The Code has been tested on Python 2.7.5
Steps:
1)Created a folder called native_instruments in the Desktop. Then using the virtualenv
command create a virtual environment for this python based project.
[kuvivek@vivekcentos native_instruments]$ virtualenv rest_api
Note: virtualenv command is available by executing the following command
[kuvivek@vivekcentos native_instruments]$
[kuvivek@vivekcentos native_instruments]$ sudo pip install virtualenv
[kuvivek@vivekcentos native_instruments]$
- Once the virtual environment is created it is required to activate the virtual environment. The command to activate the same is:
[kuvivek@vivekcentos native_instruments]$ [kuvivek@vivekcentos native_instruments]$ source rest_api/bin/activate (rest_api) [kuvivek@vivekcentos native_instruments]$ (rest_api) [kuvivek@vivekcentos native_instruments]$ which python ~/Desktop/native_instruments/rest_api/bin/python (rest_api) [kuvivek@vivekcentos native_instruments]$ (rest_api) [kuvivek@vivekcentos native_instruments]$ (rest_api) [kuvivek@vivekcentos native_instruments]$ python --version Python 2.7.5 (rest_api) [kuvivek@vivekcentos native_instruments]$
- After developing the REST API Backend framework
(rest_api) [kuvivek@vivekcentos native_instruments]$ (rest_api) [kuvivek@vivekcentos native_instruments]$ ls app.py database_setup.py docker-compose.yml Dockerfile __init__.py populate_db.py README.md requirements.txt resources.py rest_api (rest_api) [kuvivek@vivekcentos native_instruments]$
The flask web based application server need to be started. The starting point of this application server is app.py. end Inorder to start the application server, so as to expose the sought REST API calls and support the Stanadard HTTP Headers, following commands is used:
(rest_api) [kuvivek@vivekcentos native_instruments]$
(rest_api) [kuvivek@vivekcentos native_instruments]$ python app.py
* Serving Flask app "app" (lazy loading)
* Environment: production
WARNING: This is a development server. Do not use it in a production deployment.
Use a production WSGI server instead.
* Debug mode: on
* Running on http://127.0.0.1:5000/ (Press CTRL+C to quit)
* Restarting with stat
* Debugger is active!
* Debugger PIN: 113-909-490
- Now run another terminal and execute the curl commands to verify all the Standard HTTP protocols. Note: For getting errorcode, from any of the curl command, add -i option, as shown in HEAD request below.
Since there are no records initially, Hence reporting empty list.
(rest_api) [kuvivek@vivekcentos native_instruments]$
(rest_api) [kuvivek@vivekcentos native_instruments]$ curl -X GET http://127.0.0.1:5000/keys
[]
(rest_api) [kuvivek@vivekcentos native_instruments]$
(rest_api) [kuvivek@vivekcentos native_instruments]$
-
Lets push some data using the POST command
(rest_api) [kuvivek@vivekcentos native_instruments]$ (rest_api) [kuvivek@vivekcentos native_instruments]$ curl -d '{"chore1": "Wake up at 6 in the morning"}' -H "Content-Type: application/json" -X POST http://127.0.0.1:5000/keys { "chore1": "Wake up at 6 in the morning" } (rest_api) [kuvivek@vivekcentos native_instruments]$
(rest_api) [kuvivek@vivekcentos native_instruments]$ (rest_api) [kuvivek@vivekcentos native_instruments]$ curl -H "Content-Type: application/json" -X POST http://127.0.0.1:5000/keys -d '{"chore2": "Prepare breakfast and lunch box for daughter before 7:00 A.M "}' { "chore2": "Prepare breakfast and lunch box for daughter before 7:00 A.M " } (rest_api) [kuvivek@vivekcentos native_instruments]$
- Try to post the data for the same key using POST header, which is not supported But the same can be achieved via the PUT request.
(rest_api) [kuvivek@vivekcentos native_instruments]$ (rest_api) [kuvivek@vivekcentos native_instruments]$ curl -H "Content-Type: application/json" -X POST http://127.0.0.1:5000/keys -d '{"chore2": "Go for morning walk from 7:30 A.M."}' Chore title already exist. (rest_api) [kuvivek@vivekcentos native_instruments]$ (rest_api) [kuvivek@vivekcentos native_instruments]$ curl -H "Content-Type: application/json" -X PUT http://127.0.0.1:5000/keys/chore2 -d '{"chore2": "Go for morning walk from 7:30 A.M."}' Updated the chore with id chore2 (rest_api) [kuvivek@vivekcentos native_instruments]$
- Now, Query for all the keys, the second one which was modified should be updated one, from the value what was added in Step 5)
(rest_api) [kuvivek@vivekcentos native_instruments]$ (rest_api) [kuvivek@vivekcentos native_instruments]$ curl http://127.0.0.1:5000/keys [ { "chore1": "Wake up at 6 in the morning" }, { "chore2": "Go for morning walk from 7:30 A.M." } ] (rest_api) [kuvivek@vivekcentos native_instruments]$ (rest_api) [kuvivek@vivekcentos native_instruments]$
- Now lets add one more chore and then delete that chore.
(rest_api) [kuvivek@vivekcentos native_instruments]$ (rest_api) [kuvivek@vivekcentos native_instruments]$ curl -H "Content-Type: application/json" -X POST http://127.0.0.1:5000/keys -d '{"chore3": "Eat breakfast by 8:30."}' { "chore3": "Eat breakfast by 8:30." } (rest_api) [kuvivek@vivekcentos native_instruments]$ (rest_api) [kuvivek@vivekcentos native_instruments]$ curl http://127.0.0.1:5000/keys [ { "chore1": "Wake up at 6 in the morning" }, { "chore2": "Go for morning walk from 7:30 A.M." }, { "chore3": "Eat breakfast by 8:30." } ] (rest_api) [kuvivek@vivekcentos native_instruments]$ (rest_api) [kuvivek@vivekcentos native_instruments]$ (rest_api) [kuvivek@vivekcentos native_instruments]$ curl -X DELETE http://127.0.0.1:5000/keys/chore3 Removed Chore with id chore3 (rest_api) [kuvivek@vivekcentos native_instruments]$ (rest_api) [kuvivek@vivekcentos native_instruments]$ curl http://127.0.0.1:5000/keys [ { "chore1": "Wake up at 6 in the morning" }, { "chore2": "Go for morning walk from 7:30 A.M." } ] (rest_api) [kuvivek@vivekcentos native_instruments]$
- Verify whether a key exist or not using HEAD HTTP request. Since the REST API Service supported by the flask web application server gives json response in case of success and html error page with failure query. Attempting failure request first by looking for record which was deleted in the previous step.
(rest_api) [kuvivek@vivekcentos native_instruments]$ (rest_api) [kuvivek@vivekcentos native_instruments]$ curl -X HEAD -i http://127.0.0.1:5000/keys/chore3 HTTP/1.0 200 OK Content-Type: text/html; charset=utf-8 Content-Length: 21 Server: Werkzeug/0.15.5 Python/2.7.5 Date: Fri, 16 Aug 2019 06:53:07 GMT curl: (18) transfer closed with 21 bytes remaining to read (rest_api) [kuvivek@vivekcentos native_instruments]$
- Trying the HEAD Request with actual record. Here the response type is application/json, unlike previous previous response, wherein the response is an html error page.
(rest_api) [kuvivek@vivekcentos native_instruments]$ (rest_api) [kuvivek@vivekcentos native_instruments]$ curl -X HEAD -i http://127.0.0.1:5000/keys/chore2 HTTP/1.0 200 OK Content-Type: application/json Content-Length: 53 Server: Werkzeug/0.15.5 Python/2.7.5 Date: Fri, 16 Aug 2019 06:53:15 GMT curl: (18) transfer closed with 53 bytes remaining to read (rest_api) [kuvivek@vivekcentos native_instruments]$ (rest_api) [kuvivek@vivekcentos native_instruments]$
- Deleting all the keys.
(rest_api) [kuvivek@vivekcentos native_instruments]$ (rest_api) [kuvivek@vivekcentos native_instruments]$ curl -X DELETE http://127.0.0.1:5000/keys 2 records deleted (rest_api) [kuvivek@vivekcentos native_instruments]$ (rest_api) [kuvivek@vivekcentos native_instruments]$ curl http://127.0.0.1:5000/keys [] (rest_api) [kuvivek@vivekcentos native_instruments]$ (rest_api) [kuvivek@vivekcentos native_instruments]$
- Dockerizing the application. Create a Dockerfile and docker-compose.yml file for this flask web application Install docker engine and docker-compose binary and modify the app.py to expose the 5000 and allow connection from outside container. For this instead of first parameter 127.0.0.1 in the app.run() function, change it to 0.0.0.0. So that it is accessible from outside world.
Executing the following command, builds the image and launches the Web application container, and all the behaviours can be tested locally using the curl command.
(rest_api) [kuvivek@vivekcentos native_instruments]$ which docker-compose
/usr/local/bin/docker-compose
(rest_api) [kuvivek@vivekcentos native_instruments]$
(rest_api) [kuvivek@vivekcentos native_instruments]$
(rest_api) [kuvivek@vivekcentos native_instruments]$ sudo /usr/local/bin/docker-compose up
Building web
Step 1/6 : FROM python:2.7
2.7: Pulling from library/python
4ae16bd47783: Pull complete
bbab4ec87ac4: Pull complete
2ea1f7804402: Pull complete
96465440c208: Pull complete
6ac892e64b94: Pull complete
6f7ce750b843: Pull complete
886c714e5c8c: Pull complete
11129766a052: Pull complete
4a086c8425c2: Pull complete
Digest: sha256:42b8afcfec99c9d2aa2410ab680d53fdcea328d38ca876e2bd3dad089cb0ed0c
Status: Downloaded newer image for python:2.7
---> d75b4eed9ada
Step 2/6 : MAINTAINER Vivek Kumar, [email protected]
---> Running in 7705a10afef4
Removing intermediate container 7705a10afef4
---> f046790583f3
Step 3/6 : COPY ./requirements.txt /code/requirements.txt
---> 3b8d568c31e6
Step 4/6 : WORKDIR /code
---> Running in f755ab209cd5
Removing intermediate container f755ab209cd5
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Step 5/6 : RUN pip install -r requirements.txt
---> Running in 5bab97aed882
DEPRECATION: Python 2.7 will reach the end of its life on January 1st, 2020. Please upgrade your Python as Python 2.7 won't be maintained after that date. A future version of pip will drop support for Python 2.7. More details about Python 2 support in pip, can be found at https://pip.pypa.io/en/latest/development/release-process/#python-2-support
Collecting Click==7.0 (from -r requirements.txt (line 1))
Downloading https://files.pythonhosted.org/packages/fa/37/45185cb5abbc30d7257104c434fe0b07e5a195a6847506c074527aa599ec/Click-7.0-py2.py3-none-any.whl (81kB)
Collecting Flask==1.1.1 (from -r requirements.txt (line 2))
Downloading https://files.pythonhosted.org/packages/9b/93/628509b8d5dc749656a9641f4caf13540e2cdec85276964ff8f43bbb1d3b/Flask-1.1.1-py2.py3-none-any.whl (94kB)
Collecting Flask-Caching==1.7.2 (from -r requirements.txt (line 3))
Downloading https://files.pythonhosted.org/packages/bd/4e/c701bdcd566f26187398cf058ad2ca14c8b2f50b17a17f9076794ae2f8db/Flask_Caching-1.7.2-py2.py3-none-any.whl
Collecting itsdangerous==1.1.0 (from -r requirements.txt (line 4))
Downloading https://files.pythonhosted.org/packages/76/ae/44b03b253d6fade317f32c24d100b3b35c2239807046a4c953c7b89fa49e/itsdangerous-1.1.0-py2.py3-none-any.whl
Collecting Jinja2==2.10.1 (from -r requirements.txt (line 5))
Downloading https://files.pythonhosted.org/packages/1d/e7/fd8b501e7a6dfe492a433deb7b9d833d39ca74916fa8bc63dd1a4947a671/Jinja2-2.10.1-py2.py3-none-any.whl (124kB)
Collecting MarkupSafe==1.1.1 (from -r requirements.txt (line 6))
Downloading https://files.pythonhosted.org/packages/fb/40/f3adb7cf24a8012813c5edb20329eb22d5d8e2a0ecf73d21d6b85865da11/MarkupSafe-1.1.1-cp27-cp27mu-manylinux1_x86_64.whl
Collecting SQLAlchemy==1.3.6 (from -r requirements.txt (line 7))
Downloading https://files.pythonhosted.org/packages/55/98/56b7155bab287cd0c78dee26258835db36e91f2efef41f125ed6f6f1f334/SQLAlchemy-1.3.6.tar.gz (5.9MB)
Collecting Werkzeug==0.15.5 (from -r requirements.txt (line 8))
Downloading https://files.pythonhosted.org/packages/d1/ab/d3bed6b92042622d24decc7aadc8877badf18aeca1571045840ad4956d3f/Werkzeug-0.15.5-py2.py3-none-any.whl (328kB)
Building wheels for collected packages: SQLAlchemy
Building wheel for SQLAlchemy (setup.py): started
Building wheel for SQLAlchemy (setup.py): finished with status 'done'
Created wheel for SQLAlchemy: filename=SQLAlchemy-1.3.6-cp27-cp27mu-linux_x86_64.whl size=1183954 sha256=c3419564240f90ce382d9e57685e4eb1689d15ecea9c0dded7959933316fdfbb
Stored in directory: /root/.cache/pip/wheels/f2/ec/e0/d7deb0c981557e373edf7370574b7001690892afe5fea30c3c
Successfully built SQLAlchemy
Installing collected packages: Click, Werkzeug, itsdangerous, MarkupSafe, Jinja2, Flask, Flask-Caching, SQLAlchemy
Successfully installed Click-7.0 Flask-1.1.1 Flask-Caching-1.7.2 Jinja2-2.10.1 MarkupSafe-1.1.1 SQLAlchemy-1.3.6 Werkzeug-0.15.5 itsdangerous-1.1.0
WARNING: You are using pip version 19.2.2, however version 19.2.3 is available.
You should consider upgrading via the 'pip install --upgrade pip' command.
Removing intermediate container 5bab97aed882
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Step 6/6 : CMD python app.py
---> Running in 701b63fd72e5
Removing intermediate container 701b63fd72e5
---> 5ed932067546
Successfully built 5ed932067546
Successfully tagged native_instruments_web:latest
WARNING: Image for service web was built because it did not already exist. To rebuild this image you must use `docker-compose build` or `docker-compose up --build`.
Creating native_instruments_web_1_e78eaebaaf02 ... done
Attaching to native_instruments_web_1_a15cf8fef3ab
web_1_a15cf8fef3ab | * Serving Flask app "app" (lazy loading)
web_1_a15cf8fef3ab | * Environment: production
web_1_a15cf8fef3ab | WARNING: This is a development server. Do not use it in a production deployment.
web_1_a15cf8fef3ab | Use a production WSGI server instead.
web_1_a15cf8fef3ab | * Debug mode: on
web_1_a15cf8fef3ab | * Running on http://0.0.0.0:5000/ (Press CTRL+C to quit)
web_1_a15cf8fef3ab | * Restarting with stat
web_1_a15cf8fef3ab | * Debugger is active!
web_1_a15cf8fef3ab | * Debugger PIN: 697-470-609