odo add binding

Description

The odo add binding command adds a link between an Operator-backed service and a component. odo uses the Service Binding Operator to create this link.

Running this command from a directory containing a Devfile will modify the Devfile, and once pushed (using odo dev) to the cluster, it creates an instance of the ServiceBinding resource.

Running this command from a directory without a Devfile in the interactive mode will perform one or several operations, depending on your choice:

• display the YAML definition of the Service binding in the output,
• save the YAML definition of the ServiceBinding on a file,
• create an instance of the ServiceBinding resource on the cluster.

In non-interactive mode from a directory without a Devfile, the only possible operation is to display the YAML definition of the Service binding in the output.

Currently, it only allows connecting to the Operator-backed services which support binding via the Service Binding Operator. To know about the Operators supported by the Service Binding Operator, read its README.

Running the Command

Pre-requisites

• A cluster with the Service Binding Operator installed (see installation instructions for Kubernetes and OpenShift cluster)
• Operator-backed services or resources you want to bind your application to
• Optional, a directory containing a Devfile; if you don't have one, see odo init on obtaining a devfile.

Interactive Mode

In the interactive mode, you will be guided to choose:

• a service from the list of bindable service instances as supported by the Service Binding Operator,
• if a Devfile is not present in the directory, a workload resource,
• option to bind the service as a file (see Understanding Bind as Files for more information on this),
• a name for the binding.

# Add binding between a service, and the component present in the working directory in the interactive mode
odo add binding

Non-interactive mode

In the non-interactive mode, you will have to specify the following required information through the command-line:

• --service flag to specify the service you want to bind to,
• --workload flag to specify the workload resource, if a Devfile is not present in the directory,
• --name flag to specify a name for the binding (see Understanding Bind as Files for more information on this)
• --bind-as-files flag to specify if the service should be bound as a file; this flag is set to true by default.

# Add binding between a service named 'cluster-sample',
# and the component present in the working directory in the non-interactive mode
odo add binding --name mybinding --service myRedisService.Redis

Understanding Bind as Files

To connect your component with a service, you need to store some data (e.g. username, password, host address) on your component's container. If the service is bound as files, this data will be written to a file and stored on the container, else it will be injected as Environment Variables inside the container.

Note that every piece of data is stored in its own individual file or environment variable. For example, if your data includes a username and password, then 2 separate files, or 2 environment variables will be created to store them both.

Formats supported by the --service flag

The --service flag supports the following formats to specify the service name:

• <name>
• <name>.<kind>
• <name>.<kind>.<apigroup>
• <name>/<kind>
• <name>/<kind>.<apigroup>

Formats supported by the --workload flag

The --workload flag supports the following formats to specify the workload name:

• <name>.<kind>.<apigroup>
• <name>/<kind>.<apigroup>

The above formats are helpful when multiple services with the same name exist on the cluster.

Using different formats

# Add binding between a service named 'cluster-sample', and the component present in the working directory
odo add binding --service cluster-sample --name restapi-cluster-sample

# Add binding between service named 'cluster-sample' of kind 'Cluster', and APIGroup 'postgresql.k8s.enterprisedb.io',
# and the component present in the working directory 
odo add binding --service cluster-sample/Cluster.postgresql.k8s.enterprisedb.io --name restapi-cluster-sample
odo add binding --service cluster-sample.Cluster.postgresql.k8s.enterprisedb.io --name restapi-cluster-sample

# Add binding between service named 'cluster-sample' of kind 'Cluster',
# and the component present in the working directory
odo add binding --service cluster-sample/Cluster --name restapi-cluster-sample
odo add binding --service cluster-sample.Cluster --name restapi-cluster-sample