, or large responses.
• BodySkipper only runs when IsBodyDump is true and returns (skipReqBody, skipRespBody).

BodySkipper: func(c *echo.Context) (bool, bool) {
	if c.Request().Header.Get("Content-Encoding") == "gzip" {
		return true, true
	}
	return false, false
},

Attribute Limits

• LimitNameSize and LimitValueSize are byte-based, not rune-based.
• Truncation preserves valid UTF-8; values over a limit greater than 10 get a trailing ....
• RemoveNewLines replaces \n with spaces in string attributes, useful for backends such as Sentry.

Do Not Assume

• Metrics are not implemented in this middleware; do not add or document metrics unless explicitly requested.
• Echo v4 examples are wrong for this package because context types and imports differ.

Source: adlandh/echo-otel-middleware — distributed by TomeVault.