Add Linux support to venv-manager

Description

Related Issue

Motivation and Context

How Has This Been Tested?

Screenshots (if appropriate):

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.
• I have added tests to cover my changes.
• All new and existing tests passed.

applications/venv-manager/node/node.go

@@ -23,12 +23,33 @@ func (n Node) GetID() string {
 
 // FillAllFields fills all remaining fields of object with data from YangData.
 func (n *Node) FillAllFields(containerRegistryURL string) {
-	// make switch case here to differentialte between linux, arista, etc
+	// Works if linux and our gnmi target is used.
+	softwareVersion := n.YangData.System.State.SoftwareVersion
+	if softwareVersion != nil {
+		// Checks if software version is in compatible format.
+		result, _ := regexp.MatchString(`^([A-Za-z0-9\.\/])*:([A-Za-z0-9\.])*`, *softwareVersion)
+		if result {
+			n.Kind = "linux"
+			n.Image = containerRegistryURL + *softwareVersion
+			return
+		}
 
-	// specific to arista
+		n.Kind = "couldn't detect kind"
+		n.Image = "couldn't detect image"
+		return
+	}
+
+	// Specific to arista
 	regex := regexp.MustCompile(`[0-9]+\.[0-9]+\.[0-9][A-Z]`)
 	dockerTag := string(regex.FindAll([]byte(*n.YangData.Lldp.Config.SystemDescription), 1)[0])
 
+	// If it's not linux with our gnmi target and not arista, we don't support it.
+	if len(dockerTag) == 0 {
+		n.Kind = "couldn't detect kind"
+		n.Image = "couldn't detect image"
+		return
+	}
+
 	n.Kind = "ceos"
 	n.Image = containerRegistryURL + n.Kind + ":" + dockerTag
 }