docs: document environment variables

docs/environment-variables.md

@@ -0,0 +1,89 @@
+# go-ipfs environment variables
+
+## `LIBP2P_TCP_REUSEPORT` (`IPFS_REUSEPORT`)
+
+go-ipfs tries to reuse the same source port for all connections to improve NAT
+traversal. If this is an issue, you can disable it by setting
+`LIBP2P_TCP_REUSEPORT` to false.
+
+This variable was previously `IPFS_REUSEPORT`.
+
+Default: true
+
+## `IPFS_PATH`
+
+Sets the location of the IPFS repo (where the config, blocks, etc.
+are stored).
+
+Default: ~/.ipfs
+
+## `IPFS_LOGGING`
+
+Sets the log level for go-ipfs. It can be set to one of:
+
+* `CRITICAL`
+* `ERROR`
+* `WARNING`
+* `NOTICE`
+* `INFO`
+* `DEBUG`
+
+Logging can also be configured (on a subsystem by subsystem basis) at runtime
+with the `ipfs log` command.
+
+Default: `ERROR`
+
+## `IPFS_LOGGING_FMT`
+
+Sets the log message format. Can be one of:
+
+* `color`
+* `nocolor`
+
+Default: `color`
+
+## `GOLOG_FILE`
+
+Sets the file to which go-ipfs logs. By default, go-ipfs logs to standard error.
+
+## `GOLOG_TRACING_FILE`
+
+Sets the file to which go-ipfs sends tracing events. By default, tracing is
+disabled.
+
+This log can be read at runtime (without writing it to a file) using the `ipfs
+log tail` command.
+
+Warning: Enabling tracing will likely affect performance.
+
+## `IPFS_FUSE_DEBUG`
+
+Enables fuse debug logging.
+
+Default: false
+
+## `YAMUX_DEBUG`
+
+Enables debug logging for the yamux stream muxer.
+
+Default: false
+
+## `IPFS_FD_MAX`
+
+Sets the file descriptor limit for go-ipfs. If go-ipfs fails to set the file
+descriptor limit, it will log an error.
+
+Defaults: 2048
+
+## `IPFS_DIST_PATH`
+
+URL from which go-ipfs fetches repo migrations (when the daemon is launched with
+the `--migrate` flag).
+
+Default: https://ipfs.io/ipfs/$something (depends on the IPFS version)
+
+## `LIBP2P_MUX_PREFS`
+
+Tells go-ipfs which multiplexers to use in which order.
+
+Default: "/yamux/1.0.0 /mplex/6.7.0"

docs/experimental-features.md

@@ -104,51 +104,19 @@ bandwidth than the others, but is lacking on congestion control and backpressure
 logic. It is available to try out and experiment with.
 
 ### State
-Experimental
+Stable
 
 ### In Version
 0.4.5
 
 ### How to enable
-run your daemon with `--enable-mplex-experiment`
 
 To make it the default stream muxer, set the environment variable
 `LIBP2P_MUX_PREFS` as follows:
 ```
 export LIBP2P_MUX_PREFS="/mplex/6.7.0 /yamux/1.0.0 /spdy/3.1.0"
 ```
 
-To check which stream muxer is being used between any two given peers, check the
-json output of the `ipfs swarm peers` command, you'll see something like this:
-```
-$ ipfs swarm peers -v --enc=json | jq .
-{
-  "Peers": [
-    {
-      "Addr": "/ip4/104.131.131.82/tcp/4001",
-      "Peer": "QmaCpDMGvV2BGHeYERUEnRQAwe3N8SzbUtfsmvsqQLuvuJ",
-      "Latency": "46.032624ms",
-      "Muxer": "*peerstream_multiplex.conn",
-      "Streams": [
-        {
-          "Protocol": "/ipfs/bitswap/1.1.0"
-        },
-        {
-          "Protocol": "/ipfs/kad/1.0.0"
-        },
-        {
-          "Protocol": "/ipfs/kad/1.0.0"
-        }
-      ]
-    },
-    {
-...
-```
-
-### Road to being a real feature
-- [ ] Significant real world testing and performance metrics across a wide
-      variety of workloads showing that it works well.
-
 ---
 
 ## Raw Leaves for unixfs files