feat: Assignment 1; initialization

devopsHosts.tex

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+\chapter{Hosts}
+\ChapterLabel{Hosts}
+\index{hosts}
+\index{hosts!inventory}
+\index{hosts!naming convention}
+\index{development environment}
+\index{Amazon EC2}
+
+\section{Purpose}
+This chapter names the hosts that will make up the development environment for
+\CourseNumber\ and records the role, platform, and ownership of each. It is an
+inventory of intent: no machine listed here has been provisioned, and the chapter therefore
+presents no execution \gls{evidence}. It is expected to grow as later
+assignments add services to the environment.
+
+\section{Naming Convention}
+\index{hosts!naming}
+Each \gls{host} that is provisioned for this course is named
+\texttt{ssw590-\textit{role}-\textit{nn}}, where \textit{role} identifies the
+function the machine serves and \textit{nn} is a two-digit ordinal within that
+role. Naming by role rather than by instance identifier keeps the name stable
+if the underlying machine is replaced, and keeps the inventory readable when
+more than one host serves the same purpose. Hosts that already exist
+independently of this course retain their existing names.
+
+\section{Host Inventory}
+\index{hosts!table}
+The \textbf{Status} column distinguishes machines already in use from those that
+will be configured in a later assignment. A host is marked \emph{In service}
+only once it exists and is reachable.
+
+\begin{tabularx}{\linewidth}{L{3.0cm}YL{3.3cm}L{2.0cm}}
+\caption{Planned Host Inventory\label{Table:HostInventory}}\\
+\toprule \textbf{Host name} & \textbf{Role} & \textbf{Platform} & \textbf{Status}\\ \midrule
+\endfirsthead
+\multicolumn{4}{l}{\small\itshape Planned Host Inventory (continued)}\\
+\toprule \textbf{Host name} & \textbf{Role} & \textbf{Platform} & \textbf{Status}\\ \midrule
+\endhead \bottomrule \endlastfoot
+\texttt{ssw590-dev-01} & Primary Linux host for the course. Target for service configuration, deployment exercises, and command-line work. & Ubuntu Server LTS on Amazon EC2 & Planned\\
+\texttt{ssw590-build-01} & Build and integration host, kept separate from the deployment target so that a failed build cannot disturb a running service. To be provisioned only if a later assignment requires it. & Ubuntu Server LTS on Amazon EC2 & Conditional\\
+\end{tabularx}
+
+\section{Access and Ownership}
+\index{hosts!access model}
+\index{least privilege}
+All hosts listed above are owned and administered by the author. The following
+rules govern access to the Linux hosts once they are provisioned.
+
+\begin{itemize}[leftmargin=*]
+\item Interactive access is by \gls{ssh} public key only.
+      Password authentication is disabled in the server configuration.
+      The local account password recorded in \ChapterRef{Passwords} authenticates \texttt{sudo} only.
+\item Inbound \gls{ssh} is restricted by source address to the workstation
+      listed above rather than opened to the public Internet.
+\item Day-to-day work is performed by an unprivileged account. Administrative
+      rights are granted per command rather than by general membership in the
+      \texttt{sudo} group.
+\item Should a teammate require access after teams are formalized, that person
+      receives a separate named account rather than a shared login, so that
+      access can be revoked individually and actions remain attributable.
+\end{itemize}
+
+\section{Cost and Cleanup}
+\index{hosts!cost}
+\index{hosts!teardown}
+The Linux hosts are expected to run on the smallest instance size that supports
+the coursework, under whatever free-tier or credit allowance the account
+provides, with a billing alarm configured before the first instance is
+launched. Compute is billed per instance-hour, and attached storage whether or
+not the instance is running, so each additional host adds cost independently of
+how heavily it is used: provisioning \texttt{ssw590-build-01} alongside
+\texttt{ssw590-dev-01} would approximately double the compute cost of the
+environment. It is therefore left unprovisioned until an assignment requires
+builds to be isolated from the deployment target, and would be stopped between
+uses rather than run continuously; only \texttt{ssw590-dev-01} needs to remain
+available at all times.
+
+Each planned host is disposable. Teardown consists of terminating the instance,
+deleting the attached storage volume, and releasing any static address reserved
+for it; a static address left reserved after the instance is gone continues to
+be billed. Because the \gls{ami} and the configuration steps are recorded, a
+terminated host can be rebuilt rather than preserved, which is why teardown is
+treated as routine rather than exceptional.