armbian_build/extensions/ccache-remote

ccache-remote: Server Setup Guide

Redis Server

1. Install packages:

   apt install redis-server avahi-daemon avahi-utils
   

2. Configure Redis — merge the settings from misc/redis/redis-ccache.conf into /etc/redis/redis.conf, or add an include directive at the end of your existing config (include /etc/redis/redis-ccache.conf), then restart:

   sudo systemctl restart redis-server
   

   Authentication (recommended). Set a password in the config file — either via requirepass (Redis < 6) or ACL user entry (Redis 6+). See comments in misc/redis/redis-ccache.conf for both methods. Generate a URL-safe password:

   openssl rand -hex 24
   

   Important: Do not use openssl rand -base64 — base64 passwords contain /, +, and = which break URL parsing in redis:// connection strings. On the build host, pass the password in the Redis URL:

   ./compile.sh ENABLE_EXTENSIONS=ccache-remote \
     CCACHE_REMOTE_STORAGE="redis://default:YOUR_PASSWORD@192.168.1.65:6379" BOARD=...
   

   No authentication (trusted network only). If all machines are on a fully isolated private network and access control is not needed, remove requirepass, set nopass in the ACL user entry, and set protected-mode no. See comments in misc/redis/redis-ccache.conf. No password is needed in the URL:

   ./compile.sh ENABLE_EXTENSIONS=ccache-remote \
     CCACHE_REMOTE_STORAGE="redis://192.168.1.65:6379" BOARD=...
   

   For advanced security (TLS, ACL, rename-command), see: https://redis.io/docs/latest/operate/oss_and_stack/management/security/

3. Publish DNS-SD service — copy misc/avahi/ccache-redis.service to /etc/avahi/services/:

   cp misc/avahi/ccache-redis.service /etc/avahi/services/
   

   Avahi will pick it up automatically. Clients running avahi-browse -rpt _ccache._tcp will discover the Redis service.

   Or use a systemd unit that ties the announcement to redis-server lifetime (stops advertising when Redis is down):

   cp misc/systemd/ccache-avahi-redis.service /etc/systemd/system/
   systemctl enable --now ccache-avahi-redis
   

   Alternatively, publish legacy mDNS hostname:

   avahi-publish-address -R ccache.local <SERVER_IP>
   

   Or as a systemd service (/etc/systemd/system/ccache-hostname.service):

   [Unit]
   Description=Publish ccache.local hostname via Avahi
   After=avahi-daemon.service redis-server.service
   BindsTo=redis-server.service
   [Service]
   Type=simple
   ExecStart=/usr/bin/avahi-publish-address -R ccache.local <SERVER_IP>
   Restart=on-failure
   [Install]
   WantedBy=redis-server.service
   

HTTP/WebDAV Server (nginx)

1. Install nginx with WebDAV support:

   apt install nginx-extras avahi-daemon avahi-utils
   

2. Copy misc/nginx/ccache-webdav.conf to /etc/nginx/sites-available/ccache-webdav, then enable and prepare storage:

   cp misc/nginx/ccache-webdav.conf /etc/nginx/sites-available/ccache-webdav
   ln -s /etc/nginx/sites-available/ccache-webdav /etc/nginx/sites-enabled/
   mkdir -p /var/cache/ccache-webdav/ccache
   chown -R www-data:www-data /var/cache/ccache-webdav
   systemctl reload nginx
   

3. Verify:

   curl -X PUT -d "test" http://localhost:8088/ccache/test.txt
   curl http://localhost:8088/ccache/test.txt
   

   WARNING: No authentication configured. Use ONLY in a fully trusted private network.

4. Publish DNS-SD service — copy misc/avahi/ccache-webdav.service to /etc/avahi/services/:

   cp misc/avahi/ccache-webdav.service /etc/avahi/services/
   

   Or use a systemd unit that ties the announcement to nginx lifetime:

   cp misc/systemd/ccache-avahi-webdav.service /etc/systemd/system/
   systemctl enable --now ccache-avahi-webdav
   

DNS SRV Records (for remote/hosted servers)

Set CCACHE_REMOTE_DOMAIN on the client, then create DNS records.

Redis backend:

_ccache._tcp.example.com.  SRV  0 0 6379 ccache.example.com.
_ccache._tcp.example.com.  TXT  "type=redis"

HTTP/WebDAV backend:

_ccache._tcp.example.com.  SRV  0 0 8088 ccache.example.com.
_ccache._tcp.example.com.  TXT  "type=http" "path=/ccache/"

Client Requirements for mDNS

Install one of the following for .local hostname resolution:

• libnss-resolve (systemd-resolved):

  apt install libnss-resolve
  

  /etc/nsswitch.conf: hosts: files resolve [!UNAVAIL=return] dns myhostname

• libnss-mdns (standalone):

  apt install libnss-mdns
  

  /etc/nsswitch.conf: hosts: files mdns4_minimal [NOTFOUND=return] dns myhostname