Change the base docker image to ubuntu 20.04 for Beats & Elastic Agent

[nimarezainia]

Describe the enhancement:

Beats and Agent to be aligned with other Elastic products and change the default image to ubuntu 20.04

Describe a specific use case for the enhancement or feature:

[elasticmachine]

Pinging @elastic/elastic-agent-control-plane (Team:Elastic-Agent-Control-Plane)

[dsmello]

Hello, I'll try to close this issue 😄 .

@nimarezainia, What Dockerfile I must change? Those are all Dockerfiles at this project.

./metricbeat/Dockerfile
./metricbeat/module/nginx/_meta/Dockerfile
./metricbeat/module/kibana/_meta/Dockerfile
./metricbeat/module/consul/_meta/Dockerfile
./metricbeat/module/rabbitmq/_meta/Dockerfile
./metricbeat/module/couchbase/_meta/Dockerfile
./metricbeat/module/prometheus/_meta/Dockerfile
./metricbeat/module/apache/_meta/Dockerfile
./metricbeat/module/redis/_meta/Dockerfile
./metricbeat/module/traefik/_meta/Dockerfile
./metricbeat/module/php_fpm/Dockerfile
./metricbeat/module/php_fpm/_meta/Dockerfile
./metricbeat/module/dropwizard/_meta/Dockerfile
./metricbeat/module/munin/_meta/Dockerfile
./metricbeat/module/vsphere/_meta/Dockerfile
./metricbeat/module/postgresql/_meta/Dockerfile
./metricbeat/module/aerospike/_meta/Dockerfile
./metricbeat/module/kafka/_meta/Dockerfile
./metricbeat/module/envoyproxy/_meta/Dockerfile
./metricbeat/module/couchdb/_meta/Dockerfile
./metricbeat/module/openmetrics/_meta/Dockerfile
./metricbeat/module/beat/_meta/Dockerfile
./metricbeat/module/uwsgi/_meta/Dockerfile
./metricbeat/module/zookeeper/_meta/Dockerfile
./metricbeat/module/ceph/_meta/Dockerfile.jewel
./metricbeat/module/ceph/_meta/Dockerfile.nautilus
./metricbeat/module/haproxy/_meta/Dockerfile
./metricbeat/module/etcd/_meta/Dockerfile
./metricbeat/module/jolokia/_meta/Dockerfile
./metricbeat/module/golang/_meta/Dockerfile
./metricbeat/module/logstash/_meta/Dockerfile
./metricbeat/module/elasticsearch/_meta/Dockerfile
./metricbeat/module/mysql/_meta/Dockerfile
./metricbeat/module/mongodb/_meta/Dockerfile
./metricbeat/module/nats/_meta/Dockerfile
./metricbeat/module/http/_meta/Dockerfile
./metricbeat/module/memcached/_meta/Dockerfile
./libbeat/Dockerfile
./testing/environments/Dockerfile
./testing/environments/docker/mosquitto/Dockerfile
./testing/environments/docker/redis/Dockerfile
./testing/environments/docker/kerberos_kdc/Dockerfile
./testing/environments/docker/kafka/Dockerfile
./testing/environments/docker/sredis/Dockerfile
./testing/environments/docker/elasticsearch_kerberos/Dockerfile
./filebeat/input/redis/_meta/Dockerfile
./filebeat/tests/open-file-handlers/Dockerfile-log
./filebeat/tests/open-file-handlers/Dockerfile-filebeat
./filebeat/Dockerfile
./dev-tools/packaging/templates/docker/Dockerfile.elastic-agent.tmpl
./dev-tools/packaging/templates/docker/Dockerfile.tmpl
./x-pack/metricbeat/module/tomcat/_meta/Dockerfile
./x-pack/metricbeat/module/istio/_meta/Dockerfile
./x-pack/metricbeat/module/enterprisesearch/_meta/Dockerfile
./x-pack/metricbeat/module/coredns/_meta/Dockerfile
./x-pack/metricbeat/module/cockroachdb/_meta/Dockerfile
./x-pack/metricbeat/module/oracle/_meta/Dockerfile
./x-pack/metricbeat/module/ibmmq/_meta/Dockerfile
./x-pack/metricbeat/module/redisenterprise/_meta/Dockerfile
./x-pack/metricbeat/module/activemq/_meta/Dockerfile
./x-pack/metricbeat/module/mssql/_meta/Dockerfile
./x-pack/metricbeat/module/stan/_meta/Dockerfile
./x-pack/libbeat/Dockerfile
./x-pack/functionbeat/Dockerfile
./x-pack/filebeat/input/gcppubsub/_meta/Dockerfile
./x-pack/dockerlogbeat/Dockerfile.tmpl
./x-pack/elastic-agent/Dockerfile
./auditbeat/Dockerfile
./heartbeat/tests/docker_support/redis/Dockerfile
./heartbeat/Dockerfile
./packetbeat/Dockerfile

[jlind23]

I would say all of them. @ruflin for confirmation.

[ruflin]

AFAIK the two relevant ones for the build process are

./dev-tools/packaging/templates/docker/Dockerfile.elastic-agent.tmpl
./dev-tools/packaging/templates/docker/Dockerfile.tmpl

I see there are some more .tmpl files which might be relevant to change. @andrewkroh You might be able to chime in on this.

The one in the *beat/ directories are mostly used for testing and depend on Go images. I would not change these. All the Dockerfiles in the modules directory are service specific and should not be changed.

[ruflin]

@jsoriano Pinging you because I think you also touched this in the past.

[jsoriano]

Yes, the changes should be done in these Dockerfile templates, to adapt the commands that install packages to use apt-get instead of yum.

Images used are the ones in the from and buildFrom keys in the packages.yml definition file.

So in principle the files to modify are these ones:

./dev-tools/packaging/templates/docker/Dockerfile.elastic-agent.tmpl
./dev-tools/packaging/templates/docker/Dockerfile.tmpl
./dev-tools/packaging/packages.yml

[dsmello]

Hello all,
I open the PR, If U can review 😸 and give some tips.