# Access Node

The [DOME Access-Node](https://github.com/DOME-Marketplace/access-node) is a set of services, that can be used to access the DOME Marketplace. A registered participant can use it to act as a federated marketplace in DOME.

The Access-Nodes consists of 3 logical building blocks:

[![Building Blocks](https://github.com/DOME-Marketplace/integration-guide/raw/main/doc/img/building-blocks.png)](https://github.com/DOME-Marketplace/integration-guide/blob/main/doc/img/building-blocks.png)

The TM-Forum-API Service is a service providing a growing subset of the [TMForum API](https://www.tmforum.org/oda/open-apis/table)'s while using an [NGSI-LD](https://www.etsi.org/deliver/etsi_gs/CIM/001_099/009/01.06.01_60/gs_CIM009v010601p.pdf) context broker as persistence backend and change notificator.

<section aria-label="mermaid rendered output container" class="js-render-needs-enrichment render-needs-enrichment position-relative" data-host="https://viewscreen.githubusercontent.com" data-identity="6be2bc9d-0c03-4d91-8594-4f7fb80a6794" data-src="https://viewscreen.githubusercontent.com/markdown/mermaid?docs_host=https%3A%2F%2Fdocs.github.com" data-type="mermaid" id="bkmrk-%C2%A0">[![image.png](https://knowledgebase.dome-marketplace-dev.org/uploads/images/gallery/2024-05/scaled-1680-/Apximage.png)](https://knowledgebase.dome-marketplace-dev.org/uploads/images/gallery/2024-05/Apximage.png)

</section>TODO: Add description of blockchain connector

#### Overview and sub-components

The TM-Forum-API service is a cluster of individual services providing one specific API each, enabling the participant to only run the necessary subset for its use-case. Apart from offering CRUD operations on the managed entities, the service also enables the subscription to notifications based on given queries.

The services are stateless and support horizontal scaling, but require an external cache to avoid having inconsistent caches. Inconsistent caches can result from either changes due to calls to the API, or due to notifications for changes reported by the underlying persistence. If run in a single instance mode, a local cache is acceptable but for larger setups a [Redis](https://redis.io/) installation is recommended.

For reasons of convenience, the TM-Forum-API service can be deploying with an [Envoy API proxy](https://www.envoyproxy.io/) which provides the individual APIs via a single service, routed based on the path. Another convenient feature is a [RapiDoc](https://rapidocweb.com/) container, that can be deployed with the TM-Forum-API service that provides a Openapi based API documentation for the deployed services, with the functionality of querying the API too.

The requirement for the persistence is to be compliant to the NGSI-LD API v1.6 enabling the use of different available context brokers. The currently recommended Context-Broker for the access node is [Scorpio](https://github.com/ScorpioBroker/ScorpioBroker), mainly due to good cloud integration and overall support. The Scorpio context-broker allows a variety of adjustments to cover the operator's specific needs ( e.g. horizontal scaling utilizing [Kafka](https://kafka.apache.org/)) and uses [Postgresql](https://www.postgresql.org/) as it's persistence layer. The Postgresql is extended with [Postgis](https://postgis.net/) for supporting geospatial data.

#### Infrastructure requirements

The base memory consumption per deployed pod is listed below but is will increase with the amount of traffic, therefor should only be used as a rough estimate.

<table id="bkmrk-service-memory-%28mi%29-"><thead><tr><th>Service</th><th>Memory (Mi)</th></tr></thead><tbody><tr><td>TM-Forum-API Pod</td><td>250</td></tr><tr><td>Scorpio</td><td>400</td></tr><tr><td>Postgresql/Postgis</td><td>150</td></tr><tr><td>Redis</td><td>10</td></tr><tr><td> </td><td> </td></tr><tr><td> </td><td> </td></tr></tbody></table>

Apart from the database service, no other service will maintain a own persistence, therefor only for this service a persistent volume claim has to be dimensioned.

#### How to deploy

The recommended and endorsed way of deployment is via the provided helm charts ( optionally wrapped in ArgoCD Applications).

To deploy a setup, the [umbrella chart](https://helm.sh/docs/howto/charts_tips_and_tricks/#complex-charts-with-many-dependencies) of the access-node can be used as followed:

- create a configuration values file according to the own environment, as described [here](https://github.com/DOME-Marketplace/integration-guide?tab=readme-ov-file#how-to-configure).
- add helm chart repository to helm installation
    
    <div><div class="cm-editor ͼ1 ͼ2 ͼ4 ͼ1p"><div class="cm-scroller" tabindex="-1"><div aria-hidden="true" class="cm-gutters"></div><div aria-multiline="true" aria-readonly="true" autocapitalize="off" autocorrect="off" class="cm-content" contenteditable="true" role="textbox" spellcheck="false" translate="no"><div class="cm-line">helm repo add dome-access-node https://dome-marketplace.github.io/access-node</div><div class="cm-line">helm repo update</div></div></div><button class="cm-copy-button" type="button"><svg height="16" viewbox="0 0 24 24" width="16" xmlns="http://www.w3.org/2000/svg"></svg></button></div></div><div class="snippet-clipboard-content notranslate position-relative overflow-auto"><div class="zeroclipboard-container"><svg aria-hidden="true" class="octicon octicon-copy js-clipboard-copy-icon" data-view-component="true" height="16" version="1.1" viewbox="0 0 16 16" width="16"></svg>  
    </div></div>> ? All releases of the Access-Node reside in the helm-repository [https://dome-marketplace.github.io/access-node](https://dome-marketplace.github.io/access-node). In addition to that, all Pre-Release versions(build from the Pull Requests) are provided in the pre-repo [https://dome-marketplace.github.io/access-node/pre](https://dome-marketplace.github.io/access-node/pre). The pre-repo will be cleaned-up from time to time, in order to keep the index manageable.
- install the components using the prepared configuration
    
    <div><div class="cm-editor ͼ1 ͼ2 ͼ4 ͼ1q"><div class="cm-scroller" tabindex="-1"><div aria-multiline="true" aria-readonly="true" autocapitalize="off" autocorrect="off" class="cm-content" contenteditable="true" role="textbox" spellcheck="false" translate="no"><div class="cm-line">helm install &lt;RELEASE_NAME&gt; dome-access-node/access-node --namespace &lt;NAME_SPACE&gt; --version &lt;CHART_VERSION&gt; -f values.yaml</div></div><div aria-hidden="true" class="cm-layer cm-layer-above cm-cursorLayer">  
    </div></div><button class="cm-copy-button" type="button"><svg height="16" viewbox="0 0 24 24" width="16" xmlns="http://www.w3.org/2000/svg"></svg></button></div></div><div class="snippet-clipboard-content notranslate position-relative overflow-auto"><div class="zeroclipboard-container"><svg aria-hidden="true" class="octicon octicon-copy js-clipboard-copy-icon" data-view-component="true" height="16" version="1.1" viewbox="0 0 16 16" width="16"></svg>  
    </div></div>

#### How to configure

The chart is released with a set of [default values](https://github.com/DOME-Marketplace/access-node/blob/main/charts/access-node/values.yaml) which act as a good starting point for an adoption. These values are also documented, enhancing the understanding. Additionally, the [respective charts](https://github.com/FIWARE/helm-charts/tree/main/charts/tm-forum-api) of the components should be consulted.

<table id="bkmrk-component-chart-tm-f"><thead><tr><th>Component</th><th>Chart</th></tr></thead><tbody><tr><td>TM-Forum-API</td><td>[https://github.com/FIWARE/helm-charts/tree/main/charts/tm-forum-api](https://github.com/FIWARE/helm-charts/tree/main/charts/tm-forum-api)</td></tr><tr><td>blockchain-connector</td><td>[https://github.com/DOME-Marketplace/access-node/tree/main/charts/blockchain-connector](https://github.com/DOME-Marketplace/access-node/tree/main/charts/blockchain-connector)</td></tr><tr><td>broker-adapter</td><td>[https://github.com/DOME-Marketplace/access-node/tree/main/charts/broker-adapter](https://github.com/DOME-Marketplace/access-node/tree/main/charts/broker-adapter)</td></tr><tr><td>dlt-adapter</td><td>[https://github.com/DOME-Marketplace/access-node/tree/main/charts/dlt-adapter](https://github.com/DOME-Marketplace/access-node/tree/main/charts/dlt-adapter)</td></tr><tr><td>kafka</td><td>[https://github.com/bitnami/charts/tree/main/bitnami/kafka](https://github.com/bitnami/charts/tree/main/bitnami/kafka)</td></tr><tr><td>postgresql</td><td>[https://github.com/bitnami/charts/tree/main/bitnami/postgresql](https://github.com/bitnami/charts/tree/main/bitnami/postgresql)</td></tr><tr><td>scorpio-broker-aaio</td><td>[https://github.com/FIWARE/helm-charts/tree/main/charts/scorpio-broker-aaio](https://github.com/FIWARE/helm-charts/tree/main/charts/scorpio-broker-aaio)</td></tr><tr><td>scorpio-broker</td><td>[https://github.com/FIWARE/helm-charts/tree/main/charts/scorpio-broker](https://github.com/FIWARE/helm-charts/tree/main/charts/scorpio-broker)</td></tr></tbody></table>

TODO: Replace with charts [in](https://github.com/in2workspace/helm-charts/tree/main/charts) once they are used.

To have a starting point, the [this](https://github.com/DOME-Marketplace/integration-guide/blob/main/config/accessnode.yaml) minimal config reduces the configuration to items that are likely changed by integrators. TODO: include config for the blockchain components

#### How to validate a deployment

All components are configured with health and readiness checks to validate their own status, therefor being the base for a validation. These checks are utilized in the kubernetes checks as defined in the helm charts. TODO: Include RapiDoc Container for validation and add explanation here

#### How to operate

> - Management/admin APIs.
> - Instrumentation, metrics, logs, alerts

The underlying database service holds the persisted data and therefor requires a backup&amp;recovery mechanism when operated in a production environment. The use of managed database is strongly encouraged for safety and convenience.

The TM-Forum-API service used a json based log output by default, which can be parsed easily by log aggregators but can also be replaced if needed. The verbosity is controlled via [environment variables](https://github.com/FIWARE/helm-charts/blob/05552c4c97a21df68f14e78de80a56e3934e179d/charts/tm-forum-api/templates/deployment.yaml#L165) and can be fine tuned to the operators needs.

TODO: Prometheus Metrics TODO: Grafana Dashboard

#### How to update

Upgrade to both a different chart version and new configuration can be accomplished with the following command

<div id="bkmrk-1-helm-upgrade-%3Crele"><div class="cm-editor ͼ1 ͼ2 ͼ4 ͼ1r"><div class="cm-scroller" tabindex="-1"><div aria-hidden="true" class="cm-gutters"><div class="cm-gutter cm-lineNumbers"><div class="cm-gutterElement"></div></div></div><div aria-multiline="true" aria-readonly="true" autocapitalize="off" autocorrect="off" class="cm-content" contenteditable="true" role="textbox" spellcheck="false" translate="no"><div class="cm-line">helm upgrade &lt;RELEASE_NAME&gt; dome-access-node/access-node --namespace &lt;NAME_SPACE&gt; --version &lt;CHART_VERSION&gt; -f values.yaml</div></div><div aria-hidden="true" class="cm-layer cm-selectionLayer"></div></div><button class="cm-copy-button" type="button"><svg height="16" viewbox="0 0 24 24" width="16" xmlns="http://www.w3.org/2000/svg"></svg></button></div></div><div class="snippet-clipboard-content notranslate position-relative overflow-auto" id="bkmrk--1"><div class="zeroclipboard-container"><svg aria-hidden="true" class="octicon octicon-copy js-clipboard-copy-icon" data-view-component="true" height="16" version="1.1" viewbox="0 0 16 16" width="16"></svg>  
</div></div>#### Release process

Versioning of the main access-node helm chart is handled based on the labels used in the pull requests used to introduce changes and is enforced in the [build pipeline](https://github.com/DOME-Marketplace/access-node/tree/main/.github/workflows). The requester and reviewers must set the label according to the [SemVer 2.0.0](https://semver.org/) versioning scheme.

Versioning of the components and sub-charts is recommended to use the same scheme.

> Versioning, release notes, stability considerations

#### Troubleshooting

> To be filled once feedback from integrators comes in

##### Timeouts occur while querying TM-Forum-API

When encountering timeouts in calls to the TM-Forum-API service it is possible to mitigate the imminent issue by increasing the timeout of the client (called "ngsi") calling the NGSI-LD broker. The necessary [client](https://docs.micronaut.io/latest/guide/configurationreference.html#io.micronaut.http.client.ServiceHttpClientConfiguration) and [server](https://docs.micronaut.io/latest/guide/configurationreference.html#io.micronaut.http.server.HttpServerConfiguration) configuration can be handed in via [additional environment variables](https://github.com/FIWARE/helm-charts/blob/05552c4c97a21df68f14e78de80a56e3934e179d/charts/tm-forum-api/templates/deployment.yaml#L243-L249).