go__sqs_demo/back/web/home.go

242 lines
7.1 KiB
Go

package web
import (
"context"
"fmt"
"log"
"net/http"
"time"
"github.com/aws/aws-sdk-go-v2/aws/arn"
"github.com/gin-contrib/sessions"
"github.com/gin-gonic/gin"
"code.osinet.fr/fgm/sqs_demo/back/services/redriver"
)
// classifyPolicies distributes queue policies across five bins:
// - wild: policies describing a DLQ with an allowAll policy
// - closed: policies describing a DLQ with an denyAll policy
// - byQueue: policies describing a DLQ with an byQueue policy
// - sources: policies describing a queue with a DLQ
// - notSources: policies describing a queue without a DLQ
//
// Note that dead-letter queues may also be source queues, for multi-level processing, and vice-versa.
//
// For easier reading, DLQs are not listed as part of the non-source list.
func classifyPolicies(policies map[string]*redriver.QueueRedrivePolicies) (byQueue, wild, closed, sources map[string]redriver.QueueRedrivePolicies, notSources []string) {
DLQs := make(map[string]redriver.QueueRedrivePolicies)
sources = make(map[string]redriver.QueueRedrivePolicies)
wild = make(map[string]redriver.QueueRedrivePolicies)
closed = make(map[string]redriver.QueueRedrivePolicies)
byQueue = make(map[string]redriver.QueueRedrivePolicies)
nsTemp := make([]string, 0, len(notSources))
for qURL, qrp := range policies {
if qrp.QueueInfoAttributesRedriveAllowPolicy != nil {
DLQs[qURL] = *qrp
}
if qrp.QueueInfoAttributesRedrivePolicy != nil {
sources[qURL] = *qrp
} else {
nsTemp = append(nsTemp, qURL)
}
}
for _, qURL := range nsTemp {
if _, ok := DLQs[qURL]; !ok {
notSources = append(notSources, qURL)
}
}
for qURL, qrp := range DLQs {
rap := qrp.QueueInfoAttributesRedriveAllowPolicy
switch rap.RedrivePermission {
case "allowAll":
wild[qURL] = qrp
case "denyAll":
closed[qURL] = qrp
case "byQueue":
byQueue[qURL] = qrp
}
}
return
}
func policiesByURL(c *gin.Context, qURLs []string, rd redriver.Redriver, ctx context.Context) map[string]*redriver.QueueRedrivePolicies {
qMap := make(map[string]*redriver.QueueRedrivePolicies, len(qURLs))
for _, qURL := range qURLs {
name, err := redriver.NameFromURL(qURL)
if err != nil {
log.Println(http.StatusInternalServerError)
c.HTML(http.StatusInternalServerError, "500", nil)
}
qrp, err := rd.GetRedrivePolicies(ctx, name)
if err != nil || qrp == nil {
log.Println(err)
c.HTML(http.StatusInternalServerError, "500", nil)
}
qMap[qURL] = qrp
}
return qMap
}
type link struct{ URL, Text string }
// queueRow provides templates with a representation for all kinds of table cells
type queueCell struct {
Message string
Link *link
Links [][]link
}
type QueueRow [2]queueCell
func makeHomeHandler(rd redriver.Redriver, prefix string) gin.HandlerFunc {
return func(c *gin.Context) {
ctx := c.Request.Context()
sess := sessions.Default(c)
flashes := sess.Flashes()
defer func() { _ = sess.Save() }()
t0 := time.Now()
qURLs, err := rd.ListQueues(ctx, prefix)
latency := time.Since(t0)
if err != nil {
log.Printf("failed listing queues: %v", err)
c.HTML(http.StatusInternalServerError, "500", nil)
return
}
policies := policiesByURL(c, qURLs, rd, ctx)
byQueue, wild, closed, sources, notSources := classifyPolicies(policies)
// log.Printf("DLQs: %#v\nSRCs: %#v\nNoSRCs: %#v\n", maps.Keys(DLQs), maps.Keys(SRCs), NoSRCs)
rows := make([]QueueRow, 0, len(byQueue)+3) // wild, closed, notSources: sources appear within a byQueue row
rows, err = prepareSingleLeft(rows, wild, "All source queues allowed")
if err != nil {
log.Printf("failed preparing wild DLQs: %v", err)
c.HTML(http.StatusInternalServerError, "500", nil)
return
}
rows, err = prepareSingleLeft(rows, closed, "No source queue allowed")
if err != nil {
log.Printf("failed preparing closed DLQs: %v", err)
c.HTML(http.StatusInternalServerError, "500", nil)
return
}
rows, err = prepareSingleRight(rows, notSources, "No associated DLQ")
if err != nil {
log.Printf("failed converting isolated queues: %v", err)
c.HTML(http.StatusInternalServerError, "500", nil)
return
}
rows, err = prepareBindings(rows, byQueue, sources)
if err != nil {
log.Printf("failed preparing queue bindings: %v", err)
c.HTML(http.StatusInternalServerError, "500", nil)
return
}
c.HTML(http.StatusOK, "home", gin.H{
"flashes": flashes,
"latency": latency,
"prefix": prefix,
"rows": rows,
})
}
}
func prepareSingleLeft(rows []QueueRow, list map[string]redriver.QueueRedrivePolicies, msg string) ([]QueueRow, error) {
if len(list) > 0 {
row := QueueRow{
{Message: msg},
{Links: make([][]link, 1)},
}
row[1].Links[0] = make([]link, 0, len(list))
for qURL := range list {
name, err := redriver.NameFromURL(qURL)
if err != nil {
return nil, err
}
row[1].Links[0] = append(row[1].Links[0], link{URL: "/queue/" + name, Text: name})
}
rows = append(rows, row)
}
return rows, nil
}
func prepareSingleRight(rows []QueueRow, list []string, msg string) ([]QueueRow, error) {
if len(list) > 0 {
row := QueueRow{
{Links: make([][]link, 1)},
{Message: msg},
}
row[0].Links[0] = make([]link, 0, len(list))
for _, qURL := range list {
name, err := redriver.NameFromURL(qURL)
if err != nil {
return nil, err
}
row[0].Links[0] = append(row[0].Links[0], link{URL: "/queue/" + name, Text: name})
}
rows = append(rows, row)
}
return rows, nil
}
func prepareBinding(dlqURL string, DLQrp redriver.QueueRedrivePolicies, sources map[string]redriver.QueueRedrivePolicies) (*QueueRow, error) {
var left, right queueCell
dlqName, err := redriver.NameFromURL(dlqURL)
if err != nil {
return nil, fmt.Errorf("failed parsing DLQ URL %q: %w", dlqURL, err)
}
right = queueCell{Link: &link{URL: "/queue/" + dlqName, Text: dlqName}}
a, err := redriver.ARNFromURL(dlqURL)
if err != nil {
return nil, fmt.Errorf("failed converting URL %q to ARN: %w", dlqURL, err)
}
dlqARN := a.String()
var bound, unbound, elsewhere []link
for _, sourceARN := range DLQrp.SourceQueueARNs {
sa, err := arn.Parse(sourceARN)
if err != nil {
return nil, fmt.Errorf("failed parsing %q as an ARN: %w", sourceARN, err)
}
sourceURL, err := redriver.URLFromARN(sa)
if err != nil {
return nil, fmt.Errorf("failed converting ARN %q for URL: %w", sa.String(), err)
}
sourceName := sa.Resource
sourceQRP, ok := sources[sourceURL]
link := link{
URL: "/queue/" + sourceName,
Text: sourceName,
}
if ok {
switch sourceQRP.DeadLetterTargetARN {
case "":
unbound = append(unbound, link)
case dlqARN:
bound = append(bound, link)
default:
elsewhere = append(elsewhere, link)
}
} else {
unbound = append(unbound, link)
}
}
left.Links = [][]link{bound, elsewhere, unbound}
return &QueueRow{left, right}, nil
}
func prepareBindings(rows []QueueRow, DLQs, sources map[string]redriver.QueueRedrivePolicies) ([]QueueRow, error) {
for dlqURL, DLQrp := range DLQs {
row, err := prepareBinding(dlqURL, DLQrp, sources)
if err != nil || row == nil {
return nil, fmt.Errorf("failed binding DLQ %s: %w", dlqURL, err)
}
rows = append(rows, *row)
}
return rows, nil
}