Opentelemetry instrumentation not working properly with Ruby 2.6.

[dil-anandp]

I have used compatible versions of Opentelemetry instrumentation libraries for my Rails app running with image ruby:2.6.6-alpine3.12.

Gemfile

gem 'opentelemetry-sdk', '> 1.2', '>= 1.2.1'
gem 'opentelemetry-exporter-otlp', '> 0.24.2'
gem 'opentelemetry-instrumentation-all', '~> 0.33.0'

I followed https://opentelemetry.io/docs/instrumentation/ruby/automatic/.

After completing steps and doing docker-compose it is showing an error given below.

bundle/gems/opentelemetry-exporter-otlp-0.24.2/lib/opentelemetry/exporter/otlp/exporter.rb:404:in `parse_headers': headers must be a String with comma-separated URL Encoded UTF-8 k=v pairs or a Hash (ArgumentError)

Is this due to any compatibility issues with Ruby 2.6 and Otel.

[arielvalentin]

Please note that the minimum requirements for OTel Ruby are v3.0+ https://opentelemetry.io/docs/instrumentation/ruby/getting-started/#prerequisites

[arielvalentin]

You're running the jaeger in docker and running your code but then running your app on the host?

Or is your code also running as a container via docker compose?

Network and DNS rules are different if you are making requests from your host (your pc) from containers are talking to each other through docker.

[dil-anandp]

Jaegar and code both are running as containers. Also I verified that they are on same network as well. But still that port is not accessible.

Seeing this error in logs

jaegar-all-in-one | {"level":"info","ts":1705035562.0084112,"caller":"grpc@v1.60.0/resolver_wrapper.go:99","msg":"[core][Channel #5] Closing the name resolver","system":"grpc","grpc_log":true}
jaegar-all-in-one | {"level":"info","ts":1705035562.0086005,"caller":"grpc@v1.60.0/balancer_wrapper.go:178","msg":"[core][Channel #5] ccBalancerWrapper: closing","system":"grpc","grpc_log":true}
jaegar-all-in-one | {"level":"info","ts":1705035562.0086253,"caller":"grpc@v1.60.0/clientconn.go:532","msg":"[core][Channel #5] Channel Connectivity change to IDLE","system":"grpc","grpc_log":true}
jaegar-all-in-one | {"level":"info","ts":1705035562.0086365,"caller":"grpc@v1.60.0/clientconn.go:369","msg":"[core][Channel #5] Channel entering idle mode","system":"grpc","grpc_log":true}
jaegar-all-in-one | {"level":"info","ts":1705035562.0087123,"caller":"grpc/builder.go:131","msg":"Agent collector connection state change","dialTarget":"localhost:14250","status":"IDLE"}
jaegar-all-in-one | {"level":"info","ts":1705035562.0086765,"caller":"grpc@v1.60.0/clientconn.go:1223","msg":"[core][Channel #5 SubChannel #8] Subchannel Connectivity change to SHUTDOWN","system":"grpc","grpc_log":true}
jaegar-all-in-one | {"level":"info","ts":1705035562.0088468,"caller":"grpc@v1.60.0/clientconn.go:872","msg":"[core][Channel #5 SubChannel #8] Subchannel deleted","system":"grpc","grpc_log":true}

jaegar-all-in-one | {"level":"info","ts":1705034683.0680423,"caller":"grpc@v1.60.0/server.go:983","msg":"[core][Server #4] grpc: Server.Serve failed to create ServerTransport: connection error: desc = "transport: http2Server.HandleStreams received bogus greeting from client: \"GET / HTTP/1.1\\r\\nHost: lo\""","system":"grpc","grpc_log":true}

[arielvalentin]

So then the problem is with the jaeger-all-in-one container not accepting connections on 4318 and not a problem with the OTLP Exporter.

Is that correct?

[dil-anandp]

Yes. It looks like that. But I tried with adding directly Jaegar service in docker-compose.yml also.

jaegar-all-in-one:
image: jaegertracing/all-in-one:latest
ports:
- "16686:16686"
- "6831:6831/udp"
- "6832:6832/udp"
- "5778:5778"
- "4317:4317"
- "4318:4318"
- "14250:14250"
- "14268:14268"
- "14269:14269"
- "9411:9411"
environment:
COLLECTOR_ZIPKIN_HTTP_PORT: 9411
COLLECTOR_OTLP_ENABLED: true
container_name: 'jaegar-all-in-one'

Port is not listening it seems.

When tried to access it via the container shell it gives below result.

wget http://host.docker.internal:4318
Connecting to host.docker.internal:4318 (192.168.64.1:4318)
wget: can't connect to remote host (192.168.64.1): Operation timed out

Is there any issues with the http version mismatch?

[arielvalentin]

I think you may want to reach out to the jaeger community for help with this since it's outside of our area of expertise.