AS3 Forms LX (AFL) is an iControl LX Extension for creating solution tailored UI Forms and BIG-IP REST endpoints for deploying AS3 Applications.
requirements
- BIG-IP running TMOS >= 13.0
- AS3 previously installed
Download as3-forms-lx.rpm from latest releases
Install the RPM on your BIG-IP
Navigate to http://your.big-ip.host/iapps/as3-forms-lx/
This will display the list of default templates, which are also made available on github. Clicking a link to a template will present a form to fill out. Once filled in, clicking submit will apply the templated declaration to BIG-IP.
Templates can be modified by changing the files at /var/config/rest/iapps/as3-forms-lx/templates
Schemas can be modified by changing the files at /var/config/rest/iapps/as3-forms-lx/schemas
AS3 greatly simplifies application deployment on BIG-IP, but writing AS3 declarations by hand can lead to some uncomfortable outcomes.
- Copy and pasting the same declaration snippet and replacing only a few values, the 'copy-paste' workflow.
- Proliferation of unique or mutated configuration structures throughout the declaration
The next step is to write a frontend to provide a visual or simplified interface for AS3, composing declarations programatically. This approach enables network admins to deploy applications with AS3, even though they may not know AS3.
What AFL provides is a custom template expansion language, Typestache for specifying AS3 Applications, and a process for integrating these Applications into the existing configuration.
Typestache templates may be added to the system (some defaults are provided), and a schema will be auto-generated from each template. This schema is then used to render an appropriate HTML form and validate inputs before rendering the template.
When an application configuration needs to be added, a template is chosen and form values filled in. Submitting the form deploys the application to BIG-IP in a complete AS3 declaration.
Typestache is a dialect of mustache that allows a template author to specify data types to be filled in during the render phase. Types are provided in schema files, specified in a subset of JSON schema. This type information can be consumed and used to auto-generate a front end for the templates.
- Variables will be marked for replacement at render time.
- Variables are surrounded with double curly braces,
{{and}}. - Variables can specify a type:
name::type - Primitive Types
- string (default)
- text (for strings with newlines and escape characters)
- number
- integer
- boolean
- array (treated as array of strings, see extended types for other arrays)
The following is an example of a simple Typestache template that will render an AS3 declaration:
{
"class": "ADC",
"schemaVersion": "3.11.0",
"{{tenant_name}}": {
"class": "Tenant",
"{{application_name}}": {
"class": "Application",
"template": "http",
"serviceMain": {
"class": "Service_HTTP",
"virtualAddresses": ["{{virtual_address}}"],
"pool": "web_pool_{{port}}",
},
"web_pool_{{port}}": {
"class": "Pool",
"monitors": [
"http"
],
"members": [
{
"servicePort": {{port::integer}},
"serverAddresses": {{server_addresses::array}}
}
]
}
}
}
}
}The following schema will get auto-generated from the example:
{
"properties": {
"tenant_name" : {
"type": "string"
},
"application_name" : {
"type": "string"
},
"virtual_address" : {
"type": "string"
},
"server_addresses" : {
"type": "array"
},
"port" : {
"type": "integer"
},
}
}The example schema can validate the object the admin or upstream caller provides (also known as a 'view'):
{
"tenant_name" : "myTenant",
"application_name" : "simple_http_1",
"virtual_address" : "10.0.0.1",
"server_addresses" : [ "10.0.1.1", "10.0.2.2" ],
"port" : 80
}At render time, the view will get translated in the actual view the template
gets rendered with. A couple system variables, template_name and uuid are
added to be used in templates.
Variables may be used in multiple places, if a variable is annotated somewhere in the file, an unannotated version of that variable will result in a string representation of that variable. The view is filled in to provide this behavior.
{
"template_name" : "<name of the template being run>",
"uuid" : "<a uuid id generated by the system at render time>",
"tenant_name" : "myTenant",
"application_name" : "simple_http_1",
"virtual_address" : "10.0.0.1",
"server_addresses" : "[ \"10.0.1.1\", \"10.0.2.2\" ]",
"server_addresses::array" : [ "10.0.1.1", "10.0.2.2" ],
"port" : "80",
"port::integer" : 80
}The final declaration is generated by providing the previous view with the provided template:
{
"class": "ADC",
"schemaVersion": "3.11.0",
"myTenant": {
"class": "Tenant",
"simple_http_1": {
"class": "Application",
"template": "http",
"serviceMain": {
"class": "Service_HTTP",
"virtualAddresses": ["10.0.0.1"],
"pool": "web_pool_80",
},
"web_pool_80": {
"class": "Pool",
"monitors": [
"http"
],
"members": [
{
"servicePort": 80,
"serverAddresses": [ "10.0.1.1", "10.0.2.2" ]
}
]
}
}
}
}
}Typestache also allows specification of custom types using JSON schema. Schema
files can be placed into /var/config/rest/iapps/as3-forms-lx/schemas. Each
file must have a .json extension and contain valid JSON schema. Schemas listed
in the definitions will be made available to templates using the following
syntax:
name:schema_name:type
- name is the name of the variable, as before
- schema_name is the name of the JSON schema file, excluding the extension
- type is the property name of the definition being referenced
for example,
...
{
"class": {{service_type:f5:service}}
...
}
...
AFL has support for enums and custom formats can be applied to the primitive
types outlined in the previous section. The variable in the example is a
service type from the f5 schema named service_type. The service schema
is an enum containing the AS3 basic services, Service_HTTP, Service_HTTPS,
Service_L4, Service_UDP, and Service_TCP.
The definition from f5.json:
"service": {
"type": "string",
"enum": [
"Service_HTTP",
"Service_HTTPS",
"Service_TCP",
"Service_UDP",
"Service_L4"
],
"default": "Service_HTTP"
},
Arrays of primitives should work fine, but has not been tested extensively.
Objects are not supported yet.