feat: Add IPFS backend

.env.example

@@ -31,3 +31,7 @@ OPENDAL_OBS_BUCKET=<bucket>
 OPENDAL_OBS_ENDPOINT=<endpoint>
 OPENDAL_OBS_ACCESS_KEY_ID=<access_key_id>
 OPENDAL_OBS_SECRET_ACCESS_KEY=<secret_access_key>
+# ipfs
+OPENDAL_IPFS_TEST=false
+OPENDAL_IPFS_ROOT=/path/to/dir
+OPENDAL_IPFS_ENDPOINT="http://localhost:5001"

examples/ipfs.rs

@@ -0,0 +1,65 @@
+// Copyright 2022 Datafuse Labs.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+use std::env;
+
+use anyhow::Result;
+use futures::StreamExt;
+use log::info;
+use opendal::{services::ipfs, Operator};
+
+#[tokio::main]
+async fn main() -> Result<()> {
+    if env::var("RUST_LOG").is_err() {
+        env::set_var("RUST_LOG", "debug");
+    }
+    env_logger::init();
+
+    println!(
+        r#"OpenDAL IPFS Example.
+
+Available Environment Values:
+
+- OPENDAL_IPFS_ROOT: root path in mutable file system, default: /
+- OPENDAL_IPFS_ENDPOINT: ipfs endpoint, default: localhost:5001
+"#
+    );
+
+    let mut builder = ipfs::Backend::build();
+    // root must be absolute path in MFS.
+    builder.root(&env::var("OPENDAL_IPFS_ROOT").unwrap_or_else(|_| "/".to_string()));
+    builder.endpoint(
+        &env::var("OPENDAL_IPFS_ENDPOINT").unwrap_or_else(|_| "http://localhost:5001".to_string()),
+    );
+
+    let op: Operator = Operator::new(builder.build()?);
+
+    let path = "/file.txt";
+    info!("try to write file: {}", &path);
+    op.object(path).write("Hello, world!").await?;
+    info!("write file successful!");
+
+    let content = op.object(path).read().await?;
+    info!("File content: {}", String::from_utf8_lossy(&content));
+
+    let root = "/";
+    let mut list = op.object(root).list().await?;
+    info!("Listing entries in {}", &root);
+    while let Some(res) = list.next().await {
+        let item = res?;
+        info!("Found entry: {}", item.path())
+    }
+
+    Ok(())
+}

src/operator.rs

@@ -131,6 +131,7 @@ impl Operator {
             Scheme::Hdfs => services::hdfs::Backend::from_iter(it)?.into(),
             #[cfg(feature = "services-http")]
             Scheme::Http => services::http::Backend::from_iter(it)?.into(),
+            Scheme::Ipfs => services::ipfs::Backend::from_iter(it)?.into(),
             Scheme::Memory => services::memory::Builder::default().build()?.into(),
             Scheme::Gcs => services::gcs::Backend::from_iter(it)?.into(),
             Scheme::S3 => services::s3::Backend::from_iter(it)?.into(),

src/scheme.rs

@@ -52,6 +52,8 @@ pub enum Scheme {
     /// - Custom must not overwrite any existing services name.
     /// - Custom must be lowed cases.
     Custom(&'static str),
+    /// [ipfs][crate::services::ipfs]: IPFS mutable file system
+    Ipfs,
 }
 
 impl Scheme {
@@ -77,6 +79,7 @@ impl Display for Scheme {
             Scheme::Gcs => write!(f, "gcs"),
             #[cfg(feature = "services-http")]
             Scheme::Http => write!(f, "http"),
+            Scheme::Ipfs => write!(f, "ipfs"),
             Scheme::Memory => write!(f, "memory"),
             Scheme::Obs => write!(f, "obs"),
             Scheme::S3 => write!(f, "s3"),
@@ -98,6 +101,7 @@ impl FromStr for Scheme {
             #[cfg(feature = "services-http")]
             "http" | "https" => Ok(Scheme::Http),
             "gcs" => Ok(Scheme::Gcs),
+            "ipfs" => Ok(Scheme::Ipfs),
             "memory" => Ok(Scheme::Memory),
             "obs" => Ok(Scheme::Obs),
             "s3" => Ok(Scheme::S3),
@@ -116,6 +120,7 @@ impl From<Scheme> for &'static str {
             #[cfg(feature = "services-http")]
             Scheme::Http => "http",
             Scheme::Gcs => "gcs",
+            Scheme::Ipfs => "ipfs",
             Scheme::Memory => "memory",
             Scheme::Obs => "obs",
             Scheme::S3 => "s3",