--- sidebar: auto --- # Guide to Super Graph Super Graph is a micro-service that instantly and without code gives you a high performance and secure GraphQL API. Your GraphQL queries are auto translated into a single fast SQL query. No more writing API code as you develop your web frontend just make the query you need and Super Graph will do the rest. Super Graph has a rich feature set like integrating with your existing Ruby on Rails apps, joining your DB with data from remote APIs, Role and Attribute based access control, Supoport for JWT tokens, DB migrations, seeding and a lot more. ## Features - Role and Attribute based access control - Works with existing Ruby-On-Rails apps - Automatically learns database schemas and relationships - Full text search and aggregations - Rails authentication supported (Redis, Memcache, Cookie) - JWT tokens supported (Auth0, etc) - Join database with remote REST APIs - Highly optimized and fast Postgres SQL queries - GraphQL queries and mutations - A simple config file - High performance GO codebase - Tiny docker image and low memory requirements - Fuzz tested for security - Database migrations tool - Database seeding tool ## Try the demo app ```bash # clone the repository git clone https://github.com/dosco/super-graph # setup the demo rails app & database and run it docker-compose run rails_app rake db:create db:migrate db:seed # run the demo docker-compose up # signin to the demo app (user1@demo.com / 123456) open http://localhost:3000 # try the super graph web ui open http://localhost:8080 ``` ::: warning DEMO REQUIREMENTS This demo requires `docker` you can either install it using `brew` or from the docker website [https://docs.docker.com/docker-for-mac/install/](https://docs.docker.com/docker-for-mac/install/) ::: #### Trying out GraphQL We currently fully support queries and mutations. Support for `subscriptions` is work in progress. For example the below GraphQL query would fetch two products that belong to the current user where the price is greater than 10. #### GQL Query ```graphql query { users { id email picture : avatar password full_name products(limit: 2, where: { price: { gt: 10 } }) { id name description price } } } ``` In another example the below GraphQL mutation would insert a product into the database. The first part of the below example is the variable data and the second half is the GraphQL mutation. For mutations data has to always ben passed as a variable. ```json { "data": { "name": "Art of Computer Programming", "description": "The Art of Computer Programming (TAOCP) is a comprehensive monograph written by computer scientist Donald Knuth", "price": 30.5 } } ``` ```graphql mutation { product(insert: $data) { id name } } ``` The above GraphQL query returns the JSON result below. It handles all kinds of complexity without you having to writing a line of code. For example there is a while greater than `gt` and a limit clause on a child field. And the `avatar` field is renamed to `picture`. The `password` field is blocked and not returned. Finally the relationship between the `users` table and the `products` table is auto discovered and used. #### JSON Result ```json { "data": { "users": [ { "id": 1, "email": "odilia@west.info", "picture": "https://robohash.org/simur.png?size=300x300", "full_name": "Edwin Orn", "products": [ { "id": 16, "name": "Sierra Nevada Style Ale", "description": "Belgian Abbey, 92 IBU, 4.7%, 17.4°Blg", "price": 16.47 }, ... ] } ] } } ``` #### Try with an authenticated user In development mode you can use the `X-User-ID: 4` header to set a user id so you don't have to worries about cookies etc. This can be set using the *HTTP Headers* tab at the bottom of the web UI you'll see when you visit the above link. You can also directly run queries from the commandline like below. #### Querying the GQL endpoint ```bash # fetch the response json directly from the endpoint using user id 5 curl 'http://localhost:8080/api/v1/graphql' \ -H 'content-type: application/json' \ -H 'X-User-ID: 5' \ --data-binary '{"query":"{ products { name price users { email }}}"}' ``` ## Get Started Super Graph can generate your initial app for you. The generated app will have config files, database migrations and seed files among other things like docker related files. You can then add your database schema to the migrations, maybe create some seed data using the seed script and launch Super Graph. You're now good to go and can start working on your UI frontend in React, Vue or whatever. ```bash # Download and install Super Graph. You will need Go 1.13 or above git clone https://github.com/dosco/super-graph && cd super-graph && make install ``` And then create and launch you're new app ```bash # create a new app and change to it's directory super-graph new blog; cd blog # setup the app database and seed it with fake data. Docker compose will start a Postgres database for your app docker-compose run blog_api ./super-graph db:setup # and finally launch Super Graph configured for your app docker-compose up ``` Lets take a look at the files generated by Super Graph when you create a new app ```bash super-graph new blog > created 'blog' > created 'blog/Dockerfile' > created 'blog/docker-compose.yml' > created 'blog/config' > created 'blog/config/dev.yml' > created 'blog/config/prod.yml' > created 'blog/config/seed.js' > created 'blog/config/migrations' > created 'blog/config/migrations/100_init.sql' > app 'blog' initialized ``` ### Docker files Docker Compose is a great way to run multiple services while developing on your desktop or laptop. In our case we need Postgres and Super Graph to both be running and the `docker-compose.yml` is configured to do just that. The Super Graph service is named after your app postfixed with `_api`. The Dockerfile can be used build a containr of your app for production deployment. ```bash docker-compose run blog_api ./super-graph help ``` ### Config files All the config files needs to configure Super Graph for your app are contained in this folder for starters you have two `dev.yaml` and `prod.yaml`. When the `GO_ENV` environment variable is set to `development` then `dev.yaml` is used and the prod one when it's set to `production`. Stage and Test are the other two environment options, but you can set the `GO_ENV` to whatever you like (eg. `alpha-test`) and Super Graph will look for a yaml file with that name to load config from. ### Seed.js Having data flowing through your API makes building your frontend UI so much easier. When creafting say a user profile wouldn't it be nice for the API to return a fake user with name, picture and all. This is why having the ability to seed your database is important. Seeding cn also be used in production to setup some initial users like the admins or to add an initial set of products to a ecommerce store. Super Graph makes this easy by allowing you to write your seeding script in plan old Javascript. The below file that auto-generated for new apps uses our built-in functions `fake` and `graphql` to generate fake data and use GraphQL mutations to insert it into the database. ```javascript // Example script to seed database var users = []; for (i = 0; i < 10; i++) { var data = { full_name: fake.name(), email: fake.email() } var res = graphql(" \ mutation { \ user(insert: $data) { \ id \ } \ }", { data: data }) users.push(res.user) } ``` You can generate the following fake data for your seeding purposes. Below is the list of fake data functions supported by the built-in fake data library. For example `fake.image_url()` will generate a fake image url or `fake.shuffle_strings(['hello', 'world', 'cool'])` will generate a randomly shuffled version of that array of strings or `fake.rand_string(['hello', 'world', 'cool'])` will return a random string from the array provided. ``` // Person person name name_prefix name_suffix first_name last_name gender ssn contact email phone phone_formatted username password // Address address city country country_abr state state_abr status_code street street_name street_number street_prefix street_suffix zip latitude latitude_in_range longitude longitude_in_range // Beer beer_alcohol beer_hop beer_ibu beer_blg beer_malt beer_name beer_style beer_yeast // Cars vehicle vehicle_type car_maker car_model fuel_type transmission_gear_type // Text word sentence paragraph question quote // Misc generate boolean uuid // Colors color hex_color rgb_color safe_color // Internet url image_url domain_name domain_suffix ipv4_address ipv6_address simple_status_code http_method user_agent user_agent_firefox user_agent_chrome user_agent_opera user_agent_safari // Date / Time date date_range nano_second second minute hour month day weekday year timezone timezone_abv timezone_full timezone_offset // Payment price credit_card credit_card_cvv credit_card_number credit_card_number_luhn credit_card_type currency currency_long currency_short // Company bs buzzword company company_suffix job job_description job_level job_title // Hacker hacker_abbreviation hacker_adjective hacker_ingverb hacker_noun hacker_phrase hacker_verb //Hipster hipster_word hipster_paragraph hipster_sentence // File extension mine_type // Numbers number numerify int8 int16 int32 int64 uint8 uint16 uint32 uint64 float32 float32_range float64 float64_range shuffle_ints mac_address //String digit letter lexify rand_string shuffle_strings numerify ``` ### Migrations Easy database migrations is the most important thing when building products backend by a relational database. We make it super easy to manage and migrate your database. ```bash super-graph db:new create_users > created migration 'config/migrations/101_create_users.sql' ``` Migrations in Super Graph are plain old Postgres SQL. Here's an example for the above migration. ```sql -- Write your migrate up statements here CREATE TABLE public.users ( id bigint GENERATED ALWAYS AS IDENTITY PRIMARY KEY, full_name text, email text UNIQUE NOT NULL CHECK (length(email) < 255), created_at timestamptz NOT NULL NOT NULL DEFAULT NOW(), updated_at timestamptz NOT NULL NOT NULL DEFAULT NOW() ); ---- create above / drop below ---- -- Write your down migrate statements here. If this migration is irreversible -- then delete the separator line above. DROP TABLE public.users ``` We would encourage you to leverage triggers to maintain consistancy of your data for example here are a couple triggers that you can add to you init migration and across your tables. ```sql -- This trigger script will set the updated_at column everytime a row is updated CREATE OR REPLACE FUNCTION trigger_set_updated_at() RETURNS TRIGGER SET SCHEMA 'public' LANGUAGE 'plpgsql' AS $$ BEGIN new.updated_at = now(); RETURN new; END; $$; ... -- An exmple of adding this trigger to the users table CREATE TRIGGER set_updated_at BEFORE UPDATE ON public.users FOR EACH ROW EXECUTE PROCEDURE trigger_set_updated_at(); ``` ```sql -- This trigger script will set the user_id column to the current -- Super Graph user.id value everytime a row is created or updated CREATE OR REPLACE FUNCTION trigger_set_user_id() RETURNS TRIGGER SET SCHEMA 'public' LANGUAGE 'plpgsql' AS $$ BEGIN IF TG_OP = 'UPDATE' THEN new.user_id = old.user_id; ELSE new.user_id = current_setting('user.id')::int; END IF; RETURN new; END; $$; ... -- An exmple of adding this trigger to the blog_posts table CREATE TRIGGER set_user_id BEFORE INSERT OR UPDATE ON public.blog_posts FOR EACH ROW EXECUTE PROCEDURE trigger_set_user_id(); ``` ## How to GraphQL GraphQL (GQL) is a simple query syntax that's fast replacing REST APIs. GQL is great since it allows web developers to fetch the exact data that they need without depending on changes to backend code. Also if you squint hard enough it looks a little bit like JSON :smiley: The below query will fetch an `users` name, email and avatar image (renamed as picture). If you also need the users `id` then just add it to the query. ```graphql query { user { full_name email picture : avatar } } ``` Multiple tables can also be fetched using a single GraphQL query. This is very fast since the entire query is converted into a single SQL query which the database can efficiently run. ```graphql query { user { full_name email } products { name description } } ``` ### Fetching data To fetch a specific `product` by it's ID you can use the `id` argument. The real name id field will be resolved automatically so this query will work even if your id column is named something like `product_id`. ```graphql query { products(id: 3) { name } } ``` Postgres also supports full text search using a TSV index. Super Graph makes it easy to use this full text search capability using the `search` argument. ```graphql query { products(search: "ale") { name } } ``` ### Sorting To sort or ordering results just use the `order_by` argument. This can be combined with `where`, `search`, etc to build complex queries to fit you needs. ```graphql query { products(order_by: { cached_votes_total: desc }) { id name } } ``` ### Filtering Super Graph support complex queries where you can add filters, ordering,offsets and limits on the query. For example the below query will list all products where the price is greater than 10 and the id is not 5. ```graphql query { products(where: { and: { price: { gt: 10 }, not: { id: { eq: 5 } } } }) { name price } } ``` #### Nested where clause targeting related tables Sometimes you need to query a table based on a condition that applies to a related table. For example say you need to list all users who belong to an account. This query below will fetch the id and email or all users who belong to the account with id 3. ```graphql query { users(where: { accounts: { id: { eq: 3 } } }) { id email } }` ``` #### Logical Operators Name | Example | Explained | --- | --- | --- | and | price : { and : { gt: 10.5, lt: 20 } | price > 10.5 AND price < 20 or | or : { price : { greater_than : 20 }, quantity: { gt : 0 } } | price >= 20 OR quantity > 0 not | not: { or : { quantity : { eq: 0 }, price : { eq: 0 } } } | NOT (quantity = 0 OR price = 0) #### Other conditions Name | Example | Explained | --- | --- | --- | eq, equals | id : { eq: 100 } | id = 100 neq, not_equals | id: { not_equals: 100 } | id != 100 gt, greater_than | id: { gt: 100 } | id > 100 lt, lesser_than | id: { gt: 100 } | id < 100 gte, greater_or_equals | id: { gte: 100 } | id >= 100 lte, lesser_or_equals | id: { lesser_or_equals: 100 } | id <= 100 in | status: { in: [ "A", "B", "C" ] } | status IN ('A', 'B', 'C) nin, not_in | status: { in: [ "A", "B", "C" ] } | status IN ('A', 'B', 'C) like | name: { like "phil%" } | Names starting with 'phil' nlike, not_like | name: { nlike "v%m" } | Not names starting with 'v' and ending with 'm' ilike | name: { ilike "%wOn" } | Names ending with 'won' case-insensitive nilike, not_ilike | name: { nilike "%wOn" } | Not names ending with 'won' case-insensitive similar | name: { similar: "%(b\|d)%" } | [Similar Docs](https://www.postgresql.org/docs/9/functions-matching.html#FUNCTIONS-SIMILARTO-REGEXP) nsimilar, not_similar | name: { nsimilar: "%(b\|d)%" } | [Not Similar Docs](https://www.postgresql.org/docs/9/functions-matching.html#FUNCTIONS-SIMILARTO-REGEXP) has_key | column: { has_key: 'b' } | Does JSON column contain this key has_key_any | column: { has_key_any: [ a, b ] } | Does JSON column contain any of these keys has_key_all | column: [ a, b ] | Does JSON column contain all of this keys contains | column: { contains: [1, 2, 4] } | Is this array/json column a subset of value contained_in | column: { contains: "{'a':1, 'b':2}" } | Is this array/json column a subset of these value is_null | column: { is_null: true } | Is column value null or not ### Aggregations You will often find the need to fetch aggregated values from the database such as `count`, `max`, `min`, etc. This is simple to do with GraphQL, just prefix the aggregation name to the field name that you want to aggregrate like `count_id`. The below query will group products by name and find the minimum price for each group. Notice the `min_price` field we're adding `min_` to price. ```graphql query { products { name min_price } } ``` Name | Explained | --- | --- | avg | Average value count | Count the values max | Maximum value min | Minimum value stddev | [Standard Deviation](https://en.wikipedia.org/wiki/Standard_deviation) stddev_pop | Population Standard Deviation stddev_samp | Sample Standard Deviation variance | [Variance](https://en.wikipedia.org/wiki/Variance) var_pop | Population Standard Variance var_samp | Sample Standard variance All kinds of queries are possible with GraphQL. Below is an example that uses a lot of the features available. Comments `# hello` are also valid within queries. ```graphql query { products( # returns only 30 items limit: 30, # starts from item 10, commented out for now # offset: 10, # orders the response items by highest price order_by: { price: desc }, # no duplicate prices returned distinct: [ price ] # only items with an id >= 30 and < 30 are returned where: { id: { and: { greater_or_equals: 20, lt: 28 } } }) { id name price } } ``` ## Mutations In GraphQL mutations is the operation type for when you need to modify data. Super Graph supports the `insert`, `update`, `upsert` and `delete`. You can also do complex nested inserts and updates. When using mutations the data must be passed as variables since Super Graphs compiles the query into an prepared statement in the database for maximum speed. Prepared statements are are functions in your code when called they accept arguments and your variables are passed in as those arguments. ### Insert ```json { "data": { "name": "Art of Computer Programming", "description": "The Art of Computer Programming (TAOCP) is a comprehensive monograph written by computer scientist Donald Knuth", "price": 30.5 } } ``` ```graphql mutation { product(insert: $data) { id name } } ``` #### Bulk insert ```json { "data": [{ "name": "Art of Computer Programming", "description": "The Art of Computer Programming (TAOCP) is a comprehensive monograph written by computer scientist Donald Knuth", "price": 30.5 }, { "name": "Compilers: Principles, Techniques, and Tools", "description": "Known to professors, students, and developers worldwide as the 'Dragon Book' is available in a new edition", "price": 93.74 }] } ``` ```graphql mutation { product(insert: $data) { id name } } ``` ### Update ```json { "data": { "price": 200.0 }, "product_id": 5 } ``` ```graphql mutation { product(update: $data, id: $product_id) { id name } } ``` #### Bulk update ```json { "data": { "price": 500.0 }, "gt_product_id": 450.0, "lt_product_id:": 550.0 } ``` ```graphql mutation { product(update: $data, where: { price: { gt: $gt_product_id, lt: lt_product_id } }) { id name } } ``` ### Delete ```json { "data": { "price": 500.0 }, "product_id": 5 } ``` ```graphql mutation { product(delete: true, id: $product_id) { id name } } ``` #### Bulk delete ```json { "data": { "price": 500.0 } } ``` ```graphql mutation { product(delete: true, where: { price: { eq: { 500.0 } } }) { id name } } ``` ### Upsert ```json { "data": { "id": 5, "name": "Art of Computer Programming", "description": "The Art of Computer Programming (TAOCP) is a comprehensive monograph written by computer scientist Donald Knuth", "price": 30.5 } } ``` ```graphql mutation { product(upsert: $data) { id name } } ``` #### Bulk upsert ```json { "data": [{ "id": 5, "name": "Art of Computer Programming", "description": "The Art of Computer Programming (TAOCP) is a comprehensive monograph written by computer scientist Donald Knuth", "price": 30.5 }, { "id": 6, "name": "Compilers: Principles, Techniques, and Tools", "description": "Known to professors, students, and developers worldwide as the 'Dragon Book' is available in a new edition", "price": 93.74 }] } ``` ```graphql mutation { product(upsert: $data) { id name } } ``` ## Nested Mutations Often you will need to create or update multiple related items at the same time. This can be done using nested mutations. For example you might need to create a product and assign it to a user, or create a user and his products at the same time. You just have to use simple json to define you mutation and Super Graph takes care of the rest. ### Nested Insert Create a product item first and then assign it to a user ```json { "data": { "name": "Apple", "price": 1.25, "created_at": "now", "updated_at": "now", "user": { "connect": { "id": 5 } } } } ``` ```graphql mutation { product(insert: $data) { id name user { id full_name email } } } ``` Or it's reverse, create the user first and then his product ```json { "data": { "email": "thedude@rug.com", "full_name": "The Dude", "created_at": "now", "updated_at": "now", "product": { "name": "Apple", "price": 1.25, "created_at": "now", "updated_at": "now" } } } ``` ```graphql mutation { user(insert: $data) { id full_name email product { id name price } } } ``` ### Nested Updates Update a product item first and then assign it to a user ```json { "data": { "name": "Apple", "price": 1.25, "user": { "connect": { "id": 5 } } } } ``` ```graphql mutation { product(update: $data, id: 5) { id name user { id full_name email } } } ``` Or it's reverse, update a user first and then his product ```json { "data": { "email": "newemail@me.com", "full_name": "The Dude", "product": { "name": "Banana", "price": 1.25, } } } ``` ```graphql mutation { user(update: $data, id: 1) { id full_name email product { id name price } } } ``` ## Using variables Variables (`$product_id`) and their values (`"product_id": 5`) can be passed along side the GraphQL query. Using variables makes for better client side code as well as improved server side SQL query caching. The build-in web-ui also supports setting variables. Not having to manipulate your GraphQL query string to insert values into it makes for cleaner and better client side code. ```javascript // Define the request object keeping the query and the variables seperate var req = { query: '{ product(id: $product_id) { name } }' , variables: { "product_id": 5 } } // Use the fetch api to make the query fetch('http://localhost:8080/api/v1/graphql', { method: 'POST', headers: { 'Content-Type': 'application/json' }, body: JSON.stringify(req), }) .then(res => res.json()) .then(res => console.log(res.data)); ``` ## Full text search Every app these days needs search. Enought his often means reaching for something heavy like Solr. While this will work why add complexity to your infrastructure when Postgres has really great and fast full text search built-in. And since it's part of Postgres it's also available in Super Graph. ```graphql query { products( # Search for all products that contain 'ale' or some version of it search: "ale" # Return only matches where the price is less than 10 where: { price: { lt: 10 } } # Use the search_rank to order from the best match to the worst order_by: { search_rank: desc }) { id name search_rank search_headline_description } } ``` This query will use the `tsvector` column in your database table to search for products that contain the query phrase or some version of it. To get the internal relevance ranking for the search results using the `search_rank` field. And to get the highlighted context within any of the table columns you can use the `search_headline_` field prefix. For example `search_headline_name` will return the contents of the products name column which contains the matching query marked with the `` html tags. ```json { "data": { "products": [ { "id": 11, "name": "Maharaj", "search_rank": 0.243171, "search_headline_description": "Blue Moon, Vegetable Beer, Willamette, 1007 - German Ale, 48 IBU, 7.9%, 11.8°Blg" }, { "id": 12, "name": "Schneider Aventinus", "search_rank": 0.243171, "search_headline_description": "Dos Equis, Wood-aged Beer, Magnum, 1099 - Whitbread Ale, 15 IBU, 9.5%, 13.0°Blg" }, ... ``` #### Adding search to your Rails app It's really easy to enable Postgres search on any table within your database schema. All it takes is to create the following migration. In the below example we add a full-text search to the `products` table. ```ruby class AddSearchColumn < ActiveRecord::Migration[5.1] def self.up add_column :products, :tsv, :tsvector add_index :products, :tsv, using: "gin" say_with_time("Adding trigger to update the ts_vector column") do execute <<-SQL CREATE FUNCTION products_tsv_trigger() RETURNS trigger AS $$ begin new.tsv := setweight(to_tsvector('pg_catalog.english', coalesce(new.name,'')), 'A') || setweight(to_tsvector('pg_catalog.english', coalesce(new.description,'')), 'B'); return new; end $$ LANGUAGE plpgsql; CREATE TRIGGER tsvectorupdate BEFORE INSERT OR UPDATE ON products FOR EACH ROW EXECUTE PROCEDURE products_tsv_trigger(); SQL end end def self.down say_with_time("Removing trigger to update the tsv column") do execute <<-SQL DROP TRIGGER tsvectorupdate ON products SQL end remove_index :products, :tsv remove_column :products, :tsv end end ``` ## GraphQL with React This is a quick simple example using `graphql.js` [https://github.com/f/graphql.js/](https://github.com/f/graphql.js/) ```js import React, { useState, useEffect } from 'react' import graphql from 'graphql.js' // Create a GraphQL client pointing to Super Graph var graph = graphql("http://localhost:3000/api/v1/graphql", { asJSON: true }) const App = () => { const [user, setUser] = useState(null) useEffect(() => { async function action() { // Use the GraphQL client to execute a graphQL query // The second argument to the client are the variables you need to pass const result = await graph(`{ user { id first_name last_name picture_url } }`)() setUser(result) } action() }, []); return (

{ JSON.stringify(user) }

); } ``` export default App; ## Authentication You can only have one type of auth enabled. You can either pick Rails or JWT. ### Rails Auth (Devise / Warden) Almost all Rails apps use Devise or Warden for authentication. Once the user is authenticated a session is created with the users ID. The session can either be stored in the users browser as a cookie, memcache or redis. If memcache or redis is used then a cookie is set in the users browser with just the session id. Super Graph can handle all these variations including the old and new session formats. Just enable the right `auth` config based on how your rails app is configured. #### Cookie session store ```yaml auth: type: rails cookie: _app_session rails: # Rails version this is used for reading the # various cookies formats. version: 5.2 # Found in 'Rails.application.config.secret_key_base' secret_key_base: 0a248500a64c01184edb4d7ad3a805488f8097ac761b76aaa6c17c01dcb7af03a2f18ba61b2868134b9c7b79a122bc0dadff4367414a2d173297bfea92be5566 ``` #### Memcache session store ```yaml auth: type: rails cookie: _app_session rails: # Memcache remote cookie store. url: memcache://127.0.0.1 ``` #### Redis session store ```yaml auth: type: rails cookie: _app_session rails: # Redis remote cookie store url: redis://127.0.0.1:6379 password: "" max_idle: 80 max_active: 12000 ``` ### JWT Token Auth ```yaml auth: type: jwt jwt: # the two providers are 'auth0' and 'none' provider: auth0 secret: abc335bfcfdb04e50db5bb0a4d67ab9 public_key_file: /secrets/public_key.pem public_key_type: ecdsa #rsa ``` For JWT tokens we currently support tokens from a provider like Auth0 or if you have a custom solution then we look for the `user_id` in the `subject` claim of of the `id token`. If you pick Auth0 then we derive two variables from the token `user_id` and `user_id_provider` for to use in your filters. We can get the JWT token either from the `authorization` header where we expect it to be a `bearer` token or if `cookie` is specified then we look there. For validation a `secret` or a public key (ecdsa or rsa) is required. When using public keys they have to be in a PEM format file. ## Access Control It's common for APIs to control what information they return or insert based on the role of the user. In Super Graph we have two primary roles `user` and `anon` the first for users where a `user_id` is available the latter for users where it's not. ::: tip An authenticated request is one where Super Graph can extract an `user_id` based on the configured authentication method (jwt, rails cookies, etc). ::: The `user` role can be divided up into further roles based on attributes in the database. For example when fetching a list of users, a normal user can only fetch his own entry while an admin can fetch all the users within a company and an admin user can fetch everyone. In some places this is called Attribute based access control. So in way we support both. Role based access control and Attribute based access control. Super Graph allows you to create roles dynamically using a `roles_query` and ` match` config values. ### Configure RBAC ```yaml roles_query: "SELECT * FROM users WHERE users.id = $user_id" roles: - name: user tables: - name: users query: filters: ["{ id: { _eq: $user_id } }"] insert: filters: ["{ user_id: { eq: $user_id } }"] columns: ["id", "name", "description" ] presets: - created_at: "now" update: filters: ["{ user_id: { eq: $user_id } }"] columns: - id - name presets: - updated_at: "now" delete: block: true - name: admin match: users.id = 1 tables: - name: users query: filters: [] ``` This configuration is relatively simple to follow the `roles_query` parameter is the query that must be run to help figure out a users role. This query can be as complex as you like and include joins with other tables. The individual roles are defined under the `roles` parameter and this includes each table the role has a custom setting for. The role is dynamically matched using the `match` parameter for example in the above case `users.id = 1` means that when the `roles_query` is executed a user with the id `1` willbe assigned the admin role and those that don't match get the `user` role if authenticated successfully or the `anon` role. ## Remote Joins It often happens that after fetching some data from the DB we need to call another API to fetch some more data and all this combined into a single JSON response. For example along with a list of users you need their last 5 payments from Stripe. This requires you to query your DB for the users and Stripe for the payments. Super Graph handles all this for you also only the fields you requested from the Stripe API are returned. ::: tip Is this fast? Super Graph is able fetch remote data and merge it with the DB response in an efficient manner. Several optimizations such as parallel HTTP requests and a zero-allocation JSON merge algorithm makes this very fast. All of this without you having to write a line of code. ::: For example you need to list the last 3 payments made by a user. You will first need to look up the user in the database and then call the Stripe API to fetch his last 3 payments. For this to work your user table in the db has a `customer_id` column that contains his Stripe customer ID. Similiarly you could also fetch the users last tweet, lead info from Salesforce or whatever else you need. It's fine to mix up several different `remote joins` into a single GraphQL query. ### Stripe API example The configuration is self explanatory. A `payments` field has been added under the `customers` table. This field is added to the `remotes` subsection that defines fields associated with `customers` that are remote and not real database columns. The `id` parameter maps a column from the `customers` table to the `$id` variable. In this case it maps `$id` to the `customer_id` column. ```yaml tables: - name: customers remotes: - name: payments id: stripe_id url: http://rails_app:3000/stripe/$id path: data # debug: true # pass_headers: # - cookie # - host set_headers: - name: Authorization value: Bearer ``` #### How do I make use of this? Just include `payments` like you would any other GraphQL selector under the `customers` selector. Super Graph will call the configured API for you and stitch (merge) the JSON the API sends back with the JSON generated from the database query. GraphQL features like aliases and fields all work. ```graphql query { customers { id email payments { customer_id amount billing_details } } } ``` And voila here is the result. You get all of this advanced and honestly complex querying capability without writing a single line of code. ```json "data": { "customers": [ { "id": 1, "email": "linseymertz@reilly.co", "payments": [ { "customer_id": "cus_YCj3ndB5Mz", "amount": 100, "billing_details": { "address": "1 Infinity Drive", "zipcode": "94024" } }, ... ``` Even tracing data is availble in the Super Graph web UI if tracing is enabled in the config. By default it is enabled in development. Additionally there you can set `debug: true` to enable http request / response dumping to help with debugging. ![Query Tracing](/tracing.png "Super Graph Web UI Query Tracing") ## Database Relationships In most cases you don't need this configuration, Super Graph will discover and learn the relationship graph within your database automatically. It does this using `Foreign Key` relationships that you have defined in your database schema. The below configs are only needed in special cases such as when you don't use foreign keys or when you want to create a relationship between two tables where a foreign key is not defined or cannot be defined. For example in the sample below a relationship is defined between the `tags` column on the `posts` table with the `slug` column on the `tags` table. This cannot be defined as using foreign keys since the `tags` column is of type array `text[]` and Postgres for one does not allow foreign keys with array columns. ```yaml tables: - name: posts columns: - name: tags related_to: tags.slug ``` ## Configuration files Configuration files can either be in YAML or JSON their names are derived from the `GO_ENV` variable, for example `GO_ENV=prod` will cause the `prod.yaml` config file to be used. or `GO_ENV=dev` will use the `dev.yaml`. A path to look for the config files in can be specified using the `-path ` command line argument. We're tried to ensure that the config file is self documenting and easy to work with. ```yaml # Inherit config from this other config file # so I only need to overwrite some values inherits: base app_name: "Super Graph Development" host_port: 0.0.0.0:8080 web_ui: true # debug, info, warn, error, fatal, panic log_level: "debug" # enable or disable http compression (uses gzip) http_compress: true # When production mode is 'true' only queries # from the allow list are permitted. # When it's 'false' all queries are saved to the # the allow list in ./config/allow.list production: false # Throw a 401 on auth failure for queries that need auth auth_fail_block: false # Latency tracing for database queries and remote joins # the resulting latency information is returned with the # response enable_tracing: true # Watch the config folder and reload Super Graph # with the new configs when a change is detected reload_on_config_change: true # File that points to the database seeding script # seed_file: seed.js # Path pointing to where the migrations can be found migrations_path: ./config/migrations # Postgres related environment Variables # SG_DATABASE_HOST # SG_DATABASE_PORT # SG_DATABASE_USER # SG_DATABASE_PASSWORD # Auth related environment Variables # SG_AUTH_RAILS_COOKIE_SECRET_KEY_BASE # SG_AUTH_RAILS_REDIS_URL # SG_AUTH_RAILS_REDIS_PASSWORD # SG_AUTH_JWT_PUBLIC_KEY_FILE # inflections: # person: people # sheep: sheep auth: # Can be 'rails' or 'jwt' type: rails cookie: _app_session # Comment this out if you want to disable setting # the user_id via a header for testing. # Disable in production creds_in_header: true rails: # Rails version this is used for reading the # various cookies formats. version: 5.2 # Found in 'Rails.application.config.secret_key_base' secret_key_base: 0a248500a64c01184edb4d7ad3a805488f8097ac761b76aaa6c17c01dcb7af03a2f18ba61b2868134b9c7b79a122bc0dadff4367414a2d173297bfea92be5566 # Remote cookie store. (memcache or redis) # url: redis://redis:6379 # password: "" # max_idle: 80 # max_active: 12000 # In most cases you don't need these # salt: "encrypted cookie" # sign_salt: "signed encrypted cookie" # auth_salt: "authenticated encrypted cookie" # jwt: # provider: auth0 # secret: abc335bfcfdb04e50db5bb0a4d67ab9 # public_key_file: /secrets/public_key.pem # public_key_type: ecdsa #rsa database: type: postgres host: db port: 5432 dbname: app_development user: postgres password: '' #schema: "public" #pool_size: 10 #max_retries: 0 #log_level: "debug" # Set session variable "user.id" to the user id # Enable this if you need the user id in triggers, etc set_user_id: false # Define additional variables here to be used with filters variables: admin_account_id: "5" # Field and table names that you wish to block blocklist: - ar_internal_metadata - schema_migrations - secret - password - encrypted - token tables: - name: customers remotes: - name: payments id: stripe_id url: http://rails_app:3000/stripe/$id path: data # debug: true pass_headers: - cookie set_headers: - name: Host value: 0.0.0.0 # - name: Authorization # value: Bearer - # You can create new fields that have a # real db table backing them name: me table: users roles_query: "SELECT * FROM users WHERE id = $user_id" roles: - name: anon tables: - name: products limit: 10 query: columns: ["id", "name", "description" ] aggregation: false insert: allow: false update: allow: false delete: allow: false - name: user tables: - name: users query: filters: ["{ id: { _eq: $user_id } }"] - name: products query: limit: 50 filters: ["{ user_id: { eq: $user_id } }"] columns: ["id", "name", "description" ] disable_functions: false insert: filters: ["{ user_id: { eq: $user_id } }"] columns: ["id", "name", "description" ] set: - created_at: "now" update: filters: ["{ user_id: { eq: $user_id } }"] columns: - id - name set: - updated_at: "now" delete: block: true - name: admin match: id = 1000 tables: - name: users filters: [] ``` If deploying into environments like Kubernetes it's useful to be able to configure things like secrets and hosts though environment variables therfore we expose the below environment variables. This is escpecially useful for secrets since they are usually injected in via a secrets management framework ie. Kubernetes Secrets Keep in mind any value can be overwritten using environment variables for example `auth.jwt.public_key_type` converts to `SG_AUTH_JWT_PUBLIC_KEY_TYPE`. In short prefix `SG_`, upper case and all `.` should changed to `_`. #### Postgres environment variables ```bash SG_DATABASE_HOST SG_DATABASE_PORT SG_DATABASE_USER SG_DATABASE_PASSWORD ``` #### Auth environment variables ```bash SG_AUTH_RAILS_COOKIE_SECRET_KEY_BASE SG_AUTH_RAILS_REDIS_URL SG_AUTH_RAILS_REDIS_PASSWORD SG_AUTH_JWT_PUBLIC_KEY_FILE ``` ## Developing Super Graph If you want to build and run Super Graph from code then the below commands will build the web ui and launch Super Graph in developer mode with a watcher to rebuild on code changes. And the demo rails app is also launched to make it essier to test changes. ```bash # yarn is needed to build the web ui brew install yarn # yarn install dependencies and build the web ui (cd web && yarn install && yarn build) # do this the only the time to setup the database docker-compose run rails_app rake db:create db:migrate db:seed # start super graph in development mode with a change watcher docker-compose up ``` ## Learn how the code works [Super Graph codebase explained](https://supergraph.dev/internals.html) ## Apache License 2.0 Apache Public License 2.0 | Copyright © 2018-present Vikram Rangnekar