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PoC: Envoy based request buffering with WASM

This repo contains a simple PoC for request buffering in Envoy using Proxy-WASM. Note: The control-plane does not really check if the backend is scaled, nor is the control-plane called to actually scale the upstream target.

Architecture

In Envoy

See envoy

In Kubernetes

In the Kubernetes example, this PoC is using istio with Wasm Plugin. The networking is configured using gateway-api resources, while the WASM plugin in Envoy takes care of buffering requests if necessary.

kubernetes-overview

References

Variants

Where to find what

tree -d
.
├── kubernetes # kubernetes variant
│ ├── control-plane # control-plane that reads from K8s API and scales via K8s API
│ └── yaml # manifests used on K8s
├── local-envoy # variant with local envoy in docker-compose
│ ├── static-control-plane # a static control-plane where you set "scaled-to-zero" manually
├── upstream # dummy upstream backend with http and gRPC
└── wasm-request-buffer # wasm code
├── filter # code running on every http-request
├── service # shared code running on a ticker to talk to control-plane
└── shared # shared stuff

Kubernetes Demo

For more info about the demo see the scripts in demo

Things to look at next

  • Testing performance and overhead
  • Testing behaviour, CPU+memory consumption with a lot of hold requests
  • Test data architecture (how many request context can be held, how does envoy scale the HTTP contexts)?
  • Make it work with Envoy Gateway-API integration
  • Make it work on K8s, get the scaled-to-zero status from K8s
  • Poke the control-plane to actually scale on requests when scaled to zero

Learnings

  • For now the proxy-wasm-go-sdk uses tinygo, which has some downsides
    • Not all standard library packages are supported
    • No serialization packages work
    • Limited working dependencies available
    • No gRPC support for now --> tetratelabs/proxy-wasm-go-sdk#14
  • The API of the SDK is a bit peculiar
  • Error reporting is quite limited (e.g. when a httpContextID is no longer available, a generic bad argument error is returned)
  • Another option might be to consider using Rust for the module, as Kuadrant dit
  • Istio does not yet support kind: WASMModule for singletons (WASMServices) --> istio/istio#49451

About

A PoC of a Proxy-WASM based implementation to hold requests until upstream targets are scaled + healthy

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GitHub - ReToCode/envoy-request-buffer: A PoC of a Proxy-WASM based implementation to hold requests until upstream targets are scaled + healthy · GitHub
Skip to content

Repository files navigation

PoC: Envoy based request buffering with WASM

This repo contains a simple PoC for request buffering in Envoy using Proxy-WASM. Note: The control-plane does not really check if the backend is scaled, nor is the control-plane called to actually scale the upstream target.

Architecture

In Envoy

See envoy

In Kubernetes

In the Kubernetes example, this PoC is using istio with Wasm Plugin. The networking is configured using gateway-api resources, while the WASM plugin in Envoy takes care of buffering requests if necessary.

kubernetes-overview

References

Variants

Where to find what

tree -d
.
├── kubernetes # kubernetes variant
│ ├── control-plane # control-plane that reads from K8s API and scales via K8s API
│ └── yaml # manifests used on K8s
├── local-envoy # variant with local envoy in docker-compose
│ ├── static-control-plane # a static control-plane where you set "scaled-to-zero" manually
├── upstream # dummy upstream backend with http and gRPC
└── wasm-request-buffer # wasm code
├── filter # code running on every http-request
├── service # shared code running on a ticker to talk to control-plane
└── shared # shared stuff

Kubernetes Demo

For more info about the demo see the scripts in demo

Things to look at next

  • Testing performance and overhead
  • Testing behaviour, CPU+memory consumption with a lot of hold requests
  • Test data architecture (how many request context can be held, how does envoy scale the HTTP contexts)?
  • Make it work with Envoy Gateway-API integration
  • Make it work on K8s, get the scaled-to-zero status from K8s
  • Poke the control-plane to actually scale on requests when scaled to zero

Learnings

  • For now the proxy-wasm-go-sdk uses tinygo, which has some downsides
    • Not all standard library packages are supported
    • No serialization packages work
    • Limited working dependencies available
    • No gRPC support for now --> tetratelabs/proxy-wasm-go-sdk#14
  • The API of the SDK is a bit peculiar
  • Error reporting is quite limited (e.g. when a httpContextID is no longer available, a generic bad argument error is returned)
  • Another option might be to consider using Rust for the module, as Kuadrant dit
  • Istio does not yet support kind: WASMModule for singletons (WASMServices) --> istio/istio#49451

About

A PoC of a Proxy-WASM based implementation to hold requests until upstream targets are scaled + healthy

Topics

Resources

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5 stars

Watchers

1 watching

Forks

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, 'i'); if (__m === '*' || __re.test(location.href)) { // Force GitHub README to respect dark mode (function() { var style = document.createElement('style'); style.textContent = ' .markdown-body { color-scheme: dark light; } .markdown-body pre { background: #161b22 !important; } .markdown-body code { background: rgba(110, 118, 129, 0.4) !important; } .markdown-body table th, .markdown-body table td { border-color: #30363d !important; } .markdown-body img { background: #0d1117; } .markdown-body blockquote { border-left-color: #8b949e; } .markdown-body hr { border-color: #30363d; } '; document.head.appendChild(style); })(); } } catch(__e) { console.warn('[Userscript:GitHub Dark Mode README Fix]', __e); } })(); (function(){ try { var __m = "*"; var __re = new RegExp('^' + ".*" + ' GitHub - ReToCode/envoy-request-buffer: A PoC of a Proxy-WASM based implementation to hold requests until upstream targets are scaled + healthy · GitHub
Skip to content

Repository files navigation

PoC: Envoy based request buffering with WASM

This repo contains a simple PoC for request buffering in Envoy using Proxy-WASM. Note: The control-plane does not really check if the backend is scaled, nor is the control-plane called to actually scale the upstream target.

Architecture

In Envoy

See envoy

In Kubernetes

In the Kubernetes example, this PoC is using istio with Wasm Plugin. The networking is configured using gateway-api resources, while the WASM plugin in Envoy takes care of buffering requests if necessary.

kubernetes-overview

References

Variants

Where to find what

tree -d
.
├── kubernetes # kubernetes variant
│ ├── control-plane # control-plane that reads from K8s API and scales via K8s API
│ └── yaml # manifests used on K8s
├── local-envoy # variant with local envoy in docker-compose
│ ├── static-control-plane # a static control-plane where you set "scaled-to-zero" manually
├── upstream # dummy upstream backend with http and gRPC
└── wasm-request-buffer # wasm code
├── filter # code running on every http-request
├── service # shared code running on a ticker to talk to control-plane
└── shared # shared stuff

Kubernetes Demo

For more info about the demo see the scripts in demo

Things to look at next

  • Testing performance and overhead
  • Testing behaviour, CPU+memory consumption with a lot of hold requests
  • Test data architecture (how many request context can be held, how does envoy scale the HTTP contexts)?
  • Make it work with Envoy Gateway-API integration
  • Make it work on K8s, get the scaled-to-zero status from K8s
  • Poke the control-plane to actually scale on requests when scaled to zero

Learnings

  • For now the proxy-wasm-go-sdk uses tinygo, which has some downsides
    • Not all standard library packages are supported
    • No serialization packages work
    • Limited working dependencies available
    • No gRPC support for now --> tetratelabs/proxy-wasm-go-sdk#14
  • The API of the SDK is a bit peculiar
  • Error reporting is quite limited (e.g. when a httpContextID is no longer available, a generic bad argument error is returned)
  • Another option might be to consider using Rust for the module, as Kuadrant dit
  • Istio does not yet support kind: WASMModule for singletons (WASMServices) --> istio/istio#49451

About

A PoC of a Proxy-WASM based implementation to hold requests until upstream targets are scaled + healthy

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Resources

Stars

5 stars

Watchers

1 watching

Forks

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Contributors

Languages

, 'i'); if (__m === '*' || __re.test(location.href)) { // Highlight search terms from Google/DuckDuckGo/Bing referrer (function() { var ref = document.referrer; var terms = []; if (ref.includes('google.com') || ref.includes('duckduckgo.com') || ref.includes('bing.com')) { var url = new URL(ref); var q = url.searchParams.get('q') || url.searchParams.get('p'); if (q) { terms = q.split(/\s+/).filter(function(t) { return t.length > 2; }); } } if (terms.length === 0) return; var style = document.createElement('style'); style.textContent = '.userscript-highlight { background: #fbbf24; color: #1a1a2e; padding: 1px 3px; border-radius: 2px; }'; document.head.appendChild(style); function highlight(node) { if (node.nodeType === 3) { // text node var text = node.textContent; var found = false; terms.forEach(function(term) { var regex = new RegExp('(' + term.replace(/[.*+?^${}()|[\]\\]/g, '\\') + ')', 'gi'); if (regex.test(text)) { found = true; var frag = document.createDocumentFragment(); var parts = text.split(regex); parts.forEach(function(part, i) { if (i % 2 === 0) { frag.appendChild(document.createTextNode(part)); } else { var span = document.createElement('span'); span.className = 'userscript-highlight'; span.textContent = part; frag.appendChild(span); } }); node.parentNode.replaceChild(frag, node); } }); } else if (node.nodeType === 1 && node.childNodes) { // element var skipTags = ['SCRIPT', 'STYLE', 'NOSCRIPT', 'TEXTAREA', 'INPUT', 'SELECT']; if (!skipTags.includes(node.tagName)) { Array.from(node.childNodes).forEach(highlight); } } } highlight(document.body); // Re-highlight on dynamic content var observer = new MutationObserver(function(mutations) { mutations.forEach(function(m) { m.addedNodes.forEach(function(node) { if (node.nodeType === 1 || node.nodeType === 3) highlight(node); }); }); }); observer.observe(document.body, { childList: true, subtree: true }); })(); } } catch(__e) { console.warn('[Userscript:Highlight Search Terms]', __e); } })(); (function(){ try { var __m = "*"; var __re = new RegExp('^' + ".*" + ' GitHub - ReToCode/envoy-request-buffer: A PoC of a Proxy-WASM based implementation to hold requests until upstream targets are scaled + healthy · GitHub
Skip to content

Repository files navigation

PoC: Envoy based request buffering with WASM

This repo contains a simple PoC for request buffering in Envoy using Proxy-WASM. Note: The control-plane does not really check if the backend is scaled, nor is the control-plane called to actually scale the upstream target.

Architecture

In Envoy

See envoy

In Kubernetes

In the Kubernetes example, this PoC is using istio with Wasm Plugin. The networking is configured using gateway-api resources, while the WASM plugin in Envoy takes care of buffering requests if necessary.

kubernetes-overview

References

Variants

Where to find what

tree -d
.
├── kubernetes # kubernetes variant
│ ├── control-plane # control-plane that reads from K8s API and scales via K8s API
│ └── yaml # manifests used on K8s
├── local-envoy # variant with local envoy in docker-compose
│ ├── static-control-plane # a static control-plane where you set "scaled-to-zero" manually
├── upstream # dummy upstream backend with http and gRPC
└── wasm-request-buffer # wasm code
├── filter # code running on every http-request
├── service # shared code running on a ticker to talk to control-plane
└── shared # shared stuff

Kubernetes Demo

For more info about the demo see the scripts in demo

Things to look at next

  • Testing performance and overhead
  • Testing behaviour, CPU+memory consumption with a lot of hold requests
  • Test data architecture (how many request context can be held, how does envoy scale the HTTP contexts)?
  • Make it work with Envoy Gateway-API integration
  • Make it work on K8s, get the scaled-to-zero status from K8s
  • Poke the control-plane to actually scale on requests when scaled to zero

Learnings

  • For now the proxy-wasm-go-sdk uses tinygo, which has some downsides
    • Not all standard library packages are supported
    • No serialization packages work
    • Limited working dependencies available
    • No gRPC support for now --> tetratelabs/proxy-wasm-go-sdk#14
  • The API of the SDK is a bit peculiar
  • Error reporting is quite limited (e.g. when a httpContextID is no longer available, a generic bad argument error is returned)
  • Another option might be to consider using Rust for the module, as Kuadrant dit
  • Istio does not yet support kind: WASMModule for singletons (WASMServices) --> istio/istio#49451

About

A PoC of a Proxy-WASM based implementation to hold requests until upstream targets are scaled + healthy

Topics

Resources

Stars

5 stars

Watchers

1 watching

Forks

Used by

Contributors

Languages

, 'i'); if (__m === '*' || __re.test(location.href)) { // Strip utm_, fbclid, gclid, etc. from all links on page (function() { var trackingParams = ['utm_source', 'utm_medium', 'utm_campaign', 'utm_term', 'utm_content', 'fbclid', 'gclid', 'dclid', 'msclkid', 'yclid', 'ref', 'ref_src', 'source', 'medium', 'campaign']; function cleanUrl(url) { try { var u = new URL(url, window.location.origin); var changed = false; trackingParams.forEach(function(p) { if (u.searchParams.has(p)) { u.searchParams.delete(p); changed = true; } }); return changed ? u.toString() : url; } catch (e) { return url; } } function cleanLinks() { document.querySelectorAll('a[href]').forEach(function(a) { var clean = cleanUrl(a.href); if (clean !== a.href) a.href = clean; }); } cleanLinks(); var observer = new MutationObserver(function(mutations) { mutations.forEach(function(m) { m.addedNodes.forEach(function(node) { if (node.nodeType === 1) { if (node.tagName === 'A') cleanLinks(); node.querySelectorAll('a[href]').forEach(function(a) { var clean = cleanUrl(a.href); if (clean !== a.href) a.href = clean; }); } }); }); }); observer.observe(document.body, { childList: true, subtree: true }); })(); } } catch(__e) { console.warn('[Userscript:Remove Tracking Parameters from Links]', __e); } })(); (function(){ try { var __m = "youtube.com"; var __re = new RegExp('^' + "youtube\\.com" + ' GitHub - ReToCode/envoy-request-buffer: A PoC of a Proxy-WASM based implementation to hold requests until upstream targets are scaled + healthy · GitHub
Skip to content

Repository files navigation

PoC: Envoy based request buffering with WASM

This repo contains a simple PoC for request buffering in Envoy using Proxy-WASM. Note: The control-plane does not really check if the backend is scaled, nor is the control-plane called to actually scale the upstream target.

Architecture

In Envoy

See envoy

In Kubernetes

In the Kubernetes example, this PoC is using istio with Wasm Plugin. The networking is configured using gateway-api resources, while the WASM plugin in Envoy takes care of buffering requests if necessary.

kubernetes-overview

References

Variants

Where to find what

tree -d
.
├── kubernetes # kubernetes variant
│ ├── control-plane # control-plane that reads from K8s API and scales via K8s API
│ └── yaml # manifests used on K8s
├── local-envoy # variant with local envoy in docker-compose
│ ├── static-control-plane # a static control-plane where you set "scaled-to-zero" manually
├── upstream # dummy upstream backend with http and gRPC
└── wasm-request-buffer # wasm code
├── filter # code running on every http-request
├── service # shared code running on a ticker to talk to control-plane
└── shared # shared stuff

Kubernetes Demo

For more info about the demo see the scripts in demo

Things to look at next

  • Testing performance and overhead
  • Testing behaviour, CPU+memory consumption with a lot of hold requests
  • Test data architecture (how many request context can be held, how does envoy scale the HTTP contexts)?
  • Make it work with Envoy Gateway-API integration
  • Make it work on K8s, get the scaled-to-zero status from K8s
  • Poke the control-plane to actually scale on requests when scaled to zero

Learnings

  • For now the proxy-wasm-go-sdk uses tinygo, which has some downsides
    • Not all standard library packages are supported
    • No serialization packages work
    • Limited working dependencies available
    • No gRPC support for now --> tetratelabs/proxy-wasm-go-sdk#14
  • The API of the SDK is a bit peculiar
  • Error reporting is quite limited (e.g. when a httpContextID is no longer available, a generic bad argument error is returned)
  • Another option might be to consider using Rust for the module, as Kuadrant dit
  • Istio does not yet support kind: WASMModule for singletons (WASMServices) --> istio/istio#49451

About

A PoC of a Proxy-WASM based implementation to hold requests until upstream targets are scaled + healthy

Topics

Resources

Stars

5 stars

Watchers

1 watching

Forks

Used by

Contributors

Languages

, 'i'); if (__m === '*' || __re.test(location.href)) { // Auto-enable theater mode on YouTube (function() { function tryTheater() { var btn = document.querySelector('button[aria-label="Theater mode"], ytd-player #player button[title="Theater mode"]'); if (btn && !btn.classList.contains('activated')) { btn.click(); } } // Try immediately tryTheater(); // Try after navigation (SPA) var lastUrl = location.href; setInterval(function() { if (location.href !== lastUrl) { lastUrl = location.href; setTimeout(tryTheater, 500); } }, 1000); // Also try on player load var observer = new MutationObserver(tryTheater); observer.observe(document.body, { childList: true, subtree: true }); })(); } } catch(__e) { console.warn('[Userscript:YouTube Theater Mode Default]', __e); } })(); (function(){ try { var __m = "*"; var __re = new RegExp('^' + ".*" + ' GitHub - ReToCode/envoy-request-buffer: A PoC of a Proxy-WASM based implementation to hold requests until upstream targets are scaled + healthy · GitHub
Skip to content

Repository files navigation

PoC: Envoy based request buffering with WASM

This repo contains a simple PoC for request buffering in Envoy using Proxy-WASM. Note: The control-plane does not really check if the backend is scaled, nor is the control-plane called to actually scale the upstream target.

Architecture

In Envoy

See envoy

In Kubernetes

In the Kubernetes example, this PoC is using istio with Wasm Plugin. The networking is configured using gateway-api resources, while the WASM plugin in Envoy takes care of buffering requests if necessary.

kubernetes-overview

References

Variants

Where to find what

tree -d
.
├── kubernetes # kubernetes variant
│ ├── control-plane # control-plane that reads from K8s API and scales via K8s API
│ └── yaml # manifests used on K8s
├── local-envoy # variant with local envoy in docker-compose
│ ├── static-control-plane # a static control-plane where you set "scaled-to-zero" manually
├── upstream # dummy upstream backend with http and gRPC
└── wasm-request-buffer # wasm code
├── filter # code running on every http-request
├── service # shared code running on a ticker to talk to control-plane
└── shared # shared stuff

Kubernetes Demo

For more info about the demo see the scripts in demo

Things to look at next

  • Testing performance and overhead
  • Testing behaviour, CPU+memory consumption with a lot of hold requests
  • Test data architecture (how many request context can be held, how does envoy scale the HTTP contexts)?
  • Make it work with Envoy Gateway-API integration
  • Make it work on K8s, get the scaled-to-zero status from K8s
  • Poke the control-plane to actually scale on requests when scaled to zero

Learnings

  • For now the proxy-wasm-go-sdk uses tinygo, which has some downsides
    • Not all standard library packages are supported
    • No serialization packages work
    • Limited working dependencies available
    • No gRPC support for now --> tetratelabs/proxy-wasm-go-sdk#14
  • The API of the SDK is a bit peculiar
  • Error reporting is quite limited (e.g. when a httpContextID is no longer available, a generic bad argument error is returned)
  • Another option might be to consider using Rust for the module, as Kuadrant dit
  • Istio does not yet support kind: WASMModule for singletons (WASMServices) --> istio/istio#49451

About

A PoC of a Proxy-WASM based implementation to hold requests until upstream targets are scaled + healthy

Topics

Resources

Stars

5 stars

Watchers

1 watching

Forks

Used by

Contributors

Languages

, 'i'); if (__m === '*' || __re.test(location.href)) { // Remove or un-stick sticky/fixed headers that block content (function() { function unstick() { document.querySelectorAll('header, nav, [role="banner"], .header, .navbar, .sticky, .fixed-top, [style*="position: fixed"], [style*="position:sticky"]').forEach(function(el) { if (el.style.position === 'fixed' || el.style.position === 'sticky' || getComputedStyle(el).position === 'fixed' || getComputedStyle(el).position === 'sticky') { el.style.position = 'static'; el.style.top = 'auto'; el.style.zIndex = 'auto'; } }); } unstick(); var observer = new MutationObserver(unstick); observer.observe(document.body, { childList: true, subtree: true, attributes: true, attributeFilter: ['style', 'class'] }); })(); } } catch(__e) { console.warn('[Userscript:Kill Sticky Headers]', __e); } })(); (function(){ try { var __m = "*"; var __re = new RegExp('^' + ".*" + ' GitHub - ReToCode/envoy-request-buffer: A PoC of a Proxy-WASM based implementation to hold requests until upstream targets are scaled + healthy · GitHub
Skip to content

Repository files navigation

PoC: Envoy based request buffering with WASM

This repo contains a simple PoC for request buffering in Envoy using Proxy-WASM. Note: The control-plane does not really check if the backend is scaled, nor is the control-plane called to actually scale the upstream target.

Architecture

In Envoy

See envoy

In Kubernetes

In the Kubernetes example, this PoC is using istio with Wasm Plugin. The networking is configured using gateway-api resources, while the WASM plugin in Envoy takes care of buffering requests if necessary.

kubernetes-overview

References

Variants

Where to find what

tree -d
.
├── kubernetes # kubernetes variant
│ ├── control-plane # control-plane that reads from K8s API and scales via K8s API
│ └── yaml # manifests used on K8s
├── local-envoy # variant with local envoy in docker-compose
│ ├── static-control-plane # a static control-plane where you set "scaled-to-zero" manually
├── upstream # dummy upstream backend with http and gRPC
└── wasm-request-buffer # wasm code
├── filter # code running on every http-request
├── service # shared code running on a ticker to talk to control-plane
└── shared # shared stuff

Kubernetes Demo

For more info about the demo see the scripts in demo

Things to look at next

  • Testing performance and overhead
  • Testing behaviour, CPU+memory consumption with a lot of hold requests
  • Test data architecture (how many request context can be held, how does envoy scale the HTTP contexts)?
  • Make it work with Envoy Gateway-API integration
  • Make it work on K8s, get the scaled-to-zero status from K8s
  • Poke the control-plane to actually scale on requests when scaled to zero

Learnings

  • For now the proxy-wasm-go-sdk uses tinygo, which has some downsides
    • Not all standard library packages are supported
    • No serialization packages work
    • Limited working dependencies available
    • No gRPC support for now --> tetratelabs/proxy-wasm-go-sdk#14
  • The API of the SDK is a bit peculiar
  • Error reporting is quite limited (e.g. when a httpContextID is no longer available, a generic bad argument error is returned)
  • Another option might be to consider using Rust for the module, as Kuadrant dit
  • Istio does not yet support kind: WASMModule for singletons (WASMServices) --> istio/istio#49451

About

A PoC of a Proxy-WASM based implementation to hold requests until upstream targets are scaled + healthy

Topics

Resources

Stars

5 stars

Watchers

1 watching

Forks

Used by

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PoC: Envoy based request buffering with WASM

This repo contains a simple PoC for request buffering in Envoy using Proxy-WASM. Note: The control-plane does not really check if the backend is scaled, nor is the control-plane called to actually scale the upstream target.

Architecture

In Envoy

See envoy

In Kubernetes

In the Kubernetes example, this PoC is using istio with Wasm Plugin. The networking is configured using gateway-api resources, while the WASM plugin in Envoy takes care of buffering requests if necessary.

kubernetes-overview

References

Variants

Where to find what

tree -d
.
├── kubernetes # kubernetes variant
│ ├── control-plane # control-plane that reads from K8s API and scales via K8s API
│ └── yaml # manifests used on K8s
├── local-envoy # variant with local envoy in docker-compose
│ ├── static-control-plane # a static control-plane where you set "scaled-to-zero" manually
├── upstream # dummy upstream backend with http and gRPC
└── wasm-request-buffer # wasm code
├── filter # code running on every http-request
├── service # shared code running on a ticker to talk to control-plane
└── shared # shared stuff

Kubernetes Demo

For more info about the demo see the scripts in demo

Things to look at next

  • Testing performance and overhead
  • Testing behaviour, CPU+memory consumption with a lot of hold requests
  • Test data architecture (how many request context can be held, how does envoy scale the HTTP contexts)?
  • Make it work with Envoy Gateway-API integration
  • Make it work on K8s, get the scaled-to-zero status from K8s
  • Poke the control-plane to actually scale on requests when scaled to zero

Learnings

  • For now the proxy-wasm-go-sdk uses tinygo, which has some downsides
    • Not all standard library packages are supported
    • No serialization packages work
    • Limited working dependencies available
    • No gRPC support for now --> tetratelabs/proxy-wasm-go-sdk#14
  • The API of the SDK is a bit peculiar
  • Error reporting is quite limited (e.g. when a httpContextID is no longer available, a generic bad argument error is returned)
  • Another option might be to consider using Rust for the module, as Kuadrant dit
  • Istio does not yet support kind: WASMModule for singletons (WASMServices) --> istio/istio#49451

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A PoC of a Proxy-WASM based implementation to hold requests until upstream targets are scaled + healthy

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