feat: add proxy-stress-test sample app for e2e regression testing (#217)

* feat: add proxy-stress-test sample app for e2e regression testing

Go app that exercises Keploy proxy under stress conditions:
- 10+ concurrent HTTPS connections through a forward proxy (tinyproxy)
  via CONNECT tunnels, triggering TLS MITM cert generation
- PostgreSQL queries returning 50+ rows with 100KB+ payloads, testing
  wire protocol handling for large DataRow responses
- HTTP POST through CONNECT tunnel for MatchType validation

Includes Docker Compose with postgres + tinyproxy + the app.
Used by the proxy-stress-test CI pipeline in keploy/keploy.

Signed-off-by: Shubham Jain <shubham@keploy.io>
Signed-off-by: slayerjain <shubhamkjain@outlook.com>

* fix: address all Copilot review comments on sample app

- Fix module path to match repo layout (samples-go/proxy-stress-test)
- Remove dependency on external test-iid.sh in test.sh
- Remove sudo usage in test.sh for portability
- Pin tinyproxy image tag, bind proxy to localhost, restrict Allow
- Replace WARN log with normal log level
- Add actionable hint to database connection fatal
- Handle http.NewRequest error in background noise goroutine
- Redact database credentials in log output
- Check rows.Err() after iteration for mid-stream error detection
- Handle wideRows.Scan error instead of discarding
- Add nolint:gosec comment for intentional InsecureSkipVerify
- Update go.mod after module path change

Signed-off-by: Shubham Jain <shubham@keploy.io>
Signed-off-by: slayerjain <shubhamkjain@outlook.com>

* fix: consistent CLI flags, health timeout, gofmt formatting

- Use --generate-github-actions=false and --container-name consistently
  (matching other samples in the repo).
- Add max_attempts=30 timeout to health wait loop to fail fast on
  broken builds instead of looping indefinitely.
- Run gofmt on main.go to fix indentation around scan error check.

Signed-off-by: Shubham Jain <shubham@keploy.io>
Signed-off-by: slayerjain <shubhamkjain@outlook.com>

* fix: address Copilot review round 3 — naming, cleanup, timeouts

- Rename binary from repro-app to proxy-stress-test in Dockerfile.
- Update OTel service name to match sample directory name.
- Add cleanup trap (docker compose down) on script exit.
- Add curl --max-time to all requests to prevent CI hangs.
- Add docker compose down after replay phase.
- Add 5s timeout to /health db ping.
- Fix misleading "concurrently" comment (queries are sequential).

Signed-off-by: Shubham Jain <shubham@keploy.io>
Signed-off-by: slayerjain <shubhamkjain@outlook.com>

* fix: cd to script directory before running docker compose

Ensures the script works when invoked from any working directory.

Signed-off-by: Shubham Jain <shubham@keploy.io>
Signed-off-by: slayerjain <shubhamkjain@outlook.com>

* ci: add CPU/memory limits and stress parameters to docker-compose

- Set CONCURRENT_CONNS=42 and BATCH_SIZE=42 matching production
  traffic pattern from Agoda travel-card-api.
- Enable OTel with no collector to generate mock-not-found errors
  that stress the error channel during replay.
- Add BG_NOISE_CONNS=2 for background connection noise.
- Set deploy.resources.limits: cpus=0.50, memory=512M to simulate
  resource-constrained K8s pods where the bugs are observable.

Signed-off-by: Shubham Jain <shubham@keploy.io>
Signed-off-by: slayerjain <shubhamkjain@outlook.com>

---------

Signed-off-by: Shubham Jain <shubham@keploy.io>
Signed-off-by: slayerjain <shubhamkjain@outlook.com>

Author: slayerjain

proxy-stress-test/Dockerfile

@@ -0,0 +1,12 @@
+FROM golang:1.22-alpine AS builder
+
+WORKDIR /app
+COPY go.mod go.sum ./
+RUN go mod download
+COPY main.go ./
+RUN CGO_ENABLED=0 go build -o proxy-stress-test .
+
+FROM alpine:3.19
+RUN apk add --no-cache ca-certificates curl
+COPY --from=builder /app/proxy-stress-test /usr/local/bin/proxy-stress-test
+ENTRYPOINT ["proxy-stress-test"]

proxy-stress-test/docker-compose.yml

@@ -0,0 +1,61 @@
+services:
+  db:
+    image: postgres:16-alpine
+    environment:
+      POSTGRES_USER: repro
+      POSTGRES_PASSWORD: repro
+      POSTGRES_DB: reprodb
+    ports:
+      - "5432:5432"
+    volumes:
+      - ./init.sql:/docker-entrypoint-initdb.d/01-init.sql
+    healthcheck:
+      test: ["CMD-SHELL", "pg_isready -U repro -d reprodb"]
+      interval: 2s
+      timeout: 5s
+      retries: 10
+
+  proxy:
+    image: vimagick/tinyproxy:latest
+    ports:
+      - "127.0.0.1:3128:3128"
+    command: >
+      sh -c "echo 'Port 3128' > /tmp/tp.conf &&
+             echo 'Listen 0.0.0.0' >> /tmp/tp.conf &&
+             echo 'Timeout 300' >> /tmp/tp.conf &&
+             echo 'MaxClients 100' >> /tmp/tp.conf &&
+             echo 'Allow 172.16.0.0/12' >> /tmp/tp.conf &&
+             echo 'ConnectPort 443' >> /tmp/tp.conf &&
+             tinyproxy -d -c /tmp/tp.conf"
+
+  app:
+    build: .
+    container_name: proxyStressApp
+    ports:
+      - "8080:8080"
+    environment:
+      LISTEN_ADDR: ":8080"
+      DATABASE_URL: "postgres://repro:repro@db:5432/reprodb?sslmode=disable"
+      HTTPS_TARGET: "https://httpbin.org/get"
+      HTTP_PROXY_URL: "http://proxy:3128"
+      # High concurrency to stress-test cert generation and error channel.
+      # 42 matches the production traffic pattern from Agoda travel-card-api.
+      CONCURRENT_CONNS: "42"
+      BATCH_SIZE: "42"
+      # OTel enabled with no collector — generates mock-not-found errors
+      # that stress the error channel during replay.
+      OTEL_ENABLED: "true"
+      OTEL_EXPORTER_OTLP_ENDPOINT: "localhost:4318"
+      OTEL_EXPORT_INTERVAL: "500ms"
+      # Background noise connections stress error channel between tests.
+      BG_NOISE_CONNS: "2"
+    depends_on:
+      db:
+        condition: service_healthy
+    # CPU limit simulates a resource-constrained K8s pod. Without this,
+    # cert storm and error channel bugs are masked by excess CPU.
+    deploy:
+      resources:
+        limits:
+          cpus: "0.50"
+          memory: "512M"

proxy-stress-test/go.mod

@@ -0,0 +1,31 @@
+module github.com/keploy/samples-go/proxy-stress-test
+
+go 1.22.0
+
+require (
+	github.com/lib/pq v1.10.9
+	go.opentelemetry.io/otel v1.28.0
+	go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetrichttp v1.28.0
+	go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracehttp v1.28.0
+	go.opentelemetry.io/otel/sdk v1.28.0
+	go.opentelemetry.io/otel/sdk/metric v1.28.0
+)
+
+require (
+	github.com/cenkalti/backoff/v4 v4.3.0 // indirect
+	github.com/go-logr/logr v1.4.2 // indirect
+	github.com/go-logr/stdr v1.2.2 // indirect
+	github.com/google/uuid v1.6.0 // indirect
+	github.com/grpc-ecosystem/grpc-gateway/v2 v2.20.0 // indirect
+	go.opentelemetry.io/otel/exporters/otlp/otlptrace v1.28.0 // indirect
+	go.opentelemetry.io/otel/metric v1.28.0 // indirect
+	go.opentelemetry.io/otel/trace v1.28.0 // indirect
+	go.opentelemetry.io/proto/otlp v1.3.1 // indirect
+	golang.org/x/net v0.26.0 // indirect
+	golang.org/x/sys v0.21.0 // indirect
+	golang.org/x/text v0.16.0 // indirect
+	google.golang.org/genproto/googleapis/api v0.0.0-20240701130421-f6361c86f094 // indirect
+	google.golang.org/genproto/googleapis/rpc v0.0.0-20240701130421-f6361c86f094 // indirect
+	google.golang.org/grpc v1.64.0 // indirect
+	google.golang.org/protobuf v1.34.2 // indirect
+)

proxy-stress-test/go.sum

@@ -0,0 +1,55 @@
+github.com/cenkalti/backoff/v4 v4.3.0 h1:MyRJ/UdXutAwSAT+s3wNd7MfTIcy71VQueUuFK343L8=
+github.com/cenkalti/backoff/v4 v4.3.0/go.mod h1:Y3VNntkOUPxTVeUxJ/G5vcM//AlwfmyYozVcomhLiZE=
+github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
+github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/go-logr/logr v1.2.2/go.mod h1:jdQByPbusPIv2/zmleS9BjJVeZ6kBagPoEUsqbVz/1A=
+github.com/go-logr/logr v1.4.2 h1:6pFjapn8bFcIbiKo3XT4j/BhANplGihG6tvd+8rYgrY=
+github.com/go-logr/logr v1.4.2/go.mod h1:9T104GzyrTigFIr8wt5mBrctHMim0Nb2HLGrmQ40KvY=
+github.com/go-logr/stdr v1.2.2 h1:hSWxHoqTgW2S2qGc0LTAI563KZ5YKYRhT3MFKZMbjag=
+github.com/go-logr/stdr v1.2.2/go.mod h1:mMo/vtBO5dYbehREoey6XUKy/eSumjCCveDpRre4VKE=
+github.com/google/go-cmp v0.6.0 h1:ofyhxvXcZhMsU5ulbFiLKl/XBFqE1GSq7atu8tAmTRI=
+github.com/google/go-cmp v0.6.0/go.mod h1:17dUlkBOakJ0+DkrSSNjCkIjxS6bF9zb3elmeNGIjoY=
+github.com/google/uuid v1.6.0 h1:NIvaJDMOsjHA8n1jAhLSgzrAzy1Hgr+hNrb57e+94F0=
+github.com/google/uuid v1.6.0/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
+github.com/grpc-ecosystem/grpc-gateway/v2 v2.20.0 h1:bkypFPDjIYGfCYD5mRBvpqxfYX1YCS1PXdKYWi8FsN0=
+github.com/grpc-ecosystem/grpc-gateway/v2 v2.20.0/go.mod h1:P+Lt/0by1T8bfcF3z737NnSbmxQAppXMRziHUxPOC8k=
+github.com/lib/pq v1.10.9 h1:YXG7RB+JIjhP29X+OtkiDnYaXQwpS4JEWq7dtCCRUEw=
+github.com/lib/pq v1.10.9/go.mod h1:AlVN5x4E4T544tWzH6hKfbfQvm3HdbOxrmggDNAPY9o=
+github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
+github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/stretchr/testify v1.9.0 h1:HtqpIVDClZ4nwg75+f6Lvsy/wHu+3BoSGCbBAcpTsTg=
+github.com/stretchr/testify v1.9.0/go.mod h1:r2ic/lqez/lEtzL7wO/rwa5dbSLXVDPFyf8C91i36aY=
+go.opentelemetry.io/otel v1.28.0 h1:/SqNcYk+idO0CxKEUOtKQClMK/MimZihKYMruSMViUo=
+go.opentelemetry.io/otel v1.28.0/go.mod h1:q68ijF8Fc8CnMHKyzqL6akLO46ePnjkgfIMIjUIX9z4=
+go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetrichttp v1.28.0 h1:aLmmtjRke7LPDQ3lvpFz+kNEH43faFhzW7v8BFIEydg=
+go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetrichttp v1.28.0/go.mod h1:TC1pyCt6G9Sjb4bQpShH+P5R53pO6ZuGnHuuln9xMeE=
+go.opentelemetry.io/otel/exporters/otlp/otlptrace v1.28.0 h1:3Q/xZUyC1BBkualc9ROb4G8qkH90LXEIICcs5zv1OYY=
+go.opentelemetry.io/otel/exporters/otlp/otlptrace v1.28.0/go.mod h1:s75jGIWA9OfCMzF0xr+ZgfrB5FEbbV7UuYo32ahUiFI=
+go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracehttp v1.28.0 h1:j9+03ymgYhPKmeXGk5Zu+cIZOlVzd9Zv7QIiyItjFBU=
+go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracehttp v1.28.0/go.mod h1:Y5+XiUG4Emn1hTfciPzGPJaSI+RpDts6BnCIir0SLqk=
+go.opentelemetry.io/otel/metric v1.28.0 h1:f0HGvSl1KRAU1DLgLGFjrwVyismPlnuU6JD6bOeuA5Q=
+go.opentelemetry.io/otel/metric v1.28.0/go.mod h1:Fb1eVBFZmLVTMb6PPohq3TO9IIhUisDsbJoL/+uQW4s=
+go.opentelemetry.io/otel/sdk v1.28.0 h1:b9d7hIry8yZsgtbmM0DKyPWMMUMlK9NEKuIG4aBqWyE=
+go.opentelemetry.io/otel/sdk v1.28.0/go.mod h1:oYj7ClPUA7Iw3m+r7GeEjz0qckQRJK2B8zjcZEfu7Pg=
+go.opentelemetry.io/otel/sdk/metric v1.28.0 h1:OkuaKgKrgAbYrrY0t92c+cC+2F6hsFNnCQArXCKlg08=
+go.opentelemetry.io/otel/sdk/metric v1.28.0/go.mod h1:cWPjykihLAPvXKi4iZc1dpER3Jdq2Z0YLse3moQUCpg=
+go.opentelemetry.io/otel/trace v1.28.0 h1:GhQ9cUuQGmNDd5BTCP2dAvv75RdMxEfTmYejp+lkx9g=
+go.opentelemetry.io/otel/trace v1.28.0/go.mod h1:jPyXzNPg6da9+38HEwElrQiHlVMTnVfM3/yv2OlIHaI=
+go.opentelemetry.io/proto/otlp v1.3.1 h1:TrMUixzpM0yuc/znrFTP9MMRh8trP93mkCiDVeXrui0=
+go.opentelemetry.io/proto/otlp v1.3.1/go.mod h1:0X1WI4de4ZsLrrJNLAQbFeLCm3T7yBkR0XqQ7niQU+8=
+golang.org/x/net v0.26.0 h1:soB7SVo0PWrY4vPW/+ay0jKDNScG2X9wFeYlXIvJsOQ=
+golang.org/x/net v0.26.0/go.mod h1:5YKkiSynbBIh3p6iOc/vibscux0x38BZDkn8sCUPxHE=
+golang.org/x/sys v0.21.0 h1:rF+pYz3DAGSQAxAu1CbC7catZg4ebC4UIeIhKxBZvws=
+golang.org/x/sys v0.21.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
+golang.org/x/text v0.16.0 h1:a94ExnEXNtEwYLGJSIUxnWoxoRz/ZcCsV63ROupILh4=
+golang.org/x/text v0.16.0/go.mod h1:GhwF1Be+LQoKShO3cGOHzqOgRrGaYc9AvblQOmPVHnI=
+google.golang.org/genproto/googleapis/api v0.0.0-20240701130421-f6361c86f094 h1:0+ozOGcrp+Y8Aq8TLNN2Aliibms5LEzsq99ZZmAGYm0=
+google.golang.org/genproto/googleapis/api v0.0.0-20240701130421-f6361c86f094/go.mod h1:fJ/e3If/Q67Mj99hin0hMhiNyCRmt6BQ2aWIJshUSJw=
+google.golang.org/genproto/googleapis/rpc v0.0.0-20240701130421-f6361c86f094 h1:BwIjyKYGsK9dMCBOorzRri8MQwmi7mT9rGHsCEinZkA=
+google.golang.org/genproto/googleapis/rpc v0.0.0-20240701130421-f6361c86f094/go.mod h1:Ue6ibwXGpU+dqIcODieyLOcgj7z8+IcskoNIgZxtrFY=
+google.golang.org/grpc v1.64.0 h1:KH3VH9y/MgNQg1dE7b3XfVK0GsPSIzJwdF617gUSbvY=
+google.golang.org/grpc v1.64.0/go.mod h1:oxjF8E3FBnjp+/gVFYdWacaLDx9na1aqy9oovLpxQYg=
+google.golang.org/protobuf v1.34.2 h1:6xV6lTsCfpGD21XK49h7MhtcApnLqkfYgPcdHftf6hg=
+google.golang.org/protobuf v1.34.2/go.mod h1:qYOHts0dSfpeUzUFpOMr/WGzszTmLH+DiWniOlNbLDw=
+gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
+gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

proxy-stress-test/init.sql

@@ -0,0 +1,82 @@
+-- Seed data for Issue 3: Postgres large DataRow responses
+--
+-- The Keploy Postgres wire protocol parser fails when DataRow packets
+-- exceed a single TCP segment (MSS ~1460 bytes on Docker bridge).
+-- Error: "incomplete or invalid response packet (DataRow): want N bytes, have M"
+--
+-- Strategy: Make each individual row ~100KB so a SINGLE DataRow packet
+-- spans dozens of TCP segments. Query 50 rows = 5MB+ response.
+-- This guarantees TCP fragmentation even on localhost.
+
+CREATE TABLE IF NOT EXISTS large_records (
+    id          SERIAL PRIMARY KEY,
+    name        VARCHAR(255) NOT NULL,
+    description TEXT NOT NULL,
+    large_payload TEXT NOT NULL
+);
+
+-- Generate 200 rows, each with a ~100KB random payload.
+-- A single DataRow at 100KB will span ~70 TCP segments (MSS=1460).
+-- This forces the Postgres wire protocol parser to buffer across segments.
+INSERT INTO large_records (name, description, large_payload)
+SELECT
+    'record-' || i,
+    'Test record ' || i || ' — ' || repeat('description padding to increase row size ', 20),
+    -- ~100KB per row: 64 chars per md5 pair × 1600 repeats = 102,400 chars
+    repeat(
+        md5(random()::text || i::text) || md5(random()::text || (i+1000)::text),
+        1600
+    )
+FROM generate_series(1, 200) AS i;
+
+-- Also create a table with many small columns (wide rows)
+-- to trigger different DataRow encoding paths
+CREATE TABLE IF NOT EXISTS wide_records (
+    id SERIAL PRIMARY KEY,
+    col_01 TEXT, col_02 TEXT, col_03 TEXT, col_04 TEXT, col_05 TEXT,
+    col_06 TEXT, col_07 TEXT, col_08 TEXT, col_09 TEXT, col_10 TEXT,
+    col_11 TEXT, col_12 TEXT, col_13 TEXT, col_14 TEXT, col_15 TEXT,
+    col_16 TEXT, col_17 TEXT, col_18 TEXT, col_19 TEXT, col_20 TEXT
+);
+
+INSERT INTO wide_records (
+    col_01, col_02, col_03, col_04, col_05,
+    col_06, col_07, col_08, col_09, col_10,
+    col_11, col_12, col_13, col_14, col_15,
+    col_16, col_17, col_18, col_19, col_20
+)
+SELECT
+    repeat(md5(random()::text), 100),  -- ~3.2KB per column × 20 = ~64KB per row
+    repeat(md5(random()::text), 100),
+    repeat(md5(random()::text), 100),
+    repeat(md5(random()::text), 100),
+    repeat(md5(random()::text), 100),
+    repeat(md5(random()::text), 100),
+    repeat(md5(random()::text), 100),
+    repeat(md5(random()::text), 100),
+    repeat(md5(random()::text), 100),
+    repeat(md5(random()::text), 100),
+    repeat(md5(random()::text), 100),
+    repeat(md5(random()::text), 100),
+    repeat(md5(random()::text), 100),
+    repeat(md5(random()::text), 100),
+    repeat(md5(random()::text), 100),
+    repeat(md5(random()::text), 100),
+    repeat(md5(random()::text), 100),
+    repeat(md5(random()::text), 100),
+    repeat(md5(random()::text), 100),
+    repeat(md5(random()::text), 100)
+FROM generate_series(1, 50) AS i;
+
+-- Verify sizes
+SELECT 'large_records' AS tbl,
+    count(*) AS rows,
+    pg_size_pretty(avg(length(large_payload)::bigint)) AS avg_payload,
+    pg_size_pretty(sum(length(large_payload)::bigint)) AS total_payload
+FROM large_records
+UNION ALL
+SELECT 'wide_records',
+    count(*),
+    pg_size_pretty(avg(octet_length(col_01)::bigint)),
+    pg_size_pretty(sum(octet_length(col_01)::bigint) * 20)
+FROM wide_records;