Return buffered text from log endpoint if decoding fails (#15558)

To see why I think this is a good change lets look at why I am making it My disk was full, which means GC was happening agressively. So by the time I called the logging endpoint from the SDK, the logs were GC'd The error I was getting before was: ``` invalid character 'i' in literal false (expecting 'l') ``` Now the error I get is: ``` failed to decode log endpoint response as JSON: "failed to list entries: open /tmp/nomad.data.4219353875/alloc/f11fee50-2b66-a7a2-d3ec-8442cb3d557a/alloc/logs: no such file or directory" ``` Still not super descriptive but much more debugable
hashicorp · Jan 23, 2023 · f8cb64c · f8cb64c
1 parent b620ae4
commit f8cb64c
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Showing 4 changed files with 18 additions and 1 deletion.
diff --git a/.changelog/15558.txt b/.changelog/15558.txt
@@ -0,0 +1,3 @@
+```release-note:improvement
+api: improved error returned from AllocFS.Logs when response is not JSON
+```
diff --git a/api/fs.go b/api/fs.go
@@ -4,10 +4,13 @@ import (
 	"encoding/json"
 	"fmt"
 	"io"
+	"io/ioutil"
 	"net"
 	"strconv"
 	"sync"
 	"time"
+
+	"github.com/hashicorp/go-multierror"
 )
 
 const (
@@ -288,7 +291,12 @@ func (a *AllocFS) Logs(alloc *Allocation, follow bool, task, logType, origin str
 				if err == io.EOF || err == io.ErrClosedPipe {
 					close(frames)
 				} else {
-					errCh <- err
+					buf, err2 := ioutil.ReadAll(dec.Buffered())
+					if err2 != nil {
+						errCh <- fmt.Errorf("failed to decode and failed to read buffered data: %w", multierror.Append(err, err2))
+					} else {
+						errCh <- fmt.Errorf("failed to decode log endpoint response as JSON: %q", buf)
+					}
 				}
 				return
 			}

diff --git a/api/go.mod b/api/go.mod
@@ -7,6 +7,7 @@ require (
 	github.com/gorilla/websocket v1.5.0
 	github.com/hashicorp/cronexpr v1.1.1
 	github.com/hashicorp/go-cleanhttp v0.5.2
+	github.com/hashicorp/go-multierror v1.1.1
 	github.com/hashicorp/go-rootcerts v1.0.2
 	github.com/mitchellh/go-testing-interface v1.14.1
 	github.com/mitchellh/mapstructure v1.5.0
@@ -16,6 +17,7 @@ require (
 
 require (
 	github.com/google/go-cmp v0.5.9 // indirect
+	github.com/hashicorp/errwrap v1.0.0 // indirect
 	github.com/mitchellh/go-homedir v1.1.0 // indirect
 	github.com/stretchr/testify v1.8.1 // indirect
 )
diff --git a/api/go.sum b/api/go.sum
@@ -9,8 +9,12 @@ github.com/gorilla/websocket v1.5.0 h1:PPwGk2jz7EePpoHN/+ClbZu8SPxiqlu12wZP/3sWm
 github.com/gorilla/websocket v1.5.0/go.mod h1:YR8l580nyteQvAITg2hZ9XVh4b55+EU/adAjf1fMHhE=
 github.com/hashicorp/cronexpr v1.1.1 h1:NJZDd87hGXjoZBdvyCF9mX4DCq5Wy7+A/w+A7q0wn6c=
 github.com/hashicorp/cronexpr v1.1.1/go.mod h1:P4wA0KBl9C5q2hABiMO7cp6jcIg96CDh1Efb3g1PWA4=
+github.com/hashicorp/errwrap v1.0.0 h1:hLrqtEDnRye3+sgx6z4qVLNuviH3MR5aQ0ykNJa/UYA=
+github.com/hashicorp/errwrap v1.0.0/go.mod h1:YH+1FKiLXxHSkmPseP+kNlulaMuP3n2brvKWEqk/Jc4=
 github.com/hashicorp/go-cleanhttp v0.5.2 h1:035FKYIWjmULyFRBKPs8TBQoi0x6d9G4xc9neXJWAZQ=
 github.com/hashicorp/go-cleanhttp v0.5.2/go.mod h1:kO/YDlP8L1346E6Sodw+PrpBSV4/SoxCXGY6BqNFT48=
+github.com/hashicorp/go-multierror v1.1.1 h1:H5DkEtf6CXdFp0N0Em5UCwQpXMWke8IA0+lD48awMYo=
+github.com/hashicorp/go-multierror v1.1.1/go.mod h1:iw975J/qwKPdAO1clOe2L8331t/9/fmwbPZ6JB6eMoM=
 github.com/hashicorp/go-rootcerts v1.0.2 h1:jzhAVGtqPKbwpyCPELlgNWhE1znq+qwJtW5Oi2viEzc=
 github.com/hashicorp/go-rootcerts v1.0.2/go.mod h1:pqUvnprVnM5bf7AOirdbb01K4ccR319Vf4pU3K5EGc8=
 github.com/mitchellh/go-homedir v1.1.0 h1:lukF9ziXFxDFPkA1vsr5zpc1XuPDn/wFntq5mG+4E0Y=