Allow supplying MONGO_SERVER_URL via chains-config (#1113)

* Allow supplying MONGO_SERVER_URL via chains-config

Currently, when using the Mongo docstore for docdb storage backend, the
only way to supply MONGO_SERVER_URL environment variable (which contains
the credentials to connect to MongoDB) is by adding an environment
variable to the Chains controller pod. It's a farily common practice to
update the MONGO_SERVER_URL at regular intervals when the credentials
are rotated.

To facilitate this, this commit adds 2 fields to Chains' configuration:
1. storage.docdb.mongo-server-url
2. storage.docdb.mongo-server-url-dir

`storage.docdb.mongo-server-url` simply allows supplying the value of
MONGO_SERVER_URL as a field. When this field is updated, the chains
controller pod does not restart, unlike when the MONGO_SERVER_URL
environment variable is updated.

`storage.docdb.mongo-server-url-dir` allows reading MONGO_SERVER_URL
from a file in the specified directory. This allows mounting the value
of MONGO_SERVER_URL from a secret or other mechanisms. When the value of
MONGO_SERVER_URL is updated in the path, the new value is automatically
picked up and applied.

* Bump gocloud.dev/docstore/mongodocstore

This commit bumps gocloud.dev/docstore/mongodocstore to the commit at
google/go-cloud#3429 that allows MONGO_SERVER_URL rotation.

go.mod

@@ -1,10 +1,13 @@
 module github.com/tektoncd/chains
 
-go 1.21
+go 1.22
+
+toolchain go1.22.2
 
 require (
 	cloud.google.com/go/compute/metadata v0.3.0
 	cloud.google.com/go/storage v1.40.0
+	github.com/fsnotify/fsnotify v1.7.0
 	github.com/golangci/golangci-lint v1.57.2
 	github.com/google/addlicense v1.1.1
 	github.com/google/go-cmp v0.6.0
@@ -32,9 +35,10 @@ require (
 	go.opencensus.io v0.24.0
 	go.uber.org/zap v1.27.0
 	gocloud.dev v0.37.0
-	gocloud.dev/docstore/mongodocstore v0.37.0
+	gocloud.dev/docstore/mongodocstore v0.37.1-0.20240501181211-d8b9c9401f18
 	gocloud.dev/pubsub/kafkapubsub v0.37.0
 	golang.org/x/crypto v0.22.0
+	golang.org/x/exp v0.0.0-20240103183307-be819d1f06fc
 	google.golang.org/grpc v1.63.2
 	google.golang.org/protobuf v1.33.0
 	k8s.io/api v0.28.3
@@ -49,6 +53,8 @@ require (
 	4d63.com/gocheckcompilerdirectives v1.2.1 // indirect
 	4d63.com/gochecknoglobals v0.2.1 // indirect
 	cloud.google.com/go v0.112.1 // indirect
+	cloud.google.com/go/auth v0.3.0 // indirect
+	cloud.google.com/go/auth/oauth2adapt v0.2.2 // indirect
 	cloud.google.com/go/firestore v1.15.0 // indirect
 	cloud.google.com/go/iam v1.1.7 // indirect
 	cloud.google.com/go/kms v1.15.8 // indirect
@@ -105,23 +111,23 @@ require (
 	github.com/asaskevich/govalidator v0.0.0-20230301143203-a9d515a09cc2 // indirect
 	github.com/ashanbrown/forbidigo v1.6.0 // indirect
 	github.com/ashanbrown/makezero v1.1.1 // indirect
-	github.com/aws/aws-sdk-go v1.51.6 // indirect
-	github.com/aws/aws-sdk-go-v2 v1.26.0 // indirect
-	github.com/aws/aws-sdk-go-v2/config v1.27.9 // indirect
-	github.com/aws/aws-sdk-go-v2/credentials v1.17.9 // indirect
-	github.com/aws/aws-sdk-go-v2/feature/ec2/imds v1.16.0 // indirect
-	github.com/aws/aws-sdk-go-v2/internal/configsources v1.3.4 // indirect
-	github.com/aws/aws-sdk-go-v2/internal/endpoints/v2 v2.6.4 // indirect
+	github.com/aws/aws-sdk-go v1.51.30 // indirect
+	github.com/aws/aws-sdk-go-v2 v1.26.1 // indirect
+	github.com/aws/aws-sdk-go-v2/config v1.27.11 // indirect
+	github.com/aws/aws-sdk-go-v2/credentials v1.17.11 // indirect
+	github.com/aws/aws-sdk-go-v2/feature/ec2/imds v1.16.1 // indirect
+	github.com/aws/aws-sdk-go-v2/internal/configsources v1.3.5 // indirect
+	github.com/aws/aws-sdk-go-v2/internal/endpoints/v2 v2.6.5 // indirect
 	github.com/aws/aws-sdk-go-v2/internal/ini v1.8.0 // indirect
 	github.com/aws/aws-sdk-go-v2/service/ecr v1.20.2 // indirect
 	github.com/aws/aws-sdk-go-v2/service/ecrpublic v1.18.2 // indirect
-	github.com/aws/aws-sdk-go-v2/service/internal/accept-encoding v1.11.1 // indirect
-	github.com/aws/aws-sdk-go-v2/service/internal/presigned-url v1.11.6 // indirect
+	github.com/aws/aws-sdk-go-v2/service/internal/accept-encoding v1.11.2 // indirect
+	github.com/aws/aws-sdk-go-v2/service/internal/presigned-url v1.11.7 // indirect
 	github.com/aws/aws-sdk-go-v2/service/kms v1.30.0 // indirect
-	github.com/aws/aws-sdk-go-v2/service/sso v1.20.3 // indirect
-	github.com/aws/aws-sdk-go-v2/service/ssooidc v1.23.3 // indirect
-	github.com/aws/aws-sdk-go-v2/service/sts v1.28.5 // indirect
-	github.com/aws/smithy-go v1.20.1 // indirect
+	github.com/aws/aws-sdk-go-v2/service/sso v1.20.5 // indirect
+	github.com/aws/aws-sdk-go-v2/service/ssooidc v1.23.4 // indirect
+	github.com/aws/aws-sdk-go-v2/service/sts v1.28.6 // indirect
+	github.com/aws/smithy-go v1.20.2 // indirect
 	github.com/awslabs/amazon-ecr-credential-helper/ecr-login v0.0.0-20231024185945-8841054dbdb8 // indirect
 	github.com/beorn7/perks v1.0.1 // indirect
 	github.com/bkielbasa/cyclop v1.2.1 // indirect
@@ -178,7 +184,6 @@ require (
 	github.com/fatih/structtag v1.2.0 // indirect
 	github.com/felixge/httpsnoop v1.0.4 // indirect
 	github.com/firefart/nonamedreturns v1.0.4 // indirect
-	github.com/fsnotify/fsnotify v1.7.0 // indirect
 	github.com/fzipp/gocyclo v0.6.0 // indirect
 	github.com/ghostiam/protogetter v0.3.5 // indirect
 	github.com/go-chi/chi v4.1.2+incompatible // indirect
@@ -277,7 +282,7 @@ require (
 	github.com/kevinburke/ssh_config v1.2.0 // indirect
 	github.com/kisielk/errcheck v1.7.0 // indirect
 	github.com/kkHAIKE/contextcheck v1.1.5 // indirect
-	github.com/klauspost/compress v1.17.7 // indirect
+	github.com/klauspost/compress v1.17.8 // indirect
 	github.com/kulti/thelper v0.6.3 // indirect
 	github.com/kunwardeep/paralleltest v1.0.10 // indirect
 	github.com/kylelemons/godebug v1.1.0 // indirect
@@ -395,25 +400,24 @@ require (
 	github.com/yagipy/maintidx v1.0.0 // indirect
 	github.com/yeya24/promlinter v0.2.0 // indirect
 	github.com/ykadowak/zerologlint v0.1.5 // indirect
-	github.com/youmark/pkcs8 v0.0.0-20201027041543-1326539a0a0a // indirect
+	github.com/youmark/pkcs8 v0.0.0-20240424034433-3c2c7870ae76 // indirect
 	github.com/zeebo/errs v1.3.0 // indirect
 	gitlab.com/bosi/decorder v0.4.1 // indirect
 	go-simpler.org/musttag v0.9.0 // indirect
 	go-simpler.org/sloglint v0.5.0 // indirect
-	go.mongodb.org/mongo-driver v1.14.0 // indirect
+	go.mongodb.org/mongo-driver v1.15.0 // indirect
 	go.opentelemetry.io/contrib/instrumentation/google.golang.org/grpc/otelgrpc v0.49.0 // indirect
-	go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp v0.49.0 // indirect
-	go.opentelemetry.io/otel v1.24.0 // indirect
-	go.opentelemetry.io/otel/metric v1.24.0 // indirect
-	go.opentelemetry.io/otel/trace v1.24.0 // indirect
+	go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp v0.51.0 // indirect
+	go.opentelemetry.io/otel v1.26.0 // indirect
+	go.opentelemetry.io/otel/metric v1.26.0 // indirect
+	go.opentelemetry.io/otel/trace v1.26.0 // indirect
 	go.step.sm/crypto v0.44.2 // indirect
 	go.uber.org/atomic v1.11.0 // indirect
 	go.uber.org/automaxprocs v1.5.3 // indirect
 	go.uber.org/multierr v1.11.0 // indirect
-	golang.org/x/exp v0.0.0-20240103183307-be819d1f06fc // indirect
 	golang.org/x/exp/typeparams v0.0.0-20240314144324-c7f7c6466f7f // indirect
 	golang.org/x/mod v0.16.0 // indirect
-	golang.org/x/net v0.23.0 // indirect
+	golang.org/x/net v0.24.0 // indirect
 	golang.org/x/oauth2 v0.19.0 // indirect
 	golang.org/x/sync v0.7.0 // indirect
 	golang.org/x/sys v0.20.0 // indirect
@@ -423,10 +427,10 @@ require (
 	golang.org/x/tools v0.19.0 // indirect
 	golang.org/x/xerrors v0.0.0-20231012003039-104605ab7028 // indirect
 	gomodules.xyz/jsonpatch/v2 v2.4.0 // indirect
-	google.golang.org/api v0.172.0 // indirect
+	google.golang.org/api v0.176.1 // indirect
 	google.golang.org/genproto v0.0.0-20240311173647-c811ad7063a7 // indirect
 	google.golang.org/genproto/googleapis/api v0.0.0-20240314234333-6e1732d8331c // indirect
-	google.golang.org/genproto/googleapis/rpc v0.0.0-20240318140521-94a12d6c2237 // indirect
+	google.golang.org/genproto/googleapis/rpc v0.0.0-20240415180920-8c6c420018be // indirect
 	gopkg.in/go-jose/go-jose.v2 v2.6.3 // indirect
 	gopkg.in/inf.v0 v0.9.1 // indirect
 	gopkg.in/ini.v1 v1.67.0 // indirect