Web and DevOps Tools
Web and DevOps collects the small references and generators that come up when you deploy and operate a website or service. Three are lookups you keep open in a tab: every HTTP status code with its RFC section, MIME types for file extensions with the server line to serve them, and a User-Agent parser that names the browser, device or bot behind a request. Five write configuration for you: redirect rules for Apache, Nginx, Netlify and Vercel, cron schedules with their next run times, docker-compose.yml files from docker run commands, .gitignore files from templates, and chmod modes in octal or symbolic form.
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All Web & DevOps (8)
HTTP Status Codes
Every HTTP status code with meaning, RFC and when to use itMIME Type Lookup
Find the MIME type for a file extension or the reverseUser Agent Parser
Browser, OS, device and bot detection from a user agentCron Expression Generator
Build a cron schedule from plain choices and preview runsRedirect Rules Generator
301 and 302 rules for .htaccess, Nginx, Netlify and VercelDocker Run to Compose Converter
Convert docker run commands to docker-compose.yml and back.gitignore Generator
Combine .gitignore templates for languages, IDEs and OSesChmod Calculator
Unix permissions between octal, symbolic and checkboxes
Which tool do I need?
Move pages to new URLs without losing traffic
Generate 301 or 308 rules for your server and check that you are using the right code for permanent and temporary moves.
Schedule a recurring job
Build the cron expression from plain choices, preview the next runs in your time zone and get the GitHub Actions, Kubernetes or EventBridge form.
Turn docker run commands into a Compose stack
Convert the commands from a README into a compose.yaml, then add a .gitignore so env files and data folders stay out of git.
Fix "Permission denied" after a deploy
Work out the right chmod mode for files, directories, scripts and keys, and the commands to apply it to a whole tree.
Find out why a file downloads instead of displaying
Look up the correct Content-Type for the extension and the line to add to nginx, Apache or IIS, then check the response code.
Work out who is hitting your site
Parse user agents from logs to separate real browsers from search, AI and SEO crawlers, and see which status codes they get.
About Web & DevOps
Every tool runs in your browser, so you can paste internal URLs, compose files with real service names or access-log user agents without sending them anywhere. The generators check what they produce: the redirect tool flags loops and chains, the cron tool warns about dates that never occur and the day-of-month OR rule, the Docker converter lists flags that have no Compose equivalent, and the .gitignore tester shows which line ignores a path. Each tool links to a longer article on the subject for when you need the reasoning, not just the answer.
Guides
- 301, 302, 307 or 308? Writing Redirects for Apache, Nginx, Netlify and VercelThe right redirect code for pages and APIs, what each does for SEO and caching, and working rules for Apache mod_rewrite, Nginx return, Netlify _redirects and vercel.json, plus chains and loops.
- Cron Schedules Across Platforms: Crontab, GitHub, Kubernetes, AWSBuilding a cron schedule that does what you mean: the five fields, the day-of-month OR rule, time zones and daylight saving, and how GitHub, Kubernetes, Quartz and EventBridge read it.
- From docker run to Docker Compose: Every Flag MappedHow docker run flags become Compose keys, named volumes versus bind mounts, networks and service DNS, GPUs, health checks, the flags with no equivalent, the obsolete version key, and going back again.
- Linux File Permissions and chmod: 755, 644 and BeyondWhat read, write and execute mean on files and directories, octal and symbolic chmod, capital X, setuid, setgid and sticky, umask defaults, and safe recipes for web roots and SSH keys.
Frequently asked questions
Do the Web and DevOps tools connect to my server?
No. They generate text or look things up in tables that ship with the page. Nothing is uploaded, and none of them can reach your server, so you copy the output into your configuration yourself and test it there, for example with curl -I for redirects or crontab -l for schedules.
Which redirect status code should I use when moving a site?
Use 301 for pages and 308 for endpoints that receive POST or PUT requests. Both are permanent, so search engines move the old URL's signals to the new one. Use 302 or 307 only for moves you plan to undo, and test with a temporary code first because browsers cache permanent redirects.
Why do cron schedules behave differently on GitHub Actions, AWS and Kubernetes?
They read the expression with different rules. GitHub Actions uses five fields in UTC with a five-minute minimum, Kubernetes uses five fields in the controller's time zone unless spec.timeZone is set, and AWS EventBridge and Quartz use six fields with a ? in one of the day fields and Sunday counted as 1.
Is it safe to paste docker run commands with passwords into the converter?
The conversion happens in your browser and nothing is sent anywhere. Even so, move secrets out of the generated file into an env_file or Docker secrets before committing it, and list that file in .gitignore.
What permissions should web files and folders have?
Usually 644 for files and 755 for directories, owned by the deploy user, with the web server able to read them. Private keys and .env files should be 600. Avoid 777, which lets any user on the machine change your site.