Add .NET SDK installation phase

docs/BUILD-LOG.md

@@ -10,6 +10,55 @@ This file records chronological Atlas build and infrastructure milestones. Do no
 
 ### Phase
 
+Phase 2 .NET development platform.
+
+### Objective
+
+Install the .NET SDKs required for Atlas and PlotDirector development.
+
+### Changes
+
+- Added `install/phases/10-dotnet.sh`.
+- Installed .NET 8 SDK `8.0.128`.
+- Installed .NET 10 SDK `10.0.109`.
+- Used the official Ubuntu .NET backports PPA for .NET 8.
+- Used the built-in Ubuntu `resolute-updates` and `resolute-security` package sources for .NET 10.
+- Did not install .NET 9, SQL Server, nginx, or Docker.
+
+### Validation
+
+- `bash -n install/phases/10-dotnet.sh` passed.
+- `install/phases/10-dotnet.sh --help` passed.
+- `install/phases/10-dotnet.sh --dry-run` passed.
+- `install/phases/10-dotnet.sh` installed the missing SDKs.
+- A second `install/phases/10-dotnet.sh` run detected both SDKs already installed.
+- `dotnet --info`, `dotnet --list-sdks`, and `dotnet --list-runtimes` passed.
+- Temporary .NET 8 and .NET 10 console projects built and ran outside the repository.
+- `scripts/system/validate-host.sh` passed after installation.
+
+### Problems
+
+- Initial package-candidate detection in `10-dotnet.sh` was corrected after it failed under `pipefail` before installing SDK packages.
+- No unresolved .NET installation problems recorded.
+
+### Decisions
+
+- Use Ubuntu package feeds for .NET SDK installation on Ubuntu 26.04.
+
+### Git Commit
+
+Not yet committed.
+
+### Operator
+
+Codex.
+
+### Date
+
+2026-07-10
+
+### Phase
+
 Phase 2A.
 
 ### Objective

docs/REBUILD-GUIDE.md

@@ -8,7 +8,8 @@ This guide describes the planned rebuild path for Atlas. At Phase 1, the reposit
 - Shared installation framework: present.
 - System discovery script: present.
 - Host validation script: present.
-- Component installation scripts: not yet created.
+- .NET installation script: present.
+- Other component installation scripts: not yet created.
 - Configuration templates: not yet created.
 - Operational scripts: not yet created.
 - Smoke tests: not yet created.
@@ -112,8 +113,9 @@ Planned bootstrap flow:
 4. Run `scripts/system/discover-system.sh`.
 5. Run `scripts/system/validate-host.sh`.
 6. Run `install/bootstrap.sh --dry-run`.
-7. Run ordered installation scripts from `install/phases/` when they exist.
-8. Run smoke tests from `tests/` when they exist.
+7. Run `install/phases/10-dotnet.sh` when .NET SDKs are required.
+8. Run additional ordered installation scripts from `install/phases/` when they exist.
+9. Run smoke tests from `tests/` when they exist.
 
 Bootstrap command sequence is `TODO: Confirm during the relevant implementation phase.`
 
@@ -137,6 +139,22 @@ These scripts do not exist yet. When created, each script must:
 - Document rollback expectations.
 - Include or reference validation steps.
 
+Current .NET installation command:
+
+```bash
+install/phases/10-dotnet.sh
+```
+
+Current .NET verification commands:
+
+```bash
+dotnet --info
+dotnet --list-sdks
+dotnet --list-runtimes
+```
+
+The current installed SDKs are .NET 8 SDK `8.0.128` and .NET 10 SDK `10.0.109`.
+
 ## 8. Validation
 
 Minimum rebuild validation should confirm:

install/README.md

@@ -48,6 +48,21 @@ manifests/
 phases/
 ```
 
+Current Phase 2 installer:
+
+```bash
+install/phases/10-dotnet.sh
+```
+
+The .NET installer installs only the required .NET SDK packages and verifies them with `dotnet --list-sdks`.
+
+Current installed SDKs:
+
+- .NET 8 SDK `8.0.128`
+- .NET 10 SDK `10.0.109`
+
+.NET 8 is installed from the official Ubuntu .NET backports PPA. .NET 10 is installed from the built-in Ubuntu package feeds.
+
 Runtime output belongs outside the repository:
 
 - `/var/log/atlas/install/`

install/bootstrap.sh

@@ -98,4 +98,3 @@ else
 fi
 
 atlas_log_ok "Bootstrap scaffold completed"
-

install/lib/packages.sh

@@ -41,4 +41,3 @@ atlas_pending_update_count() {
 atlas_reboot_required() {
   [[ -f /var/run/reboot-required ]]
 }
-

install/lib/services.sh

@@ -55,4 +55,3 @@ atlas_service_restart() {
   atlas_log_info "Restarting service ${service_name}"
   atlas_sudo_run systemctl restart "$service_name"
 }
-

install/lib/validation.sh

@@ -65,4 +65,3 @@ atlas_gib_to_bytes() {
   local gib="$1"
   awk -v gib="$gib" 'BEGIN {printf "%.0f\n", gib * 1024 * 1024 * 1024}'
 }
-

install/manifests/baseline-commands.txt

@@ -29,4 +29,3 @@ awk|required|Text processing
 sed|required|Text processing
 grep|required|Text searching
 sudo|required|Non-interactive privileged command execution
-

install/phases/10-dotnet.sh

@@ -0,0 +1,178 @@
+#!/usr/bin/env bash
+set -Eeuo pipefail
+
+SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+INSTALL_DIR="$(cd "${SCRIPT_DIR}/.." && pwd)"
+REPO_ROOT="$(cd "${INSTALL_DIR}/.." && pwd)"
+
+# shellcheck source=install/lib/common.sh
+source "${INSTALL_DIR}/lib/common.sh"
+# shellcheck source=install/lib/logging.sh
+source "${INSTALL_DIR}/lib/logging.sh"
+# shellcheck source=install/lib/packages.sh
+source "${INSTALL_DIR}/lib/packages.sh"
+
+atlas_set_script_name "10-dotnet.sh"
+atlas_install_error_trap
+
+REQUIRED_OS_ID="ubuntu"
+REQUIRED_OS_VERSION="26.04"
+DOTNET_BACKPORTS_PPA="ppa:dotnet/backports"
+DOTNET_REQUIRED_PACKAGES=("dotnet-sdk-8.0" "dotnet-sdk-10.0")
+
+usage() {
+  cat <<'USAGE'
+Usage: install/phases/10-dotnet.sh [options]
+
+Install the Atlas .NET development SDKs from official Ubuntu package feeds.
+
+Required SDKs:
+  dotnet-sdk-8.0
+  dotnet-sdk-10.0
+
+Options:
+  --help       Show this help text.
+  --version    Show script/framework version.
+  --dry-run    Show intended actions without making changes.
+  --verbose    Print additional diagnostic output.
+
+USAGE
+}
+
+while [[ "$#" -gt 0 ]]; do
+  case "$1" in
+    --help)
+      usage
+      exit "${ATLAS_EXIT_OK}"
+      ;;
+    --version)
+      atlas_print_version
+      exit "${ATLAS_EXIT_OK}"
+      ;;
+    --dry-run)
+      atlas_enable_dry_run
+      ;;
+    --verbose)
+      atlas_enable_verbose
+      ;;
+    *)
+      atlas_usage_error "Unknown option: $1"
+      exit "${ATLAS_EXIT_USAGE}"
+      ;;
+  esac
+  shift
+done
+
+load_os_release() {
+  if [[ ! -r /etc/os-release ]]; then
+    atlas_log_error "/etc/os-release is not readable"
+    exit "${ATLAS_EXIT_PREREQ}"
+  fi
+  # shellcheck disable=SC1091
+  . /etc/os-release
+  if [[ "${ID:-}" != "${REQUIRED_OS_ID}" || "${VERSION_ID:-}" != "${REQUIRED_OS_VERSION}" ]]; then
+    atlas_log_error "Unsupported OS: ${PRETTY_NAME:-unknown}; expected Ubuntu 26.04"
+    exit "${ATLAS_EXIT_PREREQ}"
+  fi
+}
+
+package_has_candidate() {
+  local package_name="$1"
+  local candidate
+  candidate="$(apt-cache policy "$package_name" 2>/dev/null | awk -F: '/Candidate:/ {gsub(/^[ \t]+/, "", $2); print $2; exit}')"
+  [[ -n "$candidate" && "$candidate" != "(none)" ]]
+}
+
+backports_configured() {
+  grep -RqsE 'ppa\\.launchpadcontent\\.net/dotnet/backports|LP-PPA-dotnet-backports|dotnet-ubuntu-backports' /etc/apt/sources.list /etc/apt/sources.list.d 2>/dev/null
+}
+
+ensure_backports_if_needed() {
+  if package_has_candidate dotnet-sdk-8.0; then
+    atlas_log_info "dotnet-sdk-8.0 is available from configured package sources"
+    return 0
+  fi
+
+  if backports_configured; then
+    atlas_log_info "Ubuntu .NET backports repository is configured; refreshing package metadata"
+    atlas_sudo_run apt-get update
+    return 0
+  fi
+
+  atlas_log_info "dotnet-sdk-8.0 is not available; adding official Ubuntu .NET backports repository"
+  if [[ "${ATLAS_DRY_RUN}" == "1" ]]; then
+    atlas_log_info "Dry-run mode: would run add-apt-repository -y ${DOTNET_BACKPORTS_PPA}"
+    atlas_log_info "Dry-run mode: would run apt-get update"
+    return 0
+  fi
+
+  atlas_require_command add-apt-repository
+  atlas_sudo_run add-apt-repository -y "${DOTNET_BACKPORTS_PPA}"
+  atlas_sudo_run apt-get update
+}
+
+install_missing_sdks() {
+  local missing=()
+  local package_name
+
+  for package_name in "${DOTNET_REQUIRED_PACKAGES[@]}"; do
+    if atlas_package_installed "$package_name"; then
+      atlas_log_ok "${package_name} is already installed"
+    else
+      missing+=("$package_name")
+    fi
+  done
+
+  if [[ "${#missing[@]}" -eq 0 ]]; then
+    atlas_log_ok "All required .NET SDK packages are installed"
+    return 0
+  fi
+
+  for package_name in "${missing[@]}"; do
+    if [[ "${ATLAS_DRY_RUN}" == "1" ]]; then
+      atlas_log_info "Dry-run mode: would verify package candidate for ${package_name}"
+      continue
+    fi
+    if ! package_has_candidate "$package_name"; then
+      atlas_log_error "No official configured package candidate found for ${package_name}"
+      exit "${ATLAS_EXIT_PREREQ}"
+    fi
+  done
+
+  atlas_install_packages "${missing[@]}"
+}
+
+verify_dotnet() {
+  atlas_require_command dotnet
+  dotnet --list-sdks | grep -q '^8\.' || {
+    atlas_log_error ".NET 8 SDK was not found after installation"
+    exit "${ATLAS_EXIT_VALIDATION}"
+  }
+  dotnet --list-sdks | grep -q '^10\.' || {
+    atlas_log_error ".NET 10 SDK was not found after installation"
+    exit "${ATLAS_EXIT_VALIDATION}"
+  }
+  atlas_log_ok ".NET SDK verification passed"
+}
+
+main() {
+  load_os_release
+  atlas_require_sudo_noninteractive || {
+    atlas_log_error "Passwordless non-interactive sudo is required"
+    exit "${ATLAS_EXIT_PREREQ}"
+  }
+  atlas_require_command apt-cache
+  atlas_require_command apt-get
+  atlas_require_command dpkg-query
+
+  ensure_backports_if_needed
+  install_missing_sdks
+
+  if [[ "${ATLAS_DRY_RUN}" == "1" ]]; then
+    atlas_log_info "Dry-run mode: skipping post-install dotnet verification"
+  else
+    verify_dotnet
+  fi
+}
+
+main

install/phases/README.md

@@ -2,7 +2,7 @@
 
 This directory is reserved for future ordered Atlas installation phases.
 
-Phase 2A intentionally does not create speculative .NET, SQL Server, nginx, or Docker installer scripts. Future scripts should be added only when their implementation phase is approved.
+Phase 2A intentionally did not create speculative .NET, SQL Server, nginx, or Docker installer scripts. Phase 2 adds the .NET installer only.
 
 ## Naming Convention
 
@@ -18,3 +18,11 @@ Use a two-digit phase number and lower-case hyphenated component name:
 
 Each phase must source the shared framework under `install/lib/`, support dry-run behaviour where practical, and follow [../../SERVER-STANDARDS.md](../../SERVER-STANDARDS.md).
 
+## Current Phases
+
+- `10-dotnet.sh`: installs the required .NET 8 and .NET 10 SDKs from official Ubuntu package sources.
+
+Installed SDKs after the current Phase 2 run:
+
+- .NET 8 SDK `8.0.128`
+- .NET 10 SDK `10.0.109`

scripts/development/README.md

@@ -5,4 +5,3 @@ This directory is reserved for development workflow helpers that do not belong t
 Do not store secrets, generated logs, package caches, or one-off experiments here.
 
 Future structure is `TODO: Confirm during the relevant implementation phase.`
-

scripts/system/validate-host.sh

@@ -270,4 +270,3 @@ fi
 printf '\n'
 atlas_validation_summary
 atlas_validation_exit_code
-