Blog | Jeff Bailey

Learn Tmux: Sessions, Windows, Panes, and a Command Reference

September 27, 2026 · 11 min · Jeff Bailey

Learn tmux fast: sessions, windows, panes, the prefix key, and .tmux.conf, plus a searchable command reference and curated videos, podcasts, and books.

“Learn” in white and “Tmux” in yellow appear above a desk silhouette facing a glowing grid of rooms, connected by a broken thread of light.”

jq Cheat Sheet: Filters, Operators, and Output Formats

September 25, 2026 · 9 min · Jeff Bailey

jq cheat sheet for the command line: selecting values, select filters, reshaping objects, arrays and math, string helpers, output flags, and error meanings.

JQ Cheat Sheet title over a silhouetted figure guiding streams of blue and orange light through a row of glowing lens rings that narrow it into a clean beam.

Fix: ssh: connect to host github.com port 22: Connection timed out

September 21, 2026 · 4 min · Jeff Bailey

Your network blocks SSH on port 22, not your key. Route GitHub over ssh.github.com on port 443, make it permanent in ssh config, and verify with git.

Fix: SSH Port 22 Timeout title over a silhouetted figure holding a light before a sealed dark gate while a glowing orange path curves around it to a bright citadel.

Fix: Support for Password Authentication Was Removed

September 21, 2026 · 4 min · Jeff Bailey

GitHub rejects your Git password over HTTPS. Switch the remote to SSH, or create a personal access token and store it, so pushes stop asking.

A terminal showing a git push rejected because password authentication is not supported.

Fix: Too Many Authentication Failures

September 21, 2026 · 4 min · Jeff Bailey

SSH offers every key you own and the server cuts you off after six. Pin one key with IdentitiesOnly, and learn why GitHub gives a different error.

Fix: Too Many Auth Failures title over a silhouetted figure holding one glowing key before an arched gate lit by a column of lights, a huge ring of keys beside them.

Fix: Host Key Verification Failed

September 20, 2026 · 4 min · Jeff Bailey

SSH stops with “Host key verification failed.” Read the warning correctly, decide whether the key really changed, and fix it without disabling checking.

Fix: Host Key Verification Failed title over a silhouetted figure facing two glowing masks, one blue and one orange, above a red warning line.

Fix: src refspec main does not match any

September 20, 2026 · 4 min · Jeff Bailey

Git rejects the push with “src refspec main does not match any”. Four causes: no commit yet, a different branch name, a typo, and nothing committed.

Fix: src refspec Does Not Match title over a silhouetted figure beside a hollow blue wireframe rocket and a solid orange rocket glowing on its launch pad.

How to Use jq With kubectl: Practical Recipes

September 20, 2026 · 5 min · Jeff Bailey

Query Kubernetes with kubectl -o json and jq: find pods that aren’t running, containers without limits, images in use, restart counts, and node capacity.

How to Use jq With kubectl title over a silhouetted figure on an overlook sending orange beams into a vast glowing grid of stacked containers.

jq vs yq: Which One Should You Use?

September 20, 2026 · 6 min · Jeff Bailey

jq vs yq compared on YAML support, syntax, speed, and in-place edits, with tested examples and a pick for each job. They are complements, not rivals.

Title card reading 'jq vs yq: Which One Should You Use?' over a figure standing where a blue path and an orange path diverge.

Structurizr vs Mermaid vs PlantUML for C4 Diagrams

September 20, 2026 · 10 min · Jeff Bailey

Structurizr, Mermaid C4, and C4-PlantUML compared on the same model: layout quality, error checking, offline rendering, and how many views one source buys you.

Title card reading 'Structurizr vs Mermaid vs PlantUML for C4 Diagrams' over a figure among glowing boxes joined by lines.