Allow common redis and leveldb connections (#12385)

* Allow common redis and leveldb connections

Prevents multiple reopening of redis and leveldb connections to the same
place by sharing connections.

Further allows for more configurable redis connection type using the
redisURI and a leveldbURI scheme.

Signed-off-by: Andrew Thornton <art27@cantab.net>

* add unit-test

Signed-off-by: Andrew Thornton <art27@cantab.net>

* as per @lunny

Signed-off-by: Andrew Thornton <art27@cantab.net>

* add test

Signed-off-by: Andrew Thornton <art27@cantab.net>

* Update modules/cache/cache_redis.go

* Update modules/queue/queue_disk.go

* Update modules/cache/cache_redis.go

* Update modules/cache/cache_redis.go

* Update modules/queue/unique_queue_disk.go

* Update modules/queue/queue_disk.go

* Update modules/queue/unique_queue_disk.go

* Update modules/session/redis.go

Co-authored-by: techknowlogick <techknowlogick@gitea.io>
Co-authored-by: Lauris BH <lauris@nix.lv>

docs/content/doc/advanced/config-cheat-sheet.en-us.md

@@ -308,15 +308,13 @@ relation to port exhaustion.
 ## Queue (`queue` and `queue.*`)
 
 - `TYPE`: **persistable-channel**: General queue type, currently support: `persistable-channel`, `channel`, `level`, `redis`, `dummy`
-- `DATADIR`: **queues/**: Base DataDir for storing persistent and level queues. `DATADIR` for inidividual queues can be set in `queue.name` sections but will default to `DATADIR/`**`name`**.
+- `DATADIR`: **queues/**: Base DataDir for storing persistent and level queues. `DATADIR` for individual queues can be set in `queue.name` sections but will default to `DATADIR/`**`name`**.
 - `LENGTH`: **20**: Maximal queue size before channel queues block
 - `BATCH_LENGTH`: **20**: Batch data before passing to the handler
-- `CONN_STR`: **addrs=127.0.0.1:6379 db=0**: Connection string for the redis queue type.
-- `QUEUE_NAME`: **_queue**: The suffix for default redis queue name. Individual queues will default to **`name`**`QUEUE_NAME` but can be overriden in the specific `queue.name` section.
-- `SET_NAME`: **_unique**: The suffix that will added to the default redis
-set name for unique queues. Individual queues will default to
-**`name`**`QUEUE_NAME`_`SET_NAME`_ but can be overridden in the specific
-`queue.name` section.
+- `CONN_STR`: **redis://127.0.0.1:6379/0**: Connection string for the redis queue type. Options can be set using query params. Similarly LevelDB options can also be set using: **leveldb://relative/path?option=value** or **leveldb:///absolute/path?option=value**
+- `QUEUE_NAME`: **_queue**: The suffix for default redis and disk queue name. Individual queues will default to **`name`**`QUEUE_NAME` but can be overriden in the specific `queue.name` section.
+- `SET_NAME`: **_unique**: The suffix that will be added to the default redis and disk queue `set` name for unique queues. Individual queues will default to
+ **`name`**`QUEUE_NAME`_`SET_NAME`_ but can be overridden in the specific `queue.name` section.
 - `WRAP_IF_NECESSARY`: **true**: Will wrap queues with a timeoutable queue if the selected queue is not ready to be created - (Only relevant for the level queue.)
 - `MAX_ATTEMPTS`: **10**: Maximum number of attempts to create the wrapped queue
 - `TIMEOUT`: **GRACEFUL_HAMMER_TIME + 30s**: Timeout the creation of the wrapped queue if it takes longer than this to create.
@@ -459,7 +457,7 @@ set name for unique queues. Individual queues will default to
 - `ADAPTER`: **memory**: Cache engine adapter, either `memory`, `redis`, or `memcache`.
 - `INTERVAL`: **60**: Garbage Collection interval (sec), for memory cache only.
 - `HOST`: **\<empty\>**: Connection string for `redis` and `memcache`.
-   - Redis: `network=tcp,addr=127.0.0.1:6379,password=macaron,db=0,pool_size=100,idle_timeout=180`
+   - Redis: `redis://:macaron@127.0.0.1:6379/0?pool_size=100&idle_timeout=180s`
    - Memcache: `127.0.0.1:9090;127.0.0.1:9091`
 - `ITEM_TTL`: **16h**: Time to keep items in cache if not used, Setting it to 0 disables caching.
 
@@ -708,7 +706,7 @@ Task queue configuration has been moved to `queue.task`. However, the below conf
 
 - `QUEUE_TYPE`: **channel**: Task queue type, could be `channel` or `redis`.
 - `QUEUE_LENGTH`: **1000**: Task queue length, available only when `QUEUE_TYPE` is `channel`.
-- `QUEUE_CONN_STR`: **addrs=127.0.0.1:6379 db=0**: Task queue connection string, available only when `QUEUE_TYPE` is `redis`. If redis needs a password, use `addrs=127.0.0.1:6379 password=123 db=0`.
+- `QUEUE_CONN_STR`: **redis://127.0.0.1:6379/0**: Task queue connection string, available only when `QUEUE_TYPE` is `redis`. If redis needs a password, use `redis://123@127.0.0.1:6379/0`.
 
 ## Migrations (`migrations`)