opentelemetry-cli: human-friendly OpenTelemetry CLI

Provides a CLI for crafting and sending telemetry data over OTLP (OpenTelemetry Line Protocol).

Requirements

Installation

There are several ways of running this CLI.

Docker

docker pull dell/opentelemetry-cli:<version>

You can specify a version like 0.2.0 or use latest to get the most up-to-date version.

Run latest version of the CLI in a container:

# set OTEL_EXPORTER_OTLP_ENDPOINT to your OTel collector instance
export OTEL_EXPORTER_OTLP_ENDPOINT=http://127.0.0.1:4317
docker run --rm -e OTEL_EXPORTER_OTLP_ENDPOINT opentelemetry-cli:latest --help

Replace --help with any otel command, without otel itself.

PyPI

pip install otel-cli

Usage

First, define OTEL_EXPORTER_OTLP_ENDPOINT in your shell and set it to the OTLP collector instance you want to use. For a local collector, set this to http://127.0.0.1:4317 like so:

export OTEL_EXPORTER_OTLP_ENDPOINT=http://127.0.0.1:4317

Spans

To send a span, run:

otel span "span name"

To set a different service name, use the --service flag:

otel span --service "My Service" "span name"

You can also pass custom start and end dates. These should be nanoseconds since the epoch:

SPAN_START_DATE=$(date --date "2 minutes ago" +%s%N)
SPAN_END_DATE=$(date +%s%N)
otel span --start "$SPAN_START_DATE" --end "$SPAN_END_DATE" "span name"

By default, spans are reported with a status of UNKNOWN. To pass a different status, use the --status option:

otel span --status OK "successful span"
otel span --status ERROR "failed span"

To add attributes to spans, use the --attribute|-a option. It accepts attributes in a key=value format. Use multiple instances of this option to send multiple attributes.

otel span -a "my.foo=bar" -a "my.bar=baz" "span name"

otel will create a random trace ID and span ID. You can override those:

otel span --trace-id "4d999706756fd1859345f8dc6d0af218" --span-id "ac2a3b2b19ac602d"

Sending multiple spans in a trace

To create a single trace with one root span and multiple child spans, we first need to generate a trace ID for the entire trace and a span ID for the parent span. Use otel generate to create those:

TRACE_ID=$(otel generate trace_id)
PARENT_SPAN=$(otel generate span_id)

Then, when creating children span, we pass this information in the format of a TRACEPARENT:

TRACEPARENT="00-${TRACE_ID}-${PARENT_SPAN}-01"
otel span --traceparent "$TRACEPARENT" "Child A Name"
otel span --traceparent "$TRACEPARENT" "Child B Name"

Finally, send the parent span using the pre-generated IDs:

otel span --trace-id "$TRACE_ID" --span-id "$PARENT_SPAN" "Parent Span Name"

Metrics

Use otel metric to send metric data. The following metric types are currently supported:

Counter
UpDownCounter

Counter

Counters are metrics that can count only up. By specifying just the counter name, it will be incremented by 1:

otel metric counter my-counter

You can specify a different value to increase by. For example, this will increase the counter by 1024:

otel metric counter total-bytes 1024

Counters support attributes just like spans, using the -a|--attribute option.

otel metric counter my-counter -a "host.name=localhost"

By default, attributes are strings. You can set them to other types by using one of the following prefixes:

int: - value will be converted to an integer.
float: - value will be converted to a floating point number.
bool: - value will be converted to a boolean.
- Values of y, yes, t, true, on, and 1 are converted to True.
- Values of n, no, f, false, off, and 0 are converted to False.
- Values are not case-sensitive.

Example:

otel metric counter my-counter \
    -a "key1=just a string" \
    -a "int:key2=10" \
    -a "float:key3=3.14" \
    -a "bool:key4=YES"

UpDownCounter

UpDownCounters are metrics that count up or down. If not given a value, the UpDownCounter will increment by one:

otel metric updown queue-length

You can specify a different value to increase by. For example, this will increase the counter by 1024:

otel metric updown my-updowncounter 1024

To decrease the counter number, pass a negative number like so:

otel metric updown queue-length -1

Packaging

This project uses poetry to manage dependencies, build, etc.