Serverless Microservices Are The New Black

Presentation for my local Ladies of Code chapter in Manchester

Transcript

1. Serverless Microservices
   Are The New Black
   Lorna Mitchell, IBM
   

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2. Serverless
   The secret is: there ARE servers!
   @lornajane
   

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3. Serverless
   FaaS: Functions as a Service
   • write a function (many languages supported)
   • deploy it to the cloud (Lambda, Cloud Functions, etc)
   • only pay while the function is running (charged per GBsec)
   • your platform scales on demand
   @lornajane
   

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4. When To Go Serverless
   • For occasional server needs (contact form on static site)
   • To provide compute power (processing quantities of data)
   • To move heavy lifting off web platform (classic example: PDF
   generation)
   • To create a small, scalable application (focussed API,
   microservices)
   @lornajane
   

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5. Serverless Platforms
   • Amazon Lambda
   • IBM Cloud Functions (aka Apache OpenWhisk)
   • Twilio Functions
   • Azure Functions
   • Google Cloud Functions
   • .... and others arriving all the time
   @lornajane
   

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6. Getting Started
   @lornajane
   

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7. Amazon Lambda
   • Install awscli command line tool (there is also a web
   interface)
   • Set up permissions via IAM and then use aws configure
   to get that set up
   • Write some code, then zip it (e.g. index.js -> hello.zip)
   @lornajane
   

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8. Amazon Lambda
   Create your lambda function by supplying the zip file and some
   options:
   aws lambda create-function \
   --function-name hello1 \
   --runtime nodejs6.10 \
   --role "arn:aws:iam::283476131276:role/service-role/Alexa"
   --description "A demo first Lambda function" \
   --handler index.handler \
   --zip-file fileb://hello.zip
   @lornajane
   

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9. Amazon Lambda
   (if you want to edit your code and redeploy it)
   aws lambda update-function-code \
   --function-name hello1 \
   --zip-file fileb://hello.zip
   Run your lambda function:
   aws lambda invoke --function-name hello1 output.txt
   @lornajane
   

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10. Hello World Lambda
    exports.handler = function(event, context) {
    context.succeed("Hello, World!");
    };
    @lornajane
    

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11. Hello World OpenWhisk
    exports.main = function(args) {
    return({"message": "Hello, World!"});
    };
    @lornajane
    

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12. IBM Cloud Functions
    Get the bx tool with Cloud_Functions plugin, then log in
    Zip and deploy/update your code like this:
    zip hello.zip index.js
    bx wsk action update --kind nodejs:6 demo/hello1 hello.zip
    demo is the package name
    @lornajane
    

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13. Bluemix OpenWhisk
    Run your action from the CLI:
    bx wsk action invoke --blocking demo/hello1
    Enable web access and web request your action:
    bx wsk action update demo/hello1 --web true
    curl https://openwhisk.ng.bluemix.net/api/v1/web/ \
    Lorna.Mitchell_Working/demo/hello1.json
    @lornajane
    

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14. FaaS + HTTP =
    Microservices!
    @lornajane
    

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15. Microservices
    Microservices are:
    • small and modular
    • loosely coupled
    • independently developed and deployed
    • great for building components
    • decentralised
    ... they are basically small HTTP APIs
    @lornajane
    

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16. Lorna's Plans Service
    Keep a list of my travel plans, with locations and dates.
    Use a serverless platform (IBM Cloud Functions) and
    PostgreSQL
    GET /plans list all plans
    GET /plans/42 show one plan
    POST /plans create a new plan
    @lornajane
    

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17. Microservice Design Points
    I prefer RESTful-ish APIs
    • status codes are important
    • headers are for metadata
    • URLs and verbs together define what happens
    • all endpoints are stateless
    • SSL is required
    • security is a solved problem; try OAuth
    @lornajane
    

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18. Microservices + API Gateway
    @lornajane
    

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19. Fetching Plans
    Code for retrieving the plans from the database:
    1 const pgp = require('pg-promise')();
    2 function main(params) {
    3 return new Promise(function(resolve, reject) {
    4 var db = pgp(params.postgres_url, []);
    5 db.any("SELECT * FROM plans", [true])
    6 .then(function(data) {
    7 resolve({body: {plans: data}, statusCode: 200});
    8 })
    9 .catch(function(error) {
    10 reject({body: "An error occurred", statusCode: 400});
    11 });
    12 });
    @lornajane
    

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20. Fetching Plans
    Make this code run when we do GET /plans
    zip -rq get-plans.zip index.js node_modules
    bx wsk action update --kind nodejs:6 --web raw \
    plans-api/get-plans get-plans.zip
    bx wsk api create /plans GET plans-api/get-plans \
    --response-type http
    @lornajane
    

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21. Fetching Plans
    Now let's actually fetch them!
    $ curl https://service.eu.apiconnect.ibmcloud.com/.../plans
    {
    "plans": [{
    "plan_id": 1,
    "travel_date": "2018-02-28T00:00:00.000Z",
    "location": "London"
    }, {
    "plan_id": 2,
    "travel_date": "2018-05-12T00:00:00.000Z",
    "location": "Copenhagen"
    }]
    }
    @lornajane
    

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22. Making Plans
    Make a plan: parse data, insert to database
    1 const pgp = require('pg-promise')();
    2 function main(params) {
    3 return new Promise(function(resolve, reject) {
    4 var db = pgp(params.postgres_url, []);
    5 var d = new Buffer(params.__ow_body, 'base64').toString();
    6 var decoded = JSON.parse(d);
    7 db.one("INSERT INTO plans (location, travel_date) VALUES ($
    8 [decoded.location, decoded.travel_date])
    9 .then(function(data) {
    10 var r = params.base_url + "/" + data.plan_id;
    11 resolve({headers: {"Location": r}, statusCode: 303})
    12 });
    @lornajane
    

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23. Making Plans
    Deploy the code and link it to POST /plans:
    zip -rq write-plan.zip index.js node_modules
    bx wsk action update --kind nodejs:6 --web raw \
    plans-api/write-plan write-plan.zip
    bx wsk api create /plans POST plans-api/write-plan \
    --response-type http
    @lornajane
    

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24. Making Plans
    Time to actually make plans!
    $ curl -L -H "Content-Type: application/json" \
    https://service.eu.apiconnect.ibmcloud.com/.../plans \
    -d '{"location": "Turin", "travel_date": "2018-04-11"}'
    {
    "plans": [{
    "plan_id": 3,
    "travel_date": "2018-04-11T00:00:00.000Z",
    "location": "Turin"
    }]
    }
    @lornajane
    

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25. Serverless Microservices
    @lornajane
    

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26. Serverless
    Ideal for working with many small parts
    Paired with API Gateway for routing and security: perfect
    candidate for microservices
    @lornajane
    

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27. Microservices
    Service Oriented Architecture is alive and well
    • microservices expose endpoints
    • they share reusable components
    • specific components guard access to services
    • each component can be separately developed, tested and
    deployed
    @lornajane
    

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28. Resources
    • Example code:
    https://github.com/lornajane/plans-microservice
    • IBM Cloud Functions: https://www.ibm.com/cloud/functions
    • My blog: https://lornajane.net
    @lornajane
    

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