[pbs-devel] applied: [PATCH backup v4] make tasklog downloadable in the backup server backend

[Wolfgang Bumiller]

applied with a cleanup followup commit, see below

On Wed, Nov 23, 2022 at 03:52:07PM +0100, Daniel Tschlatscher wrote:
> The read_tasklog API call now stream the whole log file if the query
> parameter 'download' is set to true. If the limit parameter is set to
> 0, all lines in the tasklog will be returned in json format.
> 
> To make a file stream and a json response in the same API call work, I
> had to use one of the lower level apimethod types from the
> proxmox-router. Therefore, the routing declarations and parameter
> schemas have been changed accordingly.
> 
> Signed-off-by: Daniel Tschlatscher <d.tschlatscher at proxmox.com>
> ---
> I sent this separately, as the other 3 patches in this version do not
> concern the backup patch in any way.
> 
> Changes from v3:
> * API parameter 'download' for streaming the file directly
> * option 'limit=0' returns the whole task log
> * read_task_log_lines() function is inline in the code again as it's
>   the only occurrence and doesn't add that much readability
> 
>  src/api2/node/tasks.rs | 209 +++++++++++++++++++++++++----------------
>  1 file changed, 129 insertions(+), 80 deletions(-)
> 
> diff --git a/src/api2/node/tasks.rs b/src/api2/node/tasks.rs
> index cbd0894e..258c3e86 100644
> --- a/src/api2/node/tasks.rs
> +++ b/src/api2/node/tasks.rs
> @@ -2,10 +2,18 @@ use std::fs::File;
>  use std::io::{BufRead, BufReader};
>  
>  use anyhow::{bail, Error};
> +use futures::FutureExt;
> +use http::request::Parts;
> +use http::{header, Response, StatusCode};
> +use hyper::Body;
> +use proxmox_async::stream::AsyncReaderStream;
>  use serde_json::{json, Value};
>  
> -use proxmox_router::{list_subdirs_api_method, Permission, Router, RpcEnvironment, SubdirMap};
> -use proxmox_schema::api;
> +use proxmox_router::{
> +    list_subdirs_api_method, ApiHandler, ApiMethod, ApiResponseFuture, Permission, Router,
> +    RpcEnvironment, SubdirMap,
> +};
> +use proxmox_schema::{api, BooleanSchema, IntegerSchema, ObjectSchema, Schema};
>  use proxmox_sys::sortable;
>  
>  use pbs_api_types::{
> @@ -19,6 +27,27 @@ use crate::api2::pull::check_pull_privs;
>  use pbs_config::CachedUserInfo;
>  use proxmox_rest_server::{upid_log_path, upid_read_status, TaskListInfoIterator, TaskState};
>  
> +pub const START_PARAM_SCHEMA: Schema =
> +    IntegerSchema::new("Start at this line when reading the tasklog")
> +        .minimum(0)
> +        .default(0)
> +        .schema();
> +
> +pub const LIMIT_PARAM_SCHEMA: Schema =
> +    IntegerSchema::new("The amount of lines to read from the tasklog. Setting this parameter to 0 will return all lines until the end of the file.")

^ Please split lines longer than 100 chars, like:

    IntegerSchema::new(
        "The amount of lines to read from the tasklog. \
         Setting this parameter to 0 will return all lines until the end of the file."
    )


(...)
> +        if download {
> +            if !param["start"].is_null()
> +                || !param["limit"].is_null()
> +                || !param["test-status"].is_null()
> +            {
> +                bail!("Parameter 'download' cannot be used with other parameters");
> +            }
>  
> -    for line in BufReader::new(file).lines() {
> -        match line {
> -            Ok(line) => {
> -                count += 1;
> -                if count < start {
> -                    continue;
> -                };
> -                if limit == 0 {
> -                    continue;
> -                };
> +            let header_disp = format!("attachment; filename={}", &upid.to_string());
> +            let stream = AsyncReaderStream::new(tokio::fs::File::open(path).await?);
> +
> +            Ok(Response::builder()
> +                .status(StatusCode::OK)
> +                .header(header::CONTENT_TYPE, "text/plain")
> +                .header(header::CONTENT_DISPOSITION, &header_disp)
> +                .body(Body::wrap_stream(stream))
> +                .unwrap())

^ This could just have a `return` in front of it, so the remaining code
isn't that much indented.

> +        } else {
> +            let start = param["start"].as_u64().unwrap_or(0);
> +            let mut limit = param["limit"].as_u64().unwrap_or(50);
> +            let test_status = param["test-status"].as_bool().unwrap_or(false);
> +
> +            let file = File::open(path)?;
> +
> +            let mut count: u64 = 0;
> +            let mut lines: Vec<Value> = vec![];
> +            let read_until_end = if limit == 0 { true } else { false };

^ booleans are already booleans, please avoid this construct in the
future.

clippy can catch this btw.