Introduction ============ Workflow Designer is a [pluggable SDC designer](https://wiki.onap.org/display/DW/Generic+Designer+Support) that allows a user to design a workflow, save it, and attach it to a SDC service as an artifact. Workflow Designer also manages the definitions of activities, which can be later used as parts of the designed workflows. Components ========== The designer is comprised of the following deployment units: - Designer backend is the core component. It exposes RESTful APIs for managing workflow and activity data. The backend is agnostic to the type of a workflow artifact — its main concerns are workflow inputs and outputs, and metadata. One of the APIs enables to attach a certified workflow artifact to a SDC service, therefore the designer must be able to call an API on SDC. In order to do so, the location of a SDC server, and [SDC consumer](https://wiki.onap.org/display/DW/Consumer+creation) credentials are required. - Designer frontend serves static content of a Web application for creating and managing workflows, and forwards API requests to the backend. The static content includes JavaScript, images, CSS, etc. A major part of the Web application is Workflow Composition View — a graphical interface for arranging a workflow sequence. The Web application also produces a workflow artifact that will be sent to the backend, saved along with other data, and later used by a service. The architecture allows for different implementations of the frontend component. For example, a different technology can be used for the Composition View, which will probably also result in a different type of the artifacts (e.g. Bpmn.io vs. Camunda). - Cassandra database is used by the designer backend as the main storage for workflow data. A dedicated instance of Cassandra can be deployed, or an existing cluster may be used. - Database initialization scripts run once per deployment to create the necessary Cassandra keyspaces and tables, pre-populate data, etc. Deployment on Docker ==================== The procedure below describes manual deployment on plain Docker for development or a demo. ## 1. Database Create a dedicated instance of Cassandra. This step is optional if you already have a Cassandra cluster. The designer is not expected to have problems working with Cassandra 3.x, but has been tested with 2.1.x because this is the version used by SDC. An easy way to spin up a Cassandra instance is using a Cassandra Docker image as described in the [official documentation](https://hub.docker.com/_/cassandra/). ### Example `docker run -d --name workflow-cassandra cassandra:2.1` ## 2. Database Initialization **WARNING**: *This step must be executed only once.* `docker run -ti -e CS_HOST= -e CS_PORT= -e CS_AUTHENTICATE=true/false -e CS_USER= -e CS_PASSWORD= nexus3.onap.org:10001/onap/workflow-init:latest` ### Environment Variables - CS_HOST — Cassandra hostname or IP address. - CS_PORT — Cassandra Thrift client port. If not specified, the default of 9160 will be used. - CS_AUTHENTICATE — whether password authentication must be used to connect to Cassandra. A *false* will be assumed if this variable is not specified. - CS_USER — Cassandra username if CS_AUTHENTICATE is *true*. - CS_PASSWORD — Cassandra password if CS_AUTHENTICATE is *true*. ### Example Assuming you have created a dedicated Cassandra container as described in Database section, and the access to it is not protected with a password, the following command will initialize the database: `docker run -d --name workflow-init -e CS_HOST=$(docker inspect workflow-cassandra --format={{.NetworkSettings.IPAddress}}) nexus3.onap.org:10001/onap/workflow-init:latest` ### Troubleshooting In order to see if the Workflow Designer was successfully initialized, make sure the console does not contain error messages. You can also see the logs of the initialization container using `docker logs workflow-init` command. ## 3. Backend `docker run -d -e SDC_PROTOCL=http/https -e SDC_ENDPOINT=: -e SDC_USER= -e SDC_PASSWORD= -e CS_HOSTS= -e CS_PORT= -e CS_AUTHENTICATE=true/false -e CS_USER= -e CS_PASSWORD= -e JAVA_OPTIONS= nexus3.onap.org:10001/onap/workflow-backend:latest` ### Environment Variables - SDC_PROTOCOL — protocol to be used for calling SDC APIs (http or https). - SDC_ENDPOINT — the base path of SDC external API, in the format `host:port`, where *host* is a SDC backend server, and *port* is usually 8080. - SDC_USER — Workflow consumer username - SDC_PASSWORD — Workflow consumer password - CS_HOSTS — comma-separated list of Cassandra hostnames or IP addresses. - CS_PORT — CQL native client port. If not specified, the default of 9042 will be used. - CS_AUTHENTICATE — whether password authentication must be used to connect to Cassandra. A *false* will be assumed if this variable is not specified. - CS_USER — Cassandra username if CS_AUTHENTICATE is *true*. - CS_PASSWORD — Cassandra password if CS_AUTHENTICATE is *true*. - JAVA_OPTIONS — optionally, JVM (Java Virtual Machine) arguments. ### Example Assuming you have a dedicated Cassandra container as described in Database section, and the access to it is not protected with a password. The following command will start a backend container: `docker run -d --name workflow-backend -e SDC_PROTOCOL=http -e SDC_ENDPOINT=$(docker inspect sdc-BE --format={{.NetworkSettings.IPAddress}}):8080 -e CS_HOSTS=$(docker inspect workflow-cassandra --format={{.NetworkSettings.IPAddress}}) -e SDC_USER=workflow -e SDC_PASSWORD= -e JAVA_OPTIONS="-Xmx128m -Xms128m -Xss1m" nexus3.onap.org:10001/onap/workflow-backend:latest` ### Troubleshooting In order to verify that the Workflow Designer backend has started successfully, check the logs of the backend container. For example, by running `docker logs workflow-backend`. The logs must not contain any error messages. Application logs are located in the */var/log/ONAP/workflow-designer/backend* directory of a workflow backend container. For example, you can view the audit log by running `docker exec -ti workflow-backend less /var/log/ONAP/workflow-designer/backend/audit.log`. ## 4. Frontend `docker run -d -e BACKEND=http://: -e JAVA_OPTIONS= nexus3.onap.org:10001/onap/workflow-frontend:latest` - BACKEND — root endpoint of the RESTful APIs exposed by a workflow backend server. - JAVA_OPTIONS — optionally, JVM (Java Virtual Machine) arguments. ### Example `docker run -d --name workflow-frontend -e BACKEND=http://$(docker inspect workflow-backend --format={{.NetworkSettings.IPAddress}}):8080 -e JAVA_OPTIONS="-Xmx64m -Xms64m -Xss1m" -p 9088:8080 nexus3.onap.org:10001/onap/workflow-frontend:latest` Notice that port 8080 of the frontend container has been [mapped]( https://docs.docker.com/config/containers/container-networking/#published-ports) to port 9088 of the host machine. This makes the Workflow Designer Web application accessible from the outside world via the host machine's IP address/hostname. ### Troubleshooting In order to check if the Workflow Designer frontend has successfully started, look at the logs of the frontend container. For example, by running `docker logs workflow-frontend`. The logs should not contain error messages. Workflow frontend does not have backend logic, therefore there are no application logs. SDC Plugin Configuration ======================== In order to run as an SDC pluggable designer, Workflow Designer must be added to SDC configuration as described in [Generic plugin support](https://wiki.onap.org/display/DW/Generic+Designer+Support). If you are deploying SDC using a standard procedure (OOM or the [SDC shell script](https://wiki.onap.org/display/DW/Deploying+SDC+on+a+Linux+VM+for+Development)), the easiest way to configure the Workflow plugin is to edit the *default_attributes/Plugins/WORKFLOW* section of *AUTO.json*. ### Plugin Source The main endpoint to load Workflow Designer Web application is defined by `"pluginSourceUrl": "http://:"`. Keep in mind that the URL **must be accessible from a user's browser**. In most cases, `` will be the hostname or IP address of the machine that runs Docker engine, and `` will be a host port to which you have published port 8080 of the Workflow frontend container. ### Plugin Discovery In order to check the availability of a plugin, SDC uses `"pluginDiscoveryUrl"`. For Workflow the value is `http://:/ping`. ### Example Let's assume that hostname of the machine that runs Docker containers with the Workflow application is *workflow.example.com*, and port 8080 of the Workflow frontend is mapped to 9088 on the host. In this case the corresponding section of *AUTO.json* will look like below: ``` "Plugins": { "WORKFLOW": { "workflow_discovery_url": "http://workflow.example.com:9088/ping", "workflow_source_url": "http://workflow.example.com:9088" } }, ```