This week I've been working on a side project to build and api wrapper for podcast index. .NET is my forte, but I want to try my hands on a new stack and chose expressjs. I've created some hello-world stuff in
expressjs before, but this time I wanted to create a full-blown API.
Creating the API
API creation was comparatively straight forward. I picked typescript for expressjs and everything went smooth. I added morgan for minimal logging along with
nodemon. Also, I used
tsoa for swagger document generation. As always everything worked fine in local. 😂
Since I work from a windows machine, I had to install their command line tool for windows.
iwr https://fly.io/install.ps1 -useb | iex
I used powershell occasionally, still that looked like a strange command for me. Soon, I came to know that all these are just shorthand aliases.
iwr is the shorthand for
iex is the shorthand for
Invoke-Expression. So this command means that we send a web request to fetch the powershell file and then execute it.
-UseBasicParsing, which was not found in the MS documentation, I got it from reddit.
Create an app on fly
You can create an app in fly for your local source code by running the command
flyctl launch. This command will scan the source directory and create
fly.toml. You should be logged in for its successful completion.
I'm using some confidential keys, I got form podcastindex.org. So I had to set that in the environment variables. Fly.io helps us to set the envirionment vairables by setting the secrets. You can run the command
flyctl secrets set KEY=VALUE to set secrets. Once set, you can use
flyctl secrets list to view the list of secrets created.
Run the command
flyctl deploy for deploying your application. This command will package your application as a docker container and will deploy in one of the machines. So far so good.
Trouble 1: Deployment succeeded but endpoints are not reachable. 🙄
I got over-excited and went to auto-pilot mode. I should've reviewed the
dockerfile before deployment. In the
dockerfile it was configured the
CMD instruction as
CMD [ "npm", "run", "start" ] and I haven't added any
start script in my npm scripts. I added that and redeployed.
Trouble 2: PodcastIndex is returning unauthorized
We've set the api keys and secrets in environment variables. What could possible go wrong? 🤔
I added some logs and redeployed the app to monitor the secrets set in production. I noticed that the secret value in production is different from the actual. This issue was due to the symbol
$ in the secret string. When i ran the command
flyctl secrets set KEY=xxxx$xxxx,
$ was getting replaced with the word
flyctl. So in production it was coming as
xxxxflyctlxxxx. to fix this i had to escape the character
$ using backtick (`). I reset the secret using backtick and it worked after redeployment.
All sunday I was sitting in front of the monitor. I'm feeling bit tired and sleepy now. It was so tiresome even though it looked so simple. Definitely not a good way to spend your weekend.