fix(nextcloud-sso): register post-logout redirect URI + harden admin promotion

Two SSO follow-ups the operator hit after Nextcloud OIDC login worked.

1. Sign-out "redirect failed". On logout user_oidc redirects the browser to
   Keycloak's end_session_endpoint with post_logout_redirect_uri=<Nextcloud
   base '/'> and client_id=nextcloud but NO id_token_hint (provider
   sendIdTokenHint=0). Keycloak then validates that redirect against the
   client's post.logout.redirect.uris attribute, which was empty -> "Invalid
   redirect uri" -> the operator's "redirect failed". Register
   https://nextcloud.home.keithjackson.dev/* on the nextcloud client
   (attributes.post.logout.redirect.uris). Applied live via kcadm and captured
   here so git stays authoritative (a RealmImport no-ops on the existing realm).

2. postStart step (d) mirrors platform-admins -> built-in admin group, but the
   previous single best-effort pass ran occ group:adduser once with output
   swallowed and no retry. At early boot (container Started ~9s after create)
   that call can transiently fail (DB / maintenance race), silently dropping the
   promotion until the next restart. Harden step (d) with a verify-and-retry
   loop (like step (c)): re-read group:list and re-add any platform-admins
   member still missing from admin until verified (bounded ~30s), no-op for
   existing members.

Co-Authored-By: Claude Opus 4.8 <[email protected]>

apps/wave-1/nextcloud.yaml

@@ -126,7 +126,7 @@ spec:
               - /bin/sh
               - -c
               - "# Idempotent Keycloak OIDC wiring (R-IDP-02/06). Runs alongside the nextcloud entrypoint\n# (which installs/upgrades on first boot). Installs+enables the user_oidc app and creates OR\n# updates the \"keycloak\" login provider (occ user_oidc:provider is create-or-update by\n# identifier). Auto-discovery pulls the realm's endpoints; the `groups` claim drives Nextcloud\n# group provisioning. occ runs as www-data (owns config.php); the client secret is passed via\n# --clientsecret-env so it never lands on a command line. Safe to re-run every start; a missing\n# secret or not-yet-installed instance is skipped so the pod never crashloops (the local\n# break-glass admin still works).\nset -u\n# OCC runs occ as www-data (owns config.php). NOTE: this wrapper word-splits its args via $*,\n# so it is used ONLY for single-token subcommands (status/app:list/app:install/...). The\n# provider call below carries a MULTI-WORD value (--scope 'openid email profile') and is run as\n# ONE su -c with the scope single-quoted, so the inner shell keeps it a single argument.\nOCC() { su -s /bin/sh www-data -c \"php /var/www/html/occ $*\"; }\nNEXTCLOUD_DISCOVERY_URL=https://keycloak.home.keithjackson.dev/realms/homelab/.well-known/openid-configuration\nnextcloud_oidc_fail() {\n  echo \"[nextcloud-oidc] FAILED to configure 'keycloak' provider: $1\" >&2\n  { echo \"$(date -u +%Y-%m-%dT%H:%M:%SZ) [nextcloud-oidc] FAILED: $1\"; } >> /var/www/html/nextcloud-oidc-bootstrap.log 2>/dev/null || true\n}\n# (a) Wait for the instance to be installed AND out of maintenance mode. The entrypoint holds\n#     maintenance mode during first-boot install/upgrade; occ writes made in that window do not\n#     stick \u2014 a second race on top of the quoting bug fixed at (c).\ni=0\nuntil OCC status 2>/dev/null | grep -q \"installed: true\" && ! OCC status 2>/dev/null | grep -q \"maintenance: true\"; do\n  i=$((i + 1))\n  [ \"$i\" -ge 300 ] && { echo \"[nextcloud-oidc] occ not ready (installed/maintenance) after wait; skipping\" >&2; exit 0; }\n  sleep 2\ndone\n# Let Nextcloud's OWN server-side HTTP client reach the private-network IdP. The Keycloak\n# FQDN resolves (split-horizon) to the PRIVATE Cilium gateway VIP (RFC1918), and Nextcloud's\n# SSRF guard otherwise REFUSES that request \u2014 OCP\\Http\\Client\\LocalServerException \"violates\n# local access rules\" \u2014 during user_oidc's discovery/JWKS/token fetch AT LOGIN, surfacing to\n# the user as \"Could not reach the provider\". (The (b) curl check below uses system libcurl,\n# NOT this guard, so it passes while the browser login still failed.) Idempotent; re-applied\n# every start so it survives pod rolls / PVC rebuilds. Confirmed root cause 2026-08-27.\nOCC config:system:set allow_local_remote_servers --value=true --type=boolean >/dev/null 2>&1 \\\n  || echo \"[nextcloud-oidc] WARN: failed to set allow_local_remote_servers\" >&2\nif [ -z \"${NEXTCLOUD_OIDC_CLIENT_SECRET:-}\" ]; then\n  echo \"[nextcloud-oidc] client secret unset; skipping OIDC (break-glass admin only)\"\n  exit 0\nfi\nif ! OCC app:list 2>/dev/null | grep -q \"user_oidc\"; then\n  OCC app:install user_oidc || echo \"[nextcloud-oidc] app:install user_oidc failed\" >&2\nfi\nOCC app:enable user_oidc >/dev/null 2>&1 || true\n# (b) Wait up to ~90s for the Keycloak discovery doc to be reachable (HTTP 200) before registering.\nd=0; disc_ok=0\nwhile [ \"$d\" -lt 45 ]; do\n  if [ \"$(curl -sS -o /dev/null -w '%{http_code}' --max-time 5 \"$NEXTCLOUD_DISCOVERY_URL\" 2>/dev/null)\" = \"200\" ]; then\n    disc_ok=1; break\n  fi\n  d=$((d + 1)); sleep 2\ndone\n[ \"$disc_ok\" = 1 ] || nextcloud_oidc_fail \"Keycloak discovery endpoint not reachable (HTTP 200) within timeout\"\n# (c) Configure (create-or-update by identifier) then VERIFY it persisted; retry the whole cycle.\n#     HARDENED: run as ONE su -c so www-data's shell parses --scope='openid email profile' as a\n#     single argument. The previous `OCC user_oidc:provider ... --scope=\"openid email profile\"`\n#     form fed the value back through the wrapper's $*, which SPLIT it into extra\
-                \ positionals ->\n#     occ \"Too many arguments\" -> silent failure on EVERY boot. Secret via --clientsecret-env\n#     (never on argv). The verify-then-retry loop guarantees the provider actually persisted.\nr=0; reg_ok=0\nwhile [ \"$r\" -lt 10 ]; do\n  su -s /bin/sh www-data -c \"php /var/www/html/occ user_oidc:provider keycloak \\\n    --clientid=nextcloud \\\n    --clientsecret-env=NEXTCLOUD_OIDC_CLIENT_SECRET \\\n    --discoveryuri=$NEXTCLOUD_DISCOVERY_URL \\\n    --scope='openid email profile' \\\n    --unique-uid=0 \\\n    --mapping-uid=preferred_username \\\n    --mapping-email=email \\\n    --mapping-display-name=name \\\n    --group-provisioning=1 \\\n    --mapping-groups=groups\" >/dev/null 2>&1 || true\n  if OCC user_oidc:provider 2>/dev/null | grep -q \"keycloak\"; then\n    reg_ok=1; break\n  fi\n  r=$((r + 1)); sleep 3\ndone\nif [ \"$reg_ok\" = 1 ]; then\n  echo \"[nextcloud-oidc] provider 'keycloak' configured and verified\"\nelse\n  nextcloud_oidc_fail \"user_oidc:provider ran but the provider did not persist after retries\"\nfi\n# (d) Promote Keycloak 'platform-admins' members to Nextcloud admins (#5). user_oidc 8.11 has\n#     NO native group->admin mapping (occ user_oidc:provider offers group PROVISIONING and a\n#     login WHITELIST only), so mirror the provisioned 'platform-admins' membership into the\n#     built-in 'admin' group (the sole source of admin rights in Nextcloud). Idempotent every\n#     start: occ group:adduser is a no-op for an existing member. A user is promotable only\n#     AFTER their first OIDC login provisions them into the group, so a brand-new admin gains\n#     rights on their next login + the following pod start (or run `occ group:adduser admin\n#     <uid>` once). The LOCAL break-glass admin is unaffected (docs/15). The group name is\n#     passed to php as argv (never interpolated) so group:list JSON parses robustly.\nADMIN_SRC_GROUP=platform-admins\nadmin_members=$(su -s /bin/sh www-data -c \"php /var/www/html/occ group:list --output=json\" 2>/dev/null \\\n  | php -r '$d=json_decode(stream_get_contents(STDIN),true);$g=$argv[1];if(is_array($d)&&!empty($d[$g])&&is_array($d[$g])){foreach($d[$g] as $u){echo $u,\"\\n\";}}' -- \"$ADMIN_SRC_GROUP\" 2>/dev/null)\nfor uid in $admin_members; do\n  if OCC group:adduser admin \"$uid\" >/dev/null 2>&1; then\n    echo \"[nextcloud-oidc] ensured '$uid' is a Nextcloud admin (member of $ADMIN_SRC_GROUP)\"\n  fi\ndone\n"
+                \ positionals ->\n#     occ \"Too many arguments\" -> silent failure on EVERY boot. Secret via --clientsecret-env\n#     (never on argv). The verify-then-retry loop guarantees the provider actually persisted.\nr=0; reg_ok=0\nwhile [ \"$r\" -lt 10 ]; do\n  su -s /bin/sh www-data -c \"php /var/www/html/occ user_oidc:provider keycloak \\\n    --clientid=nextcloud \\\n    --clientsecret-env=NEXTCLOUD_OIDC_CLIENT_SECRET \\\n    --discoveryuri=$NEXTCLOUD_DISCOVERY_URL \\\n    --scope='openid email profile' \\\n    --unique-uid=0 \\\n    --mapping-uid=preferred_username \\\n    --mapping-email=email \\\n    --mapping-display-name=name \\\n    --group-provisioning=1 \\\n    --mapping-groups=groups\" >/dev/null 2>&1 || true\n  if OCC user_oidc:provider 2>/dev/null | grep -q \"keycloak\"; then\n    reg_ok=1; break\n  fi\n  r=$((r + 1)); sleep 3\ndone\nif [ \"$reg_ok\" = 1 ]; then\n  echo \"[nextcloud-oidc] provider 'keycloak' configured and verified\"\nelse\n  nextcloud_oidc_fail \"user_oidc:provider ran but the provider did not persist after retries\"\nfi\n# (d) Promote Keycloak 'platform-admins' members to Nextcloud admins (#5). user_oidc 8.11 has\n#     NO native group->admin mapping (occ user_oidc:provider offers group PROVISIONING and a\n#     login WHITELIST only), so mirror the provisioned 'platform-admins' membership into the\n#     built-in 'admin' group (the sole source of admin rights in Nextcloud). Idempotent every\n#     start: occ group:adduser is a no-op for an existing member. A user is promotable only\n#     AFTER their first OIDC login provisions them into the group, so a brand-new admin gains\n#     rights on their next login + the following pod start (or run `occ group:adduser admin\n#     <uid>` once). The LOCAL break-glass admin is unaffected (docs/15). The group name is\n#     passed to php as argv (never interpolated) so group:list JSON parses robustly.\nADMIN_SRC_GROUP=platform-admins\n# HARDENED (verify-and-retry, like step (c)): the previous single pass ran `occ group:adduser`\n# exactly once with its output swallowed (>/dev/null 2>&1) and NO retry, so an early-boot\n# transient failure (DB / maintenance race in the first seconds after container start) silently\n# dropped the promotion until the NEXT pod restart. This loop re-reads group:list and re-adds\n# any platform-admins member still missing from 'admin' until all are verified (bounded ~30s);\n# it is a no-op for members already in 'admin'. Group names are passed to php as argv (never\n# interpolated) so the JSON parses robustly.\nparse_group() { su -s /bin/sh www-data -c \"php /var/www/html/occ group:list --output=json\" 2>/dev/null | php -r '$d=json_decode(stream_get_contents(STDIN),true);$g=$argv[1];if(is_array($d)&&!empty($d[$g])&&is_array($d[$g])){foreach($d[$g] as $u){echo $u,\"\\n\";}}' -- \"$1\" 2>/dev/null; }\np=0\nwhile [ \"$p\" -lt 15 ]; do\n  current_admins=$(parse_group admin)\n  missing=0\n  for uid in $(parse_group \"$ADMIN_SRC_GROUP\"); do\n    if printf '%s\\n' \"$current_admins\" | grep -qxF -- \"$uid\"; then\n      continue\n    fi\n    missing=1\n    if OCC group:adduser admin \"$uid\" >/dev/null 2>&1; then\n      echo \"[nextcloud-oidc] ensured '$uid' is a Nextcloud admin (member of $ADMIN_SRC_GROUP)\"\n    fi\n  done\n  [ \"$missing\" = 0 ] && break\n  p=$((p + 1)); sleep 2\ndone\n[ \"$p\" -ge 15 ] && nextcloud_oidc_fail \"could not promote all $ADMIN_SRC_GROUP members into 'admin' after retries\"\n"
       volumes:
       - name: data
         persistentVolumeClaim:

platform/keycloak/keycloak-realm-import.yaml

@@ -207,6 +207,14 @@ spec:
           - https://nextcloud.home.keithjackson.dev/apps/user_oidc/code
         webOrigins:
           - https://nextcloud.home.keithjackson.dev
+        # Post-logout redirect allow-list (#logout "redirect failed"). On sign-out user_oidc redirects the
+        # browser to Keycloak's end_session_endpoint with post_logout_redirect_uri=<Nextcloud base '/'> and
+        # client_id=nextcloud but NO id_token_hint (provider sendIdTokenHint=0), so Keycloak validates the
+        # redirect against this client attribute — empty => "Invalid redirect uri" => the operator's
+        # "redirect failed". The wildcard covers the base URL and any logout landing path. Keycloak stores
+        # this as the client attribute `post.logout.redirect.uris` (## separates multiple values).
+        attributes:
+          post.logout.redirect.uris: https://nextcloud.home.keithjackson.dev/*
         defaultClientScopes:
           - email
           - profile