Big-Data-HPC-Platform/dockerfiles

Docker images

Docker images related to HPCC are structured as follows

hpccsystems/platform-build-base

This image contains all the development packages required to build the hpcc platform, but no HPCC code or sources. It changes rarely. The current version is tagged 7.8 and is based on Ubuntu 18.04 base image

hpccsystems/platform-build

Building this image builds an installation package (.deb file) for a specified git tag of the HPCC platform sources. The Dockerfile takes two arguments, naming the version of the platform-build-base image to use, and the git tag to use. Sources are fetched from github. An image will be pushed to Dockerhub for every public tag on the HPCC-Platform repository in GitHub, which developers can use as a base for their own development.

There is a second Dockerfile inplatform-build-incremental that can be used by developers working on a branch that is not yet tagged or merged into upstream, that uses hpccsystems/platform-build as a base in order to avoid the need for full rebuilds each time the image is built.

hpccsystems/plaform-core

This uses the .deb file from a hpccsystems/plaform-build image to install a copy of the full platform code, without specialization to a specific component.

hpccsystems/dali
hpccsystems/roxie
hpccsystems/esp
etc

These are specializations of the platform-core image to run a specific component. Portions of the platform-core that are not needed by this component may be removed. These images are the ones that are referred to in helm scripts etc when launching a cloud cluster.

If launched without further parameters or configuration, a system with default settings can be started, but it will be more normal to apply some configuration at container launch time.

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Helm chart

The Helm chart in hpcc/ can be used to deploy an entire HPCC environment to a K8s cluster.

values.yaml sections

global:

# The global section applies to all components within the HPCC system.

dali: esp: roxie: eclccserver: etc

# Each section will specify a list of one or more components of the specified type
# Within each section, there's a map specifying settings specific to that instance of the component,
# including (at least) name, plus any other required settings (which vary according to component type).

Template structure

There are some helper templates in _util.tpl to assist in generation of the k8s yaml for each component. Many of these are used for standard boilerplate that ends up in every component:

hpcc.utils.addImageAttrs

• adds information about the container image source, version and pull mode hpcc.utils.addConfigVolumeMount hpcc.utils.addConfigVolume
• add information that mount the global and local configuration information into /etc/config using k8s ConfigMap hpcc.utils.generateConfigMap
• generates local and global config files for the above hpcc.utils.configArg
• generates the parameter to pass to the container naming the config file hpcc.utils.daliArg
• generates the parameter to pass to the container naming the dali to connect to

Configuration files

Each component can specify local configuration via config: or configFile: settings - configFile names a file that is copied verbatim into the relevant ConfigMap, while config: allows the config file's contents to be specified inline.

In addition, global config info (same for every component) is generated into a global.json file and made available via ConfigMap mechanism. So far, this only contains

"version": {{ .root.Values.global.image.version | quote }}

but we can add more.

Roxie modes under K8s

When running under K8s, Roxie has 3 fundamental modes of operation:

1. Scalable array of one-way roxie servers

   Set localSlave=true, replicas=initial number of pods

2. Per-channel-scalable array of combined servers/slaves

   localSlave=false, numChannels=nn, replicas=initial number of pods per channel (default 2)

   There will be numChannels*replicas pods in total

3. Scalable array of servers with per-channel-scalable array of slaves

   localSlave=false, numChannels=nn, replicas=pods/channel, serverReplicas=initial number of server pods

   There will be numChannels*replicas slave pods and serverReplicas server pods in total

   This mode is somewhat experimental at present!