Rob Allen's DevNotes – Developing software in the Real World

Using a separate master password in 1Password for Mac

I really like the 1Password password manager and recently switched to using the subscription based account. This allows access to my passwords via the web so, as you can imagine, I have a very strong 35 character master password set. On my Mac, I use the 1Password app and that requires me to enter my master password reasonably frequently, so this very long password is not so desirable here. I'm comfortable that a 12 character… continue reading.

Posted on 10 July 2019 in Software Leave a comment

Running PHP applications on Azure App Engine

Azure App Service is a way to host your web application in a container without having to think about the server. It's the same PaaS concept as AWS Elastic Beanstalk and supports all the main web programming languages. It also supports Windows and Linux OS containers. I have a client that is moving an on-premises PHP application to App Service and so have been looking at what I needed to do to deploy it there.… continue reading.

Posted on 3 July 2019 in Azure, PHP One comment so far

Step debugging sphinx-build in PyCharm

I've been trying to solve an issue with the rst2pdf Sphinx extension which allows you to use rst2pdf to create a PDF of your Sphinx documentation rather than using Sphinx's default pdfTeX builder. In order to understand what was happening, I really wanted to inspect variable at certain stages of the process, which is easiest with a step debugger. As I already use PhpStorm for step debugging PHP, I fired up PyCharm and worked out… continue reading.

Posted on 26 June 2019 in Python, rst2pdf Leave a comment

PHP Architect: Serverless PHP With Bref, Part 2

Part two of my article on using Serverless PHP using Bref has been published! In part one, I introduced Bref as we wrote a simple "Hello World" application. Part follows this up exploring a more complete serverless application, my Project365 website. This S3 hosted static website is build using a serverless PHP function that connects to the Flickr API to retrieve my my one-photo-per-day images and present them on a single page per year. In… continue reading.

Posted on 19 June 2019 in AWS Lambda, More Rob, PHP Leave a comment

Keyboard shortcut to Save as PDF on Mac

I regularly print to PDF on my Mac, This is done from the print dialog by selecting Save as PDF from the drop down in the bottom left of the dialog which is a bit of a pain to get using the mouse. I recently discovered that I could create a keyboard shortcut to make this much easier. In System Preferences -> Keyboard -> Shortcuts -> App Shortcuts you can create a keyboard shortcut to… continue reading.

Posted on 12 June 2019 in Computing, Software View all 2 comments

Extracting the base name of a file in Bash

I have a handy bash script that transcodes videos using Don Meton's video_transcoding tools. This script was written in a hurry and one limitation it had was that it re-transcoded any source file even if the output file already existed. The script looked like this:

#!/usr/bin/env bash

readonly source_dir="${1:-MKV}"
readonly output_dir="${2:-MP4}"

for file in "$source_dir"/*.mkv; do
    ./transcode.sh "$file" "$output_dir"
done

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#!/usr/bin/env bash

readonly source_dir="${1:-MKV}"

readonly output_dir="${2:-MP4}"

for file in "$source_dir"/*.mkv; do

./transcode.sh "$file" "$output_dir"

done

What it should do is only run transcode.sh if the output file doesn't exist, so I updated it. Parameter expansion to the rescue! I needed to extract the base… continue reading.

Posted on 5 June 2019 in Development Leave a comment

Circular dependencies in AWS SAM Policies

I'm trying to tighten up the policies of my AWS Lambda function so that it only has access to the one S3 bucket that it needed, so I added an S3CrudPolicy with the BucketName referencing the bucket that's defined in the template. The relevant part of template.yaml looks like this:

Resources:
    ImagesBucket:
        Type: AWS::S3::Bucket
        Properties:
            BucketName: !Sub "${ProjectName}-${UniqueKey}-images"

    ResizeFunction:
        Type: AWS::Serverless::Function
        Properties:
            FunctionName: resize
			# ...
            Events:
                CreateThumbnailEvent:
                    Type: S3
                    Properties:
                        Bucket: !Ref ImagesBucket
                        Events: s3:ObjectCreated:*
            Policies:
                - S3CrudPolicy:
                    BucketName: !Ref ImagesBucket

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Resources:

ImagesBucket:

Type: AWS::S3::Bucket

Properties:

BucketName: !Sub "${ProjectName}-${UniqueKey}-images"

ResizeFunction:

Type: AWS::Serverless::Function

Properties:

FunctionName: resize

# ...

Events:

CreateThumbnailEvent:

Type: S3

Properties:

Bucket: !Ref ImagesBucket

Events: s3:ObjectCreated:*

Policies:

- S3CrudPolicy:

BucketName: !Ref ImagesBucket

However, this creates an error:

Failed to create the changeset: Waiter ChangeSetCreateComplete failed: Waiter encountered
a terminal failure state Status: FAILED. Reason: Circular dependency between resources:
[ImagesBucket, ResizeFunctionRole, ResizeFunction, ResizeFunctionCreateThumbnailEventPermission]

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Failed to create the changeset: Waiter ChangeSetCreateComplete failed: Waiter encountered

a terminal failure state Status: FAILED. Reason: Circular dependency between resources:

[ImagesBucket, ResizeFunctionRole, ResizeFunction, ResizeFunctionCreateThumbnailEventPermission]

(Who is this waiter anyway? This isn't a restaurant!) Solution To solve this, instead of referencing ImageBucket in… continue reading.

Posted on 29 May 2019 in AWS Lambda Leave a comment

Changing the AWS API Gateway response status code in SAM

When creating an API with AWS Lambda and Api Gateway, I discovered that a client request to a given resource with a verb that wasn't supported resulted in an unexpected response. You can see this from this curl command to the /test resource which is only defined for GET:

$ curl -i -X PUT https://mh5rwr9q25.execute-api.eu-west-2.amazonaws.com/prod/test
HTTP/2 403
content-type: application/json
content-length: 42

{"message":"Missing Authentication Token"}

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$ curl -i -X PUT https://mh5rwr9q25.execute-api.eu-west-2.amazonaws.com/prod/test

HTTP/2 403

content-type: application/json

content-length: 42

{"message":"Missing Authentication Token"}

Given that I can GET the /Prod/hello resource, I would not expect to see 405 Method Not Allowed for PUT, and 403 Forbidden is a… continue reading.

Posted on 21 May 2019 in AWS Lambda Leave a comment

My Bref Makefile

In order to use Bref efficiently, I've developed a Makefile so that I don't have to remember all the various commands required. In particular, looking up the correct parameters to sam package & sam deploy is a pain and it's much easier to type make deploy and it all works as I expect. It looks like this:

Posted on 15 May 2019 in AWS Lambda, PHP View all 2 comments

PHP Architect: Serverless PHP With Bref, Part 1

I've written a two-part series on Serverless PHP on AWS Lambda using Matthieu Napoli's Bref for php[architect]. Part one has been published in the May 2019 issue and if you're not already a subscriber, you should be! If you just want to learn about Bref though, then my introduction to Bref is available for free, just for you!

Posted on 9 May 2019 in AWS Lambda, More Rob, PHP One comment so far