[pbs-devel] [PATCH proxmox-backup v2] fix #4095: make http client read proxy config from envvars

[Stefan Hanreich <s.hanreich@proxmox.com>]

In order to be able to use a proxy with the proxmox-backup-client, use
ProxyConfig for parsing proxy server config from the environment. Also
added a section in the documentation that describes how to configure the
environment if a proxy server should be used.

Signed-off-by: Stefan Hanreich <s.hanreich@proxmox.com>
---
 docs/backup-client.rst        | 11 +++++++++++
 pbs-client/src/http_client.rs |  7 +++++++
 2 files changed, 18 insertions(+)

diff --git a/docs/backup-client.rst b/docs/backup-client.rst
index cc56d17e..f5cbbf67 100644
--- a/docs/backup-client.rst
+++ b/docs/backup-client.rst
@@ -69,6 +69,17 @@ Environment Variables
   When set, this value is used to verify the server certificate (only used if
   the system CA certificates cannot validate the certificate).
 
+``ALL_PROXY``
+  When set, the client uses the specified HTTP proxy for all connections to the
+  backup server. Currently only HTTP proxies are supported. Valid proxy
+  configurations have the following format:
+  `[http://][user:password@]<host>[:port]`. Default `port` is 1080, if not
+  otherwise specified.
+
+
+.. Note:: The recommended solution for shielding hosts is using tunnels such as
+   wireguard, instead of using an HTTP proxy.
+
 
 .. Note:: Passwords must be valid UTF-8 and may not contain newlines. For your
    convenience, Proxmox Backup Server only uses the first line as password, so
diff --git a/pbs-client/src/http_client.rs b/pbs-client/src/http_client.rs
index 4ef1350b..491b603b 100644
--- a/pbs-client/src/http_client.rs
+++ b/pbs-client/src/http_client.rs
@@ -23,6 +23,7 @@ use proxmox_sys::linux::tty;
 
 use proxmox_async::broadcast_future::BroadcastFuture;
 use proxmox_http::client::{HttpsConnector, RateLimiter};
+use proxmox_http::ProxyConfig;
 use proxmox_http::uri::{build_authority, json_object_to_query};
 
 use pbs_api_types::percent_encoding::DEFAULT_ENCODE_SET;
@@ -389,6 +390,12 @@ impl HttpClient {
             )))));
         }
 
+        let proxy_config = ProxyConfig::from_proxy_env()?;
+        if let Some(config) = proxy_config {
+            log::info!("Using proxy connection: {}:{}", config.host, config.port);
+            https.set_proxy(config);
+        }
+
         let client = Client::builder()
             //.http2_initial_stream_window_size( (1 << 31) - 2)
             //.http2_initial_connection_window_size( (1 << 31) - 2)
-- 
2.30.2