add sops-decrypt.sh to decrypt all secrets

shared/sops-decrypt.sh

@@ -0,0 +1,41 @@
+#!/usr/bin/env bash
+
+# Summary:
+# - Scans all first-level subdirectories in the current working directory (each treated as a "service").
+# - If a service contains ./<service>/secrets.sops.yaml, decrypts it with sops.
+# - Splits the decrypted YAML into individual key/value pairs and writes each value to a separate file:
+#     /run/secrets/<service>/<key>
+# - Output matches Docker "secrets" convention: one file per secret
+
+# Assumptions:
+# - ./<service>/secrets.sops.yaml is a flat, single-level key: value YAML map encrypted with sops (dotenv-like, but in YAML)
+# - sops, age and yq (mikefarah) are installed and in PATH
+# - The script is executed from the "services root" directory: its direct children are service directories (e.g. ./immich/, ./caddy/, ...)
+# - For systemd, set WorkingDirectory to this directory.
+
+set -euo pipefail
+umask 077   # 0600 by default
+
+OUT_ROOT="/run/secrets"
+
+for service_dir in ./*/; do
+  service_name="${service_dir#./}"      # remove leading './': './service/' -> 'service/'
+  service_name="${service_name%/}"      # remove trailing '/': 'service/' -> 'service'
+
+  secrets_file="./${service_name}/secrets.sops.yaml"
+  [[ -f "$secrets_file" ]] || continue
+
+  out_dir="${OUT_ROOT}/${service_name}"
+  mkdir -p -- "$out_dir"
+
+  sops -d "$secrets_file" \
+  | yq -r -0 'to_entries[] | .key, .value' \
+  | while IFS= read -r -d '' key && IFS= read -r -d '' value; do
+      [[ "$key" =~ ^[A-Za-z0-9_][-A-Za-z0-9_]*$ ]] || { echo "skip bad key: $key" >&2; continue; }
+      tmp_val="$(mktemp "${out_dir}/.${key}.XXXXXX")"
+      printf '%s' "$value" > "$tmp_val"
+      mv -f -- "$tmp_val" "${out_dir}/${key}"
+    done
+
+  echo "sops ok: ${service_name}"
+done