http-api: T2768: example using GraphQL for high-level config operations

(cherry picked from commit b168b4cc7da456f14714d917cdc7a1c6b8df9af5)

16 files changed, 270 insertions, 2 deletions

diff --git a/data/templates/https/nginx.default.tmpl b/data/templates/https/nginx.default.tmpl
index 625ef4486..d25e5193a 100644
--- a/data/templates/https/nginx.default.tmpl
+++ b/data/templates/https/nginx.default.tmpl
@@ -41,7 +41,7 @@ server {
         ssl_protocols TLSv1.2 TLSv1.3;
 
         # proxy settings for HTTP API, if enabled; 503, if not
-        location ~ /(retrieve|configure|config-file|image|generate|show|docs|openapi.json|redoc) {
+        location ~ /(retrieve|configure|config-file|image|generate|show|docs|openapi.json|redoc|graphql) {
 {% if server.api %}
                 proxy_pass http://localhost:{{ server.api.port }};
                 proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
diff --git a/python/vyos/defaults.py b/python/vyos/defaults.py
index ca5e02834..dacdbdef2 100644
--- a/python/vyos/defaults.py
+++ b/python/vyos/defaults.py
@@ -23,7 +23,10 @@ directories = {
   "migrate": "/opt/vyatta/etc/config-migrate/migrate",
   "log": "/var/log/vyatta",
   "templates": "/usr/share/vyos/templates/",
-  "certbot": "/config/auth/letsencrypt"
+  "certbot": "/config/auth/letsencrypt",
+  "api_schema": "/usr/libexec/vyos/services/api/graphql/graphql/schema/",
+  "api_templates": "/usr/libexec/vyos/services/api/graphql/recipes/templates/"
+
 }
 
 cfg_group = 'vyattacfg'
diff --git a/src/services/api/graphql/graphql/__init__.py b/src/services/api/graphql/graphql/__init__.py
new file mode 100644
index 000000000..e69de29bb
--- /dev/null
+++ b/src/services/api/graphql/graphql/__init__.py
diff --git a/src/services/api/graphql/graphql/directives.py b/src/services/api/graphql/graphql/directives.py
new file mode 100644
index 000000000..651421c35
--- /dev/null
+++ b/src/services/api/graphql/graphql/directives.py
@@ -0,0 +1,17 @@
+from ariadne import SchemaDirectiveVisitor, ObjectType
+from . mutations import make_resolver
+
+class DataDirective(SchemaDirectiveVisitor):
+    """
+    Class providing implementation of 'generate' directive in schema.
+
+    """
+    def visit_field_definition(self, field, object_type):
+        name = f'{field.type}'
+        # field.type contains the return value of the mutation; trim value
+        # to produce canonical name
+        name = name.replace('Result', '', 1)
+
+        func = make_resolver(name)
+        field.resolve = func
+        return field
diff --git a/src/services/api/graphql/graphql/mutations.py b/src/services/api/graphql/graphql/mutations.py
new file mode 100644
index 000000000..98c665c9a
--- /dev/null
+++ b/src/services/api/graphql/graphql/mutations.py
@@ -0,0 +1,60 @@
+
+from importlib import import_module
+from typing import Any, Dict
+from ariadne import ObjectType, convert_kwargs_to_snake_case, convert_camel_case_to_snake
+from graphql import GraphQLResolveInfo
+from makefun import with_signature
+
+from .. import state
+
+mutation = ObjectType("Mutation")
+
+def make_resolver(mutation_name):
+    """Dynamically generate a resolver for the mutation named in the
+    schema by 'mutation_name'.
+
+    Dynamic generation is provided using the package 'makefun' (via the
+    decorator 'with_signature'), which provides signature-preserving
+    function wrappers; it provides several improvements over, say,
+    functools.wraps.
+
+    :raise Exception:
+        encapsulating ConfigErrors, or internal errors
+    """
+    class_name = mutation_name.replace('create', '', 1).replace('delete', '', 1)
+    func_base_name = convert_camel_case_to_snake(class_name)
+    resolver_name = f'resolve_create_{func_base_name}'
+    func_sig = '(obj: Any, info: GraphQLResolveInfo, data: Dict)'
+
+    @mutation.field(mutation_name)
+    @convert_kwargs_to_snake_case
+    @with_signature(func_sig, func_name=resolver_name)
+    async def func_impl(*args, **kwargs):
+        try:
+            if 'data' not in kwargs:
+                return {
+                    "success": False,
+                    "errors": ['missing data']
+                }
+
+            data = kwargs['data']
+            session = state.settings['app'].state.vyos_session
+
+            mod = import_module(f'api.graphql.recipes.{func_base_name}')
+            klass = getattr(mod, class_name)
+            k = klass(session, data)
+            k.configure()
+
+            return {
+                "success": True,
+                "data": data
+            }
+        except Exception as error:
+            return {
+                "success": False,
+                "errors": [str(error)]
+            }
+
+    return func_impl
+
+
diff --git a/src/services/api/graphql/graphql/schema/dhcp_server.graphql b/src/services/api/graphql/graphql/schema/dhcp_server.graphql
new file mode 100644
index 000000000..a7ee75d40
--- /dev/null
+++ b/src/services/api/graphql/graphql/schema/dhcp_server.graphql
@@ -0,0 +1,35 @@
+input dhcpServerConfigInput {
+    sharedNetworkName: String
+    subnet: String
+    defaultRouter: String
+    dnsServer: String
+    domainName: String
+    lease: Int
+    range: Int
+    start: String
+    stop: String
+    dnsForwardingAllowFrom: String
+    dnsForwardingCacheSize: Int
+    dnsForwardingListenAddress: String
+}
+
+type dhcpServerConfig {
+    sharedNetworkName: String
+    subnet: String
+    defaultRouter: String
+    dnsServer: String
+    domainName: String
+    lease: Int
+    range: Int
+    start: String
+    stop: String
+    dnsForwardingAllowFrom: String
+    dnsForwardingCacheSize: Int
+    dnsForwardingListenAddress: String
+}
+
+type createDhcpServerResult {
+    data: dhcpServerConfig
+    success: Boolean!
+    errors: [String]
+}
diff --git a/src/services/api/graphql/graphql/schema/interface_ethernet.graphql b/src/services/api/graphql/graphql/schema/interface_ethernet.graphql
new file mode 100644
index 000000000..fdcf97bad
--- /dev/null
+++ b/src/services/api/graphql/graphql/schema/interface_ethernet.graphql
@@ -0,0 +1,18 @@
+input interfaceEthernetConfigInput {
+    interface: String
+    address: String
+    replace: Boolean = true
+    description: String
+}
+
+type interfaceEthernetConfig {
+    interface: String
+    address: String
+    description: String
+}
+
+type createInterfaceEthernetResult {
+    data: interfaceEthernetConfig
+    success: Boolean!
+    errors: [String]
+}
diff --git a/src/services/api/graphql/graphql/schema/schema.graphql b/src/services/api/graphql/graphql/schema/schema.graphql
new file mode 100644
index 000000000..8a5e17962
--- /dev/null
+++ b/src/services/api/graphql/graphql/schema/schema.graphql
@@ -0,0 +1,15 @@
+schema {
+    query: Query
+    mutation: Mutation
+}
+
+type Query {
+    _dummy: String
+}
+
+directive @generate on FIELD_DEFINITION
+
+type Mutation {
+    createDhcpServer(data: dhcpServerConfigInput) : createDhcpServerResult @generate
+    createInterfaceEthernet(data: interfaceEthernetConfigInput) : createInterfaceEthernetResult @generate
+}
diff --git a/src/services/api/graphql/recipes/__init__.py b/src/services/api/graphql/recipes/__init__.py
new file mode 100644
index 000000000..e69de29bb
--- /dev/null
+++ b/src/services/api/graphql/recipes/__init__.py
diff --git a/src/services/api/graphql/recipes/dhcp_server.py b/src/services/api/graphql/recipes/dhcp_server.py
new file mode 100644
index 000000000..3edb3028e
--- /dev/null
+++ b/src/services/api/graphql/recipes/dhcp_server.py
@@ -0,0 +1,13 @@
+
+from . recipe import Recipe
+
+class DhcpServer(Recipe):
+    def __init__(self, session, command_file):
+        super().__init__(session, command_file)
+
+    # Define any custom processing of parameters here by overriding
+    # configure:
+    #
+    # def configure(self):
+    #     self.data = transform_data(self.data)
+    #     super().configure()
diff --git a/src/services/api/graphql/recipes/interface_ethernet.py b/src/services/api/graphql/recipes/interface_ethernet.py
new file mode 100644
index 000000000..f88f5924f
--- /dev/null
+++ b/src/services/api/graphql/recipes/interface_ethernet.py
@@ -0,0 +1,13 @@
+
+from . recipe import Recipe
+
+class InterfaceEthernet(Recipe):
+    def __init__(self, session, command_file):
+        super().__init__(session, command_file)
+
+    # Define any custom processing of parameters here by overriding
+    # configure:
+    #
+    # def configure(self):
+    #     self.data = transform_data(self.data)
+    #     super().configure()
diff --git a/src/services/api/graphql/recipes/recipe.py b/src/services/api/graphql/recipes/recipe.py
new file mode 100644
index 000000000..8fbb9e0bf
--- /dev/null
+++ b/src/services/api/graphql/recipes/recipe.py
@@ -0,0 +1,49 @@
+from ariadne import convert_camel_case_to_snake
+import vyos.defaults
+from vyos.template import render
+
+class Recipe(object):
+    def __init__(self, session, data):
+        self._session = session
+        self.data = data
+        self._name = convert_camel_case_to_snake(type(self).__name__)
+
+    @property
+    def data(self):
+        return self.__data
+
+    @data.setter
+    def data(self, data):
+        if isinstance(data, dict):
+            self.__data = data
+        else:
+            raise ValueError("data must be of type dict")
+
+    def configure(self):
+        session = self._session
+        data = self.data
+        func_base_name = self._name
+
+        tmpl_file = f'{func_base_name}.tmpl'
+        cmd_file = f'/tmp/{func_base_name}.cmds'
+        tmpl_dir = vyos.defaults.directories['api_templates']
+
+        try:
+            render(cmd_file, tmpl_file, data, location=tmpl_dir)
+            commands = []
+            with open(cmd_file) as f:
+                lines = f.readlines()
+            for line in lines:
+                commands.append(line.split())
+            for cmd in commands:
+                if cmd[0] == 'set':
+                    session.set(cmd[1:])
+                elif cmd[0] == 'delete':
+                    session.delete(cmd[1:])
+                else:
+                    raise ValueError('Operation must be "set" or "delete"')
+            session.commit()
+        except Exception as error:
+            raise error
+
+
diff --git a/src/services/api/graphql/recipes/templates/dhcp_server.tmpl b/src/services/api/graphql/recipes/templates/dhcp_server.tmpl
new file mode 100644
index 000000000..629ce83c1
--- /dev/null
+++ b/src/services/api/graphql/recipes/templates/dhcp_server.tmpl
@@ -0,0 +1,9 @@
+set service dhcp-server shared-network-name {{ shared_network_name }} subnet {{ subnet }} default-router {{ default_router }}
+set service dhcp-server shared-network-name {{ shared_network_name }} subnet {{ subnet }} dns-server {{ dns_server }}
+set service dhcp-server shared-network-name {{ shared_network_name }} subnet {{ subnet }} domain-name {{ domain_name }}
+set service dhcp-server shared-network-name {{ shared_network_name }} subnet {{ subnet }} lease {{ lease }}
+set service dhcp-server shared-network-name {{ shared_network_name }} subnet {{ subnet }} range {{ range }} start {{ start }}
+set service dhcp-server shared-network-name {{ shared_network_name }} subnet {{ subnet }} range {{ range }} stop {{ stop }}
+set service dns forwarding allow-from {{ dns_forwarding_allow_from }}
+set service dns forwarding cache-size {{ dns_forwarding_cache_size }}
+set service dns forwarding listen-address {{ dns_forwarding_listen_address }}
diff --git a/src/services/api/graphql/recipes/templates/interface_ethernet.tmpl b/src/services/api/graphql/recipes/templates/interface_ethernet.tmpl
new file mode 100644
index 000000000..d9d7ed691
--- /dev/null
+++ b/src/services/api/graphql/recipes/templates/interface_ethernet.tmpl
@@ -0,0 +1,5 @@
+{% if replace %}
+delete interfaces ethernet {{ interface }} address
+{% endif %}
+set interfaces ethernet {{ interface }} address {{ address }}
+set interfaces ethernet {{ interface }} description {{ description }}
diff --git a/src/services/api/graphql/state.py b/src/services/api/graphql/state.py
new file mode 100644
index 000000000..63db9f4ef
--- /dev/null
+++ b/src/services/api/graphql/state.py
@@ -0,0 +1,4 @@
+
+def init():
+    global settings
+    settings = {}
diff --git a/src/services/vyos-http-api-server b/src/services/vyos-http-api-server
index cbf321dc8..cb4ce4072 100755
--- a/src/services/vyos-http-api-server
+++ b/src/services/vyos-http-api-server
@@ -36,10 +36,16 @@ from starlette.datastructures import FormData, MutableHeaders
 from starlette.formparsers import FormParser, MultiPartParser
 from multipart.multipart import parse_options_header
 
+from ariadne import make_executable_schema, load_schema_from_path, snake_case_fallback_resolvers
+from ariadne.asgi import GraphQL
+
 import vyos.config
+import vyos.defaults
 
 from vyos.configsession import ConfigSession, ConfigSessionError
 
+import api.graphql.state
+
 DEFAULT_CONFIG_FILE = '/etc/vyos/http-api.conf'
 CFG_GROUP = 'vyattacfg'
 
@@ -603,6 +609,25 @@ def show_op(data: ShowModel):
 
     return success(res)
 
+###
+# GraphQL integration
+###
+
+api.graphql.state.init()
+
+from api.graphql.graphql.mutations import mutation
+from api.graphql.graphql.directives import DataDirective
+
+api_schema_dir = vyos.defaults.directories['api_schema']
+
+type_defs = load_schema_from_path(api_schema_dir)
+
+schema = make_executable_schema(type_defs, mutation, snake_case_fallback_resolvers, directives={"generate": DataDirective})
+
+app.add_route('/graphql', GraphQL(schema, debug=True))
+
+###
+
 if __name__ == '__main__':
     # systemd's user and group options don't work, do it by hand here,
     # else no one else will be able to commit
@@ -626,6 +651,8 @@ if __name__ == '__main__':
     app.state.vyos_debug = True if server_config['debug'] == 'true' else False
     app.state.vyos_strict = True if server_config['strict'] == 'true' else False
 
+    api.graphql.state.settings['app'] = app
+
     try:
         uvicorn.run(app, host=server_config["listen_address"],
                          port=int(server_config["port"]),