Contents of app.py<\/h2>\n\r\nimport os\r\nfrom flask import Flask, jsonify\r\n\r\napp = Flask(__name__)\r\n\r\n@app.route('\/')\r\ndef home():\r\n environment_variables = { key: os.environ[key] for key in os.environ.keys() }\r\n return jsonify(environment_variables)\r\n\r\nif __name__ == '__main__':\r\n port = int(os.getenv("PORT", "5678"))\r\n app.run(host='0.0.0.0', port=port)\r\n<\/pre>\nWhen we run the above script, we first import the Python modules that we will use in our application. <\/p>\n
After that, we create an instance of Flask that will help give us a web interface to check the environment variables. Using the Flask instance, we then apply the route()<\/a> decorator on the home<\/code> function. <\/p>\nWithin the home<\/code> function, we store the environment variables as a dictionary and use jsonify<\/a> to return that dictionary as a HTTP response.<\/p>\nAfter the definition of the home function, we then attempt to extract a port number from the environment. Finally, we run the flask application to listen to that port.<\/p>\n
Contents of manifest.yml<\/h2>\n\r\n---\r\napplications:\r\n- name: FlaskViewCFEnv\r\n memory: 256MB\r\n disk_quota: 256MB\r\n random-route: true\r\n buildpack: python_buildpack\r\n command: python app.py\r\n instances: 1\r\n<\/pre>\nWhen Cloud Foundry look up manifest.yml, it does the following:<\/p>\n
\n- name our application FlaskViewCFEnv<\/strong>.<\/li>\n
- allocate 256MB<\/strong> of ram for our application to use.<\/li>\n
- allocate 256MB<\/strong> of disk space for our application to use.<\/li>\n
- randomly allocate a route for this application.<\/li>\n
- build the container with the Python Buildpack<\/a>.<\/li>\n
- run app.py with the Python binary.<\/li>\n
- spawn one computing instance to run our application<\/li>\n<\/ul>\n
Contents of requirements.txt<\/h2>\n\r\nFlask==1.0.2\r\n<\/pre>\nSince our Python 3 Flask application requires the Flask microframework<\/a>, we specify it in requirements.txt.<\/p>\nContents of runtime.txt<\/h2>\n\r\npython-3.7.3\r\n<\/pre>\nWhen we leave out runtime.txt<\/code>, Cloud Foundry will use Python 2 runtime to run our Python Flask application. Therefore, we specify that we want to run our Python 3 Flask application with version the Python 3.6.7 runtime.<\/p>\nDeploying the Python 3 Flask application to Cloud Foundry and using it to probe the environment variables<\/h2>\n
Once I had created the files, I then <\/p>\n
\n- navigate to the directory that contains the files for my Cloud Foundry application.<\/li>\n
- use cf login<\/a> to select the corresponding Cloud Foundry space<\/a> to deploy my application.<\/li>\n
- use cf push<\/a> to deploy my application.<\/li>\n
- use my browser to access the URL that Cloud Foundry had allocated to my application. My application will then return the environment variables that Cloud Foundry had supplied to it.<\/li>\n<\/ul>\n\n
\n - \n \n
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Save\n <\/a>\n <\/li>\n <\/ul>\n ","protected":false},"excerpt":{"rendered":"When I was trying to build a Python 3 Flask application on Cloud Foundry, I wanted to quickly check the environment variables that Cloud Foundry will supply to my application.<\/p>\n
As a result of that, I created a Python 3 Flask application that will probe the environment variables that it receives from Cloud Foundry.<\/p>\n
This post lists the files that constitute that Python 3 Flask application.<\/p>\n","protected":false},"author":1,"featured_media":1501,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"advanced_seo_description":"","jetpack_seo_html_title":"","jetpack_seo_noindex":false,"jetpack_post_was_ever_published":false,"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"footnotes":""},"categories":[375,4],"tags":[607,584,226,233,254],"jetpack_featured_media_url":"https:\/\/www.techcoil.com\/blog\/wp-content\/uploads\/Cloud-Foundry-logo.gif","jetpack_shortlink":"https:\/\/wp.me\/p245TQ-oc","jetpack-related-posts":[],"jetpack_likes_enabled":true,"jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/www.techcoil.com\/blog\/wp-json\/wp\/v2\/posts\/1500"}],"collection":[{"href":"https:\/\/www.techcoil.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.techcoil.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.techcoil.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.techcoil.com\/blog\/wp-json\/wp\/v2\/comments?post=1500"}],"version-history":[{"count":0,"href":"https:\/\/www.techcoil.com\/blog\/wp-json\/wp\/v2\/posts\/1500\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.techcoil.com\/blog\/wp-json\/wp\/v2\/media\/1501"}],"wp:attachment":[{"href":"https:\/\/www.techcoil.com\/blog\/wp-json\/wp\/v2\/media?parent=1500"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.techcoil.com\/blog\/wp-json\/wp\/v2\/categories?post=1500"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.techcoil.com\/blog\/wp-json\/wp\/v2\/tags?post=1500"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}
When we run the above script, we first import the Python modules that we will use in our application. <\/p>\n
After that, we create an instance of Flask that will help give us a web interface to check the environment variables. Using the Flask instance, we then apply the route()<\/a> decorator on the Within the After the definition of the home function, we then attempt to extract a port number from the environment. Finally, we run the flask application to listen to that port.<\/p>\n When Cloud Foundry look up manifest.yml, it does the following:<\/p>\n Since our Python 3 Flask application requires the Flask microframework<\/a>, we specify it in requirements.txt.<\/p>\n When we leave out Once I had created the files, I then <\/p>\n When I was trying to build a Python 3 Flask application on Cloud Foundry, I wanted to quickly check the environment variables that Cloud Foundry will supply to my application.<\/p>\n As a result of that, I created a Python 3 Flask application that will probe the environment variables that it receives from Cloud Foundry.<\/p>\n This post lists the files that constitute that Python 3 Flask application.<\/p>\n","protected":false},"author":1,"featured_media":1501,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"advanced_seo_description":"","jetpack_seo_html_title":"","jetpack_seo_noindex":false,"jetpack_post_was_ever_published":false,"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"footnotes":""},"categories":[375,4],"tags":[607,584,226,233,254],"jetpack_featured_media_url":"https:\/\/www.techcoil.com\/blog\/wp-content\/uploads\/Cloud-Foundry-logo.gif","jetpack_shortlink":"https:\/\/wp.me\/p245TQ-oc","jetpack-related-posts":[],"jetpack_likes_enabled":true,"jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/www.techcoil.com\/blog\/wp-json\/wp\/v2\/posts\/1500"}],"collection":[{"href":"https:\/\/www.techcoil.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.techcoil.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.techcoil.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.techcoil.com\/blog\/wp-json\/wp\/v2\/comments?post=1500"}],"version-history":[{"count":0,"href":"https:\/\/www.techcoil.com\/blog\/wp-json\/wp\/v2\/posts\/1500\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.techcoil.com\/blog\/wp-json\/wp\/v2\/media\/1501"}],"wp:attachment":[{"href":"https:\/\/www.techcoil.com\/blog\/wp-json\/wp\/v2\/media?parent=1500"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.techcoil.com\/blog\/wp-json\/wp\/v2\/categories?post=1500"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.techcoil.com\/blog\/wp-json\/wp\/v2\/tags?post=1500"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}home<\/code> function. <\/p>\nhome<\/code> function, we store the environment variables as a dictionary and use jsonify<\/a> to return that dictionary as a HTTP response.<\/p>\nContents of manifest.yml<\/h2>\n
\r\n---\r\napplications:\r\n- name: FlaskViewCFEnv\r\n memory: 256MB\r\n disk_quota: 256MB\r\n random-route: true\r\n buildpack: python_buildpack\r\n command: python app.py\r\n instances: 1\r\n<\/pre>\n
\n
Contents of requirements.txt<\/h2>\n
\r\nFlask==1.0.2\r\n<\/pre>\n
Contents of runtime.txt<\/h2>\n
\r\npython-3.7.3\r\n<\/pre>\n
runtime.txt<\/code>, Cloud Foundry will use Python 2 runtime to run our Python Flask application. Therefore, we specify that we want to run our Python 3 Flask application with version the Python 3.6.7 runtime.<\/p>\nDeploying the Python 3 Flask application to Cloud Foundry and using it to probe the environment variables<\/h2>\n
\n
\n
Share\n <\/a>\n <\/li>\n Tweet\n <\/a>\n <\/li>\n Share\n <\/a>\n <\/li>\n Save\n <\/a>\n <\/li>\n <\/ul>\n ","protected":false},"excerpt":{"rendered":"