/// <inheritdoc/>
/// <remarks>
/// This method updates the <paramref name="serviceType"/> and/or <paramref name="serviceName"/> values for
/// cases where "vanilla" OpenStack values were specified but Rackspace exposes the compatible services under
/// different names in the service catalog.
/// </remarks>
protected override Uri GetBaseAddressImpl(Access access, string serviceType, string serviceName, string region, bool internalAddress)
{
if (string.IsNullOrEmpty(serviceName))
{
switch (serviceType)
{
case "cdn":
serviceName = "rackCDN";
serviceType = "rax:cdn";
break;
case "compute":
serviceName = "cloudServersOpenStack";
break;
case "volume":
serviceName = "cloudBlockStorage";
break;
case "object-store":
serviceName = "cloudFiles";
break;
case "database":
serviceType = "rax:database";
serviceName = "cloudDatabases";
break;
case "queuing":
serviceType = "rax:queues";
serviceName = "cloudQueues";
break;
}
}
return base.GetBaseAddressImpl(access, serviceType, serviceName, region, internalAddress);
}
/// <inheritdoc/>
/// <remarks>
/// This implementation returns <paramref name="region"/> if it is non-<see langword="null"/>. If
/// <paramref name="region"/> is <see langword="null"/>, the default region for the specified
/// <see cref="Access"/> is returned if available; otherwise, this method returns <see langword="null"/>.
/// </remarks>
protected override string GetEffectiveRegion(Access access, string region)
{
string effectiveRegion = base.GetEffectiveRegion(access, region);
if (effectiveRegion == null)
effectiveRegion = access.User.GetDefaultRegion();
return effectiveRegion;
}
/// <summary>
/// This method provides the core implementation of <see cref="GetBaseAddressAsync"/> after the
/// <see cref="OpenStack.Services.Identity.V2.Access"/> details are obtained from the Identity Service.
/// </summary>
/// <param name="access">An <see cref="OpenStack.Services.Identity.V2.Access"/> object containing the details
/// for the authenticated user.</param>
/// <param name="serviceType">The service type to locate.</param>
/// <param name="serviceName">The preferred name of the service.</param>
/// <param name="region">The preferred region for the service. This method calls
/// <see cref="GetEffectiveRegion"/> with this value to obtain the actual region to consider for this
/// algorithm.</param>
/// <param name="internalAddress">
/// <para><see langword="true"/> to return a base address for accessing the service over a local network.</para>
/// <para>-or-</para>
/// <para><see langword="false"/> to return a base address for accessing the service over a public network (the
/// Internet).</para></param>
/// <returns>A <see cref="Uri"/> containing the absolute base address for accessing the service.</returns>
/// <exception cref="ArgumentNullException">
/// <para>If <paramref name="access"/> is <see langword="null"/>.</para>
/// <para>-or-</para>
/// <para>If <paramref name="serviceType"/> is <see langword="null"/>.</para>
/// </exception>
/// <exception cref="ArgumentException">If <paramref name="serviceType"/> is empty.</exception>
protected virtual Uri GetBaseAddressImpl(Access access, string serviceType, string serviceName, string region, bool internalAddress)
{
if (access == null)
throw new ArgumentNullException("access");
if (serviceType == null)
throw new ArgumentNullException("serviceType");
if (string.IsNullOrEmpty(serviceType))
throw new ArgumentException("serviceType cannot be empty", "serviceType");
if (access.ServiceCatalog == null)
throw new InvalidOperationException("The authentication information provided by the Identity Service did not include a service catalog.");
List<ServiceCatalogEntry> services = access.ServiceCatalog.Where(sc => string.Equals(sc.Type, serviceType, StringComparison.OrdinalIgnoreCase)).ToList();
if (services.Count == 0)
throw new InvalidOperationException(string.Format("The service catalog provided by the Identity Service did not include any service with the type '{0}'.", serviceType));
if (serviceName != null)
{
// If any service matches the preferred name, filter the entire list. Otherwise, simply ignore the
// preferred name and continue.
List<ServiceCatalogEntry> namedServices = services.Where(sc => string.Equals(sc.Name, serviceName, StringComparison.OrdinalIgnoreCase)).ToList();
if (namedServices.Count > 0)
services = namedServices;
}
// Treat each endpoint individually for the purpose of endpoint selection.
List<Tuple<ServiceCatalogEntry, Endpoint>> endpoints =
services.SelectMany(service => service.Endpoints.Select(endpoint => Tuple.Create(service, endpoint))).ToList();
string effectiveRegion = GetEffectiveRegion(access, region);
// Locate all endpoints in the effective region. (Note that null and empty are equivalent for regions.)
List<Tuple<ServiceCatalogEntry, Endpoint>> regionEndpoints =
endpoints.Where(i => string.Equals(i.Item2.Region ?? string.Empty, effectiveRegion ?? string.Empty, StringComparison.OrdinalIgnoreCase)).ToList();
// Use filtered results if possible, otherwise only consider "global" endpoints.
if (regionEndpoints.Count > 0)
endpoints = regionEndpoints;
else
endpoints.RemoveAll(i => !string.IsNullOrEmpty(i.Item2.Region));
if (effectiveRegion == null && !endpoints.Any())
throw new InvalidOperationException("No region was provided, no default region is available for the current credentials, and the service does not provide a region-independent endpoint.");
Tuple<ServiceCatalogEntry, Endpoint> serviceEndpoint = endpoints.FirstOrDefault();
if (internalAddress)
serviceEndpoint = endpoints.FirstOrDefault(i => i.Item2.InternalUrl != null);
else
serviceEndpoint = endpoints.FirstOrDefault(i => i.Item2.PublicUrl != null);
if (serviceEndpoint == null)
throw new InvalidOperationException("No endpoint matching the specified parameters was located in the service catalog.");
Uri baseAddress;
if (internalAddress)
baseAddress = serviceEndpoint.Item2.InternalUrl;
else
baseAddress = serviceEndpoint.Item2.PublicUrl;
Uri adjustedBaseAddress = FilterBaseAddress(baseAddress);
return adjustedBaseAddress;
}
/// <summary>
/// Gets the effective region to use for locating services in the service catalog, for the specified
/// <see cref="OpenStack.Services.Identity.V2.Access"/> information and preferred <paramref name="region"/>.
/// </summary>
/// <remarks>
/// The default implementation simply returns <paramref name="region"/>. Specific vendors may extend this
/// functionality to provide a default value or other region selections as appropriate for their users and
/// service offerings.
/// </remarks>
/// <param name="access">The <see cref="OpenStack.Services.Identity.V2.Access"/> object providing details for
/// the authenticated user.</param>
/// <param name="region">The preferred region, as specified in the call to
/// <see cref="GetBaseAddressAsync"/>.</param>
/// <returns>The effective region to use for service location in <see cref="GetBaseAddressImpl"/>.</returns>
/// <exception cref="ArgumentNullException">If <paramref name="access"/> is <see langword="null"/>.</exception>
protected virtual string GetEffectiveRegion(Access access, string region)
{
if (access == null)
throw new ArgumentNullException("access");
return region;
}
/// <summary>
/// Authenticates the credentials provided in <see cref="AuthenticationRequest"/> with the OpenStack Identity
/// Service V2.
/// </summary>
/// <remarks>
/// <para>This method caches the authentication result, and returns the cached result of a previous
/// authentication request when possible to avoid unnecessary calls to the Identity API. If a cached
/// authentication result is available but has either expired or will expire soon (see
/// <see cref="ExpirationOverlap"/>), the cached result is discarded and the credentials are re-authenticated
/// with the Identity Service.</para>
/// </remarks>
/// <param name="cancellationToken">The <see cref="CancellationToken"/> that the task will observe.</param>
/// <returns>
/// A <see cref="Task"/> representing the asynchronous operation. When the task completes successfully, the
/// <see cref="Task{TResult}.Result"/> property will contain an <see cref="Access"/> instance providing the
/// authentication result.
/// </returns>
/// <exception cref="HttpWebException">
/// If an error occurs during an HTTP request as part of authenticating with the Identity API.
/// </exception>
protected virtual Task<Access> AuthenticateAsync(CancellationToken cancellationToken)
{
Access access = Access;
if (access != null && access.Token != null)
{
Token token = access.Token;
// Note: this code uses lifting to null to cover the case where token.ExpiresAt is null
DateTimeOffset? effectiveExpiration = token.ExpiresAt - ExpirationOverlap;
if (effectiveExpiration > DateTimeOffset.Now)
return CompletedTask.FromResult(access);
}
return
IdentityService.AuthenticateAsync(AuthenticationRequest, cancellationToken)
.Select(
task =>
{
_access = task.Result;
return task.Result;
});
}
