{"record":{"id":"0c7eb436b65b4812","repo":"kubernetes/kops","slug":"invalid-base-channel-location-q","errorCode":null,"errorMessage":"invalid base channel location: %q","messagePattern":"invalid base channel location: %q","errorType":"exception","errorClass":null,"httpStatus":null,"severity":"error","filePath":"pkg/apis/kops/channel.go","lineNumber":121,"sourceCode":"\tKopsVersion string `json:\"kopsVersion,omitempty\"`\n}\n\n// ResolveChannel maps a channel to an absolute URL (possibly a VFS URL)\n// If the channel is the well-known \"none\" value, we return (nil, nil)\nfunc ResolveChannel(location string) (*url.URL, error) {\n\tif location == \"none\" {\n\t\treturn nil, nil\n\t}\n\n\tu, err := url.Parse(location)\n\tif err != nil {\n\t\treturn nil, fmt.Errorf(\"invalid channel location: %q\", location)\n\t}\n\n\tif !u.IsAbs() {\n\t\tbase, err := url.Parse(DefaultChannelBase)\n\t\tif err != nil {\n\t\t\treturn nil, fmt.Errorf(\"invalid base channel location: %q\", DefaultChannelBase)\n\t\t}\n\t\tklog.V(4).Infof(\"resolving %q against default channel location %q\", location, DefaultChannelBase)\n\t\tu = base.ResolveReference(u)\n\t}\n\n\treturn u, nil\n}\n\n// LoadChannel loads a Channel object from the specified VFS location\nfunc LoadChannel(vfsContext *vfs.VFSContext, location string) (*Channel, error) {\n\tresolvedURL, err := ResolveChannel(location)\n\tif err != nil {\n\t\treturn nil, err\n\t}\n\n\tif resolvedURL == nil {\n\t\treturn &Channel{}, nil\n\t}","sourceCodeStart":103,"sourceCodeEnd":139,"githubUrl":"https://github.com/kubernetes/kops/blob/4c8573c808a73d578c5eadc86d410646ea0b0d73/pkg/apis/kops/channel.go#L103-L139","documentation":"ResolveChannel turns a user-supplied channel location string into an absolute URL. If the location is not absolute, kOps parses its built-in DefaultChannelBase and resolves the relative location against it. This error means parsing the hard-coded DefaultChannelBase URL failed, which indicates an internal build/configuration corruption of the default channel constant rather than anything the caller passed.","triggerScenarios":"Calling LoadChannel or ResolveChannel with a relative channel location (e.g. \"stable\") when url.Parse(DefaultChannelBase) returns an error — practically only when the compiled-in DefaultChannelBase constant is malformed or overridden by a bad build/link-time replacement.","commonSituations":"Custom kOps builds that rewrite DefaultChannelBase to an invalid URL; corrupted source vendoring; automated tooling that patches the constant with a typo (e.g. missing scheme like \"https/channels.example.com\").","solutions":["Check the compiled-in value of DefaultChannelBase in pkg/apis/kops/channel.go and correct any typo (must be a valid absolute URL with scheme).","Rebuild kOps from unmodified upstream source (make kops) to rule out a corrupted or patched binary.","As a workaround, pass a fully absolute channel URL (e.g. https://raw.githubusercontent.com/kubernetes/kops/master/channels/stable) so the base-parsing branch is never taken."],"exampleFix":"// before (bad build-time override)\nDefaultChannelBase = \"https//kops.s3.amazonaws.com/channels\"\n// after\nDefaultChannelBase = \"https://kops.s3.amazonaws.com/channels\"","handlingStrategy":"validation","validationCode":"u, err := url.Parse(location)\nif err != nil { return err }\nif !u.IsAbs() {\n    if _, err := url.Parse(kops.DefaultChannelBase); err != nil {\n        return fmt.Errorf(\"kops build has invalid DefaultChannelBase: %w\", err)\n    }\n}","typeGuard":"func isAbsoluteURL(s string) bool { u, err := url.Parse(s); return err == nil && u.IsAbs() }","tryCatchPattern":"u, err := kops.ResolveChannel(location)\nif err != nil {\n    if strings.Contains(err.Error(), \"invalid base channel location\") {\n        // fall back to absolute channel URL\n        u, err = kops.ResolveChannel(defaultChannelURLAbsolute)\n    }\n    return err\n}","preventionTips":["Always pass absolute https:// channel URLs to avoid the base-resolution branch entirely","Never patch DefaultChannelBase without validating it with url.Parse in a unit test","Pin and verify kOps builds from upstream source"],"tags":["kops","channel","url-parsing","configuration"],"backgroundTag":"invalid-base-url","analyzedSha":"4c8573c808a73d578c5eadc86d410646ea0b0d73","analyzedAt":"2026-09-05T04:13:19.212Z","contentChangedAt":"2026-09-05T04:13:19.212Z","schemaVersion":2},"datasetVersion":"2026-09-12T07:17:12.445Z"}