initv1.0.0

3 files changed, 230 insertions, 0 deletions

diff --git a/README b/README
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+++ b/README
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+populate - source code installer
+
+populate can install sources from various locations into a directory.
+Currently populate knows how to install (local) files, Git repositories, and
+symlinks.  Following example illustrates them all.
+
+
+Example: Install some source to /var/src
+----------------------------------------
+
+First we have to create a "sentinel file" that tells populate it's okay to
+install (and remove!) files from our target location:
+
+    touch /var/src/.populate
+
+Next we'll run populate with a source specification:
+
+    populate root@localhost/var/src <<EOF
+    {
+      "mystuff": {
+        "type": "file",
+        "file": {
+          "path": "/path/to/mystuff-1.0"
+        }
+      },
+      "nixos-config": {
+        "type": "symlink",
+        "symlink": {
+          "target": "mystuff/configuration.nix"
+        }
+      },
+      "nixpkgs": {
+        "type": "git",
+        "git": {
+          "ref": "8bf31d7d27cae435d7c1e9e0ccb0a320b424066f",
+          "url": "https://github.com/NixOS/nixpkgs"
+        }
+      }
+    }
+    EOF
diff --git a/bin/populate b/bin/populate
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+++ b/bin/populate
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+#! /bin/sh
+set -efu
+
+self=$(readlink -f "$0")
+prefix=${self%/bin/*}
+libdir=$prefix/lib
+
+debug=false
+force=false
+origin_host=${HOSTNAME-cat /proc/sys/kernel/hostname}
+origin_user=$LOGNAME
+target_spec=
+
+
+fail=true
+
+error() {
+  echo "error: $1" >&2
+  fail=false
+}
+
+for arg; do
+  case $arg in
+    --debug)
+      debug=true
+      ;;
+    --force)
+      force=true
+      ;;
+    -*)
+      error "bad argument: $arg"
+      ;;
+    *)
+      if test -n "$target_spec"; then
+        error "bad argument: $arg"
+      else
+        target_spec=$arg
+      fi
+      ;;
+  esac
+done
+
+if test -z "$target_spec"; then
+  error 'no target specified'
+fi
+
+if test "$fail" != true; then
+  exit 1
+fi
+
+
+script=$(jq -e -r \
+    --argjson use_force "$force" \
+    --arg target_spec "$target_spec" \
+    --arg origin_host "$origin_host" \
+    --arg origin_user "$origin_user" \
+    -f "$libdir/populate.jq")
+
+
+if test "$debug" = true; then
+  echo "$script"
+else
+  eval "$script"
+fi
diff --git a/lib/populate.jq b/lib/populate.jq
new file mode 100644
index 0000000..23e16e8
--- /dev/null
+++ b/lib/populate.jq
@@ -0,0 +1,126 @@
+def default(value; f): if . == null then value else f end;
+def default(value): default(value; .);
+
+($target_spec
+  | match("^(?:([^@]+)@)?([^:/]+)(?::([^/]*))?(/.*)?")
+  | {
+    user: .captures[0].string | default("root"),
+    host: .captures[1].string,
+    port: .captures[2].string | default(22;
+      if test("^[0-9]+$") then fromjson else
+        error(@json "bad target port: \(.)")
+      end),
+    path: .captures[3].string | default("/var/src"),
+  }
+)
+  as $target |
+
+(($target.host == $origin_host) and ($target.user == $origin_user))
+  as $is_local |
+
+
+to_entries |
+map(select(.value.type == "file")) as $file_sources |
+map(select(.value.type == "git")) as $git_sources |
+map(select(.value.type == "symlink")) as $symlink_sources |
+
+($file_sources + $symlink_sources) as $rsync_sources |
+
+
+# Safeguard to prevent clobbering of misspelled targets.
+# This script must run at target first.
+def checktarget_script:
+  @sh "if ! test -f \($target.path)/.populate; then",
+  @sh "  echo error: missing sentinel file: \($target.host):\($target.path)/.populate >&2",
+  @sh "  exit 1",
+  @sh "fi";
+
+
+def git_script:
+  @sh "fetch_git(){(",
+  #@sh "  export SSL_CERT_FILE=/etc/ssl/certs/ca-certificates.crt",
+
+  @sh "  dst_dir=\($target.path)/$1",
+  @sh "  src_url=$2",
+  @sh "  src_ref=$3",
+
+  @sh "  if ! test -e \"$dst_dir\"; then",
+  @sh "    git clone \"$src_url\" \"$dst_dir\"",
+  @sh "  fi",
+
+  @sh "  cd \"$dst_dir\"",
+
+  @sh "  if ! url=$(git config remote.origin.url); then",
+  @sh "    git remote add origin \"$src_url\"",
+  @sh "  elif test \"$url\" != \"$src_url\"; then",
+  @sh "    git remote set-url origin \"$src_url\"",
+  @sh "  fi",
+
+  # TODO resolve src_ref to commit hash",
+  @sh "  hash=$src_ref",
+
+  @sh "  if ! test \"$(git log --format=%H -1)\" = \"$hash\"; then",
+  @sh "    git fetch origin",
+  @sh "    git checkout \"$hash\" -- \"$dst_dir\"",
+  @sh "    git checkout -f \"$hash\"",
+  @sh "  fi",
+
+  @sh "  git clean -dxf",
+  @sh ")}",
+  ($git_sources[] |
+  @sh "fetch_git \(.key) \(.value.git.url) \(.value.git.ref)");
+
+
+def rsync_script:
+  @sh "srcdir=$(mktemp -dt populate.XXXXXXXX)",
+  @sh "chmod 0755 \"$srcdir\"",
+  @sh "trap cleanup EXIT",
+  @sh "cleanup() {",
+  @sh "  (set +f; rm -f \"$srcdir\"/*)",
+  @sh "  rmdir \"$srcdir\"",
+  @sh "}",
+
+  ($symlink_sources[] |
+  @sh "ln -s \(.value.symlink.target) \"$srcdir\"/\(.key)"),
+
+  @sh "proot \\",
+  ($file_sources[] |
+  @sh "    -b \(.value.file.path):\"$srcdir\"/\(.key) \\"),
+  @sh "    rsync \\",
+  @sh "        -vFrlptD \\",
+  @sh "        --delete \\",
+  @sh "        -f \("P /*", ($rsync_sources[] | "R /\(.key)")) \\",
+  @sh "        \"$srcdir\"/ \\",
+  (if $is_local then
+  @sh "        \($target.path)"
+  else
+  # ControlPersist=no so we reuse existing control sockets but if we
+  # create a new one, then remove it immediately after we are done so
+  # this script does not hang.
+  @sh "        -e \("ssh -o ControlPersist=no -p \($target.port)") \\",
+  @sh "        \($target.user)@\($target.host):\($target.path)"
+  end);
+
+
+def compile:
+  [
+    @sh "set -euf",
+    .[]
+  ]
+  | map(select(. != null)) | join("\n");
+
+
+def ssh_target:
+  @sh "echo \(compile) \\",
+  @sh "  | ssh \($target.user)@\($target.host) -p \($target.port) -T";
+
+
+[
+  (if $use_force then null else checktarget_script end),
+  git_script
+]
+| (if $is_local then . else [ssh_target] end),
+[
+  rsync_script
+]
+| compile