ETCDCTL_API=2 not working

jocafi commented 4 weeks ago

Name and Version

docker.io/bitnami/etcd:3.5.13

What architecture are you using?

amd64

What steps will reproduce the bug?

To reproduce the error, deploy the docker containers below on any swarm environment:

First, create the network: docker network create --driver overlay net-postgres

services:
  etcd1:
    image: docker.io/bitnami/etcd:3.5.13
    hostname: 'etcd1'
    networks:
      - net-postgres
    environment:
      #https://github.com/bitnami/containers/tree/main/bitnami/etcd
      - ALLOW_NONE_AUTHENTICATION=yes
      - ETCD_NAME=etcd1
      - ETCDCTL_API=2
      - ETCD_INITIAL_ADVERTISE_PEER_URLS=http://etcd1:2380
      - ETCD_LISTEN_PEER_URLS=http://0.0.0.0:2380
      - ETCD_LISTEN_CLIENT_URLS=http://0.0.0.0:2379
      - ETCD_ADVERTISE_CLIENT_URLS=http://etcd1:2379
      - ETCD_INITIAL_CLUSTER_TOKEN=etcd-cluster
      - ETCD_INITIAL_CLUSTER=etcd1=http://etcd1:2380
      - ETCD_INITIAL_CLUSTER_STATE=new
    deploy:
      replicas: 1
      placement:
        constraints:
          - "node.role==manager"

  ## Add the curl service
  # curl http://etcd1:2379/v2/keys/message -XPUT -d value="Hello world"
  curl:
    image: curlimages/curl:latest
    hostname: 'curl'
    command: tail -f /dev/null
    networks:
      - net-postgres

networks:
  net-postgres:
    external: true

Enter into the 'curl' container. For example:

docker exec -it baf4e89159d0 sh

Show the version:

$ curl -L http://etcd1:2379/version
{"etcdserver":"3.5.13","etcdcluster":"3.5.0"}

Try some v2 commands described at https://etcd.io/docs/v2.3/api/ Example:

$ curl http://etcd1:2379/v2/keys/message -XPUT -d value="Hello world"
404 page not found

Here is also another example of how to reproduce the error: https://github.com/zalando/spilo/issues/995

What is the expected behavior?

When using the option ETCDCTL_API=2, the etcd server should be compatible with the v2 API as described at https://hub.docker.com/r/bitnami/etcd and https://etcd.io/docs/v2.3/api/

What do you see instead?

I get HTTP-Status 404: 404 page not found

migruiz4 commented 3 weeks ago

Hi @jocafi,

Several things to consider about your use case:

The env variable ETCDCTL_API is used along with the command etcdctl ( e.g ETCDCTL_API=2 etcdctl ...), but in your case you are using curl.
You are using etcd v3.5.x, which, as mentioned in the upstream CHANGELOG is the latest version supporting V2 API.
Starting etcd v3.4.x, the V2 API is disabled by default. Enabling it requires the env variable ETCD_ENABLE_V2=true (or alternatively the --enable-v2 flag).
The URL you shared corresponds to etcd v2.3 (https://etcd.io/docs/v2.3/api/), make sure the documentation matching your etcd version: https://etcd.io/docs/v3.5/op-guide/configuration/

As mentioned, by adding ETCD_ENABLE_V2=true to the etcd container you should be able to use the /v2 API:

~ $ curl http://etcd1:2379/v2/keys
{"action":"get","node":{"dir":true}}

jocafi commented 2 weeks ago

Many thanks @migruiz4 for the detailed explanation.

I replaced "ETCDCTL_API=2" by "ETCD_ENABLE_V2=true" and it worked. Now I do not get the error "404 page not found".

Please update the documentation at https://hub.docker.com/r/bitnami/etcd

My error comes from the information there. There is not mention about "ETCD_ENABLE_V2" and "ETCDCTL_API" seems no to work.

Feel free to close this ticket. Thanks again!

bitnami / containers