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Verify Downloaded Files with SHA-256 Checksums
Practice using SHA-256 checksums to verify file integrity, detect corrupted or modified files, and confirm that downloaded data matches the original.
Challenges
Focused, hands-on problems for sharpening your DevOps and server-side skills. Some teach specific concepts while others mirror real-world scenarios. Every challenge includes hints, feedback, and automated solution checks.
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Call an HTTP API with curl: Authenticating with Basic Auth and Bearer Tokens
Practice authenticating to an HTTP API from the command line using both a username and password and a bearer token, and learn a couple of tricks along the way.
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Call an HTTP API with curl: Processing JSON Responses with jq
Practice one of the most common command-line combinations for HTTP API access: fetch a JSON response with curl and pipe it into jq to pretty print, reshape, or get only the relevant parts.
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Call an HTTP API with curl: Reading Resources
Learn the basics of accessing HTTP APIs from the command line: call different endpoints, read the response body, headers, and status code, follow redirects, and request an alternative representation of a server resource.
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DNS 101: Resolve Public, Internal, and Local Hostnames
Practice manually resolving public domains, internal hostnames, and locally defined names to the corresponding IP addresses so you feel confident next time a DNS issue occurs.
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Inspect Network Interfaces, IP Addresses, and Routes on a Linux Host
Practice reading the network configuration of Linux hosts: find interface names, IP and MAC addresses, the default gateway, and detect which routes a server uses to reach different destinations.
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Run a Glibc-incompatible Binary Using chroot
by Başar Subaşı
Export an Alpine container rootfs using crane, set up a chroot environment, and execute a musl-linked binary that fails to run on the host system.
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Kill a Stubborn Process with SIGKILL
by Başar Subaşı
A stubborn process is running on the system, kill it :)
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Debug a Failing Kubernetes Job
by Omkar Shelke
A Job manifest at /home/laborant/batch-job.yaml is exiting with a non-zero exit status. The Job has limited retries configured. Inspect the cluster and the manifest to find the bug, fix it, and reapply.
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Utilize POSIX Threads for Concurrency
by Başar Subaşı
Refactor a slow, single-threaded C file downloader that fetches files sequentially into a multi-threaded program using POSIX Threads (pthreads) to achieve concurrent downloads.