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Transitioning to Containerized Services

Red Hat OpenStack Platform 13

A basic guide to working with OpenStack Platform containerized services

OpenStack Documentation Team

Abstract

This guide provides some basic information to help users get accustomed working with OpenStack Platform services running in containers.

Chapter 1. Introduction

Past versions of Red Hat OpenStack Platform used services managed with Systemd. However, more recent version of OpenStack Platform now use containers to run services. Some administrators might not have a good understanding of how containerized OpenStack Platform services operate, and so this guide aims to help you understand OpenStack Platform container images and containerized services. This includes:

  • How to obtain and modify container images
  • How to manage containerized services in the overcloud
  • Understanding how containers differ from Systemd services

The main goal is to help you gain enough knowledge of containerized OpenStack Platform services to transition from a Systemd-based environment to a container-based environment.

1.1. Containerized Services and Kolla

Each of the main Red Hat OpenStack Platform services run in containers. This provides a method of keep each service within its own isolated namespace separated from the host. This means:

  • The deployment of services is performed by pulling container images from the Red Hat Custom Portal and running them.
  • The management functions, like starting and stopping services, operate through the docker command.
  • Upgrading containers require pulling new container images and replacing the existing containers with newer versions.

Red Hat OpenStack Platform uses a set of containers built and managed with the kolla toolset.

Chapter 2. Obtaining and modifying container images

A containerized overcloud requires access to a registry with the required container images. This chapter provides information on how to prepare the registry and your overcloud configuration to use container images for Red Hat OpenStack Platform.

This guide provides several use cases to configure your overcloud to use a registry. Before attempting one of these use cases, it is recommended to familiarize yourself with how to use the image preparation command. See Section 2.2, “Container image preparation command usage” for more information.

2.1. Registry Methods

Red Hat OpenStack Platform supports the following registry types:

Remote Registry
The overcloud pulls container images directly from registry.access.redhat.com. This method is the easiest for generating the initial configuration. However, each overcloud node pulls each image directly from the Red Hat Container Catalog, which can cause network congestion and slower deployment. In addition, all overcloud nodes require internet access to the Red Hat Container Catalog.
Local Registry
The undercloud uses the docker-distribution service to act as a registry. This allows the director to synchronize the images from registry.access.redhat.com and push them to the docker-distribution registry. When creating the overcloud, the overcloud pulls the container images from the undercloud’s docker-distribution registry. This method allows you to store a registry internally, which can speed up the deployment and decrease network congestion. However, the undercloud only acts as a basic registry and provides limited life cycle management for container images.
Note

The docker-distribution service acts separately from docker. docker is used to pull and push images to the docker-distribution registry and does not serve the images to the overcloud. The overcloud pulls the images from the docker-distribution registry.

Satellite Server
Manage the complete application life cycle of your container images and publish them through a Red Hat Satellite 6 server. The overcloud pulls the images from the Satellite server. This method provides an enterprise grade solution to store, manage, and deploy Red Hat OpenStack Platform containers.

Select a method from the list and continue configuring your registry details.

2.2. Container image preparation command usage

This section provides an overview on how to use the openstack overcloud container image prepare command, including conceptual information on the command’s various options.

Generating a Container Image Environment File for the Overcloud

One of the main uses of the openstack overcloud container image prepare command is to create an environment file that contains a list of images the overcloud uses. You include this file with your overcloud deployment commands, such as openstack overcloud deploy. The openstack overcloud container image prepare command uses the following options for this function:

--output-env-file
Defines the resulting environment file name.

The following snippet is an example of this file’s contents:

parameter_defaults:
  DockerAodhApiImage: registry.access.redhat.com/rhosp13/openstack-aodh-api:latest
  DockerAodhConfigImage: registry.access.redhat.com/rhosp13/openstack-aodh-api:latest
...

Generating a Container Image List for Import Methods

If you aim to import the OpenStack Platform container images to a different registry source, you can generate a list of images. The syntax of list is primarily used to import container images to the container registry on the undercloud, but you can modify the format of this list to suit other import methods, such as Red Hat Satellite 6.

The openstack overcloud container image prepare command uses the following options for this function:

--output-images-file
Defines the resulting file name for the import list.

The following is an example of this file’s contents:

container_images:
- imagename: registry.access.redhat.com/rhosp13/openstack-aodh-api:latest
- imagename: registry.access.redhat.com/rhosp13/openstack-aodh-evaluator:latest
...

Setting the Namespace for Container Images

Both the --output-env-file and --output-images-file options require a namespace to generate the resulting image locations. The openstack overcloud container image prepare command uses the following options to set the source location of the container images to pull:

--namespace
Defines the namespace for the container images. This is usually a hostname or IP address with a directory.
--prefix
Defines the prefix to add before the image names.

As a result, the director generates the image names using the following format:

  • [NAMESPACE]/[PREFIX][IMAGE NAME]

Setting Container Image Tags

The openstack overcloud container image prepare command uses the latest tag for each container image by default. However, you can select a specific tag for an image version using one of the following options:

--tag-from-label
Use the value of the specified container image labels to discover the versioned tag for every image.
--tag
Sets the specific tag for all images. All OpenStack Platform container images use the same tag to provide version synchronicity. When using in combination with --tag-from-label, the versioned tag is discovered starting from this tag.

2.3. Container images for additional services

The director only prepares container images for core OpenStack Platform Services. Some additional features use services that require additional container images. You enable these services with environment files. The openstack overcloud container image prepare command uses the following option to include environment files and their respective container images:

-e
Include environment files to enable additional container images.

The following table provides a sample list of additional services that use container images and their respective environment file locations within the /usr/share/openstack-tripleo-heat-templates directory.

ServiceEnvironment File

Ceph Storage

environments/ceph-ansible/ceph-ansible.yaml

Collectd

environments/services-docker/collectd.yaml

Congress

environments/services-docker/congress.yaml

Fluentd

environments/services-docker/fluentd-client.yaml

OpenStack Bare Metal (ironic)

environments/services-docker/ironic.yaml

OpenStack Data Processing (sahara)

environments/services-docker/sahara.yaml

OpenStack EC2-API

environments/services-docker/ec2-api.yaml

OpenStack Key Manager (barbican)

environments/services-docker/barbican.yaml

OpenStack Load Balancing-as-a-Service (octavia)

environments/services-docker/octavia.yaml

OpenStack Shared File System Storage (manila)

environments/services-docker/manila.yaml

Sensu

environments/services-docker/sensu-client.yaml

The next few sections provide examples of including additional services.

Ceph Storage

If deploying a Red Hat Ceph Storage cluster with your overcloud, you need to include the /usr/share/openstack-tripleo-heat-templates/environments/ceph-ansible/ceph-ansible.yaml environment file. This file enables the composable containerized services in your overcloud and the director needs to know these services are enabled to prepare their images.

In addition to this environment file, you also need to define the Ceph Storage container location, which is different from the OpenStack Platform services. Use the --set option to set the following parameters specific to Ceph Storage:

--set ceph_namespace
Defines the namespace for the Ceph Storage container image. This functions similar to the --namespace option.
--set ceph_image
Defines the name of the Ceph Storage container image. Usually,this is rhceph-3-rhel7.
--set ceph_tag
Defines the tag to use for the Ceph Storage container image. This functions similar to the --tag option. When --tag-from-label is specified, the versioned tag is discovered starting from this tag.

The following snippet is an example that includes Ceph Storage in your container image files:

$ openstack overcloud container image prepare \
  ...
  -e /usr/share/openstack-tripleo-heat-templates/environments/ceph-ansible/ceph-ansible.yaml \
  --set ceph_namespace=registry.access.redhat.com/rhceph \
  --set ceph_image=rhceph-3-rhel7 \
  --tag-from-label {version}-{release} \
  ...

OpenStack Bare Metal (ironic)

If deploying OpenStack Bare Metal (ironic) in your overcloud, you need to include the /usr/share/openstack-tripleo-heat-templates/environments/services-docker/ironic.yaml environment file so the director can prepare the images. The following snippet is an example on how to include this environment file:

$ openstack overcloud container image prepare \
  ...
  -e /usr/share/openstack-tripleo-heat-templates/environments/services-docker/ironic.yaml \
  ...

OpenStack Data Processing (sahara)

If deploying OpenStack Data Processing (sahara) in your overcloud, you need to include the /usr/share/openstack-tripleo-heat-templates/environments/services-docker/sahara.yaml environment file so the director can prepare the images. The following snippet is an example on how to include this environment file:

$ openstack overcloud container image prepare \
  ...
  -e /usr/share/openstack-tripleo-heat-templates/environments/services-docker/sahara.yaml \
  ...

2.4. Using the Red Hat registry as a remote registry source

Red Hat hosts the overcloud container images on registry.access.redhat.com. Pulling the images from a remote registry is the simplest method because the registry is already setup and all you require is the URL and namespace of the image you aim to pull. However, during overcloud creation, the overcloud nodes all pull images from the remote repository, which can congest your external connection. If that is a problem, you can either:

  • Setup a local registry
  • Host the images on Red Hat Satellite 6

Procedure

  1. To pull the images directly from registry.access.redhat.com in your overcloud deployment, an environment file is required to specify the image parameters. The following command automatically creates this environment file:

    (undercloud) $ openstack overcloud container image prepare \
      --namespace=registry.access.redhat.com/rhosp13 \
      --prefix=openstack- \
      --tag-from-label {version}-{release} \
      --output-env-file=/home/stack/templates/overcloud_images.yaml
    • Use the -e option to include any environment files for optional services.
    • If using Ceph Storage, include the additional parameters to define the Ceph Storage container image location: --set ceph_namespace, --set ceph_image, --set ceph_tag.
  2. This creates an overcloud_images.yaml environment file, which contains image locations, on the undercloud. You include this file with your deployment.

2.5. Using the undercloud as a local registry

You can configure a local registry on the undercloud to store overcloud container images. This method involves the following:

  • The director pulls each image from the registry.access.redhat.com.
  • The director pushes each images to the docker-distribution registry running on the undercloud.
  • The director creates the overcloud.
  • During the overcloud creation, the nodes pull the relevant images from the undercloud’s docker-distribution registry.

This keeps network traffic for container images within your internal network, which does not congest your external network connection and can speed the deployment process.

Procedure

  1. Find the address of the local undercloud registry. The address will use the following pattern:

    <REGISTRY IP ADDRESS>:8787

    Use the IP address of your undercloud, which you previously set with the local_ip parameter in your undercloud.conf file. For the commands below, the address is assumed to be 192.168.24.1:8787.

  2. Create a template to upload the the images to the local registry, and the environment file to refer to those images:

    (undercloud) $ openstack overcloud container image prepare \
      --namespace=registry.access.redhat.com/rhosp13 \
      --push-destination=192.168.24.1:8787 \
      --prefix=openstack- \
      --tag-from-label {version}-{release} \
      --output-env-file=/home/stack/templates/overcloud_images.yaml \
      --output-images-file /home/stack/local_registry_images.yaml
    • Use the -e option to include any environment files for optional services.
    • If using Ceph Storage, include the additional parameters to define the Ceph Storage container image location: --set ceph_namespace, --set ceph_image, --set ceph_tag.
  3. This creates two files:

    • local_registry_images.yaml, which contains container image information from the remote source. Use this file to pull the images from the Red Hat Container Registry (registry.access.redhat.com) to the undercloud.
    • overcloud_images.yaml, which contains the eventual image locations on the undercloud. You include this file with your deployment.

      Check that both files exist.

  4. Pull the container images from registry.access.redhat.com to the undercloud.

    (undercloud) $ sudo openstack overcloud container image upload \
      --config-file  /home/stack/local_registry_images.yaml \
      --verbose

    Pulling the required images might take some time depending on the speed of your network and your undercloud disk.

    Note

    The container images consume approximately 10 GB of disk space.

  5. The images are now stored on the undercloud’s docker-distribution registry. To view the list of images on the undercloud’s docker-distribution registry using the following command:

    (undercloud) $  curl http://192.0.2.5:8787/v2/_catalog | jq .repositories[]

    To view a list of tags for a specific image, use the skopeo command:

    (undercloud) $ skopeo inspect --tls-verify=false docker://192.0.2.5:8787/rhosp13/openstack-keystone | jq .RepoTags[]

    To verify a tagged image, use the skopeo command:

    (undercloud) $ skopeo inspect --tls-verify=false docker://192.0.2.5:8787/rhosp13/openstack-keystone:13.0-44

The registry configuration is ready.

2.6. Using a Satellite server as a registry

Red Hat Satellite 6 offers registry synchronization capabilities. This provides a method to pull multiple images into a Satellite server and manage them as part of an application life cycle. The Satellite also acts as a registry for other container-enabled systems to use. For more details information on managing container images, see "Managing Container Images" in the Red Hat Satellite 6 Content Management Guide.

The examples in this procedure use the hammer command line tool for Red Hat Satellite 6 and an example organization called ACME. Substitute this organization for your own Satellite 6 organization.

Procedure

  1. Create a template to pull images to the local registry:

    $ source ~/stackrc
    (undercloud) $ openstack overcloud container image prepare \
      --namespace=rhosp13 \
      --prefix=openstack- \
      --output-images-file /home/stack/satellite_images \
    • Use the -e option to include any environment files for optional services.
    • If using Ceph Storage, include the additional parameters to define the Ceph Storage container image location: --set ceph_namespace, --set ceph_image, --set ceph_tag.
    Note

    This version of the openstack overcloud container image prepare command targets the registry on the registry.access.redhat.com to generate an image list. It uses different values than the openstack overcloud container image prepare command used in a later step.

  2. This creates a file called satellite_images with your container image information. You will use this file to synchronize container images to your Satellite 6 server.
  3. Remove the YAML-specific information from the satellite_images file and convert it into a flat file containing only the list of images. The following sed commands accomplish this:

    (undercloud) $ awk -F ':' '{if (NR!=1) {gsub("[[:space:]]", ""); print $2}}' ~/satellite_images > ~/satellite_images_names

    This provides a list of images that you pull into the Satellite server.

  4. Copy the satellite_images_names file to a system that contains the Satellite 6 hammer tool. Alternatively, use the instructions in the Hammer CLI Guide to install the hammer tool to the undercloud.
  5. Run the following hammer command to create a new product (OSP13 Containers) to your Satellite organization:

    $ hammer product create \
      --organization "ACME" \
      --name "OSP13 Containers"

    This custom product will contain our images.

  6. Add the base container image to the product:

    $ hammer repository create \
      --organization "ACME" \
      --product "OSP13 Containers" \
      --content-type docker \
      --url https://registry.access.redhat.com \
      --docker-upstream-name rhosp13/openstack-base \
      --name base
  7. Add the overcloud container images from the satellite_images file.

    $ while read IMAGE; do \
      IMAGENAME=$(echo $IMAGE | cut -d"/" -f2 | sed "s/openstack-//g" | sed "s/:.*//g") ; \
      hammer repository create \
      --organization "ACME" \
      --product "OSP13 Containers" \
      --content-type docker \
      --url https://registry.access.redhat.com \
      --docker-upstream-name $IMAGE \
      --name $IMAGENAME ; done < satellite_images_names
  8. Synchronize the container images:

    $ hammer product synchronize \
      --organization "ACME" \
      --name "OSP13 Containers"

    Wait for the Satellite server to complete synchronization.

    Note

    Depending on your configuration, hammer might ask for your Satellite server username and password. You can configure hammer to automatically login using a configuration file. See the "Authentication" section in the Hammer CLI Guide.

  9. If your Satellite 6 server uses content views, create a new content view version to incorporate the images.
  10. Check the tags available for the base image:

    $ hammer docker tag list --repository "base" \
      --organization "ACME" \
      --product "OSP13 Containers"

    This displays tags for the OpenStack Platform container images.

  11. Return to the undercloud and generate an environment file for the images on your Satellite server. The following is an example command for generating the environment file:

    (undercloud) $ openstack overcloud container image prepare \
      --namespace=satellite6.example.com:5000 \
      --prefix=acme-osp13_containers- \
      --tag-from-label {version}-{release} \
      --output-env-file=/home/stack/templates/overcloud_images.yaml
    Note

    This version of the openstack overcloud container image prepare command targets the Satellite server. It uses different values than the openstack overcloud container image prepare command used in a previous step.

    When running this command, include the following data:

    • --namespace - The URL and port of the registry on the Satellite server. The default registry port on Red Hat Satellite is 5000. For example, --namespace=satellite6.example.com:5000.
    • --prefix= - The prefix is based on a Satellite 6 convention. This differs depending on whether you use content views:

      • If you use content views, the structure is [org]-[environment]-[content view]-[product]-. For example: acme-production-myosp13-osp13_containers-.
      • If you do not use content views, the structure is [org]-[product]-. For example: acme-osp13_containers-.
    • --tag-from-label {version}-{release} - Identifies the latest tag for each image.
    • -e - Include any environment files for optional services.
    • --set ceph_namespace, --set ceph_image, --set ceph_tag - If using Ceph Storage, include the additional parameters to define the Ceph Storage container image location. Note that ceph_image now includes a Satellite-specific prefix. This prefix is the same value as the --prefix option. For example:

      --set ceph_image=acme-osp13_containers-rhceph-3-rhel7

      This ensures the overcloud uses the Ceph container image using the Satellite naming convention.

  12. This creates an overcloud_images.yaml environment file, which contains the image locations on the Satellite server. You include this file with your deployment.

The registry configuration is ready.

2.7. Modifying containers images

Red Hat provides a set of pre-built container images through the Red Hat Container Catalog (registry.access.redhat.com). It is possible to modify these images and add additional layers to them. This is useful for adding RPMs for certified 3rd party drivers to the containers.

Note

To ensure continued support for modified OpenStack Platform container images, ensure that the resulting images comply with the "Red Hat Container Support Policy".

This example shows how to customize the latest openstack-keystone image. However, these instructions can also apply to other images:

Procedure

  1. Pull the image you aim to modify. For example, for the openstack-keystone image:

    $ sudo docker pull registry.access.redhat.com/rhosp12/openstack-keystone:latest
  2. Check the default user on the original image. For example, for the openstack-keystone image:

    $ sudo docker run -it registry.access.redhat.com/rhosp12/openstack-keystone:latest whoami
    root
    Note

    The openstack-keystone image uses root as the default user. Other images use specific users. For example, openstack-glance-api uses glance for the default user.

  3. Create a Dockerfile to build an additional layer on an existing container image. The following is an example that pulls the latest OpenStack Identity (keystone) image from the Container Catalog and installs a custom RPM file to the image:

    FROM registry.access.redhat.com/rhosp12/openstack-keystone
    MAINTAINER Acme
    LABEL name="rhosp12/openstack-keystone-acme" vendor="Acme" version="2.1" release="1"
    
    # switch to root and install a custom RPM, etc.
    USER root
    COPY custom.rpm /tmp
    RUN rpm -ivh /tmp/custom.rpm
    
    # switch the container back to the default user
    USER root
  4. Build and tag the new image. For example, to build with a local Dockerfile stored in the /home/stack/keystone directory and tag it to your undercloud’s local registry:

    $ docker build /home/stack/keystone -t "192.168.24.1:8787/rhosp12/openstack-keystone-acme:rev1"
  5. Push the resulting image to the undercloud’s local registry:

    $ docker push 192.168.24.1:8787/rhosp12/openstack-keystone-acme:rev1
  6. Edit your overcloud container images environment file (usually overcloud_images.yaml) and change the appropriate parameter to use the custom container image.
Warning

The Container Catalog publishes container images with a complete software stack built into it. When the Container Catalog releases a container image with updates and security fixes, your existing custom container will not include these updates and will require rebuilding using the new image version from the Catalog.

Chapter 3. Deploying and updating an overcloud with containers

This chapter provides info on how to create a container-based overcloud and keep it updated.

3.1. Deploying an overcloud

This procedure demonstrates how to deploy an overcloud with minimum configuration. The result will be a basic two-node overcloud (1 Controller node, 1 Compute node).

Procedure

  1. Source the stackrc file:

    $ source ~/stackrc
  2. Run the deploy command and include the file containing your overcloud image locations (usually overcloud_images.yaml):

    (undercloud) $ openstack overcloud deploy --templates \
      -e /home/stack/templates/overcloud_images.yaml \
      --ntp-server pool.ntp.org
  3. Wait until the overcloud completes deployment.

3.2. Updating an overcloud

For information on updating a containerized overcloud, see the Keeping Red Hat OpenStack Platform Updated guide.

Chapter 4. Working with containerized services

This chapter provides some examples of commands to manage containers and how to troubleshoot your OpenStack Platform containers

4.1. Managing containerized services

The overcloud runs most OpenStack Platform services in containers. In certain situations, you might need to control the individual services on a host. This section provides some common docker commands you can run on an overcloud node to manage containerized services. For more comprehensive information on using docker to manage containers, see "Working with Docker formatted containers" in the Getting Started with Containers guide.

Note

Before running these commands, check that you are logged into an overcloud node and not running these commands on the undercloud.

Listing containers and images

To list running containers:

$ sudo docker ps

To also list stopped or failed containers, add the --all option:

$ sudo docker ps --all

To list container images:

$ sudo docker images

Inspecting container properties

To view the properties of a container or container images, use the docker inspect command. For example, to inspect the keystone container:

$ sudo docker inspect keystone

Managing basic container operations

To restart a containerized service, use the docker restart command. For example, to restart the keystone container:

$ sudo docker restart keystone

To stop a containerized service, use the docker stop command. For example, to stop the keystone container:

$ sudo docker stop keystone

To start a stopped containerized service, use the docker start command. For example, to start the keystone container:

$ sudo docker start keystone
Note

Any changes to the service configuration files within the container revert after restarting the container. This is because the container regenerates the service configuration based upon files on the node’s local file system in /var/lib/config-data/puppet-generated/. For example, if you edit /etc/keystone/keystone.conf within the keystone container and restart the container, the container regenerates the configuration using /var/lib/config-data/puppet-generated/keystone/etc/keystone/keystone.conf on the node’s local file system, which overwrites any the changes made within the container before the restart.

Monitoring containers

To check the logs for a containerized service, use the docker logs command. For example, to view the logs for the keystone container:

$ sudo docker logs keystone

Accessing containers

To enter the shell for a containerized service, use the docker exec command to launch /bin/bash. For example, to enter the shell for the keystone container:

$ sudo docker exec -it keystone /bin/bash

To enter the shell for the keystone container as the root user:

$ sudo docker exec --user 0 -it <NAME OR ID> /bin/bash

To exit from the container:

# exit

4.2. Troubleshooting containerized services

If a containerized service fails during or after overcloud deployment, use the following recommendations to determine the root cause for the failure:

Note

Before running these commands, check that you are logged into an overcloud node and not running these commands on the undercloud.

Checking the container logs

Each container retains standard output from its main process. This output acts as a log to help determine what actually occurs during a container run. For example, to view the log for the keystone container, use the following command:

$ sudo docker logs keystone

In most cases, this log provides the cause of a container’s failure.

Inspecting the container

In some situations, you might need to verify information about a container. For example, use the following command to view keystone container data:

$ sudo docker inspect keystone

This provides a JSON object containing low-level configuration data. You can pipe the output to the jq command to parse specific data. For example, to view the container mounts for the keystone container, run the following command:

$ sudo docker inspect keystone | jq .[0].Mounts

You can also use the --format option to parse data to a single line, which is useful for running commands against sets of container data. For example, to recreate the options used to run the keystone container, use the following inspect command with the --format option:

$ sudo docker inspect --format='{{range .Config.Env}} -e "{{.}}" {{end}} {{range .Mounts}} -v {{.Source}}:{{.Destination}}{{if .Mode}}:{{.Mode}}{{end}}{{end}} -ti {{.Config.Image}}' keystone
Note

The --format option uses Go syntax to create queries.

Use these options in conjunction with the docker run command to recreate the container for troubleshooting purposes:

$ OPTIONS=$( sudo docker inspect --format='{{range .Config.Env}} -e "{{.}}" {{end}} {{range .Mounts}} -v {{.Source}}:{{.Destination}}{{if .Mode}}:{{.Mode}}{{end}}{{end}} -ti {{.Config.Image}}' keystone )
$ sudo docker run --rm $OPTIONS /bin/bash

Running commands in the container

In some cases, you might need to obtain information from within a container through a specific Bash command. In this situation, use the following docker command to execute commands within a running container. For example, to run a command in the keystone container:

$ sudo docker exec -ti keystone <COMMAND>
Note

The -ti options run the command through an interactive pseudoterminal.

Replace <COMMAND> with your desired command. For example, each container has a health check script to verify the service connection. You can run the health check script for keystone with the following command:

$ sudo docker exec -ti keystone /openstack/healthcheck

To access the container’s shell, run docker exec using /bin/bash as the command:

$ sudo docker exec -ti keystone /bin/bash

Exporting a container

When a container fails, you might need to investigate the full contents of the file. In this case, you can export the full file system of a container as a tar archive. For example, to export the keystone container’s file system, run the following command:

$ sudo docker export keystone -o keystone.tar

This command create the keystone.tar archive, which you can extract and explore.

Chapter 5. Comparing Systemd services to containerized services

This chapter provides some reference material to show how containerized services differ from Systemd services.

5.1. Systemd service commands vs containerized service commands

The following table shows some similarities between Systemd-based commands and their Docker equivalents. This helps identify the type of service operation you aim to perform.

FunctionSystemd-basedDocker-based

List all services

systemctl list-units -t service

docker ps --all

List active services

systemctl list-units -t service --state active

docker ps

Check status of service

systemctl status openstack-nova-api

docker ps --filter "name=nova_api$" --all

Stop service

systemctl stop openstack-nova-api

docker stop nova_api

Start service

systemctl start openstack-nova-api

docker start nova_api

Restart service

systemctl restart openstack-nova-api

docker restart nova_api

Show service configuration

systemctl show openstack-nova-api

systemctl cat openstack-nova-api

docker inspect nova_api

Show service logs

journalctl -u openstack-nova-api

docker logs nova_api

5.2. Systemd services vs containerized services

The following table shows Systemd-based OpenStack services and their container-based equivalents.

OpenStack serviceSystemd servicesDocker containers

aodh

openstack-aodh-evaluator

openstack-aodh-listener

openstack-aodh-notifier

httpd (openstack-aodh-api)

aodh_listener

aodh_api

aodh_notifier

aodh_evaluator

ceilometer

openstack-ceilometer-central

openstack-ceilometer-collector

openstack-ceilometer-notification

httpd (openstack-ceilometer-api)

ceilometer_agent_notification

ceilometer_agent_central

cinder

openstack-cinder-api

openstack-cinder-scheduler

openstack-cinder-volume

cinder_scheduler

cinder_api

openstack-cinder-volume-docker-0

glance

openstack-glance-api

openstack-glance-registry

glance_api

gnocchi

openstack-gnocchi-metricd

openstack-gnocchi-statsd

httpd (openstack-gnocchi-api)

gnocchi_statsd

gnocchi_api

gnocchi_metricd

heat

openstack-heat-api-cfn

openstack-heat-api-cloudwatch

openstack-heat-api

openstack-heat-engine

heat_api_cfn

heat_engine

heat_api

horizon

httpd (openstack-dashboard)

horizon

keystone

httpd (openstack-keystone)

keystone

neutron

neutron-dhcp-agent

neutron-l3-agent

neutron-metadata-agent

neutron-openvswitch-agent

neutron-server

neutron_ovs_agent

neutron_l3_agent

neutron_metadata_agent

neutron_dhcp

neutron_api

nova

openstack-nova-api

openstack-nova-conductor

openstack-nova-consoleauth

openstack-nova-novncproxy

openstack-nova-scheduler

nova_metadata

nova_api

nova_conductor

nova_vnc_proxy

nova_consoleauth

nova_api_cron

nova_scheduler

nova_placement

panko

 

panko_api

swift

openstack-swift-account-auditor

openstack-swift-account-reaper

openstack-swift-account-replicator

openstack-swift-account

openstack-swift-container-auditor

openstack-swift-container-replicator

openstack-swift-container-updater

openstack-swift-container

openstack-swift-object-auditor

openstack-swift-object-expirer

openstack-swift-object-replicator

openstack-swift-object-updater

openstack-swift-object

openstack-swift-proxy

swift_proxy

swift_account_server

swift_container_auditor

swift_object_expirer

swift_object_updater

swift_container_replicator

swift_account_auditor

swift_object_replicator

swift_container_server

swift_rsync

swift_account_reaper

swift_account_replicator

swift_object_auditor

swift_object_server

swift_container_update

5.3. Systemd log locations vs containerized log locations

The following table shows Systemd-based OpenStack logs and their equivalents for containers. All container-based log locations are available on the physical host and are mounted to the container.

OpenStack serviceSystemd service logsDocker container logs

aodh

/var/log/aodh/

/var/log/containers/aodh/

/var/log/containers/httpd/aodh-api/

ceilometer

/var/log/ceilometer/

/var/log/containers/ceilometer/

cinder

/var/log/cinder/

/var/log/containers/cinder/

/var/log/containers/httpd/cinder-api/

glance

/var/log/glance/

/var/log/containers/glance/

gnocchi

/var/log/gnocchi/

/var/log/containers/gnocchi/

/var/log/containers/httpd/gnocchi-api/

heat

/var/log/heat/

/var/log/containers/heat/

/var/log/containers/httpd/heat-api/

/var/log/containers/httpd/heat-api-cfn/

horizon

/var/log/horizon/

/var/log/containers/horizon/

/var/log/containers/httpd/horizon/

keystone

/var/log/keystone/

/var/log/containers/keystone

/var/log/containers/httpd/keystone/

databases

/var/log/mariadb/

/var/log/mongodb/

/var/log/mysqld.log

/var/log/containers/mysql/

neutron

/var/log/neutron/

/var/log/containers/neutron/

/var/log/containers/httpd/neutron-api/

nova

/var/log/nova/

/var/log/containers/nova/

/var/log/containers/httpd/nova-api/

/var/log/containers/httpd/nova-placement/

panko

 

/var/log/containers/panko/

/var/log/containers/httpd/panko-api/

rabbitmq

/var/log/rabbitmq/

/var/log/containers/rabbitmq/

redis

/var/log/redis/

/var/log/containers/redis/

swift

/var/log/swift/

/var/log/containers/swift/

5.4. Systemd configuration vs containerized configuration

The following table shows Systemd-based OpenStack configuration and their equivalents for containers. All container-based configuration locations are available on the physical host, are mounted to the container, and are merged (via kolla) into the configuration within each respective container.

OpenStack serviceSystemd service configurationDocker container configuration

aodh

/etc/aodh/

/var/lib/config-data/puppet-generated/aodh/

ceilometer

/etc/ceilometer/

/var/lib/config-data/puppet-generated/ceilometer/etc/ceilometer/

cinder

/etc/cinder/

/var/lib/config-data/puppet-generated/cinder/etc/cinder/

glance

/etc/glance/

/var/lib/config-data/puppet-generated/glance_api/etc/glance/

gnocchi

/etc/gnocchi/

/var/lib/config-data/puppet-generated/gnocchi/etc/gnocchi/

haproxy

/etc/haproxy/

/var/lib/config-data/puppet-generated/haproxy/etc/haproxy/

heat

/etc/heat/

/var/lib/config-data/puppet-generated/heat/etc/heat/

/var/lib/config-data/puppet-generated/heat_api/etc/heat/

/var/lib/config-data/puppet-generated/heat_api_cfn/etc/heat/

horizon

/etc/openstack-dashboard/

/var/lib/config-data/puppet-generated/horizon/etc/openstack-dashboard/

keystone

/etc/keystone/

/var/lib/config-data/puppet-generated/keystone/etc/keystone/

databases

/etc/my.cnf.d/

/etc/my.cnf

/var/lib/config-data/puppet-generated/mysql/etc/my.cnf.d/

neutron

/etc/neutron/

/var/lib/config-data/puppet-generated/neutron/etc/neutron/

nova

/etc/nova/

/var/lib/config-data/puppet-generated/nova/etc/nova/

/var/lib/config-data/puppet-generated/nova_placement/etc/nova/

panko

 

/var/lib/config-data/puppet-generated/panko/etc/panko

rabbitmq

/etc/rabbitmq/

/var/lib/config-data/puppet-generated/rabbitmq/etc/rabbitmq/

redis

/etc/redis/

/etc/redis.conf

/var/lib/config-data/puppet-generated/redis/etc/redis/

/var/lib/config-data/puppet-generated/redis/etc/redis.conf

swift

/etc/swift/

/var/lib/config-data/puppet-generated/swift/etc/swift/

/var/lib/config-data/puppet-generated/swift_ringbuilder/etc/swift/

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